Sample records for dose ionizing radiation

  1. Irradiators for measuring the biological effects of low dose-rate ionizing radiation fields

    E-Print Network [OSTI]

    Davidson, Matthew Allen

    2011-01-01T23:59:59.000Z

    Biological response to ionizing radiation differs with radiation field. Particle type, energy spectrum, and dose-rate all affect biological response per unit dose. This thesis describes methods of spectral analysis, ...

  2. Low dose ionizing radiation detection using conjugated polymers

    SciTech Connect (OSTI)

    Silva, E.A.B.; Borin, J.F.; Nicolucci, P.; Graeff, C.F.O.; Netto, T. Ghilardi; Bianchi, R.F. [Departamento de Fisica e Matematica, FFCLRP, Universidade de Sao Paulo, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, SP (Brazil); Centro de Cie circumflex ncias das Imagens e Fisica Medica, Hospital das Clinicas, FMRP, Universidade de Sao Paulo, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, SP (Brazil); Departamento de Engenharia de Sistemas Integraveis, Escola Politecnica da Universidade de Sao Paulo, Av. Prof. Luciano Gualberto, 158, Sao Paulo, SP (Brazil)

    2005-03-28T23:59:59.000Z

    In this work, the effect of gamma radiation on the optical properties of poly[2-methoxy-5-(2{sup '}-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) is studied. The samples were irradiated at room temperature with different doses from 0 Gy to 152 Gy using a {sup 60}Co gamma ray source. For thin films, significant changes in the UV-visible spectra were only observed at high doses (>1 kGy). In solution, shifts in absorption peaks are observed at low doses (<10 Gy), linearly dependent on dose. The shifts are explained by conjugation reduction, and possible causes are discussed. Our results indicate that MEH-PPV solution can be used as a dosimeter adequate for medical applications.

  3. Cancer risks attributable to low doses of ionizing radiation: Assessing what we really know

    E-Print Network [OSTI]

    Brenner, David Jonathan

    Triangle Park, NC 27711; jOffice of Radiation and Indoor Air, Environmental Protection Agency, WashingtonCancer risks attributable to low doses of ionizing radiation: Assessing what we really know David J Infirmary, Oxford OX2 6ME, United Kingdom; dRadiation and Genome Stability Unit, Medical Research Council

  4. Mammalian Tissue Response to Low Dose Ionizing Radiation: The Role of Oxidative Metabolism and Intercellular Communication

    SciTech Connect (OSTI)

    Azzam, Edouard I

    2013-01-16T23:59:59.000Z

    The objective of the project was to elucidate the mechanisms underlying the biological effects of low dose/low dose rate ionizing radiation in organs/tissues of irradiated mice that differ in their susceptibility to ionizing radiation, and in human cells grown under conditions that mimic the natural in vivo environment. The focus was on the effects of sparsely ionizing cesium-137 gamma rays and the role of oxidative metabolism and intercellular communication in these effects. Four Specific Aims were proposed. The integrated outcome of the experiments performed to investigate these aims has been significant towards developing a scientific basis to more accurately estimate human health risks from exposures to low doses ionizing radiation. By understanding the biochemical and molecular changes induced by low dose radiation, several novel markers associated with mitochondrial functions were identified, which has opened new avenues to investigate metabolic processes that may be affected by such exposure. In particular, a sensitive biomarker that is differentially modulated by low and high dose gamma rays was discovered.

  5. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stark, Karolina; Scott, David E.; Tsyusko, Olga; Coughlin, Daniel P.; Hinton, Thomas G.; Amendola, Roberto

    2015-04-30T23:59:59.000Z

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³?Cs at 0.13, 2.4, 21, and 222 mGy d?¹, resulting in total doses up to 15.8 Gy. Radiation treatments did notmore »affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d?¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.« less

  6. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stark, Karolina [Stockholm Univ. (Sweden); Univ. of Georgia, Aiken, SC (United States); Scott, David E. [Univ. of Georgia, Aiken, SC (United States); Tsyusko, Olga [Univ. of Georgia, Aiken, SC (United States); Univ. of Kentucky, Lexington, KY (United States); Coughlin, Daniel P. [Univ. of Georgia, Aiken, SC (United States); Hinton, Thomas G. [Univ. of Georgia, Aiken, SC (United States); Inst. of Radiation Protection and Nuclear Safety, Cadarache (France); Amendola, Roberto [ENEA, (Italy)

    2015-04-30T23:59:59.000Z

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development –embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of ¹³?Cs at 0.13, 2.4, 21, and 222 mGy d?¹, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d?¹ and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.

  7. Medical imaging using ionizing radiation: Optimization of dose and image quality in fluoroscopy

    SciTech Connect (OSTI)

    Jones, A. Kyle, E-mail: kyle.jones@mdanderson.org [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Balter, Stephen [Departments of Radiology and Medicine, Columbia University, New York, New York 10032 (United States)] [Departments of Radiology and Medicine, Columbia University, New York, New York 10032 (United States); Rauch, Phillip [Retired-Henry Ford Health System, Detroit, Michigan 48202 (United States)] [Retired-Henry Ford Health System, Detroit, Michigan 48202 (United States); Wagner, Louis K. [Department of Diagnostic and Interventional Imaging, The University of Texas Medical School at Houston, Houston, Texas 77030 (United States)] [Department of Diagnostic and Interventional Imaging, The University of Texas Medical School at Houston, Houston, Texas 77030 (United States)

    2014-01-15T23:59:59.000Z

    The 2012 Summer School of the American Association of Physicists in Medicine (AAPM) focused on optimization of the use of ionizing radiation in medical imaging. Day 2 of the Summer School was devoted to fluoroscopy and interventional radiology and featured seven lectures. These lectures have been distilled into a single review paper covering equipment specification and siting, equipment acceptance testing and quality control, fluoroscope configuration, radiation effects, dose estimation and measurement, and principles of flat panel computed tomography. This review focuses on modern fluoroscopic equipment and is comprised in large part of information not found in textbooks on the subject. While this review does discuss technical aspects of modern fluoroscopic equipment, it focuses mainly on the clinical use and support of such equipment, from initial installation through estimation of patient dose and management of radiation effects. This review will be of interest to those learning about fluoroscopy, to those wishing to update their knowledge of modern fluoroscopic equipment, to those wishing to deepen their knowledge of particular topics, such as flat panel computed tomography, and to those who support fluoroscopic equipment in the clinic.

  8. Ionizing radiation detector

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1990-01-01T23:59:59.000Z

    An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

  9. 22.01 Introduction to Ionizing Radiation, Fall 2003

    E-Print Network [OSTI]

    Coderre, Jeffrey A.

    Introduction to basic properties of ionizing radiations and their uses in medicine, industry, science, and environmental studies. Discusses natural and man-made radiation sources, energy deposition and dose calculations, ...

  10. Ionizing Radiation Injury (South Carolina)

    Broader source: Energy.gov [DOE]

    This legislation applies to employers that have more than one employee who engages in activities which involve the presence of ionizing radiation. Employers with less than three employees can...

  11. Alloy nanoparticle synthesis using ionizing radiation

    DOE Patents [OSTI]

    Nenoff, Tina M. (Sandia Park, NM); Powers, Dana A. (Albuquerque, NM); Zhang, Zhenyuan (Durham, NC)

    2011-08-16T23:59:59.000Z

    A method of forming stable nanoparticles comprising substantially uniform alloys of metals. A high dose of ionizing radiation is used to generate high concentrations of solvated electrons and optionally radical reducing species that rapidly reduce a mixture of metal ion source species to form alloy nanoparticles. The method can make uniform alloy nanoparticles from normally immiscible metals by overcoming the thermodynamic limitations that would preferentially produce core-shell nanoparticles.

  12. EXTRAPOLATING RADIATION-INDUCED CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES

    E-Print Network [OSTI]

    Brenner, David Jonathan

    risk; National Council on Radiation Protection and Measurements INTRODUCTION THERE IS considerablePaper EXTRAPOLATING RADIATION-INDUCED CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES David J. Brenner* Abstract--There is strong evidence that ionizing radiation increases cancer risks at high doses

  13. Radiative feedback from ionized gas

    E-Print Network [OSTI]

    S. C. O. Glover

    2007-03-28T23:59:59.000Z

    H2 formation in metal-free gas occurs via the intermediate H- or H2+ ions. Destruction of these ions by photodissociation therefore serves to suppress H2 formation. In this paper, I highlight the fact that several processes that occur in ionized primordial gas produce photons energetic enough to photodissociate H- or H2+ and outline how to compute the photodissociation rates produced by a particular distribution of ionized gas. I also show that there are circumstances of interest, such as during the growth of HII regions around the first stars, in which this previously overlooked form of radiative feedback is of considerable importance.

  14. Total ionizing dose effects of domestic SiGe HBTs under different dose rate

    E-Print Network [OSTI]

    Mo-Han, Liu; Wu-Ying, Ma; Xin, Wang; Qi, Guo; Cheng-Fa, He; Ke, Jiang; Xiao-Long, Li; Ming-Zhu, Xiong

    2015-01-01T23:59:59.000Z

    The total ionizing radiation (TID) response of commercial NPN silicon germanium hetero-junction bipolar transistors (SiGe HBTs) produced domestic were investigated under the dose rate of 800mGy(Si)/s and 1.3mGy(Si)/s with Co-60 gamma irradiation source, respectively. The changes of the transistor parameter such as Gummel characteristics, excess base current before and after irradiation are investigated. The results of the experiments shows that for the KT1151, the radiation damage have slightly difference under the different dose rate after the prolonged annealing, shows an time dependent effect(TDE). But for the KT9041, the degradations of low dose rate irradiation are more higher than the high dose rate, demonstrate that there have potential enhanced low dose rate sensitive(ELDRS) effect exist on KT9041. The underlying physical mechanisms of the different dose rates response induced by the gamma ray are detailed discussed.

  15. Ionizing Radiation in Smoothed Particle Hydrodynamics

    E-Print Network [OSTI]

    O. Kessel-Deynet; A. Burkert

    2000-02-11T23:59:59.000Z

    A new method for the inclusion of ionizing radiation from uniform radiation fields into 3D Smoothed Particle Hydrodynamics (SPHI) simulations is presented. We calculate the optical depth for the Lyman continuum radiation from the source towards the SPHI particles by ray-tracing integration. The time-dependent ionization rate equation is then solved locally for the particles within the ionizing radiation field. Using test calculations, we explore the numerical behaviour of the code with respect to the implementation of the time-dependent ionization rate equation. We also test the coupling of the heating caused by the ionization to the hydrodynamical part of the SPHI code.

  16. SCIENTIFIC CORRESPONDENCE Radiation doses

    E-Print Network [OSTI]

    Shlyakhter, Ilya

    -- ation doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk

  17. A link between solar events and congenital malformations: Is ionizing radiation enough to explain it?

    E-Print Network [OSTI]

    Overholt, A C; Atri, D

    2015-01-01T23:59:59.000Z

    Cosmic rays are known to cause biological effects directly and through ionizing radiation produced by their secondaries. These effects have been detected in airline crews and other specific cases where members of the population are exposed to above average secondary fluxes. Recent work has found a correlation between solar particle events and congenital malformations. In this work we use the results of computational simulations to approximate the ionizing radiation from such events as well as longer term increases in cosmic ray flux. We find that the amounts of ionizing radiation produced by these events are insufficient to produce congenital malformations under the current paradigm regarding muon ionizing radiation. We believe that further work is needed to determine the correct ionizing radiation contribution of cosmogenic muons. We suggest that more extensive measurements of muon radiation effects may show a larger contribution to ionizing radiation dose than currently assumed.

  18. Analytical models for total dose ionization effects in MOS devices.

    SciTech Connect (OSTI)

    Campbell, Phillip Montgomery; Bogdan, Carolyn W.

    2008-08-01T23:59:59.000Z

    MOS devices are susceptible to damage by ionizing radiation due to charge buildup in gate, field and SOI buried oxides. Under positive bias holes created in the gate oxide will transport to the Si / SiO{sub 2} interface creating oxide-trapped charge. As a result of hole transport and trapping, hydrogen is liberated in the oxide which can create interface-trapped charge. The trapped charge will affect the threshold voltage and degrade the channel mobility. Neutralization of oxidetrapped charge by electron tunneling from the silicon and by thermal emission can take place over long periods of time. Neutralization of interface-trapped charge is not observed at room temperature. Analytical models are developed that account for the principal effects of total dose in MOS devices under different gate bias. The intent is to obtain closed-form solutions that can be used in circuit simulation. Expressions are derived for the aging effects of very low dose rate radiation over long time periods.

  19. Metabolomic Response of Human Skin Tissue to Low Dose Ionizing...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    for IR exposure at low doses can help provide a scientific basis for establishing radiation protection standards. Little is known regarding the physiological responses to...

  20. Composite scintillators for detection of ionizing radiation

    DOE Patents [OSTI]

    Dai, Sheng (Knoxville, TN) [Knoxville, TN; Stephan, Andrew Curtis (Knoxville, TN) [Knoxville, TN; Brown, Suree S. (Knoxville, TN) [Knoxville, TN; Wallace, Steven A. (Knoxville, TN) [Knoxville, TN; Rondinone, Adam J [Knoxville, TN

    2010-12-28T23:59:59.000Z

    Applicant's present invention is a composite scintillator having enhanced transparency for detecting ionizing radiation comprising a material having optical transparency wherein said material comprises nano-sized objects having a size in at least one dimension that is less than the wavelength of light emitted by the composite scintillator wherein the composite scintillator is designed to have selected properties suitable for a particular application.

  1. Ionizing radiation post-curing of objects produced by stereolithography and other methods

    DOE Patents [OSTI]

    Howell, David H. (Knoxville, TN); Eberle, Claude C. (Knoxville, TN); Janke, Christopher J. (Oliver Springs, TN)

    2000-01-01T23:59:59.000Z

    An object comprised of a curable material and formed by stereolithography or another three-dimensional prototyping method, in which the object has undergone initial curing, is subjected to post-curing by ionizing radiation, such as an electron beam having a predetermined beam output energy, which is applied in a predetermined dosage and at a predetermined dose rate. The post-cured object exhibits a property profile which is superior to that which existed prior to the ionizing radiation post-curing.

  2. The effect of thymosin on the survival of CBA/J mice exposed to lethal and acute doses of ionizing radiation

    E-Print Network [OSTI]

    Huchton, Roger Lynn

    1978-01-01T23:59:59.000Z

    and after 875 R whole-body X-radiatron to two groups of 15 mice. Control groups recexved equivalent amounts of sterile saline in corresponding treatment regimens. Though a slight decrease zn the mean time-to-death for the thymosin-in7ected au. ce... was noted, the difference in the mean time-to-deaths for the two groups was not significantly different. For the second investigation, two groups of 18 mice were exposed to 700 R whole-body X-radiation. Daily subcutaneous injections of thymosrn were...

  3. Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

    SciTech Connect (OSTI)

    Kleiman, Norman Jay [Columbia University] [Columbia University

    2013-11-30T23:59:59.000Z

    The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9, influence cataract development and thus radiosensitivity. These observations have direct applicability to various human populations including accidentally exposed individuals, interventional medical workers, astronauts and nuclear plant workers.

  4. Spatiotemporal characterization of ionizing radiation induced DNA damage foci and their relation to chromatin organization

    E-Print Network [OSTI]

    Costes, Sylvain V

    2010-01-01T23:59:59.000Z

    to ionizing radiation are nuclear marks of permanentto ionizing radiation are nuclear marks of permanentvisible nuclear domains referred to as radiation-induced

  5. Low-dose radiation impacts skin sensitivity | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Low-dose radiation impacts skin sensitivity Low-dose radiation impacts skin sensitivity Released: April 06, 2015 Systems approach suggests alterations in stability of cells and...

  6. Rules and Regulations for Control of Ionizing Radiation (Arkansas)

    Broader source: Energy.gov [DOE]

    The Rules and Regulations for Control of Ionizing Radiation are the Arkansas state laws made in accordance the federal Nuclear Regulatory Commission Rules. Any contractor with the US DOE or US...

  7. LSU School of Dentistry Laser Safety : Clinical SAFETY PROCEDURES FOR LASER (NON-IONIZING) RADIATION

    E-Print Network [OSTI]

    -IONIZING) RADIATION 1. PURPOSE This procedure sets forth the Louisiana State University (LSU) System non-ionizing radiation safety policy and procedural requirements of the program. The use of the term non-ionizing radiation in this document is defined as meaning non-ionizing radiation produced as a result of normal

  8. High pressure argon ionization chamber systems for the measurement of environmental radiation exposure rates

    E-Print Network [OSTI]

    DeCampo, J A; Raft, P D

    1972-01-01T23:59:59.000Z

    High pressure argon ionization chamber systems for the measurement of environmental radiation exposure rates

  9. Radiation Leukemogenesis at Low Dose Rates

    SciTech Connect (OSTI)

    Weil, Michael; Ullrich, Robert

    2013-09-25T23:59:59.000Z

    The major goals of this program were to study the efficacy of low dose rate radiation exposures for the induction of acute myeloid leukemia (AML) and to characterize the leukemias that are caused by radiation exposures at low dose rate. An irradiator facility was designed and constructed that allows large numbers of mice to be irradiated at low dose rates for protracted periods (up to their life span). To the best of our knowledge this facility is unique in the US and it was subsequently used to study radioprotectors being developed for radiological defense (PLoS One. 7(3), e33044, 2012) and is currently being used to study the role of genetic background in susceptibility to radiation-induced lung cancer. One result of the irradiation was expected; low dose rate exposures are ineffective in inducing AML. However, another result was completely unexpected; the irradiated mice had a very high incidence of hepatocellular carcinoma (HCC), approximately 50%. It was unexpected because acute exposures are ineffective in increasing HCC incidence above background. This is a potential important finding for setting exposure limits because it supports the concept of an 'inverse dose rate effect' for some tumor types. That is, for the development of some tumor types low dose rate exposures carry greater risks than acute exposures.

  10. The ionizing radiation environment in space and its effects

    SciTech Connect (OSTI)

    Adams, Jim; Falconer, David; Fry, Dan [Center for Space Plasma and Aeronomic Research (CSPAR), UA Huntsville (United States); Space Radiation Analysis Group, NASA Johnson Space Center (United States)

    2012-11-20T23:59:59.000Z

    The ionizing radiation environment in space poses a hazard for spacecraft and space crews. The hazardous components of this environment are reviewed and those which contribute to radiation hazards and effects identified. Avoiding the adverse effects of space radiation requires design, planning, monitoring and management. Radiation effects on spacecraft are avoided largely though spacecraft design. Managing radiation exposures of space crews involves not only protective spacecraft design and careful mission planning. Exposures must be managed in real time. The now-casting and forecasting needed to effectively manage crew exposures is presented. The techniques used and the space environment modeling needed to implement these techniques are discussed.

  11. Agriculture-related radiation dose calculations

    SciTech Connect (OSTI)

    Furr, J.M.; Mayberry, J.J.; Waite, D.A.

    1987-10-01T23:59:59.000Z

    Estimates of radiation dose to the public must be made at each stage in the identification and qualification process leading to siting a high-level nuclear waste repository. Specifically considering the ingestion pathway, this paper examines questions of reliability and adequacy of dose calculations in relation to five stages of data availability (geologic province, region, area, location, and mass balance) and three methods of calculation (population, population/food production, and food production driven). Calculations were done using the model PABLM with data for the Permian and Palo Duro Basins and the Deaf Smith County area. Extra effort expended in gathering agricultural data at succeeding environmental characterization levels does not appear justified, since dose estimates do not differ greatly; that effort would be better spent determining usage of food types that contribute most to the total dose; and that consumption rate and the air dispersion factor are critical to assessment of radiation dose via the ingestion pathway. 17 refs., 9 figs., 32 tabs.

  12. Non-Targeted Effects Induced by Ionizing Radiation: Mechanisms and Potential Impact on Radiation Induced Health Effects

    SciTech Connect (OSTI)

    Morgan, William F.; Sowa, Marianne B.

    2015-01-01T23:59:59.000Z

    Not-targeted effects represent a paradigm shift from the "DNA centric" view that ionizing radiation only elicits biological effects and subsequent health consequences as a result of an energy deposition event in the cell nucleus. While this is likely true at higher radiation doses (> 1Gy), at low doses (< 100mGy) non-targeted effects associated with radiation exposure might play a significant role. Here definitions of non-targeted effects are presented, the potential mechanisms for the communication of signals and signaling networks from irradiated cells/tissues are proposed, and the various effects of this intra- and intercellular signaling are described. We conclude with speculation on how these observations might lead to and impact long-term human health outcomes.

  13. A study of the response of a gas ionization chamber to different sources of ionizing radiation

    E-Print Network [OSTI]

    Zamble?-Die?guez, Filiberto Edmundo

    1988-01-01T23:59:59.000Z

    ; is the effective average energy to produce one pair (for values, see Table I). Charged particles produced by ionization lose their energy rather quickly in multiple collisions with the gas molecules and assume the thermal energy distribution of the gas. When... of aluminum extrusion ionization chambers to this kind of radiation was investigated. Also, since the TAMU counter is a prototype (1 in x 7in x 7in) of the chambers installed at CDF (1 in x 84in x 84in), the pad-to-wire signal ratio had to be measured...

  14. Evaluation and Control of Radiation Dose to the Embryo/Fetus Guide for Use with Title 10, Code of Federal Regulations, Part 835, Occupational Radiation Protection

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1999-04-29T23:59:59.000Z

    This Guide provides an acceptable methodology for establishing and operating a program to control fetal exposure to ionizing radiation and evaluate the resultant dose that will comply with U.S. Department of Energy (DOE) requirements specified in Title 10 of the Code of Federal Regulations (CFR), Part 835, Occupational Radiation Protection (DOE 1998), hereinafter referred to as 10 CFR 835.

  15. DNA-nuclear matrix interactions and ionizing radiation sensitivity

    SciTech Connect (OSTI)

    Schwartz, J.L. (Argonne National Lab., IL (United States) Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology); Vaughan, A.T.M. (Loyola Univ., Hines, IL (United States). Dept. of Radiotherapy)

    1993-01-01T23:59:59.000Z

    The association between inherent ionizing radiation sensitivity and DNA supercoil unwinding in mammalian cells suggests that the DNA-nuclear matrix attachment region (MAR) plays an important role in radiation response. In radioresistant cells, the MAR structure may exist in a more stable, open configuration, limiting DNA unwinding following strand break induction and maintaining DNA ends in close proximity for more rapid and accurate rejoining. In addition, the open configuration at these matrix attachment sites may serve to facilitate rapid DNA processing of breaks by providing (1) sites for repair proteins to collect and (2) energy to drive enzymatic reactions.

  16. DNA-nuclear matrix interactions and ionizing radiation sensitivity

    SciTech Connect (OSTI)

    Schwartz, J.L. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Vaughan, A.T.M. [Loyola Univ., Hines, IL (United States). Dept. of Radiotherapy

    1993-03-01T23:59:59.000Z

    The association between inherent ionizing radiation sensitivity and DNA supercoil unwinding in mammalian cells suggests that the DNA-nuclear matrix attachment region (MAR) plays an important role in radiation response. In radioresistant cells, the MAR structure may exist in a more stable, open configuration, limiting DNA unwinding following strand break induction and maintaining DNA ends in close proximity for more rapid and accurate rejoining. In addition, the open configuration at these matrix attachment sites may serve to facilitate rapid DNA processing of breaks by providing (1) sites for repair proteins to collect and (2) energy to drive enzymatic reactions.

  17. Organic materials and devices for detecting ionizing radiation

    DOE Patents [OSTI]

    Doty, F. Patrick (Livermore, CA); Chinn, Douglas A. (Livermore, CA)

    2007-03-06T23:59:59.000Z

    A .pi.-conjugated organic material for detecting ionizing radiation, and particularly for detecting low energy fission neutrons. The .pi.-conjugated materials comprise a class of organic materials whose members are intrinsic semiconducting materials. Included in this class are .pi.-conjugated polymers, polyaromatic hydrocarbon molecules, and quinolates. Because of their high resistivities (.gtoreq.10.sup.9 ohmcm), these .pi.-conjugated organic materials exhibit very low leakage currents. A device for detecting and measuring ionizing radiation can be made by applying an electric field to a layer of the .pi.-conjugated polymer material to measure electron/hole pair formation. A layer of the .pi.-conjugated polymer material can be made by conventional polymer fabrication methods and can be cast into sheets capable of covering large areas. These sheets of polymer radiation detector material can be deposited between flexible electrodes and rolled up to form a radiation detector occupying a small volume but having a large surface area. The semiconducting polymer material can be easily fabricated in layers about 10 .mu.m to 100 .mu.m thick. These thin polymer layers and their associated electrodes can be stacked to form unique multi-layer detector arrangements that occupy small volume.

  18. Infrared luminescence for real time ionizing radiation detection

    SciTech Connect (OSTI)

    Veronese, Ivan, E-mail: ivan.veronese@unimi.it; Mattia, Cristina De; Cantone, Marie Claire [Dipartimento di Fisica, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Fasoli, Mauro; Chiodini, Norberto; Vedda, Anna [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca, Via Cozzi 55, 20125 Milano (Italy); Mones, Eleonora [Medical Physics Department, Azienda Ospedaliera Maggiore della Carità, Corso Mazzini 18, 28100 Novara (Italy)

    2014-08-11T23:59:59.000Z

    Radio-luminescence (RL) optical fiber sensors enable a remote, punctual, and real time detection of ionizing radiation. However, the employment of such systems for monitoring extended radiation fields with energies above the Cerenkov threshold is still challenging, since a spurious luminescence, namely, the “stem effect,” is also generated in the passive fiber portion exposed to radiation. Here, we present experimental measurements on Yb-doped silica optical fibers irradiated with photon fields of different energies and sizes. The results demonstrate that the RL of Yb{sup 3+}, displaying a sharp emission line at about 975?nm, is free from any spectral superposition with the spurious luminescence. This aspect, in addition with the suitable linearity, reproducibility, and sensitivity properties of the Yb-doped fibers, paves the way to their use in applications where an efficient stem effect removal is required.

  19. Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: An FTIR microspectroscopic imaging study

    SciTech Connect (OSTI)

    Cakmak G.; Miller L.; Zorlu, F.; Severcan, F.

    2012-03-03T23:59:59.000Z

    Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH{sub 2} groups of lipids decreased significantly and the carbonyl esters, olefinic=CH and CH{sub 3} groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.

  20. Electronic dose conversion technique using a NaI(Tl) detector for assessment of exposure dose rate from environmental radiation

    SciTech Connect (OSTI)

    Cho, G.; Kim, H.K. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)] [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of); Woo, H.; Oh, G. [Korea Electric Power Research Inst., Taejon (Korea, Republic of)] [Korea Electric Power Research Inst., Taejon (Korea, Republic of); Ha, D.K. [Samchang Enterprise Co., Anyang (Korea, Republic of)] [Samchang Enterprise Co., Anyang (Korea, Republic of)

    1998-06-01T23:59:59.000Z

    An electronic dose conversion technique to assess the exposure dose rate due to environmental radiation especially from terrestrial sources was developed. For a 2 x 2 inch cylindrical NaI(Tl) scintillation detector, pulse-height spectra were obtained for gamma-rays of energy up to 3 MeV by Monte Carlo simulation. Based on the simulation results and the experimentally fitted energy resolution, dose conversion factors were calculated by a numerical decomposition method. These calculated dose conversion factors were, then, electronically implemented to a developed dose conversion unit (DCU) which is a microprocessor-controlled single channel analyzer (SCA) with variable discrimination levels. The simulated spectra were confirmed by measurement of several monoenergetic gamma spectra with a multichannel analyzer (MCA). The converted exposure dose rates from the implemented dose conversion algorithm in the DCU were also evaluated for a field test in the vicinity of the nuclear power plant at Kori as well as for several standard sources, and the results were in good agreement with separate measurement by a high pressure ionization chamber (HPIC) within a 6.4% deviation.

  1. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOE Patents [OSTI]

    Karl, Jr., Robert R. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  2. DdrB Protein, an Alternative Deinococcus radiodurans SSB Induced by Ionizing Radiation*

    E-Print Network [OSTI]

    Cox, Michael M.

    mechanisms protect D. radiodurans from ionizing radiation- induced DNA damage. Several proposals have beenDdrB Protein, an Alternative Deinococcus radiodurans SSB Induced by Ionizing Radiation* Received radiation (IR). DdrB is one of five proteins induced to high levels in Deino- coccus following extreme IR

  3. Guidance for Preparing Research Proposals Involving Diagnostic Use of Ionizing Radiation in Human Use Research

    E-Print Network [OSTI]

    Kay, Mark A.

    Guidance for Preparing Research Proposals Involving Diagnostic Use of Ionizing Radiation in Human Use Research Introduction This guidance has been prepared by the Clinical Radiation Safety Committee of ionizing radiation. CRSCo serves under California Department of Health Services regulations and Nuclear

  4. Radiation dose rates from UF{sub 6} cylinders

    SciTech Connect (OSTI)

    Friend, P.J. [Urenco, Capenhurst (United Kingdom)

    1991-12-31T23:59:59.000Z

    This paper describes the results of many studies, both theoretical and experimental, which have been carried out by Urenco over the last 15 years into radiation dose rates from uranium hexafluoride (UF{sub 6}) cylinders. The contents of the cylinder, its history, and the geometry all affect the radiation dose rate. These factors are all examined in detail. Actual and predicted dose rates are compared with levels permitted by IAEA transport regulations.

  5. DWARF GALAXIES WITH IONIZING RADIATION FEEDBACK. I. ESCAPE OF IONIZING PHOTONS

    SciTech Connect (OSTI)

    Kim, Ji-hoon; Krumholz, Mark R.; Goldbaum, Nathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States); Wise, John H. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA (United States); Turk, Matthew J. [Department of Astronomy and Astrophysics, Columbia University, New York, NY (United States); Abel, Tom, E-mail: me@jihoonkim.org [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA (United States)

    2013-10-01T23:59:59.000Z

    We describe a new method for simulating ionizing radiation and supernova feedback in the analogs of low-redshift galactic disks. In this method, which we call star-forming molecular cloud (SFMC) particles, we use a ray-tracing technique to solve the radiative transfer equation for ultraviolet photons emitted by thousands of distinct particles on the fly. Joined with high numerical resolution of 3.8 pc, the realistic description of stellar feedback helps to self-regulate star formation. This new feedback scheme also enables us to study the escape of ionizing photons from star-forming clumps and from a galaxy, and to examine the evolving environment of star-forming gas clumps. By simulating a galactic disk in a halo of 2.3 × 10{sup 11} M{sub ?}, we find that the average escape fraction from all radiating sources on the spiral arms (excluding the central 2.5 kpc) fluctuates between 0.08% and 5.9% during a ?20 Myr period with a mean value of 1.1%. The flux of escaped photons from these sources is not strongly beamed, but manifests a large opening angle of more than 60° from the galactic pole. Further, we investigate the escape fraction per SFMC particle, f{sub esc}(i), and how it evolves as the particle ages. We discover that the average escape fraction f{sub esc} is dominated by a small number of SFMC particles with high f{sub esc}(i). On average, the escape fraction from an SFMC particle rises from 0.27% at its birth to 2.1% at the end of a particle lifetime, 6 Myr. This is because SFMC particles drift away from the dense gas clumps in which they were born, and because the gas around the star-forming clumps is dispersed by ionizing radiation and supernova feedback. The framework established in this study brings deeper insight into the physics of photon escape fraction from an individual star-forming clump and from a galactic disk.

  6. attenuates ionizing radiation-induced: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Article Influence of XRCC1 Genetic Polymorphisms on Ionizing Radiation-Induced DNA Damage and Repair CiteSeer Summary: License, which permits unrestricted use, distribution,...

  7. Intensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective

    E-Print Network [OSTI]

    Coello, Carlos A. Coello

    Intensity Modulated Beam Radiation Therapy Dose Optimization with Multiobjective Evolutionary will be di- agnosed with cancer. Half of these will be treated with radiation therapy [1]. In teletherapy or external radiotherapy beams of penetrating radiation are directed at the tumor. Along their path through

  8. The effects of diet and ionizing radiation on azoxymethane induced colon carcinogenesis

    E-Print Network [OSTI]

    Mann, John Clifford

    2006-10-30T23:59:59.000Z

    The ability of ionizing radiation to enhance colon carcinogenesis and the role of diet in this process has not been documented. We hypothesized that radiation would enhance the formation of aberrant crypt foci, ACF, known precursor lesions to colon...

  9. Progress in high-dose radiation dosimetry. Final report

    SciTech Connect (OSTI)

    Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.; Chadwick, K.H.

    1981-01-01T23:59:59.000Z

    The last decade has witnessed a deluge of new high-dose dosimetry techniques and expended applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Requirements for a stable and reliable transfer dose meters have led to further developments of several important high-dose systems: thermoluminescent materials, radiochromic dyes, ceric-cerous solutions analyzed by high-frequency oscillometry. A number of other prospective dosimeters are also treated in this review. In addition, an IAEA program of high-dose intercomparison and standardization for industrial radiation processing is described.

  10. Progress in high-dose radiation dosimetry. Final report

    SciTech Connect (OSTI)

    Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.; Chadwick, K.H.

    1981-01-01T23:59:59.000Z

    The last decade has witnessed a deluge of new high-dose dosimetry techniques and expended applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Requirements for a stable and reliable transfer dose meters have led to further developments of several important high-dose systems: thermoluminescent materials, radiochromic dyes, ceric-cerous solutions analyzed by high-frequency oscillometry. A number of other prospective dosimeters also treated in this review. In addition, an IAEA programme of high-dose intercomparison and standardization for industrial radiation processing is described.

  11. The oncogenic action of ionizing radiation on rat skin

    SciTech Connect (OSTI)

    Burns, F.J.; Garte, S.J.

    1992-01-01T23:59:59.000Z

    The multistage theory of carcinogenesis specifies that cells progress to cancer through a series of discrete, irreversible genetic alterations, but data on radiation-induced cancer incidence in rat skin suggests that an intermediate repairable alteration may occur. Data are presented on cancer induction in rat skin exposed to an electron beam (LET=0.34 keV/[mu]), a neon ion beam (LET=45) or an argon ion beam (LET=125). The rats were observed for tumors at least 78 weeks with squamous and basal cell carcinomas observed. The total cancer yield was fitted by the quadratic equation, and the equation parameters were estimated by linear regression for each type of radiation. Analysis of the DNA from the electron-induced carcinomas indicated that K-ras and/or c-myc oncogenes were activated. In situ hybridization indicated that the cancers contain subpopulations of cells with differing amounts of c-myc and H-ras amplification. The results are consistent with the idea that ionizing radiation produces stable, carcinogenically relevant lesions via 2 repairable events at low LET and via a non-repairable linked event pathway at high LET; either pathway may advance the cell by 1 stage. The proliferative response of rat epidermis following exposure to ionizing radiation was quantified by injection of [sup 14]C-thymidine. The return of these cells to S-phase a second time was detected by a second label ([sup 3]H). When the labeled cells were in G1-phase, the dorsal skin was irradiated with X-rays. All labeling indices were determined. The [sup 14]C labeling index was constant and unaffected by the radiation. The proportion of all cells entering S-phase averaged 3.5% at 18 hr and increased after 44, 52 and 75 hr to average levels of 11.8%, 5. 3%, and 6.6% at 0, 10 and 25 Gy respectively. The proportion of S-phase cells labeled with [sup 14]C increased after 42 hr and remained relatively constant thereafter.

  12. On the Escape of Ionizing Radiation from Starbursts

    E-Print Network [OSTI]

    Heckman, T; Meurer, G; Leitherer, C; Calzetti, D; Martin, C L

    2001-01-01T23:59:59.000Z

    Far-ultraviolet spectra obtained with $FUSE$ show that the strong $CII\\lambda$1036 interstellar absorption-line is essentially black in five of the UV-brightest local starburst galaxies. Since the opacity of the neutral ISM below the Lyman-edge will be significantly larger than in the $CII$ line, these data provide strong constraints on the escape of ionizing radiation from these starbursts. Interpreted as a a uniform absorbing slab, the implied optical depth at the Lyman edge is huge ($\\tau_0 \\geq 10^2$). Alternatively, the areal covering factor of opaque material is typically $\\geq$ 94%. Thus, the fraction of ionizing stellar photons that escape the ISM of each galaxy is small: our conservative estimates typically yield $f_{esc} \\leq 6%$. Inclusion of extinction due to dust will further decrease $f_{esc}$. An analogous analysis of the rest-UV spectrum of the star-forming galaxy $MS 1512-CB58$ at $z$ =2.7 leads to similar constraints on $f_{esc}$. These new results agree with the constraints provided by dire...

  13. Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation

    SciTech Connect (OSTI)

    Nicolay, Nils H., E-mail: n.nicolay@dkfz.de [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sommer, Eva; Lopez, Ramon; Wirkner, Ute [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Trinh, Thuy [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sisombath, Sonevisay [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Debus, Jürgen [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Ho, Anthony D.; Saffrich, Rainer [Department of Hematology and Oncology, Heidelberg University Hospital, Heidelberg (Germany); Huber, Peter E. [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany)

    2013-12-01T23:59:59.000Z

    Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression.

  14. Assessment of the Technologies for Molecular Biodosimetry for Human Low-Dose Radiation Exposure Symposium

    SciTech Connect (OSTI)

    Matthew A. Coleman Ph.D.; Narayani Ramakrishnan, Ph.D.; Sally A. Amundson; James D. Tucker, Ph.D.; Stephen D. Dertinger, Ph.D.; Natalia I. Ossetrova, Ph.D.; Tao Chen

    2009-11-16T23:59:59.000Z

    Exposure to ionizing radiation produces few immediate outwardly-visible clinical signs, yet, depending on dose, can severely damage vital physiological functions within days to weeks and produce long-lasting health consequences among survivors. In the event of a radiological accident, the rapid evaluation of the individual absorbed dose is paramount to discriminate the worried but unharmed from those individuals who must receive medical attention. Physical, clinical and biological dosimetry are usually combined for the best dose assessment. However, because of the practical limits of physical and clinical dosimetry, many attempts have been made to develop a dosimetry system based on changes in biological parameters, including techniques for hematology, biochemistry, immunology, cytogenetics, etc. Lymphocyte counts and chromosome aberrations analyses are among the methods that have been routinely used for estimating radiation dose. However, these assays require several days to a week to be completed and therefore cannot be used to obtain a fast estimate of the dose during the first few days after exposure when the information would be most critical for identifying victims of radiation accidents who could benefit the most by medical intervention. The steadily increasing sophistication in our understanding of the early biochemical responses of irradiated cells and tissues provides the opportunity for developing mechanism-based biosignatures of exposure. Compelling breakthroughs have been made in the technologies for genome-scale analysis of cellular transcriptional and proteomic profiles. There have also been major strides in the mechanistic understanding of the early events in DNA damage and radiation damage products, as well as in the cellular pathways that lead to radiation injury. New research with genomic- and proteomic-wide tools is showing that within minutes to hours after exposure to ionizing radiation protein machines are modified and activated, and large-scale changes occur in the gene expression profile involving a broad variety of cell-process pathways after a wide range of both low (<10 cGy) and high dose (>10 cGy) exposures. Evaluation of these potential gene and protein biomarkers for early and late diagnostic information will be critical for determining the efficacy of the signatures to both low and high dose IR exposures. Also needed are approaches that enable rapid handling and processing for mass-casualty and population triage scenarios. Development of in vivo model system will be crucial for validating both the biological and the instrumentation for biodosimetry. Such studies will also help further understanding of the molecular mechanisms of the biological effects of radiation and the differences of responses due to individual genetic variation.

  15. IONIZING RADIATION FROM z = 4-10 GALAXIES

    SciTech Connect (OSTI)

    Razoumov, Alexei O. [Institute for Computational Astrophysics, Department of Astronomy and Physics, Saint Mary's University, Halifax, NS, B3H 3C3 (Canada); Sommer-Larsen, Jesper, E-mail: razoumov@ap.smu.c, E-mail: jslarsen@astro.ku.d [Excellence Cluster Universe, Technische Universitaet Muenchen, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2010-02-20T23:59:59.000Z

    We compute the escape of ionizing radiation from galaxies in the redshift interval z = 4-10, i.e., during and after the epoch of reionization, using a high-resolution set of galaxies, formed in fully cosmological simulations. The simulations invoke early, energetic feedback, and the galaxies evolve into a realistic population at z = 0. Our galaxies cover nearly four orders of magnitude in masses (10{sup 7.8}-10{sup 11.5} M{sub sun}) and more than five orders in star formation rates (10{sup -3.5}-10{sup 1.7} M{sub sun} yr{sup -1}), and we include an approximate treatment of dust absorption. We show that the source-averaged Lyman limit escape fraction at z = 10.4 is close to 80% declining monotonically with time as more massive objects build up at lower redshifts. Although the amount of dust absorption is uncertain to 1-1.5 dex, it is tightly correlated with metallicity; we find that dust is unlikely to significantly impact the observed UV output. These results support reionization by stellar radiation from low-luminosity dwarf galaxies and are also compatible with Lyman continuum observations and theoretical predictions at z {approx} 3-4.

  16. Radiation protection instrumentation - ambient and/or directional dose equivalent (rate) meters and/or monitors for beta, X and gamma radiation part 2: high range beta and photon dose and dose rate portable instruments for emergency radiation protection purposes

    E-Print Network [OSTI]

    International Electrotechnical Commission. Geneva

    2007-01-01T23:59:59.000Z

    Radiation protection instrumentation - ambient and/or directional dose equivalent (rate) meters and/or monitors for beta, X and gamma radiation

  17. Detecting excess ionizing radiation by electromagnetic breakdown of air

    SciTech Connect (OSTI)

    Granatstein, Victor L.; Nusinovich, Gregory S. [Center for Applied Electromagnetics, Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)

    2010-09-15T23:59:59.000Z

    A scheme is proposed for detecting a concealed source of ionizing radiation by observing the occurrence of breakdown in atmospheric air by an electromagnetic wave whose electric field surpasses the breakdown field in a limited volume. The volume is chosen to be smaller than the reciprocal of the naturally occurring concentration of free electrons. The pulse duration of the electromagnetic wave must exceed the avalanche breakdown time (10-200 ns) and could profitably be as long as the statistical lag time in ambient air (typically, microseconds). Candidate pulsed electromagnetic sources over a wavelength range, 3 mm>{lambda}>10.6 {mu}m, are evaluated. Suitable candidate sources are found to be a 670 GHz gyrotron oscillator with 200 kW, 10 {mu}s output pulses and a Transversely Excited Atmospheric-Pressure (TEA) CO{sub 2} laser with 30 MW, 100 ns output pulses. A system based on 670 GHz gyrotron would have superior sensitivity. A system based on the TEA CO{sub 2} laser could have a longer range >100 m.

  18. Method for detecting radiation dose utilizing thermoluminescent material

    DOE Patents [OSTI]

    Miller, S.D.; McDonald, J.C.; Eichner, F.N.; Durham, J.S.

    1992-08-04T23:59:59.000Z

    The amount of ionizing radiation to which a thermoluminescent material has been exposed is determined by first cooling the thermoluminescent material and then optically stimulating the thermoluminescent material by exposure to light. Visible light emitted by the thermoluminescent material as it is allowed to warm up to room temperature is detected and counted. The thermoluminescent material may be annealed by exposure to ultraviolet light. 5 figs.

  19. ORISE: Radiation Dose Estimates and Other Compendia

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated CodesTransparencyDOENurse Triage LinesCytogeneticHowResponseDose Estimates

  20. An evaluation of theories concerning the health effects of low-dose radiation exposures

    E-Print Network [OSTI]

    Wei, Elizabeth J. (Elizabeth Jay)

    2012-01-01T23:59:59.000Z

    The danger of high, acute doses of radiation is well documented, but the effects of low-dose radiation below 100 mSv is still heavily debated. Four theories concerning the effects of lowdose radiation are presented here: ...

  1. applying ionizing radiation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    mechanisms of aging and those of radiation, including oxidative stress, chromosomal damage, apoptosis, stem cell exhaustion and inflammation. The association between radiation...

  2. We can do better than effective dose for estimating or comparing low-dose radiation risks

    E-Print Network [OSTI]

    Brenner, David Jonathan

    of the radiation risks they are trying to control. Ã? 2012 ICRP. Published by Elsevier Ltd. All rights reserved Effective dose (ICRP, 1977) represents an attempt to provide a quantity which is proportional of the International Commission on Radiological Protection. 124 #12;and hereditary effects. Specifically, it is the sum

  3. Development of Pattern Recognition Software for Tracks of Ionizing Radiation In Medipix2-Based

    E-Print Network [OSTI]

    Vilalta, Ricardo

    by a TimePix version of the hybrid semiconductor Medipix2 pixel detector system. Such a software tool would predict the type of source of radiation captured by the pixel detector device. Such tool would bridge classification of sources of ionizing radiation as captured by the hybrid semiconductor pixel detector Medipix2

  4. Inhibition of ERK Oscillations by Ionizing Radiation and Reactive Oxygen Species

    SciTech Connect (OSTI)

    Shankaran, Harish; Chrisler, William B.; Sontag, Ryan L.; Weber, Thomas J.

    2010-12-28T23:59:59.000Z

    The shuttling of activated protein kinases between the cytoplasm and nucleus is an essential feature of normal growth factor signaling cascades. Here we demonstrate that transforming growth factor alpha (TGF?) induces oscillations in extracellular signal regulated kinase (ERK) cytoplasmic-nuclear translocations in human keratinocytes. TGF?-dependent ERK oscillations mediated through the epidermal growth factor receptor (EGFR) are inhibited by low dose X-irradiation (10?cGy) and low concentrations of hydrogen peroxide (0.32–3.26?µM H2O2) used as a model reactive oxygen species (ROS). A fluorescent indicator dye (H2-DCFDA) was used to measure cellular ROS levels following X-irradiation, 12-O-tetradecanoyl phorbol-13-acetate (TPA) and H2O2. X-irradiation did not generate significant ROS production while 0.32?µM H2O2 and TPA induced significant increases in ROS levels with H2O2? >?TPA. TPA alone induced transactivation of the EGFR but did not induce ERK oscillations. TPA as a cotreatment did not inhibit TGF?-stimulated ERK oscillations but qualitatively altered TGF?-dependent ERK oscillation characteristics (amplitude, time-period). Collectively, these observations demonstrate that TGF?-induced ERK oscillations are inhibited by ionizing radiation/ROS and perturbed by epigenetic carcinogen in human keratinocytes. © 2010 Wiley-Liss, Inc.

  5. Estimated cumulative radiation dose from PET/CT in children with malignancies: reply to Gelfand et al

    E-Print Network [OSTI]

    Chawla, Soni C.; Boechat, M. Ines; McNitt-Gray, Michael

    2010-01-01T23:59:59.000Z

    radiation dose from PET/CT in children with malignancies.radiation dose from PET/CT in children with malig- nancies:radiation dose from PET/CT in children with malignancies:

  6. astrophysical ionizing radiation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    accrete towards the bottom of the gravitational potential, converting gravitational energy into thermal (and radiation) energy. The magnetorotational instability (MRI), an...

  7. Early Brain Response to Low-Dose Radiation Exposure Involves Molecular Networks and Pathways Associated with Cognitive Functions, Advanced Aging and Alzheimer's Disease

    SciTech Connect (OSTI)

    Lowe, Xiu R; Bhattacharya, Sanchita; Marchetti, Francesco; Wyrobek, Andrew J.

    2008-06-06T23:59:59.000Z

    Understanding the cognitive and behavioral consequences of brain exposures to low-dose ionizing radiation has broad relevance for health risks from medical radiation diagnostic procedures, radiotherapy, environmental nuclear contamination, as well as earth orbit and space missions. Analyses of transcriptome profiles of murine brain tissue after whole-body radiation showed that low-dose exposures (10 cGy) induced genes not affected by high dose (2 Gy), and low-dose genes were associated with unique pathways and functions. The low-dose response had two major components: pathways that are consistently seen across tissues, and pathways that were brain tissue specific. Low-dose genes clustered into a saturated network (p < 10{sup -53}) containing mostly down-regulated genes involving ion channels, long-term potentiation and depression, vascular damage, etc. We identified 9 neural signaling pathways that showed a high degree of concordance in their transcriptional response in mouse brain tissue after low-dose radiation, in the aging human brain (unirradiated), and in brain tissue from patients with Alzheimer's disease. Mice exposed to high-dose radiation did not show these effects and associations. Our findings indicate that the molecular response of the mouse brain within a few hours after low-dose irradiation involves the down-regulation of neural pathways associated with cognitive dysfunctions that are also down regulated in normal human aging and Alzheimer's disease.

  8. Intensity Modulated Radiation Therapy With Dose Painting to Treat Rhabdomyosarcoma

    SciTech Connect (OSTI)

    Yang, Joanna C.; Dharmarajan, Kavita V. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wexler, Leonard H. [Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); La Quaglia, Michael P. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Happersett, Laura [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wolden, Suzanne L., E-mail: woldens@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-11-01T23:59:59.000Z

    Purpose: To examine local control and patterns of failure in rhabdomyosarcoma patients treated with intensity modulated radiation therapy (RT) with dose painting (DP-IMRT). Patients and Methods: A total of 41 patients underwent DP-IMRT with chemotherapy for definitive treatment. Nineteen also underwent surgery with or without intraoperative RT. Fifty-six percent had alveolar histologic features. The median interval from beginning chemotherapy to RT was 17 weeks (range, 4-25). Very young children who underwent second-look procedures with or without intraoperative RT received reduced doses of 24-36 Gy in 1.4-1.8-Gy fractions. Young adults received 50.4 Gy to the primary tumor and lower doses of 36 Gy in 1.8-Gy fractions to at-risk lymph node chains. Results: With 22 months of median follow-up, the actuarial local control rate was 90%. Patients aged {<=}7 years who received reduced overall and fractional doses had 100% local control, and young adults had 79% (P=.07) local control. Three local failures were identified in young adults whose primary target volumes had received 50.4 Gy in 1.8-Gy fractions. Conclusions: DP-IMRT with lower fractional and cumulative doses is feasible for very young children after second-look procedures with or without intraoperative RT. DP-IMRT is also feasible in adolescents and young adults with aggressive disease who would benefit from prophylactic RT to high-risk lymph node chains, although dose escalation might be warranted for improved local control. With limited follow-up, it appears that DP-IMRT produces local control rates comparable to those of sequential IMRT in patients with rhabdomyosarcoma.

  9. Does nitrate deposition following astrophysical ionizing radiation events pose an additional threat to amphibians?

    E-Print Network [OSTI]

    Brian C. Thomas; Michelle D. Honeyman

    2008-06-27T23:59:59.000Z

    It is known that amphibians are especially susceptible to the combination of heightened UVB radiation and increased nitrate concentrations. Various astrophysical events have been suggested as sources of ionizing radiation that could pose a threat to life on Earth, through destruction of the ozone layer and subsequent increase in UVB, followed by deposition of nitrate. In this study, we investigate whether the nitrate deposition following an ionizing event is sufficiently large to cause an additional stress beyond that of the heightened UVB previously considered. We have converted predicted nitrate depositions to concentration values, utilizing data from the New York State Department of Environmental Conservation Acid Rain Monitoring Network web site. Our results show that the increase in nitrate concentration in bodies of water following the most intense ionization event likely in the last billion years would not be sufficient to cause a serious additional stress on amphibian populations and may actually provide some benefit by acting as fertilizer.

  10. Radiation Therapy Photon Beams Dose Conformation According to Dose Distribution Around Intracavitary-Applied Brachytherapy Sources

    SciTech Connect (OSTI)

    Jurkovic, Slaven [Department of Radiotherapy and Oncology, University Hospital, Rijeka (Croatia)], E-mail: slaven.jurkovic@ri.htnet.hr; Zauhar, Gordana [Department of Physics, School of Medicine, Rijeka (Croatia); Faj, Dario [Department of Radiotherapy and Oncology, University Hospital, Osijek (Croatia); Radojcic, Deni Smilovic; Svabic, Manda [Department of Radiotherapy and Oncology, University Hospital, Rijeka (Croatia)

    2010-04-01T23:59:59.000Z

    Intracavitary application of brachytherapy sources followed by external beam radiation is essential for the local treatment of carcinoma of the cervix. Due to very high doses to the central portion of the target volume delivered by brachytherapy sources, this part of the target volume must be shielded while being irradiated by photon beams. Several shielding techniques are available, from rectangular block and standard cervix wedge to more precise, customized step wedge filters. Because the calculation of a step wedge filter's shape was usually based on effective attenuation coefficient, an approach that accounts, in a more precise way, for the scattered radiation, is suggested. The method was verified under simulated clinical conditions using film dosimetry. Measured data for various compensators were compared to the numerically determined sum of the dose distribution around brachytherapy sources and one of compensated beam. Improvements in total dose distribution are demonstrated, using our method. Agreement between calculation and measurements were within 3%. Sensitivity of the method on sources displacement during treatment has also been investigated.

  11. Evaluation of Radiation Dose Effects on Rat Bones Using Synchrotron Radiation Computed Microtomography

    SciTech Connect (OSTI)

    Nogueira, Liebert Parreiras; Braz, Delson [Nuclear Instrumentation Laboratory / COPPE / UFRJ, P.O. Box 68509, 21945-970, Rio de Janeiro (Brazil); Barroso, Regina Cely [Physics Institute / State University of Rio de Janeiro, 20550-900, Rio de Janeiro (Brazil); Almeida, Carlos Eduardo de; Andrade, Cherley Borba [Laboratory of Radiological Sciences / State University of Rio de Janeiro, Rio de Janeiro (Brazil); Tromba, Giuliana [Sincrotrone Trieste SCpA, Strada Statale S.S. 14 km 163.5, 34012 Basovizza, Trieste (Italy)

    2011-12-13T23:59:59.000Z

    In this work, we investigated the consequences of irradiation in the femora and ribs of rats submitted to radiation doses of 5 Gy. Three different sites in femur specimens (head, distal metaphysis and distal epiphysis) and one in ribs (ventral) were imaged using synchrotron radiation microcomputed tomography to assess trabecular bone microarchitecture. Histomorphometric quantification was calculated directly from the 3D microtomographic images using synchrotron radiation. The 3D microtomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. A better understanding of the biological interactions that occur after exposure to photon radiation is needed in order to optimize therapeutic regimens and facilitate development and strategies that decrease radiation-induced side effects in humans. Results showed significant differences between irradiated and non-irradiated specimens, mostly in head and distal metaphysis bone sites.

  12. Sequential Treatment by Ionizing Radiation and Sodium Arsenite Dramatically Accelerates TRAIL-Mediated Apoptosis of

    E-Print Network [OSTI]

    is critically important in the translocation of death receptor to the cell surface. Moreover, sodium arsenite and further down-regulates cFLIP levels in melanoma cells. We have evaluated the effects of sequentialSequential Treatment by Ionizing Radiation and Sodium Arsenite Dramatically Accelerates TRAIL

  13. Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1

    SciTech Connect (OSTI)

    Battista, John R

    2010-02-22T23:59:59.000Z

    The primary objectives of this proposal was to define the subset of proteins required for the ionizing radiation (IR) resistance of Deinococcus radiodurans R1, characterize the activities of those proteins, and apply what was learned to problems of interest to the Department of Energy.

  14. Detection of Ionizing Radiation by Plasma-Panel Sensors: Cosmic Muons, Ion Beams, and Cancer Therapy

    SciTech Connect (OSTI)

    Friedman, Dr. Peter S. [Integrated Sensors, LLC; Ferretti, Claudio [University of Michigan; Ball, Robert [University of Michigan; Beene, James R [ORNL; Ben Moshe, M. [Tel Aviv University; Benhammou, Yan [Tel Aviv University; Chapman, J. Wehrley [University of Michigan; Levin, Daniel S. [University of Michigan; Silver, Yiftah [Tel Aviv University; Weaverdyck, Curtis [University of Michigan; Zhou, Bing [University of Michigan; Etzion, E [Tel Aviv University; Moshe, M. [Tel Aviv University; Bentefour, E [Ion Beam Applications

    2012-01-01T23:59:59.000Z

    The plasma panel sensor is an ionizing photon and particle radiation detector derived from PDP technology with high gain and nanosecond response. Experimental results in detecting cosmic ray muons and beta particles from radioactive sources are described along with applications including high energy and nuclear physics, homeland security and cancer therapeutics.

  15. absorbed radiation dose: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    10 Absorbed dose in target cell nuclei and dose conversion coefficient of radon progeny Biology and Medicine Websites Summary: Absorbed dose in target cell nuclei and...

  16. Mass-Analyzed Threshold Ionization (MATI) Spectroscopy of Atoms and Molecules using VUV Synchrotron Radiation

    SciTech Connect (OSTI)

    Kostko, Oleg; Kim, Sang Kyu; Leone, Stephen R.; Ahmed, Musahid

    2009-01-28T23:59:59.000Z

    Mass-analyzed threshold ionization (MATI) spectroscopy using synchrotron radiation (Advanced Light Source, Lawrence Berkeley National Laboratory) has been performed for Ar, N2, O2, N2O, H2O, C2H2, and C6H6. MATI allows for a better determination of ionization energies compared to those derived from photoionization efficiency curves traditionally used in synchrotron photoionization mass spectrometry. The separation of the long-lived Rydberg state from the directly-formed prompt ion, essential for a meaningful MATI spectrum, has been accomplished by employing an arrangement of ion optics coupled to unique electric-field pulsing schemes. For Ar, a number of resolved bands below the ionization energy are observed, and these are ascribed to high-n,l Rydberg states prepared in the MATI scheme. The first vibrational stateresolved MATI spectra of N2 and O2 are reported and spectral characteristics are discussed in comparison with previously-reported threshold photoelectron spectroscopic studies. While MATI performed with synchrotron radiation is intrinsically less sensitive compared to laser based sources, this work demonstrates that MATI spectroscopy performed with widely tunable VUV radiation is a complementary technique for studying the ionization spectroscopy of polyatomic molecules.

  17. Apparatus and method for the simultaneous detection of neutrons and ionizing electromagnetic radiation

    DOE Patents [OSTI]

    Bell, Zane W. (Oak Ridge, TN)

    2000-01-01T23:59:59.000Z

    A sensor for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising: a sensor for the detection of gamma radiation, the sensor defining a sensing head; the sensor further defining an output end in communication with the sensing head; and an exterior neutron-sensitive material configured to form around the sensing head; wherein the neutron-sensitive material, subsequent to the capture of the neutron, fissions into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the first excited state decaying via the emission of a single gamma ray at 478 keV which can in turn be detected by the sensing head; and wherein the sensing head can also detect the ionizing electromagnetic radiation from an incident radiation field without significant interference from the neutron-sensitive material. A method for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising the steps of: providing a gamma ray sensitive detector comprising a sensing head and an output end; conforming an exterior neutron-sensitive material configured to form around the sensing head of the detector; capturing neutrons by the sensing head causing the neutron-sensitive material to fission into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the state decaying via the emission of a single gamma ray at 478 keV; sensing gamma rays entering the detector through the neutron-sensitive material; and producing an output through a readout device coupled to the output end; wherein the detector provides an output which is proportional to the energy of the absorbed ionizing electromagnetic radiation.

  18. Tritium: a model for low level long-term ionizing radiation exposure

    SciTech Connect (OSTI)

    Carsten, A.L.

    1984-01-01T23:59:59.000Z

    The somatic, cytogenetic and genetic effects of single and chronic tritiated water (HTO) ingestion in mice was investigated. This study serves not only as an evaluation of tritium toxicity (TRITOX) but due to its design involving long-term low concentration ingestion of HTO may serve as a model for low level long-term ionizing radiation exposure in general. Long-term studies involved animals maintained on HTO at concentrations of 0.3 ..mu..Ci/ml, 1.0 ..mu..Ci/ml, 3.0 ..mu..Ci/ml or depth dose equivalent chronic external exposures to /sup 137/Cs gamma rays. Maintenance on 3.0 ..mu..Ci/ml resulted in no effect on growth, life-time shortening or bone marrow cellularity, but did result in a reduction of bone marrow stem cells, an increase in DLM's in second generation animals maintained on this regimen and cytogenetic effects as indicated by increased sister chromatid exchanges (SCE's) in bone marrow cells, increased chromosome aberrations in the regenerating liver and an increase in micronuclei in red blood cells. Biochemical and microdosimetry studies showed that animals placed on the HTO regimen reached tritium equilibrium in the body water in approximately 17 to 21 days with a more gradual increase in bound tritium. When animals maintained for 180 days on 3.0 ..mu..Ci/ml HTO were placed on a tap water regimen, the tritium level in tissue dropped from the equilibrium value of 2.02 ..mu..Ci/ml before withdrawal to 0.001 ..mu..Ci/ml at 28 days. 18 references.

  19. Low dose radiation interations with the transformation growth factor (TGF)-beta pathway 

    E-Print Network [OSTI]

    Maslowski, Amy Jesse

    2009-05-15T23:59:59.000Z

    A major limiting factor for long-term, deep-space missions is the radiation dose to astronauts. Because the dose to the astronauts is a mixed field of low- and high-LET radiation, there is a need to understand the effects of both radiation types...

  20. Whole-Body Biodistribution and Estimation of Radiation-Absorbed Doses of the Dopamine D1

    E-Print Network [OSTI]

    Shen, Jun

    Whole-Body Biodistribution and Estimation of Radiation-Absorbed Doses of the Dopamine D1 Receptor and Behaviour, Monash University, Clayton, Victoria, Australia The present study estimated radiation of interest were drawn on compressed planar images of source organs that could be iden- tified. Radiation dose

  1. Technical specifications manual for the MARK-1 pulsed ionizing radiation detection system. Volume 1

    SciTech Connect (OSTI)

    Lawrence, R.S.; Harker, Y.D.; Jones, J.L.; Hoggan, J.M.

    1993-03-01T23:59:59.000Z

    The MARK-1 detection system was developed by the Idaho National Engineering Laboratory for the US Department of Energy Office of Arms Control and Nonproliferation. The completely portable system was designed for the detection and analysis of intense photon emissions from pulsed ionizing radiation sources. This manual presents the technical design specifications for the MARK-1 detection system and was written primarily to assist the support or service technician in the service, calibration, and repair of the system. The manual presents the general detection system theory, the MARK-1 component design specifications, the acquisition and control software, the data processing sequence, and the system calibration procedure. A second manual entitled: Volume 2: Operations Manual for the MARK-1 Pulsed Ionizing Radiation Detection System (USDOE Report WINCO-1108, September 1992) provides a general operational description of the MARK-1 detection system. The Operations Manual was written primarily to assist the field operator in system operations and analysis of the data.

  2. Self-consistent solution of cosmological radiation-hydrodynamics and chemical ionization

    SciTech Connect (OSTI)

    Reynolds, Daniel R. [Mathematics, Southern Methodist University, Dallas, TX 75275-0156 (United States)], E-mail: reynolds@smu.edu; Hayes, John C. [Lawrence Livermore National Lab, P.O. Box 808, L-551, Livermore, CA 94551 (United States)], E-mail: jchayes@llnl.gov; Paschos, Pascal [Ctr. for Astrophysics and Space Sciences, U.C. San Diego, La Jolla, CA 92093 (United States)], E-mail: ppaschos@minbari.ucsd.edu; Norman, Michael L. [Ctr. for Astrophysics and Space Sciences, U.C. San Diego, La Jolla, CA 92093 (United States); Physics Department, U.C. San Diego, La Jolla, CA 92093 (United States)], E-mail: mlnorman@ucsd.edu

    2009-10-01T23:59:59.000Z

    We consider a PDE system comprising compressible hydrodynamics, flux-limited diffusion radiation transport and chemical ionization kinetics in a cosmologically-expanding universe. Under an operator-split framework, the cosmological hydrodynamics equations are solved through the piecewise parabolic method, as implemented in the Enzo community hydrodynamics code. The remainder of the model, including radiation transport, chemical ionization kinetics, and gas energy feedback, form a stiff coupled PDE system, which we solve using a fully-implicit inexact Newton approach, and which forms the crux of this paper. The inner linear Newton systems are solved using a Schur complement formulation, and employ a multigrid-preconditioned conjugate gradient solver for the inner Schur systems. We describe this approach and provide results on a suite of test problems, demonstrating its accuracy, robustness, and scalability to very large problems.

  3. Dwarf galaxies with ionizing radiation feedback. II. Spatially resolved star formation relation

    SciTech Connect (OSTI)

    Kim, Ji-hoon; Krumholz, Mark R.; Goldbaum, Nathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Wise, John H. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Turk, Matthew J. [Department of Astronomy and Astrophysics, Columbia University, New York, NY 10027 (United States); Abel, Tom, E-mail: me@jihoonkim.org [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States)

    2013-12-10T23:59:59.000Z

    We investigate the spatially resolved star formation relation using a galactic disk formed in a comprehensive high-resolution (3.8 pc) simulation. Our new implementation of stellar feedback includes ionizing radiation as well as supernova explosions, and we handle ionizing radiation by solving the radiative transfer equation rather than by a subgrid model. Photoheating by stellar radiation stabilizes gas against Jeans fragmentation, reducing the star formation rate (SFR). Because we have self-consistently calculated the location of ionized gas, we are able to make simulated, spatially resolved observations of star formation tracers, such as H? emission. We can also observe how stellar feedback manifests itself in the correlation between ionized and molecular gas. Applying our techniques to the disk in a galactic halo of 2.3 × 10{sup 11} M {sub ?}, we find that the correlation between SFR density (estimated from mock H? emission) and H{sub 2} density shows large scatter, especially at high resolutions of ?75 pc that are comparable to the size of giant molecular clouds (GMCs). This is because an aperture of GMC size captures only particular stages of GMC evolution and because H? traces hot gas around star-forming regions and is displaced from the H{sub 2} peaks themselves. By examining the evolving environment around star clusters, we speculate that the breakdown of the traditional star formation laws of the Kennicutt-Schmidt type at small scales is further aided by a combination of stars drifting from their birthplaces and molecular clouds being dispersed via stellar feedback.

  4. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    DOE Patents [OSTI]

    Britton, Jr., Charles L. (Alcoa, TN); Buckner, Mark A. (Oak Ridge, TN); Hanson, Gregory R. (Clinton, TN); Bryan, William L. (Knoxville, TN)

    2011-05-03T23:59:59.000Z

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes insitu polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  5. Space charge dosimeters for extremely low power measurements of radiation in shipping containers

    DOE Patents [OSTI]

    Britton, Jr.; Charles L. (Alcoa, TN); Buckner, Mark A. (Oak Ridge, TN); Hanson, Gregory R. (Clinton, TN); Bryan, William L. (Knoxville, TN)

    2011-04-26T23:59:59.000Z

    Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

  6. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1994-08-16T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  7. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1995-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  8. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, L.H.

    1995-10-17T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  9. Gamma radiation field intensity meter

    DOE Patents [OSTI]

    Thacker, Louis H. (Knoxville, TN)

    1994-01-01T23:59:59.000Z

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  10. JOUENAL DE PHYSIQUE CoZZoque C7, suppZ6rnent au n07, Tome 40, J u i l l e t 2979, vage C7-743 IONIZATION OF ISOLATED DEUTERIUM PELLETS BY NEODYMIUM LASER RADIATION

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    IONIZATION OF ISOLATED DEUTERIUM PELLETS BY NEODYMIUM LASER RADIATION H. Baurnhacker, H. Brinkschulte, W

  11. Estimation of Internal Radiation Dose from both Immediate Releases and Continued Exposures to Contaminated Materials

    SciTech Connect (OSTI)

    Napier, Bruce A.

    2012-03-26T23:59:59.000Z

    A brief description is provided of the basic concepts related to 'internal dose' and how it differs from doses that result from radioactive materials and direct radiation outside of the body. The principles of radiation dose reconstruction, as applied to both internal and external doses, is discussed based upon a recent publication prepared by the US National Council on Radiation Protection and Measurements. Finally, ideas are introduced related to residual radioactive contamination in the environment that has resulted from the releases from the damaged reactors and also to the management of wastes that may be generated in both regional cleanup and NPP decommissioning.

  12. Second Solid Cancers After Radiation Therapy: A Systematic Review of the Epidemiologic Studies of the Radiation Dose-Response Relationship

    SciTech Connect (OSTI)

    Berrington de Gonzalez, Amy, E-mail: berringtona@mail.nih.gov [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Gilbert, Ethel; Curtis, Rochelle; Inskip, Peter; Kleinerman, Ruth; Morton, Lindsay; Rajaraman, Preetha; Little, Mark P. [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)] [Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)

    2013-06-01T23:59:59.000Z

    Rapid innovations in radiation therapy techniques have resulted in an urgent need for risk projection models for second cancer risks from high-dose radiation exposure, because direct observation of the late effects of newer treatments will require patient follow-up for a decade or more. However, the patterns of cancer risk after fractionated high-dose radiation are much less well understood than those after lower-dose exposures (0.1-5 Gy). In particular, there is uncertainty about the shape of the dose-response curve at high doses and about the magnitude of the second cancer risk per unit dose. We reviewed the available evidence from epidemiologic studies of second solid cancers in organs that received high-dose exposure (>5 Gy) from radiation therapy where dose-response curves were estimated from individual organ-specific doses. We included 28 eligible studies with 3434 second cancer patients across 11 second solid cancers. Overall, there was little evidence that the dose-response curve was nonlinear in the direction of a downturn in risk, even at organ doses of ?60 Gy. Thyroid cancer was the only exception, with evidence of a downturn after 20 Gy. Generally the excess relative risk per Gray, taking account of age and sex, was 5 to 10 times lower than the risk from acute exposures of <2 Gy among the Japanese atomic bomb survivors. However, the magnitude of the reduction in risk varied according to the second cancer. The results of our review provide insights into radiation carcinogenesis from fractionated high-dose exposures and are generally consistent with current theoretical models. The results can be used to refine the development of second solid cancer risk projection models for novel radiation therapy techniques.

  13. Genetic Factors Affecting Susceptibility to Low Dose & Low Dose-Rate Radiation

    SciTech Connect (OSTI)

    Bedford, Joel

    2014-04-18T23:59:59.000Z

    Our laboratory has, among other things, developed and used the gamma H2AX focus assay and other chromosomal and cell killing assays to show that differences in this DNA double strand break (dsb) related response can be clearly and distinctly demonstrated for cells which are mildly hyper-radiosensitive such as those associated with A-T heterozygosity. We have found this level of mild hypersensitivity for cells from some 20 to 30 % of apparently normal individuals and from apparently normal parents of Retinoblastoma patients. We found significant differences in gene expression in somatic cells from unaffected parents of Rb patients as compared with normal controls, suggesting that these parents may harbor some as yet unidentified genetic abnormality. In other experiments we sought to determine the extent of differences in normal human cellular reaponses to radiation depending on their irradiation in 2D monolayer vs 3D organized acinar growth conditions. We exmined cell reproductive death, chromosomal aberration induction, and the levels of ?-H2AX foci in cells after single acute gamma-ray doses and immediately after 20 hours of irradiation at a dose rate of 0.0017 Gy/min. We found no significant differences in the dose-responses of these cells under the 2D or 3D growth conditions. While this does not mean such differences cannot occur in other situations, it does mean that they do not generally or necessarily occur. In another series of studies in collaboration with Dr Chuan Li, with supprt from this current grant. We reported a role for apoptotic cell death in promoting wound healing and tissue regeneration in mice. Apoptotic cells released growth signals that stimulated the proliferation of progenitor or stem cells. In yet another collaboration with Dr, B. Chen with funds from this grant, the relative radiosensitivity to cell killing as well as chromosomal instability of 13 DNA-PKcs site-directed mutant cell lines (defective at phosphorylation sites or kinase activity) were examined after exposure of synchronized G1 cells to 137Cs c rays. DNA-PKcs mutant cells defective in phosphorylation at multiple sites withinthe T2609 cluster or within the PI3K domain displayed extreme radiosensitivity. Cells defective at the S2056 cluster or T2609 single site alone were only mildly radiosensitive, but cells defective at even one site in both the S2056 and T2609 clusters were maximally radiosensitive. Thus a synergism between the capacity for phosphorylation at the S2056 and T2609 clusterswas found to be critical for induction of radiosensitivity.

  14. Evaluation of Radiation Dose Reduction during CT Scans Using Oxide Bismuth and Nano-Barium Sulfate Shields

    E-Print Network [OSTI]

    Seoung, Youl-Hun

    2015-01-01T23:59:59.000Z

    The purpose of the present study was to evaluate radiation dose reduction and image quality during CT scanning by using a new dose reduction fiber sheet (DRFS) with commercially available bismuth shields. These DRFS were composed of nano-barium sulfate (BaSO4), filling the gaps left by the large oxide bismuth (Bi2O3) particle sizes. The radiation dose was measured five times at directionss of 12 o'clock from the center of the polymethyl methacrylate (PMMA) head phantom to calculate an average value using a CT ionization chamber. The image quality measured CT transverse images of the PMMA head phantom depending on X-ray tube voltages and the type of shielding. Two regions of interest in CT transverse images were chosen from the right and left areas under the surface of the PMMA head phantom and from ion chamber holes located at directions of 12 o'clock from the center of the PMMA head phantom. The results of this study showed that the new DRFS shields could reduce dosages to 15.61%, 23.05%, and 22.71% more in ...

  15. Implications of Intercellular Signaling for Radiation Therapy: A Theoretical Dose-Planning Study

    SciTech Connect (OSTI)

    McMahon, Stephen J., E-mail: stephen.mcmahon@qub.ac.uk [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); McGarry, Conor K. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland (United Kingdom); Butterworth, Karl T. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); O'Sullivan, Joe M. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Clinical Oncology, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland (United Kingdom); Hounsell, Alan R. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom); Radiotherapy Physics, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland (United Kingdom); Prise, Kevin M. [Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland (United Kingdom)

    2013-12-01T23:59:59.000Z

    Purpose: Recent in vitro results have shown significant contributions to cell killing from signaling effects at doses that are typically used in radiation therapy. This study investigates whether these in vitro observations can be reconciled with in vivo knowledge and how signaling may have an impact on future developments in radiation therapy. Methods and Materials: Prostate cancer treatment plans were generated for a series of 10 patients using 3-dimensional conformal therapy, intensity modulated radiation therapy (IMRT), and volumetric modulated arc therapy techniques. These plans were evaluated using mathematical models of survival following modulated radiation exposures that were developed from in vitro observations and incorporate the effects of intercellular signaling. The impact on dose–volume histograms and mean doses were evaluated by converting these survival levels into “signaling-adjusted doses” for comparison. Results: Inclusion of intercellular communication leads to significant differences between the signalling-adjusted and physical doses across a large volume. Organs in low-dose regions near target volumes see the largest increases, with mean signaling-adjusted bladder doses increasing from 23 to 33 Gy in IMRT plans. By contrast, in high-dose regions, there is a small decrease in signaling-adjusted dose due to reduced contributions from neighboring cells, with planning target volume mean doses falling from 74 to 71 Gy in IMRT. Overall, however, the dose distributions remain broadly similar, and comparisons between the treatment modalities are largely unchanged whether physical or signaling-adjusted dose is compared. Conclusions: Although incorporating cellular signaling significantly affects cell killing in low-dose regions and suggests a different interpretation for many phenomena, their effect in high-dose regions for typical planning techniques is comparatively small. This indicates that the significant signaling effects observed in vitro are not contradicted by comparison with clinical observations. Future investigations are needed to validate these effects in vivo and to quantify their ranges and potential impact on more advanced radiation therapy techniques.

  16. Applied Radiation and Isotopes 64 (2006) 6062 Weak energy dependence of EBT gafchromic film dose

    E-Print Network [OSTI]

    Yu, K.N.

    2006-01-01T23:59:59.000Z

    , radiation-sensi- tive, polymer between two protective layers of polyester, which allows the filmApplied Radiation and Isotopes 64 (2006) 60­62 Weak energy dependence of EBT gafchromic film dose are common in radiation therapy. r 2005 Elsevier Ltd. All rights reserved. Keywords: Radiochromic film

  17. SU-E-J-160: Comparing the Setup Accuracy of Non-Ionizing Patient Localization Systems with CBCT to Reduce Imaging Dose in Prone Breast Treatments

    SciTech Connect (OSTI)

    Chung, E; Yamamoto, T; Mayadev, J; Dieterich, S [UC Davis Medical Center, Sacramento, CA (United States)

    2014-06-01T23:59:59.000Z

    Purpose: CBCT is the current gold standard to verify prone breast patient setup. We investigated in a phantom if non-ionizing localization systems can replace ionizing localization systems for prone breast treatments. Methods: An anthropomorphic phantom was positioned on a prone breast board. Electromagnetic transponders were attached on the left chest surface. The CT images of the phantom were imported to the treatment planning system. The isocenter was set to the center of the transponders. The positions of the isocenter and transponders transferred to the transponder tracking system. The posterior phantom surface was contoured and exported to the optical surface tracking system. A CBCT was taken for the initial setup alignment on the treatment machine. Using the electromagnetic and optical localization systems, the deviation of the phantom setup from the original CT images was measured. This was compared with the difference between the original CT and kV-CBCT images. Results: For the electromagnetic localization system, the phantom position deviated from the original CT in 1.5 mm, 0.0 mm and 0.5 mm in the anterior-posterior (AP), superior-inferior (SI) and left-right (LR) directions. For the optical localization system, the phantom position deviated from the original CT in 2.0 mm, ?2.0 mm and 0.1 mm in the AP, SI and LR directions. For the CBCT, the phantom position deviated from the original CT in 4.0 mm, 1.0 mm and ?1.0 mm in the AP, SI and LR directions. The measured values from the non-ionizing localization systems differed from those with the CBCT less than 3.0 mm in all directions. Conclusions: This phantom study showed the feasibility of using a combination of non-ionizing localization systems to achieve a similar setup accuracy as CBCT for prone breast patients. This could potentially eliminate imaging dose. As a next step, we are expanding this study to actual patients. This work has been in part supported by Departmental Research Award RODEPT1-JS001, Department of Radiation Oncology, UC Davis Medical Center.

  18. Electron density and temperature measurement by continuum radiation emitted from weakly ionized atmospheric pressure plasmas

    SciTech Connect (OSTI)

    Park, Sanghoo; Choe, Wonho, E-mail: wchoe@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Youn Moon, Se [High-enthalpy Plasma Research Center, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju 561-756 (Korea, Republic of); Park, Jaeyoung [5771 La Jolla Corona Drive, La Jolla, CA 92037 (United States)

    2014-02-24T23:59:59.000Z

    The electron-atom neutral bremsstrahlung continuum radiation emitted from weakly ionized plasmas is investigated for electron density and temperature diagnostics. The continuum spectrum in 450–1000?nm emitted from the argon atmospheric pressure plasma is found to be in excellent agreement with the neutral bremsstrahlung formula with the electron-atom momentum transfer cross-section given by Popovi?. In 280–450?nm, however, a large discrepancy between the measured and the neutral bremsstrahlung emissivities is observed. We find that without accounting for the radiative H{sub 2} dissociation continuum, the temperature, and density measurements would be largely wrong, so that it should be taken into account for accurate measurement.

  19. Integral radiation dose to normal structures with conformal external beam radiation

    SciTech Connect (OSTI)

    Aoyama, Hidefumi [Department of Human Oncology, University of Wisconsin, Madison, WI (United States) and Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo (Japan)]. E-mail: hao@radi.med.hokudai.ac.jp; Westerly, David Clark [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Mackie, Thomas Rockwell [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); TomoTherapy Inc., Madison, WI (United States); Olivera, Gustavo H. [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); TomoTherapy Inc., Madison, WI (United States); Bentzen, Soren M. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Patel, Rakesh R. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Jaradat, Hazim [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Tome, Wolfgang A. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Ritter, Mark A. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Mehta, Minesh P. [Department of Human Oncology, University of Wisconsin, Madison, WI (United States)

    2006-03-01T23:59:59.000Z

    Background: This study was designed to evaluate the integral dose (ID) received by normal tissue from intensity-modulated radiotherapy (IMRT) for prostate cancer. Methods and Materials: Twenty-five radiation treatment plans including IMRT using a conventional linac with both 6 MV (6MV-IMRT) and 20 MV (20MV-IMRT), as well as three-dimensional conformal radiotherapy (3DCRT) using 6 MV (6MV-3DCRT) and 20 MV (20MV-3DCRT) and IMRT using tomotherapy (6MV) (Tomo-IMRT), were created for 5 patients with localized prostate cancer. The ID (mean dose x tissue volume) received by normal tissue (NTID) was calculated from dose-volume histograms. Results: The 6MV-IMRT resulted in 5.0% lower NTID than 6MV-3DCRT; 20 MV beam plans resulted in 7.7%-11.2% lower NTID than 6MV-3DCRT. Tomo-IMRT NTID was comparable to 6MV-IMRT. Compared with 6MV-3DCRT, 6MV-IMRT reduced IDs to the rectal wall and penile bulb by 6.1% and 2.7%, respectively. Tomo-IMRT further reduced these IDs by 11.9% and 16.5%, respectively. The 20 MV did not reduce IDs to those structures. Conclusions: The difference in NTID between 3DCRT and IMRT is small. The 20 MV plans somewhat reduced NTID compared with 6 MV plans. The advantage of tomotherapy over conventional IMRT and 3DCRT for localized prostate cancer was demonstrated in regard to dose sparing of rectal wall and penile bulb while slightly decreasing NTID as compared with 6MV-3DCRT.

  20. Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage

    E-Print Network [OSTI]

    Adrian L. Melott; Brian C. Thomas

    2009-02-02T23:59:59.000Z

    Based on the intensity and rates of various kinds of intense ionizing radiation events such as supernovae and gamma-ray bursts, it is likely that the Earth has been subjected to one or extinction level events during the Phanerozoic. These induce changes in atmospheric chemistry so that the level of Solar ultraviolet-B radiation reaching the surface and near-surface waters may be doubled for up to a decade. This UVB level is known from experiment to be more than enough to kill off many kinds of organisms, particularly phytoplankton. It could easily induce a crash of the photosynthetic-based food chain in the oceans. Regularities in the latitudinal distribution of damage are apparent in simulations of the atmospheric changes. We previously proposed that the late Ordovician extinction is a plausible candidate for a contribution from an ionizing radiation event, based on environmental selectivity in trilobites. To test a null hypothesis based on this proposal, we confront latitudinal differential extinction rates predicted from the simulations with data from a published analysis of latitudinal gradients in the Ordovician extinction. The pattern of UVB damage always shows a strong maximum at some latitude, with substantially lower intensity to the north and south of this maximum. We find that the pattern of damage predicted from our simulations is consistent with the data assuming a burst approximately over the South Pole, and no further north than -75 degrees. We predict that any land mass (such as parts of north China, Laurentia, and New Guinea) which then lay north of the equator should be a refuge from UVB effects, and show a different pattern of extinction in the first strike of the end-Ordovician extinction, if induced by such a radiation event.

  1. COLUMBIA UNIVERSITY Radiation Safety Program

    E-Print Network [OSTI]

    Jia, Songtao

    for increased protection from ionizing radiation for declared pregnant radiation workers. The radiation doseCOLUMBIA UNIVERSITY Radiation Safety Program Medical Center - T: 212-305-0303 F: 212 regulations of the Rules of the City of New York, Article 175, Radiation Control, there is a requirement

  2. Total dose radiation response of plasma-damaged NMOS devices

    SciTech Connect (OSTI)

    Yue, J.; Lo, E.; Flanery, M. [Honeywell Solid-State Electronic Center, Plymouth, MN (United States)] [Honeywell Solid-State Electronic Center, Plymouth, MN (United States)

    1997-11-01T23:59:59.000Z

    Plasma-damaged NMOS devices were subjected to the X-ray total dose irradiation. Unlike the traditional hot-carrier or Fowler-Nordheim (F-N) stress where the hole trap generation is less pronounced, this study shows enhanced hole trap and interface trap generation on plasma-damaged devices after total dose irradiation.

  3. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOE Patents [OSTI]

    Majewski, S.; Kross, B.J.; Zorn, C.J.; Majewski, L.A.

    1996-10-22T23:59:59.000Z

    An optimized examination system and method based on the Reverse Geometry X-Ray{trademark} (RGX{trademark}) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging. 5 figs.

  4. Examination system utilizing ionizing radiation and a flexible, miniature radiation detector probe

    DOE Patents [OSTI]

    Majewski, Stanislaw (Grafton, VA); Kross, Brian J. (Yorktown, VA); Zorn, Carl J. (Yorktown, VA); Majewski, Lukasz A. (Grafton, VA)

    1996-01-01T23:59:59.000Z

    An optimized examination system and method based on the Reverse Geometry X-Ray.RTM. (RGX.RTM.) radiography technique are presented. The examination system comprises a radiation source, at least one flexible, miniature radiation detector probe positioned in appropriate proximity to the object to be examined and to the radiation source with the object located between the source and the probe, a photodetector device attachable to an end of the miniature radiation probe, and a control unit integrated with a display device connected to the photodetector device. The miniature radiation detector probe comprises a scintillation element, a flexible light guide having a first end optically coupled to the scintillation element and having a second end attachable to the photodetector device, and an opaque, environmentally-resistant sheath surrounding the flexible light guide. The probe may be portable and insertable, or may be fixed in place within the object to be examined. An enclosed, flexible, liquid light guide is also presented, which comprises a thin-walled flexible tube, a liquid, preferably mineral oil, contained within the tube, a scintillation element located at a first end of the tube, closures located at both ends of the tube, and an opaque, environmentally-resistant sheath surrounding the flexible tube. The examination system and method have applications in non-destructive material testing for voids, cracks, and corrosion, and may be used in areas containing hazardous materials. In addition, the system and method have applications for medical and dental imaging.

  5. Reduction of radiation dose to radiosensitive organs and its tradeoff with image quality in Computed Tomography

    E-Print Network [OSTI]

    Zhang, Di

    2012-01-01T23:59:59.000Z

    helical multislice computed tomography examination. MedicalRadiation Dose in X-Ray Computed Tomography. AAPM report NO.of X-ray equipment for computed tomography. (2002). American

  6. Radiation Safety Edward O'Connell

    E-Print Network [OSTI]

    /Bureau of Environmental Radiation Protection (BERP) · Regulatory Compliance ­ State Sanitary 16 · Required Radiation to cause ionization depends on the energy #12;Radiation Can Cause Ionization #12;Units of Measurements millirem per year. · At 50,000 feet, the dose rate is about 1 millirem per hour. · There are areas

  7. assessing radiation dose: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

  8. accumulated radiation dose: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

  9. annual radiation dose: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    doses and cancer rates to the workers m the first Soviet atom-bomb facility, near 2 Chelyabinsk and 4,600 at the plutonium sep- aration plant. If we allow for an average work...

  10. Radiation-induced chromosomal aberrations at different dose-rates

    E-Print Network [OSTI]

    McDaniel, Jackson Dean

    1965-01-01T23:59:59.000Z

    and sincere gratitude to Dr. G. M. Krise, for his advice and generosity, and to Dr. S. 0. Brown, for his vigilance throughout the course of this investigaticn. To Dr. H. R. Crookshank, I would like to acknowledge my indebtedness for serving as a sember... testicular cells eight hours postirradiation in animals given a total-body dose of 300 r at various dose rates . ; . . . . . . . . . . . , . . . . . . . . . . 17 II. Percentage of cells with aberrations per total dividing cells in the rat testes eight...

  11. Page 1 of 3 RADIATION DOSE IS MORE THAN A NUMBER!

    E-Print Network [OSTI]

    Perkins, Richard A.

    , Former Director of Radiological Physics Center, MD Anderson Cancer Center #12;Page 2 of 3 RADIATION DOSE of Radiation Larry Dewerd, University of Wisconsin Will Hanson, Former Director of Radiological Physics Center for solicited research Service ­ NIH-based facility (RPC-like) or fee for service or private non-profit (AAALAC

  12. Analysis of radiation doses from operation of postulated commercial spent fuel transportation systems: Main report

    SciTech Connect (OSTI)

    Schneider, K.J.; Hostick, C.J.; Ross, W.A.; Peterson, R.W.; Smith, R.I.; Stiles, D.L.; Daling, P.M.; Weakley, S.A.; Grinde, R.B.; Young, J.R.

    1987-11-01T23:59:59.000Z

    This report contains a system study of estimated radiation doses to the public and workers resulting from the transport of spent fuel from commercial nuclear power reactors to a geologic repository. The report contains a detailed breakdown of activities and a description of time/distance/dose-rate estimates for each activity within the system. Collective doses are estimated for each of the major activities at the reactor site, in transit, and at the repository receiving facility. Annual individual doses to the maximally exposed individuals or groups of individuals are also estimated. A total of 17 alternatives and subalternatives to the postulated reference transportation system are identified, conceptualized, and their dose-reduction potentials and costs estimated. Resulting ratios of ..delta..cost/..delta..collective system dose for each alternative relative to the postulated reference transportation system are given. Most of the alternatives evaluated are estimated to provide both cost and dose reductions. Major reductions in transportation system dose and cost are estimated to result from using higher-capacity rail and truck casks, and particularly when replacing legalweight truck casks with ''advanced design'' overweight truck casks. The greatest annual dose reduction to the highest exposed individual workers (i.e., at the repository) is estimated to be achieved by using remote handling equipment for the cask handling operations at the repository. Additional shielding is also effective in reducing doses to both radiation workers at the reactor and repository and to transport workers. 69 refs., 36 figs., 156 tabs.

  13. Radiation Dose-Volume Effects and the Penile Bulb

    SciTech Connect (OSTI)

    Roach, Mack, E-mail: mroach@radonc.ucsf.ed [Department of Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States); Nam, Jiho [Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States); Gagliardi, Giovanna [Department of Medical Physics, Karolinska University Hospital and Karolinska Institutet, Stockholm (Sweden); El Naqa, Issam; Deasy, Joseph O. [Department of Radiation Oncology, School of Medicine, Washington University in St. Louis, St. Louis, MO (United States); Marks, Lawrence B. [Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC (United States)

    2010-03-01T23:59:59.000Z

    The dose, volume, and clinical outcome data for penile bulb are reviewed for patients treated with external-beam radiotherapy. Most, but not all, studies find an association between impotence and dosimetric parameters (e.g., threshold doses) and clinical factors (e.g., age, comorbid diseases). According to the data available, it is prudent to keep the mean dose to 95% of the penile bulb volume to <50 Gy. It may also be prudent to limit the D70 and D90 to 70 Gy and 50 Gy, respectively, but coverage of the planning target volume should not be compromised. It is acknowledged that the penile bulb may not be the critical component of the erectile apparatus, but it seems to be a surrogate for yet to be determined structure(s) critical for erectile function for at least some techniques.

  14. Spatially resolved measurement of high doses in microbeam radiation therapy using samarium doped fluorophosphate glasses

    SciTech Connect (OSTI)

    Okada, Go; Morrell, Brian; Koughia, Cyril; Kasap, Safa [Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9 (Canada); Edgar, Andy; Varoy, Chris [School of Chemical and Physical Sciences and MacDiarmid Institute, Victoria University of Wellington, Kelburn Parade (New Zealand); Belev, George; Wysokinski, Tomasz [Canadian Light Source Inc., University of Saskatchewan, Saskatoon, SK S7N 0X4 (Canada); Chapman, Dean [Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK S7N 5E5 (Canada)

    2011-09-19T23:59:59.000Z

    The measurement of spatially resolved high doses in microbeam radiation therapy has always been a challenging task, where a combination of high dose response and high spatial resolution (microns) is required for synchrotron radiation peaked around 50 keV. The x-ray induced Sm{sup 3+}{yields} Sm{sup 2+} valence conversion in Sm{sup 3+} doped fluorophosphates glasses has been tested for use in x-ray dosimetry for microbeam radiation therapy. The conversion efficiency depends almost linearly on the dose of irradiation up to {approx}5 Gy and saturates at doses exceeding {approx}80 Gy. The conversion shows strong correlation with x-ray induced absorbance of the glass which is related to the formation of phosphorus-oxygen hole centers. When irradiated through a microslit collimator, a good spatial resolution and high ''peak-to-valley'' contrast have been observed by means of confocal photoluminescence microscopy.

  15. Standard Guide for Absorbed-Dose Mapping in Radiation Processing Facilities

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2003-01-01T23:59:59.000Z

    1.1 This document provides guidance in determining absorbed-dose distributions in products, materials or substances irradiated in gamma, X-ray (bremsstrahlung) and electron beam facilities. Note 1—For irradiation of food and the radiation sterilization of health care products, other specific ISO and ISO/ASTM standards containing dose mapping requirements exist. For food irradiation, see ISO/ASTM 51204, Practice for Dosimetry in Gamma Irradiation Facilities for Food Processing and ISO/ASTM 51431, Practice for Dosimetry in Electron and Bremsstrahlung Irradiation Facilities for Food Processing. For the radiation sterilization of health care products, see ISO 11137: 1995, Sterilization of Health Care Products Requirements for Validation and Routine Control Radiation Sterilization. In those areas covered by ISO 11137, that standard takes precedence. ISO/ASTM Practice 51608, ISO/ASTM Practice 51649, and ISO/ASTM Practice 51702 also contain dose mapping requirements. 1.2 Methods of analyzing the dose map data ar...

  16. Radiation and litigation : analyses of the ALARA principle and low dose radiation in the courts, and the future of radiation in court cases

    E-Print Network [OSTI]

    Esparza, Enrique

    2006-01-01T23:59:59.000Z

    Currently there are a growing number of radiation workers. In order to ensure the safety of the employees, regulations have been established by the federal government and state governments to limit the dose equivalent to ...

  17. 75Radiation Dose and Distance This iconic photo was

    E-Print Network [OSTI]

    on March 15, a few days after the Japan 2011 earthquake, which caused severe damage to the Fukushima Press/Kyodo News) The devastating Japan 2011 earthquake damaged the nuclear reactors in Fukushima, which: Date Distance (km) Location Dose Rate (microSeiverts/hr) March 15 1 km Fukushima #2 plant 8,200 March

  18. Staff Radiation Doses in a Real-Time Display Inside the Angiography Room

    SciTech Connect (OSTI)

    Sanchez, Roberto, E-mail: rmsanchez.hcsc@salud.madrid.org; Vano, E.; Fernandez, J. M. [Hospital Clinico San Carlos, Medical Physics Department (Spain); Gallego, J. J. [Universidad Complutense de Madrid, Radiology Department (Spain)

    2010-12-15T23:59:59.000Z

    MethodsThe evaluation of a new occupational Dose Aware System (DAS) showing staff radiation doses in real time has been carried out in several angiography rooms in our hospital. The system uses electronic solid-state detectors with high-capacity memory storage. Every second, it archives the dose and dose rate measured and is wirelessly linked to a base-station screen mounted close to the diagnostic monitors. An easy transfer of the values to a data sheet permits further analysis of the scatter dose profile measured during the procedure, compares it with patient doses, and seeks to find the most effective actions to reduce operator exposure to radiation.ResultsThe cumulative occupational doses measured per procedure (shoulder-over lead apron) ranged from 0.6 to 350 {mu}Sv when the ceiling-suspended screen was used, and DSA (Digital Subtraction Acquisition) runs were acquired while the personnel left the angiography room. When the suspended screen was not used and radiologists remained inside the angiography room during DSA acquisitions, the dose rates registered at the operator's position reached up to 1-5 mSv/h during fluoroscopy and 12-235 mSv/h during DSA acquisitions. In such case, the cumulative scatter dose could be more than 3 mSv per procedure.ConclusionReal-time display of doses to staff members warns interventionists whenever the scatter dose rates are too high or the radiation protection tools are not being properly used, providing an opportunity to improve personal protection accordingly.

  19. Calculation of radiation therapy dose using all particle Monte Carlo transport

    DOE Patents [OSTI]

    Chandler, William P. (Tracy, CA); Hartmann-Siantar, Christine L. (San Ramon, CA); Rathkopf, James A. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    The actual radiation dose absorbed in the body is calculated using three-dimensional Monte Carlo transport. Neutrons, protons, deuterons, tritons, helium-3, alpha particles, photons, electrons, and positrons are transported in a completely coupled manner, using this Monte Carlo All-Particle Method (MCAPM). The major elements of the invention include: computer hardware, user description of the patient, description of the radiation source, physical databases, Monte Carlo transport, and output of dose distributions. This facilitated the estimation of dose distributions on a Cartesian grid for neutrons, photons, electrons, positrons, and heavy charged-particles incident on any biological target, with resolutions ranging from microns to centimeters. Calculations can be extended to estimate dose distributions on general-geometry (non-Cartesian) grids for biological and/or non-biological media.

  20. Calculation of radiation therapy dose using all particle Monte Carlo transport

    DOE Patents [OSTI]

    Chandler, W.P.; Hartmann-Siantar, C.L.; Rathkopf, J.A.

    1999-02-09T23:59:59.000Z

    The actual radiation dose absorbed in the body is calculated using three-dimensional Monte Carlo transport. Neutrons, protons, deuterons, tritons, helium-3, alpha particles, photons, electrons, and positrons are transported in a completely coupled manner, using this Monte Carlo All-Particle Method (MCAPM). The major elements of the invention include: computer hardware, user description of the patient, description of the radiation source, physical databases, Monte Carlo transport, and output of dose distributions. This facilitated the estimation of dose distributions on a Cartesian grid for neutrons, photons, electrons, positrons, and heavy charged-particles incident on any biological target, with resolutions ranging from microns to centimeters. Calculations can be extended to estimate dose distributions on general-geometry (non-Cartesian) grids for biological and/or non-biological media. 57 figs.

  1. Static jaw collimation settings to minimize radiation dose to normal brain tissue during stereotactic radiosurgery

    SciTech Connect (OSTI)

    Han, Eun Young, E-mail: eyhan@uams.edu [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Zhang Xin; Yan Yulong; Sharma, Sunil; Penagaricano, Jose [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Moros, Eduardo [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Corry, Peter [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR (United States)

    2012-01-01T23:59:59.000Z

    At University of Arkansas for Medical Sciences (UAMS) intracranial stereotactic radiosurgery (SRS) is performed by using a linear accelerator with an add-on micromultileaf collimator (mMLC). In our clinical setting, static jaws are automatically adapted to the furthest edge of the mMLC-defined segments with 2-mm (X jaw) and 5-mm (Y jaw) margin and the same jaw values are applied for all beam angles in the treatment planning system. This additional field gap between the static jaws and the mMLC allows additional radiation dose to normal brain tissue. Because a radiosurgery procedure consists of a single high dose to the planning target volume (PTV), reduction of unnecessary dose to normal brain tissue near the PTV is important, particularly for pediatric patients whose brains are still developing or when a critical organ, such as the optic chiasm, is near the PTV. The purpose of this study was to minimize dose to normal brain tissue by allowing minimal static jaw margin around the mMLC-defined fields and different static jaw values for each beam angle or arc. Dose output factors were measured with various static jaw margins and the results were compared with calculated doses in the treatment planning system. Ten patient plans were randomly selected and recalculated with zero static jaw margins without changing other parameters. Changes of PTV coverage, mean dose to predefined normal brain tissue volume adjacent to PTV, and monitor units were compared. It was found that the dose output percentage difference varied from 4.9-1.3% for the maximum static jaw opening vs. static jaw with zero margins. The mean dose to normal brain tissue at risk adjacent to the PTV was reduced by an average of 1.9%, with negligible PTV coverage loss. This dose reduction strategy may be meaningful in terms of late effects of radiation, particularly in pediatric patients. This study generated clinical knowledge and tools to consistently minimize dose to normal brain tissue.

  2. On the use of age-specific effective dose coefficients in radiation protection of the public

    SciTech Connect (OSTI)

    Kocher, D.C.; Eckerman, K.F.

    1998-11-01T23:59:59.000Z

    Current radiation protection standards for the public include a limit on effective dose in any year for individuals in critical groups. This paper considers the question of how the annual dose limit should be applied in controlling routine exposures of populations consisting of individuals of all ages. The authors assume that the fundamental objective of radiation protection is limitation of lifetime risk and, therefore, that standards for controlling routine exposures of the public should provide a reasonable correspondence with lifetime risk, taking into account the age dependence of intakes and doses and the variety of radionuclides and exposure pathways of concern. Using new calculations of the per capita (population-averaged) risk of cancer mortality per unit activity inhaled or ingested in the US Environmental Protection Agency`s Federal Guidance Report No. 13, the authors show that applying a limit on annual effective dose only to adults, which was the usual practice in radiation protection of the public before the development of age-specific effective dose coefficients, provides a considerably better correspondence with lifetime risk than applying the annual dose limit to the critical group of any age.

  3. Radiation dose estimates for typical piloted NTR lunar and Mars mission engine operations

    SciTech Connect (OSTI)

    Schnitzler, B.G. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Borowski, S.K. (National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center)

    1991-01-01T23:59:59.000Z

    The natural and manmade radiation environments to be encountered during lunar and Mars missions are qualitatively summarized. The computational methods available to characterize the radiation environment produced by an operating nuclear propulsion system are discussed. Mission profiles and vehicle configurations are presented for a typical all-propulsive, fully reusable lunar mission and for a typical all-propulsive Mars mission. Estimates of crew location biological doses are developed for all propulsive maneuvers. Post-shutdown dose rates near the nuclear engine are estimated at selected mission times. 15 refs., 4 figs.

  4. RADIATION DOSE ESTIMATES TO ADULTS AND CHILDREN FROM VARIOUS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah47,193.70COMMUNITYResponses: QuestionDaniel Hartsock CIMMS,RADIATION

  5. Biological dosimetry - the use of hematological variables in the estimation of radiation dose

    E-Print Network [OSTI]

    Barranco, Samuel Christopher

    1962-01-01T23:59:59.000Z

    of 103 roentgens per hour by a Co" source, operated by the Agricultural and Mechanical College of Texas. They received doses ranging from 0 r to 685 r at graduated increments of 13'I r . A complete hematology picture was obtained on each rat... itself [Sheedy, 1962]. A survey of the literature concerning radiation accidents [Wald and Thoma, 1961] reveals that exposures to less than 100 r rarely result in clinical symptomology; hence, for our present purposes the radiation syndrome [certain...

  6. Radiation Dose to the Lens During Craniospinal Irradiation-An Improvement in Proton Radiotherapy Technique

    SciTech Connect (OSTI)

    Cochran, David M. [Division of Health Sciences and Technology, Harvard Medical School and Massachusetts Institute of Technology, Cambridge, MA (United States); Yock, Torunn I.; Adams, Judith A. C. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States); Tarbell, Nancy J. [Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA (United States)], E-mail: ntarbell@partners.org

    2008-04-01T23:59:59.000Z

    Purpose: To evaluate the effect of angle modification of cranial field proton beam therapy on the radiation dose delivered to the lens during craniospinal irradiation (CSI). Methods and Materials: Thirty-nine patients with central nervous system tumors who received CSI with a posterior fossa boost were analyzed for the radiation dose to the lens. Thirteen patients received cranial field treatment using standard opposed-lateral proton beams, and 26 patients received treatment with angled posterior-oblique proton beams. The lens dose in a test case also was evaluated by comparing conventional X-rays with the two proton beam planning methods by using a CMS/Xio three-dimensional planning system. Results: Substantial lens dose sparing was realized with the angling of the cranial proton beams 15{sup o}-20{sup o} to the posterior. In the 39 treated patients who were analyzed (median age, 7 years), average dose delivered to the lens was decreased by approximately 50% by angling of the proton beams, with the average maximum dose decreasing from 74% to 40% of the prescribed dose (p < 0.0001). Significant lens sparing was seen in patients 10 years and younger (median age, 6 years; p < 0.0001), whereas an insignificant decrease was seen in older patients (median age, 16 years; p = 0.14). With the opposed-lateral technique (median age, 6 years), the lens dose increased significantly with decreasing age (p = 0.002), whereas there was no effect of age on lens dose in the angled beam-treated group (median age, 8.5 years; p = 0.73). Conclusion: The present study clearly shows an advantage in sparing of the lens dose by angling the beams used during proton beam CSI. This effect is most pronounced in patients 10 years and younger because of anatomic effects of sinus development.

  7. Low dose radiation hypersensitivity and clustered DNA damages in human fibroblasts exposed to low dose and dose rate protons or 137CS y-rays

    SciTech Connect (OSTI)

    Bennett P. V.; Bennett, P.V.; Keszenman, D.J.; Johnson, A.M.; Sutherland, B.M.; Wilson, P.F.

    2013-05-14T23:59:59.000Z

    Effective radioprotection for human space travelers hinges upon understanding the individual properties of charged particles. A significant fraction of particle radiation astronauts will encounter in space exploratory missions will come from high energy protons in galactic cosmic radiation (GCR) and/or possible exposures to lower energy proton flux from solar particle events (SPEs). These potential exposures present major concerns for NASA and others, in planning and executing long term space exploratory missions. We recently reported cell survival and transformation (acquisition of anchorage-independent growth in soft agar) frequencies in apparently normal NFF-28 primary human fibroblasts exposed to 0-30 cGy of 50MeV, 100MeV (SPE-like), or 1000 MeV (GCR-like) monoenergetic protons. These were modeled after 1989 SPE energies at an SPE-like low dose-rate (LDR) of 1.65 cGy/min or high dose rate (HDR) of 33.3 cGy/min delivered at the NASA Space Radiation Laboratory (NSRL) at BNL.

  8. Radiation Dose and Subsequent Risk for Stomach Cancer in Long-term Survivors of Cervical Cancer

    SciTech Connect (OSTI)

    Kleinerman, Ruth A., E-mail: kleinerr@mail.nih.gov [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Rockville, Maryland (United States); Smith, Susan A. [Department of Radiation Physics, University of Texas M D Anderson Cancer Center, Houston, Texas (United States); Holowaty, Eric [Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario (Canada); Hall, Per [Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm (Sweden); Pukkala, Eero [Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki (Finland); Vaalavirta, Leila [Department of Oncology, Helsinki University Central Hospital, Helsinki (Finland); Stovall, Marilyn; Weathers, Rita [Department of Radiation Physics, University of Texas M D Anderson Cancer Center, Houston, Texas (United States); Gilbert, Ethel [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services, Rockville, Maryland (United States); Aleman, Berthe M.P. [Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam (Netherlands); Kaijser, Magnus [Clinical Epidemiology Unit, Department of Medicine, Karolinska Institute, Stockholm (Sweden); Andersson, Michael [Department of Oncology, Copenhagen University Hospital, Copenhagen (Denmark); Storm, Hans [Cancer Prevention and Documentation, Danish Cancer Society, Copenhagen (Denmark); Joensuu, Heikki [Department of Oncology, Helsinki University Central Hospital, Helsinki (Finland); Lynch, Charles F. [Department of Epidemiology, University of Iowa, Iowa City, Iowa (United States); and others

    2013-08-01T23:59:59.000Z

    Purpose: To assess the dose–response relationship for stomach cancer after radiation therapy for cervical cancer. Methods and Materials: We conducted a nested, matched case–control study of 201 cases and 378 controls among 53,547 5-year survivors of cervical cancer diagnosed from 1943 to 1995, from 5 international, population-based cancer registries. We estimated individual radiation doses to the site of the stomach cancer for all cases and to corresponding sites for the matched controls (overall mean stomach tumor dose, 2.56 Gy, range 0.03-46.1 and after parallel opposed pelvic fields, 1.63 Gy, range 0.12-6.3). Results: More than 90% of women received radiation therapy, mostly with external beam therapy in combination with brachytherapy. Stomach cancer risk was nonsignificantly increased (odds ratio 1.27-2.28) for women receiving between 0.5 and 4.9 Gy to the stomach cancer site and significantly increased at doses ?5 Gy (odds ratio 4.20, 95% confidence interval 1.41-13.4, P{sub trend}=.047) compared with nonirradiated women. A highly significant radiation dose–response relationship was evident when analyses were restricted to the 131 cases (251 controls) whose stomach cancer was located in the middle and lower portions of the stomach (P{sub trend}=.003), whereas there was no indication of increasing risk with increasing dose for 30 cases (57 controls) whose cancer was located in the upper stomach (P{sub trend}=.23). Conclusions: Our findings show for the first time a significant linear dose–response relationship for risk of stomach cancer in long-term survivors of cervical cancer.

  9. Subsequent Malignancies in Children Treated for Hodgkin's Disease: Associations With Gender and Radiation Dose

    SciTech Connect (OSTI)

    Constine, Louis S. [Department of Radiation Oncology, James P. Wilmot Cancer Center at University of Rochester, Rochester, NY (United States); Department of Pediatrics, James P. Wilmot Cancer Center at University of Rochester, Rochester, NY (United States)], E-mail: louis_constine@urmc.rochester.edu; Tarbell, Nancy [Department of Pediatric Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Hudson, Melissa M. [Department of Hematology-Oncology, St. Jude Children's Research Hospital, Memphis, TN (United States); Schwartz, Cindy [Department of Hematology-Oncology, Johns Hopkins Hospital, Baltimore, MD (United States); Fisher, Susan G. [Department of Community and Preventative Medicine, James P. Wilmot Cancer Center at University of Rochester, Rochester, NY (United States); Muhs, Ann G. B.A. [Department of Radiation Oncology, James P. Wilmot Cancer Center at University of Rochester, Rochester, NY (United States); Basu, Swati K. [Department of Community and Preventative Medicine, James P. Wilmot Cancer Center at University of Rochester, Rochester, NY (United States); Kun, Larry E. [Department of Radiological Sciences, St. Jude Children's Research Hospital, Memphis, TN (United States); Ng, Andrea; Mauch, Peter [Department of Radiation Oncology, Brigham and Women's Hospital, Boston, MA (United States); Sandhu, Ajay [Department of Radiation Oncology, University of California Medical Center-San Diego, San Diego, CA (United States); Culakova, Eva [Department of Community and Preventative Medicine, James P. Wilmot Cancer Center at University of Rochester, Rochester, NY (United States); Lyman, Gary [Department of Medicine, Duke University Medical Center, Durham, NC (United States); Mendenhall, Nancy [Department of Radiation Oncology, University of Florida Medical Center, Gainesville, FL (United States)

    2008-09-01T23:59:59.000Z

    Purpose: Subsequent malignant neoplasms (SMNs) are a dominant cause of morbidity and mortality in children treated for Hodgkin's disease (HD). We evaluated select demographic and therapeutic factors associated with SMNs, specifically gender and radiation dose. Methods and Materials: A total of 930 children treated for HD at five institutions between 1960 and 1990 were studied. Mean age at diagnosis was 13.6 years, and mean follow-up was 16.8 years (maximum, 39.4 years). Treatment included radiation alone (43%), chemotherapy alone (9%), or both (48%). Results: We found that SMNs occurred in 102 (11%) patients, with a 25-year actuarial rate of 19%. With 15,154 patient years of follow-up, only 7.18 cancers were expected (standardized incidence ratio [SIR] = 14.2; absolute excess risk [AER] = 63 cases/10,000 years). The SIR for female subjects, 19.93, was significantly greater than for males, 8.41 (p < 0.0001). After excluding breast cancer, the SIR for female patients was 15.4, still significantly greater than for male patients (p = 0.0012). Increasing radiation dose was associated with an increasing SIR (p = 0.0085). On univariate analysis, an increased risk was associated with female gender, increasing radiation dose, and age at treatment (12-16 years). Using logistic regression, mantle radiation dose increased risk, and this was 2.5-fold for female patients treated with more than 35 Gy primarily because of breast cancer. Conclusions: Survivors of childhood HD are at risk for SMNs, and this risk is greater for female individuals even after accounting for breast cancer. Although SMNs occur in the absence of radiation therapy, the risk increases with RT dose.

  10. Th Cell Gene Expression and Function in Response to Low Dose and Acute Radiation

    SciTech Connect (OSTI)

    Daila S. Gridley, PhD

    2012-03-30T23:59:59.000Z

    FINAL TECHNICAL REPORT Supported by the Low Dose Radiation Research Program, Office of Science U.S. Department of Energy Grant No. DE-FG02-07ER64345 Project ID: 0012965 Award Register#: ER64345 Project Manager: Noelle F. Metting, Sc.D. Phone: 301-903-8309 Division SC-23.2 noelle.metting@science.doe.gov Submitted March 2012 To: https://www.osti.gov/elink/241.3.jsp Title: Th Cell Gene Expression and Function in Response to Low Dose and Acute Radiation PI: Daila S. Gridley, Ph.D. Human low dose radiation data have been derived primarily from studies of space and airline flight personnel, nuclear plant workers and others exposed occupationally, as well as victims in the vicinity of atomic bomb explosions. The findings remain inconclusive due to population inconsistencies and complex interactions among total dose, dose rate, radiation quality and age at exposure. Thus, safe limits for low dose occupational irradiation are currently based on data obtained with doses far exceeding the levels expected for the general population and health risks have been largely extrapolated using the linear-nonthreshold dose-response model. The overall working hypothesis of the present study is that priming with low dose, low-linear energy transfer (LET) radiation can ameliorate the response to acute high-dose radiation exposure. We also propose that the efficacy of low-dose induced protection will be dependent upon the form and regimen of the high-dose exposure: photons versus protons versus simulated solar particle event protons (sSPE). The emphasis has been on gene expression and function of CD4+ T helper (Th) lymphocytes harvested from spleens of whole-body irradiated C57BL/6 mice, a strain that provides the genetic background for many genetically engineered strains. Evaluations of the responses of other selected cells, tissues such as skin, and organs such as lung, liver and brain were also initiated (partially funded by other sources). The long-term goal is to provide information that will be useful in estimating human health risks due to radiation that may occur during exposures in the work environment, nuclear/radiological catastrophes, as well as radiotherapy. Several papers have been published, accepted for publication or are in preparation. A number of poster and oral presentations have been made at scientific conferences and workshops. Archived tissues of various types will continue to be evaluated via funding from other sources (the DoE Low Dose Radiation Research Program, Office of Science and this specific grant will be appropriately included in the Acknowledgements of all subsequent publications/presentations). A post-doc and several students have participated in this study. More detailed description of the accomplishments is described in attached file.

  11. Radiation bronchitis and stenosis secondary to high dose rate endobronchial irradiation

    SciTech Connect (OSTI)

    Speiser, B.L. (St. Joseph's Hospital and Medical Center, Phoenix, AZ (United States)); Spratling, L.

    1993-03-15T23:59:59.000Z

    The purpose of the study was to describe a new clinical entity observed in follow-up bronchoscopies in patients who were treated with high dose rate and medium dose rate remote afterloading brachytherapy of the tracheobronchial tree. Patients were treated by protocol with medium dose rate, 47 patients receiving 1000 cGy at a 5 mm depth times three fractions, high dose rate 144 patients receiving 1000 cGy at a 10 mm depth for three fractions and high dose rate 151 patients receiving cGy at a 10 mm depth for three fractions followed by bronchoscopy. Incidence of this entity was 9% for the first group, 12% for the second, and 13% for the third group. Reactions were grade 1 consisting of mild inflammatory response with a partial whitish circumferential membrane in an asymptomatic patient; grade 2, thicker complete white circumferential membrane with cough and/or obstructive problems requiring intervention; grade 3, severe inflammatory response with marked membranous exudate and mild fibrotic reaction; and grade 4 a predominant fibrotic reaction with progressive stenosis. Variables associated with a slightly increased incidence of radiation bronchitis and stenosis included: large cell carcinoma histology, curative intent, prior laser photoresection, and/or concurrent external radiation. Survival was the strongest predictor of the reaction. Radiation bronchitis and stenosis is a new clinical entity that must be identified in bronchial brachytherapy patients and treated appropriately. 23 refs., 3 figs., 7 tabs.

  12. Modeling proton intensity gradients and radiation dose equivalents in the inner

    E-Print Network [OSTI]

    Pringle, James "Jamie"

    Modeling proton intensity gradients and radiation dose equivalents in the inner heliosphere using exposure in IP space. In this paper, we utilize EMMREM to study the radial dependence of proton peak crossfield diffusion at large radial distances. Our results show that radial dependencies of proton peak

  13. Page 1 of 3 RADIATION DOSE IS MORE THAN A NUMBER!

    E-Print Network [OSTI]

    Magee, Joseph W.

    Page 1 of 3 RADIATION DOSE IS MORE THAN A NUMBER! Agenda National Institute of Standards Metting, DOE Janice Huff, NASA 12:00 PM Important Concepts in Radiobiology Dosimetry David Followill, MD.m. Dosimetry Larry Dewerd, University of Wisconsin Current Calibration and Standardization Methods 4:15 p

  14. Regulation Of Nf=kb And Mnsod In Low Dose Radiation Induced Adaptive Protection Of Mouse And Human Skin Cells

    SciTech Connect (OSTI)

    Jian Li

    2012-11-07T23:59:59.000Z

    A sampling of publications resulting from this grant is provided. One is on the subject of NF-κB-Mediated HER2 Overexpression in Radiation-Adaptive Resistance. Another is on NF-κB-mediated adaptive resistance to ionizing radiation.

  15. Radiation dose fractionation studies with hypoxic cell radiosensitizers using a murine tumor. [X-ray; mice

    SciTech Connect (OSTI)

    Hill, R.P.

    1982-03-01T23:59:59.000Z

    The ability of five nitroimidazoles, metronidazole (MET), misonidazole (MISO), desmethymisonidazole (DMM), SR 2508 and SR 2555, to sensitize the KHT sarcoma to radiation treatment has been compared for drug doses in the range 0-1.5 g/Kg. Single radiation doses or two different daily fractionation schedules (4 fractions of 5 Gy each or 7 fraction of 3 Gy each) were used; the tumor cell survival was determined using either an in vivo or in vitro colony assay. Each radiation (100 kVp X rays at 11 Gy/min) treatment was given locally, 60-70 min (MET) or 30-40 min (other drugs) after either intraperitoneal (MET, MISO, DMM) or intraveous (SR 2508, SR 2555) injection of the drugs; these times have been shown to be optimum for this tumor. For the single doses and both fractionation schedules the tumor cell survival, following the irradiation treatment, declined as the drug dose increased in the range 0 to 0.75 g/Kg for all the drugs, but above this dose level a plateau was reached and the amount of sensitization remained essentially constant. In this plateau region the reduction in survival achieved was similar for single doses and 5 Gy fraction but was less for 3 Gy fractions, indicating that sensitization was smaller for the smaller dose fractions. For the 4 x 5 Gy fractionation schedule the plateau level of survival was lowest for MISO, DMM and SR 2508, slightly higher for SR 2555 and much higher for MET. For the 3 Gy fractions SR 2508 appeared slightly less effective than MISO and DMM.

  16. Parotid Glands Dose–Effect Relationships Based on Their Actually Delivered Doses: Implications for Adaptive Replanning in Radiation Therapy of Head-and-Neck Cancer

    SciTech Connect (OSTI)

    Hunter, Klaudia U. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Fernandes, Laura L. [Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Vineberg, Karen A.; McShan, Daniel; Antonuk, Alan E. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cornwall, Craig [Department of Hospital Dentistry, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Mathew J. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biostatistics, University of Michigan, Ann Arbor, Michigan (United States); Balter, James M. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Eisbruch, Avraham, E-mail: eisbruch@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2013-11-15T23:59:59.000Z

    Purpose: Doses actually delivered to the parotid glands during radiation therapy often exceed planned doses. We hypothesized that the delivered doses correlate better with parotid salivary output than the planned doses, used in all previous studies, and that determining these correlations will help make decisions regarding adaptive radiation therapy (ART) aimed at reducing the delivered doses. Methods and Materials: In this prospective study, oropharyngeal cancer patients treated definitively with chemoirradiation underwent daily cone-beam computed tomography (CBCT) with clinical setup alignment based on the C2 posterior edge. Parotid glands in the CBCTs were aligned by deformable registration to calculate cumulative delivered doses. Stimulated salivary flow rates were measured separately from each parotid gland pretherapy and periodically posttherapy. Results: Thirty-six parotid glands of 18 patients were analyzed. Average mean planned doses was 32 Gy, and differences from planned to delivered mean gland doses were ?4.9 to +8.4 Gy, median difference +2.2 Gy in glands in which delivered doses increased relative to planned. Both planned and delivered mean doses were significantly correlated with posttreatment salivary outputs at almost all posttherapy time points, without statistically significant differences in the correlations. Large dispersions (on average, SD 3.6 Gy) characterized the dose–effect relationships for both. The differences between the cumulative delivered doses and planned doses were evident at first fraction (r=.92, P<.0001) because of complex setup deviations (eg, rotations and neck articulations), uncorrected by the translational clinical alignments. Conclusions: After daily translational setup corrections, differences between planned and delivered doses in most glands were small relative to the SDs of the dose–saliva data, suggesting that ART is not likely to gain measurable salivary output improvement in most cases. These differences were observed at first treatment, indicating potential benefit for more complex setup corrections or adaptive interventions in the minority of patients with large deviations detected early by CBCT.

  17. Molecular stress response in the CNS of mice after systemic exposureto interferon-alpha, ionizing radiation and ketamine

    SciTech Connect (OSTI)

    Lowe, Xiu R.; Marchetti, Francesco; Lu, Xiaochen; Wyrobek, Andrew J.

    2009-03-03T23:59:59.000Z

    We previously showed that the expression of troponin T1 (Tnnt 1) was induced in the central nervous system (CNS) of adultmice 30 min after treatment with ketamine, a glutamate N-methyl-D-aspartic acid (NMDA) receptor antagonist. We hypothesized that Tnnt 1 expression may be an early molecular biomarker of stress response in the CNS of mice. To further evaluate this hypothesis, we investigated the regional expression of Tnnt 1 in the mouse brain using RNA in situ hybridization 4 h after systemic exposure to interferon-a (IFN-a) and gamma ionizing radiation, both of which have be associated with wide ranges of neuropsychiatric complications. Adult B6C3F1 male mice were treated with either human IFN-a (a single i.p. injection at 1 x 105 IU/kg) or whole body gamma-radiation (10 cGy or 2 Gy). Patterns of Tnnt 1 transcript expression were compared in various CNS regions after IFN-a, radiation and ketamine treatments (previous study). Tnnt 1 expression was consistently induced in pyramidal neurons of cerebral cortex and hippocampus after all treatment regimens including 10 cGy of ionizing radiation. Regional expression of Tnnt 1 was induced in Purkinje cells of cerebellum after ionizing radiation and ketamine treatment; but not after IFN-a treatment. None of the three treatments induced Tnnt 1 expression in glial cells. The patterns of Tnnt 1 expression in pyramidal neurons of cerebral cortex andhippocampus, which are both known to play important roles in cognitive function, memory and emotion, suggest that the expression of Tnnt 1 may be an early molecular biomarker of induced CNS stress.

  18. Nominal effective radiation doses delivered during clinical trials of boron neutron capture therapy

    SciTech Connect (OSTI)

    Capala, J.; Diaz, A.Z.; Chanana, A.D.

    1997-12-31T23:59:59.000Z

    Boron neutron capture therapy (BNCT) is a binary system that, in theory, should selectively deliver lethal, high linear energy transfer (LET) radiation to tumor cells dispersed within normal tissues. It is based on the nuclear reaction 10-B(n, {alpha})7-Li, which occurs when the stable nucleus of boron-10 captures a thermal neutron. Due to the relatively high cross-section of the 10-B nucleus for thermal neutron capture and short ranges of the products of this reaction, tumor cells in the volume exposed to thermal neutrons and containing sufficiently high concentration of 10-B would receive a much higher radiation dose than the normal cells contained within the exposed volume. Nevertheless, radiation dose deposited in normal tissue by gamma and fast neutron contamination of the neutron beam, as well as neutron capture in nitrogen, 14-N(n,p)14-C, hydrogen, 1-H(n,{gamma})2-H, and in boron present in blood and normal cells, limits the dose that can be delivered to tumor cells. It is, therefore, imperative for the success of the BNCT the dosed delivered to normal tissues be accurately determined in order to optimize the irradiation geometry and to limit the volume of normal tissue exposed to thermal neutrons. These are the major objectives of BNCT treatment planning.

  19. Measurement of absorbed dose-to-water for an HDR {sup 192}Ir source with ionization chambers in a sandwich setup

    SciTech Connect (OSTI)

    Araki, Fujio; Kouno, Tomohiro; Ohno, Takeshi [Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto 862-0976 (Japan)] [Department of Health Sciences, Faculty of Life Sciences, Kumamoto University, 4-24-1 Kuhonji, Kumamoto 862-0976 (Japan); Kakei, Kiyotaka; Yoshiyama, Fumiaki [Department of Radiotherapy, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto 860-8556 (Japan)] [Department of Radiotherapy, Kumamoto University Hospital, 1-1-1 Honjyo, Kumamoto 860-8556 (Japan); Kawamura, Shinji [Department of Radiotherapy, Miyazaki University Hospital, 5200 Kihara Ohaza Kiyotake-Machi, Miyazaki 889-1692 (Japan)] [Department of Radiotherapy, Miyazaki University Hospital, 5200 Kihara Ohaza Kiyotake-Machi, Miyazaki 889-1692 (Japan)

    2013-09-15T23:59:59.000Z

    Purpose: In this study, a dedicated device for ion chamber measurements of absorbed dose-to-water for a Nucletron microSelectron-v2 HDR {sup 192}Ir brachytherapy source is presented. The device uses two ionization chambers in a so-called sandwich assembly. Using this setup and by taking the average reading of the two chambers, any dose error due to difficulties in absolute positioning (centering) of the source in between the chambers is cancelled to first order. The method's accuracy was examined by comparing measurements with absorbed dose-to-water determination based on the AAPM TG-43 protocol.Methods: The optimal source-to-chamber distance (SCD) for {sup 192}Ir dosimetry was determined from ion chamber measurements in a water phantom. The {sup 192}Ir source was sandwiched between two Exradin A1SL chambers (0.057 cm{sup 3}) at the optimal SCD separation. The measured ionization was converted to the absorbed dose-to-water using a {sup 60}Co calibration factor and a Monte Carlo-calculated beam quality conversion factor, k{sub Q}, for {sup 60}Co to {sup 192}Ir. An uncertainty estimate of the proposed method was determined based on reproducibility of measurements at different institutions for the same type of source.Results: The optimal distance for the A1SL chamber measurements was determined to be 5 cm from the {sup 192}Ir source center, considering the depth dependency of k{sub Q} for {sup 60}Co to {sup 192}Ir and the chamber positioning. The absorbed dose to water measured at (5 cm, 90°) on the transverse axis was 1.3% lower than TG-43 values and its reproducibility and overall uncertainty were 0.8% and 1.7%, respectively. The measurement doses at anisotropic points agreed within 1.5% with TG-43 values.Conclusions: The ion chamber measurement of absorbed dose-to-water with a sandwich method for the {sup 192}Ir source provides a more accurate, direct, and reference dose compared to the dose-to-water determination based on air-kerma strength in the TG-43 protocol. Due to the simple but accurate assembly, the sandwich measurement method is useful for daily dose management of {sup 192}Ir sources.

  20. Radiation-Induced Rib Fractures After Hypofractionated Stereotactic Body Radiation Therapy: Risk Factors and Dose-Volume Relationship

    SciTech Connect (OSTI)

    Asai, Kaori [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)] [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Shioyama, Yoshiyuki, E-mail: shioyama@radiol.med.kyushu-u.ac.jp [Department of Heavy Particle Therapy and Radiation Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)] [Department of Heavy Particle Therapy and Radiation Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Nakamura, Katsumasa; Sasaki, Tomonari; Ohga, Saiji; Nonoshita, Takeshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)] [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Yoshitake, Tadamasa [Department of Heavy Particle Therapy and Radiation Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)] [Department of Heavy Particle Therapy and Radiation Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Ohnishi, Kayoko [Department of Radiology, National Center for Global Health and Medicine, Tokyo (Japan)] [Department of Radiology, National Center for Global Health and Medicine, Tokyo (Japan); Terashima, Kotaro; Matsumoto, Keiji [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)] [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Hirata, Hideki [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)] [Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)] [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)

    2012-11-01T23:59:59.000Z

    Purpose: The purpose of this study was to clarify the incidence, the clinical risk factors, and the dose-volume relationship of radiation-induced rib fracture (RIRF) after hypofractionated stereotactic body radiation therapy (SBRT). Methods and Materials: One hundred sixteen patients treated with SBRT for primary or metastatic lung cancer at our institution, with at least 6 months of follow-up and no previous overlapping radiation exposure, were included in this study. To determine the clinical risk factors associated with RIRF, correlations between the incidence of RIRF and the variables, including age, sex, diagnosis, gross tumor volume diameter, rib-tumor distance, and use of steroid administration, were analyzed. Dose-volume histogram analysis was also conducted. Regarding the maximum dose, V10, V20, V30, and V40 of the rib, and the incidences of RIRF were compared between the two groups divided by the cutoff value determined by the receiver operating characteristic curves. Results: One hundred sixteen patients and 374 ribs met the inclusion criteria. Among the 116 patients, 28 patients (46 ribs) experienced RIRF. The estimated incidence of rib fracture was 37.7% at 3 years. Limited distance from the rib to the tumor (<2.0 cm) was the only significant risk factor for RIRF (p = 0.0001). Among the dosimetric parameters used for receiver operating characteristic analysis, the maximum dose showed the highest area under the curve. The 3-year estimated risk of RIRF and the determined cutoff value were 45.8% vs. 1.4% (maximum dose, {>=}42.4 Gy or less), 51.6% vs. 2.0% (V40, {>=}0.29 cm{sup 3} or less), 45.8% vs. 2.2% (V30, {>=}1.35 cm{sup 3} or less), 42.0% vs. 8.5% (V20, {>=}3.62 cm{sup 3} or less), or 25.9% vs. 10.5% (V10, {>=}5.03 cm{sup 3} or less). Conclusions: The incidence of RIRF after hypofractionated SBRT is relatively high. The maximum dose and high-dose volume are strongly correlated with RIRF.

  1. Scintillator Waveguide For Sensing Radiation

    DOE Patents [OSTI]

    Bliss, Mary (West Richland, WA); Craig, Richard A. (West Richland, WA); Reeder; Paul L. (Richland, WA)

    2003-04-22T23:59:59.000Z

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  2. ASSESSMENT OF UNCERTAINTY IN THE RADIATION DOSES FOR THE TECHA RIVER DOSIMETRY SYSTEM

    SciTech Connect (OSTI)

    Napier, Bruce A.; Degteva, M. O.; Anspaugh, L. R.; Shagina, N. B.

    2009-10-23T23:59:59.000Z

    In order to provide more accurate and precise estimates of individual dose (and thus more precise estimates of radiation risk) for the members of the ETRC, a new dosimetric calculation system, the Techa River Dosimetry System-2009 (TRDS-2009) has been prepared. The deterministic version of the improved dosimetry system TRDS-2009D was basically completed in April 2009. Recent developments in evaluation of dose-response models in light of uncertain dose have highlighted the importance of different types of uncertainties in the development of individual dose estimates. These include uncertain parameters that may be either shared or unshared within the dosimetric cohort, and also the nature of the type of uncertainty as aleatory or epistemic and either classical or Berkson. This report identifies the nature of the various input parameters and calculational methods incorporated in the Techa River Dosimetry System (based on the TRDS-2009D implementation), with the intention of preparing a stochastic version to estimate the uncertainties in the dose estimates. This report reviews the equations, databases, and input parameters, and then identifies the author’s interpretations of their general nature. It presents the approach selected so that the stochastic, Monte-Carlo, implementation of the dosimetry System - TRDS-2009MC - will provide useful information regarding the uncertainties of the doses.

  3. A revised model of the kidney for medical internal radiation dose calculations

    E-Print Network [OSTI]

    Patel, Jyoti Shivabhai

    1988-01-01T23:59:59.000Z

    are frequently the organs receiving the highest level of radioactivity and, therefore, the largest radiation dose. Short lived radiopharmaceuticals, that are now injected in millicurie quantities in nuclear medicine for rapid-sequence imaging of the brain... radionuclides (Appendix B). 17 These include the following radionuclides presently used in nuclear medicine: P-32, Cr-51, Co-57, Ga-67, Tc-99m, In-ill, I-123, Xe-127, I-131, Xe-133, and T1-201. If the radionuclide emits penetrating radiation, the code...

  4. Nuclear Decay Data in the MIRD (Medical Internal Radiation Dose) Format

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    MIRD is a database of evaluated nuclear decay data for over 2,100 radioactive nuclei. Data are extracted from ENSDF, processed by the program RadList, and used for medical internal radiation dose calculations. When using the MIRD interface, tables of nuclear and atomic radiations from nuclear decay and decay scheme drawings will be produced in the MIRD format from the Evaluated Nuclear Structure Data File (ENSDF) for the specified nuclide. Output may be either HTML-formatted tables and JPEG drawings, PostScript tables and drawings, or PDF tables and drawings.

  5. Effective gamma-ray doses due to natural radiation from soils of southeastern Brazil

    SciTech Connect (OSTI)

    Silveira, M. A. G.; Moreira, R. H.; Bellini, B. S. [Centro Universitario da FEI, Sao Bernardo do Campo, Sao Paulo (Brazil); Medina, N. H.; Aguiar, V. A. P. [Instituto de Fisica da Universidade de Sao Paulo, Sao Paulo (Brazil)

    2010-08-04T23:59:59.000Z

    We have used gamma-ray spectrometry to study the distribution of natural radiation from soils of southeastern Brazil: Billings reservoir, Sao Bernardo do Campo Parks, Diadema Parks, Interlagos region, Sao Paulo, and soil from Sao Paulo and Rio de Janeiro beaches. In most of the regions studied we have found that the dose due the external exposure to gamma-rays, proceeding from natural terrestrial elements, are between the values 0.3 and 0.6 mSv/year, established by the United Nations Scientific Committee on the Effects of Atomic Radiation.

  6. Radiation dose reduction in medical CT through equally sloped tomography Benjamin P. Fahimian1,2,6

    E-Print Network [OSTI]

    Soatto, Stefano

    Council on Radiation Protection & Measurements10 , CT accounts for about 15% of the total radiological50Radiation dose reduction in medical CT through equally sloped tomography Benjamin P. Fahimian1 Department of Radiation Oncology, Stanford University, Stanford, CA 94305 3 Biomedical Physics

  7. Short CommunicationJ. Radiat. Res., 53, 475481 (2012) Triphasic Low-dose Response in Zebrafish Embryos Irradiated by

    E-Print Network [OSTI]

    Yu, K.N.

    2012-01-01T23:59:59.000Z

    the linear no-threshold (LNT) hypothesis for radiation protection considerations, which assumes that the riskShort CommunicationJ. Radiat. Res., 53, 475­481 (2012) Triphasic Low-dose Response in Zebrafish, the experimental data were in line with induc- tion of radiation-induced bystander effect as well as rescue effect

  8. High-dose MVCT image guidance for stereotactic body radiation therapy

    SciTech Connect (OSTI)

    Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D.; Chao, Edward; Lucas, Dan; Flynn, Ryan T.; Miften, Moyed [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States); Accuray Inc., Madison, Wisconsin 53717 (United States); Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242 (United States); Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)

    2012-08-15T23:59:59.000Z

    Purpose: Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image noise compared with kilovoltage CT. The goal of this work was to investigate the use of increased imaging doses on a clinical tomotherapy machine to improve image quality for SBRT image guidance. Methods: Two nonstandard, high-dose imaging modes were created on a tomotherapy machine by increasing the linear accelerator (LINAC) pulse rate from the nominal setting of 80 Hz, to 160 Hz and 300 Hz, respectively. Weighted CT dose indexes (wCTDIs) were measured for the standard, medium, and high-dose modes in a 30 cm solid water phantom using a calibrated A1SL ion chamber. Image quality was assessed from scans of a customized image quality phantom. Metrics evaluated include: contrast-to-noise ratios (CNRs), high-contrast spatial resolution, image uniformity, and percent image noise. In addition, two patients receiving SBRT were localized using high-dose MVCT scans. Raw detector data collected after each scan were used to reconstruct standard-dose images for comparison. Results: MVCT scans acquired using a pitch of 1.0 resulted in wCTDI values of 2.2, 4.7, and 8.5 cGy for the standard, medium, and high-dose modes respectively. CNR values for both low and high-contrast materials were found to increase with the square root of dose. Axial high-contrast spatial resolution was comparable for all imaging modes at 0.5 lp/mm. Image uniformity was improved and percent noise decreased as the imaging dose increased. Similar improvements in image quality were observed in patient images, with decreases in image noise being the most notable. Conclusions: High-dose imaging modes are made possible on a clinical tomotherapy machine by increasing the LINAC pulse rate. Increasing the imaging dose results in increased CNRs; making it easier to distinguish the boundaries of low contrast objects. The imaging dose levels observed in this work are considered acceptable at our institution for SBRT treatments delivered in 3-5 fractions.

  9. Optically erasable samarium-doped fluorophosphate glasses for high-dose measurements in microbeam radiation therapy

    SciTech Connect (OSTI)

    Morrell, B.; Okada, G.; Vahedi, S.; Koughia, C., E-mail: cyril.koughia@usask.ca; Kasap, S. O. [Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada); Edgar, A.; Varoy, C. [School of Chemical and Physical Sciences and MacDiarmid Institute, Victoria University of Wellington, Wellington 6140 (New Zealand); Belev, G.; Wysokinski, T.; Chapman, D. [Canadian Light Source, Inc., University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9 (Canada); Sammynaiken, R. [Saskatchewan Structural Sciences Centre, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9 (Canada)

    2014-02-14T23:59:59.000Z

    Previous work has demonstrated that fluorophosphate (FP) glasses doped with trivalent samarium (Sm{sup 3+}) can be used as a dosimetric detector in microbeam radiation therapy (MRT) to measure high radiation doses and large dose variations with a resolution in the micrometer range. The present work addresses the use of intense optical radiation at 405?nm to erase the recorded dose information in Sm{sup 3+}-doped FP glass plates and examines the underlying physics. We have evaluated both the conversion and optical erasure of Sm{sup 3+}-doped FP glasses using synchrotron-generated high-dose x-rays at the Canadian Light Source. The Sm-ion valency conversion is accompanied by the appearance of x-ray induced optical absorbance due to the trapping of holes and electrons into phosphorus-oxygen hole (POHC) and electron (POEC) capture centers. Nearly complete Sm{sup 2+} to Sm{sup 3+} reconversion (erasure) may be achieved by intense optical illumination. Combined analysis of absorbance and electron spin resonance measurements indicates that the optical illumination causes partial disappearance of the POHC and the appearance of new POEC. The suggested model for the observed phenomena is based on the release of electrons during the Sm{sup 2+} to Sm{sup 3+} reconversion process, the capture of these electrons by POHC (and hence their disappearance), or by PO groups, with the appearance of new and/or additional POEC. Optical erasure may be used as a practical means to erase the recorded data and permits the reuse of these Sm-doped FP glasses in monitoring dose in MRT.

  10. Radiation Dose-Volume Effects in the Stomach and Small Bowel

    SciTech Connect (OSTI)

    Kavanagh, Brian D., E-mail: Brian.Kavanagh@ucdenver.ed [Department of Radiation Oncology, University of Colorado-Denver School of Medicine, Aurora, CO (United States); Pan, Charlie C. [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, ON (Canada); Das, Shiva K. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Ten Haken, Randall K.; Miften, Moyed [Department of Radiation Oncology, University of Colorado-Denver School of Medicine, Aurora, CO (United States)

    2010-03-01T23:59:59.000Z

    Published data suggest that the risk of moderately severe (>=Grade 3) radiation-induced acute small-bowel toxicity can be predicted with a threshold model whereby for a given dose level, D, if the volume receiving that dose or greater (VD) exceeds a threshold quantity, the risk of toxicity escalates. Estimates of VD depend on the means of structure segmenting (e.g., V15 = 120 cc if individual bowel loops are outlined or V45 = 195 cc if entire peritoneal potential space of bowel is outlined). A similar predictive model of acute toxicity is not available for stomach. Late small-bowel/stomach toxicity is likely related to maximum dose and/or volume threshold parameters qualitatively similar to those related to acute toxicity risk. Concurrent chemotherapy has been associated with a higher risk of acute toxicity, and a history of abdominal surgery has been associated with a higher risk of late toxicity.

  11. Automated systems for measuring dose and radiation quality as a function of time

    SciTech Connect (OSTI)

    Braby, L.A.; Conroy, T.J.; Elegy, D.C.; Brackenbush, L.W. [Pacific Northwest Lab., Richland, WA (United States); Badhwar, G.D. [Johnson Space Center, Houston, TX (United States)

    1992-09-01T23:59:59.000Z

    A compact, modular, tissue equivalent proportional counter system has been developed for use in space. The data acquisition system consists of a microcomputer, multi channel analyzer, memory, and power converter on individual circuit cards which can be used in various combinations for specific measurement requirements. The system uses separate, interchangeable detectors, each with its preamplifier and shaping amplifier connected directly to the detector. The microprocessor provides the computing power of a personal computer, and utilizes an operating system which is compatible with a subset of MSDOS. Experiment procedures can be programmed in high level languages and down loaded to the microprocessor. A typical application, used to characterize the dose rates due to trapped radiations in space, monitors the dose rate and records energy deposition spectra frequently when the dose rate is high. The microprocessor also measures and records system operation characteristics such as MCA linearity, proportional counter gain, and power supply voltages on a periodic basis.

  12. Environmental Radiation Dose Reconstruction for U.S. and Russian Weapons Production Facilities: Hanford and Mayak

    SciTech Connect (OSTI)

    Ansbaugh, Lynn R.; Degteva, M. O.; Kozheurov, V. P.; Napier, Bruce A.; Tolstykh, E. I.; Vorobiova, M. I.

    2003-05-01T23:59:59.000Z

    Another way to look at Cold War legacies is to examine the major environmental releases that resulted from past operation of Cold War-related facilities for the manufacture of nuclear weapons. Examining these historical releases and the resultant radiation dose to individuals living near these facilities is called environmental dose reconstruction. Dose reconstructions have been performed or are underway at most large Cold War installations in the United States, such as the Hanford facility; several are also underway in other countries, such as at the Mayak facility in Russia. The efforts in the United States are mostly based on historical operating records and current conditions, which are used to estimate environmental releases, transport, and human exposure. The Russian efforts are largely based on environmental measurements and measurements of human subjects; environmental transport modelling, when conducted, is used to organize and validate the measurements. Past operation of Cold War-related facilities for the manufacture of nuclear weapons has resulted in major releases of radionuclides into the environment. Reconstruction of the historical releases and the resultant radiation dose to individuals in the public living near these facilities is called environmental dose reconstruction. Dose reconstructions have been performed or are underway at most large Cold War installations in the United States; several are also underway in other countries. The types of activity performed, the operating histories, and the radionuclide releases vary widely across the different facilities. The U.S. Hanford Site and the Russian Mayak Production Association are used here to illustrate the nature of the assessed problems and the range of approaches developed to solve them.

  13. Osteoradionecrosis and Radiation Dose to the Mandible in Patients With Oropharyngeal Cancer

    SciTech Connect (OSTI)

    Tsai, Chiaojung Jillian [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hofstede, Theresa M. [Department of Dental Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Dental Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Sturgis, Erich M. [Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Head and Neck Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Garden, Adam S., E-mail: agarden@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lindberg, Mary E. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Wei Qingyi [Department of Epidemiology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Epidemiology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Tucker, Susan L. [Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Dong Lei [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2013-02-01T23:59:59.000Z

    Purpose: To determine the association between radiation doses delivered to the mandible and the occurrence of osteoradionecrosis (ORN). Methods and Materials: We reviewed the records of 402 oropharyngeal cancer patients with stage T1 or T2 disease treated with definitive radiation between January 2000 and October 2008 for the occurrence of ORN. Demographic and treatment variables were compared between patients with ORN and those without. To examine the dosimetric relationship further, a nested case-control comparison was performed. One to 2 ORN-free patients were selected to match each ORN patient by age, sex, radiation type, treatment year, and cancer subsite. Detailed radiation treatment plans for the ORN cases and matched controls were reviewed. Mann-Whitney test and conditional logistic regression were used to compare relative volumes of the mandible exposed to doses ranging from 10 Gy-60 Gy in 10-Gy increments. Results: In 30 patients (7.5%), ORN developed during a median follow-up time of 31 months, including 6 patients with grade 4 ORN that required major surgery. The median time to develop ORN was 8 months (range, 0-71 months). Detailed radiation treatment plans were available for 25 of the 30 ORN patients and 40 matched ORN-free patients. In the matched case-control analysis, there was a statistically significant difference between the volumes of mandible in the 2 groups receiving doses between 50 Gy (V50) and 60 Gy (V60). The most notable difference was seen at V50, with a P value of .02 in the multivariate model after adjustment for the matching variables and dental status (dentate or with extraction). Conclusions: V50 and V60 saw the most significant differences between the ORN group and the comparison group. Minimizing the percent mandibular volume exposed to 50 Gy may reduce ORN risk.

  14. Correlation of radiation absorbed dose to the human thyroid using the FBX dosimeter and external probe techniques 

    E-Print Network [OSTI]

    Bateman, Sarah Caroline Louisa

    1986-01-01T23:59:59.000Z

    calculational dose response. 25 9 Counts per minute of "'I as obtained using a 1" x 1" Nal external probe bioassay system as a function of '"I activity present. 26 INTRODUCTION The objective of this research is to measure the radiation absorbed dose from... dosimeter system, the energy imparted by radiation causes the ferrous ions present in the solution to be converted to ferric ions, so that the number of iona converted is proportional to the radiation absorbed dose (Gu78a). However in the FBX dosimeter...

  15. Decision Regret in Men Undergoing Dose-Escalated Radiation Therapy for Prostate Cancer

    SciTech Connect (OSTI)

    Steer, Anna N. [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia)] [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Aherne, Noel J., E-mail: noel.aherne@ncahs.health.nsw.gov.au [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Rural Clinical School Faculty of Medicine, University of New South Wales, Coffs Harbour (Australia); Gorzynska, Karen; Hoffman, Matthew; Last, Andrew; Hill, Jacques [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia)] [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Shakespeare, Thomas P. [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia) [Department of Radiation Oncology, North Coast Cancer Institute, Coffs Harbour (Australia); Rural Clinical School Faculty of Medicine, University of New South Wales, Coffs Harbour (Australia)

    2013-07-15T23:59:59.000Z

    Purpose: Decision regret (DR) is a negative emotion associated with medical treatment decisions, and it is an important patient-centered outcome after therapy for localized prostate cancer. DR has been found to occur in up to 53% of patients treated for localized prostate cancer, and it may vary depending on treatment modality. DR after modern dose-escalated radiation therapy (DE-RT) has not been investigated previously, to our knowledge. Our primary aim was to evaluate DR in a cohort of patients treated with DE-RT. Methods and Materials: We surveyed 257 consecutive patients with localized prostate cancer who had previously received DE-RT, by means of a validated questionnaire. Results: There were 220 responses (85.6% response rate). Image-guided intensity modulated radiation therapy was given in 85.0% of patients and 3-dimensional conformal radiation therapy in 15.0%. Doses received included 73.8 Gy (34.5% patients), 74 Gy (53.6%), and 76 Gy (10.9%). Neoadjuvant androgen deprivation (AD) was given in 51.8% of patients and both neoadjuvant and adjuvant AD in 34.5%. The median follow-up time was 23 months (range, 12-67 months). In all, 3.8% of patients expressed DR for their choice of treatment. When asked whether they would choose DE-RT or AD again, only 0.5% probably or definitely would not choose DE-RT again, compared with 8.4% for AD (P<.01). Conclusion: Few patients treated with modern DE-RT express DR, with regret appearing to be lower than in previously published reports of patients treated with radical prostatectomy or older radiation therapy techniques. Patients experienced more regret with the AD component of treatment than with the radiation therapy component, with implications for informed consent. Further research should investigate regret associated with individual components of modern therapy, including AD, radiation therapy and surgery.

  16. Spatial and dose–response analysis of fibrotic lung changes after stereotactic body radiation therapy

    SciTech Connect (OSTI)

    Vinogradskiy, Yevegeniy; Diot, Quentin; Kavanagh, Brian; Schefter, Tracey; Gaspar, Laurie; Miften, Moyed [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)] [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado 80045 (United States)

    2013-08-15T23:59:59.000Z

    Purpose: Stereotactic body radiation therapy (SBRT) is becoming the standard of care for early stage nonoperable lung cancers. Accurate dose–response modeling is challenging for SBRT because of the decreased number of clinical toxicity events. As a surrogate for a clinical toxicity endpoint, studies have proposed to use radiographic changes in follow up computed tomography (CT) scans to evaluate lung SBRT normal tissue effects. The purpose of the current study was to use local fibrotic lung regions to spatially and dosimetrically evaluate lung changes in patients that underwent SBRT.Methods: Forty seven SBRT patients treated at our institution from 2003 to 2009 were used for the current study. Our patient cohort had a total of 148 follow up CT scans ranging from 3 to 48 months post-therapy. Post-treatment scans were binned into intervals of 3, 6, 12, 18, 24, 30, and 36 months after the completion of treatment. Deformable image registration was used to align the follow up CT scans with the pretreatment CT and dose distribution. Areas of visible fibrotic changes were contoured. The centroid of each gross tumor volume (GTV) and contoured fibrosis volume was calculated and the fibrosis volume location and movement (magnitude and direction) relative to the GTV and 30 Gy isodose centroid were analyzed. To perform a dose–response analysis, each voxel in the fibrosis volume was sorted into 10 Gy dose bins and the average CT number value for each dose bin was calculated. Dose–response curves were generated by plotting the CT number as a function of dose bin and time posttherapy.Results: Both fibrosis and GTV centroids were concentrated in the upper third of the lung. The average radial movement of fibrosis centroids relative to the GTV centroids was 2.6 cm with movement greater than 5 cm occurring in 11% of patients. Evaluating dose–response curves revealed an overall trend of increasing CT number as a function of dose. The authors observed a CT number plateau at doses ranging from 30 to 50 Gy for the 3, 6, and 12 months posttherapy time points. There was no evident plateau for the dose–response curves generated using data from the 18, 24, 30, and 36 months posttherapy time points.Conclusions: Regions of local fibrotic lung changes in patients that underwent SBRT were evaluated spatially and dosimetrically. The authors found that the average fibrosis movement was 2.6 cm with movement greater than 5 cm possible. Evaluating dose–response curves revealed an overall trend of increasing CT number as a function of dose. Furthermore, our dose–response data also suggest that one of the possible explanations of the CT number plateau effect may be the time posttherapy of the acquired data. Understanding normal tissue dose–response is important for reducing toxicity after SBRT, especially in cases where larger tumors are treated. The methods presented in the current work build on prior quantitative studies and further enhance the understanding of normal lung dose–response after SBRT.

  17. Technology Assessment and Roadmap for the Emergency Radiation Dose Assessment Program

    SciTech Connect (OSTI)

    Turteltaub, K W; Hartman-Siantar, C; Easterly, C; Blakely, W

    2005-10-03T23:59:59.000Z

    A Joint Interagency Working Group (JIWG) under the auspices of the Department of Homeland Security Office of Research and Development conducted a technology assessment of emergency radiological dose assessment capabilities as part of the overall need for rapid emergency medical response in the event of a radiological terrorist event in the United States. The goal of the evaluation is to identify gaps and recommend general research and development needs to better prepare the Country for mitigating the effects of such an event. Given the capabilities and roles for responding to a radiological event extend across many agencies, a consensus of gaps and suggested development plans was a major goal of this evaluation and road-mapping effort. The working group consisted of experts representing the Departments of Homeland Security, Health and Human Services (Centers for Disease Control and the National Institutes of Health), Food and Drug Administration, Department of Defense and the Department of Energy's National Laboratories (see appendix A for participants). The specific goals of this Technology Assessment and Roadmap were to: (1) Describe the general context for deployment of emergency radiation dose assessment tools following terrorist use of a radiological or nuclear device; (2) Assess current and emerging dose assessment technologies; and (3) Put forward a consensus high-level technology roadmap for interagency research and development in this area. This report provides a summary of the consensus of needs, gaps and recommendations for a research program in the area of radiation dosimetry for early response, followed by a summary of the technologies available and on the near-term horizon. We then present a roadmap for a research program to bring present and emerging near-term technologies to bear on the gaps in radiation dose assessment and triage. Finally we present detailed supporting discussion on the nature of the threats we considered, the status of technology today, promising emerging technologies and references for further reading.

  18. Calculation of laser induced impulse based on the laser supported detonation wave model with dissociation, ionization and radiation

    SciTech Connect (OSTI)

    Gan, Li, E-mail: ligan0001@gmail.com; Mousen, Cheng; Xiaokang, Li [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha (China)] [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha (China)

    2014-03-15T23:59:59.000Z

    In the laser intensity range that the laser supported detonation (LSD) wave can be maintained, dissociation, ionization and radiation take a substantial part of the incidence laser energy. There is little treatment on the phenomenon in the existing models, which brings obvious discrepancies between their predictions and the experiment results. Taking into account the impact of dissociation, ionization and radiation in the conservations of mass, momentum and energy, a modified LSD wave model is developed which fits the experimental data more effectively rather than the existing models. Taking into consideration the pressure decay of the normal and the radial rarefaction, the laser induced impulse that is delivered to the target surface is calculated in the air; and the dependencies of impulse performance on laser intensity, pulse width, ambient pressure and spot size are indicated. The results confirm that the dissociation is the pivotal factor of the appearance of the momentum coupling coefficient extremum. This study focuses on a more thorough understanding of LSD and the interaction between laser and matter.

  19. MOLECULAR MECHANISM OF SUPPRESSION OF NEOPLASTIC TRANSFORMATION BY LOW DOSES OF LOW LET RADIATION

    SciTech Connect (OSTI)

    J.LESIE REDPATH, PH.D.

    2011-03-29T23:59:59.000Z

    We are currently funded (9/01-8/04) by the DOE Low Dose Radiation Research Program to examine mechanisms underlying the suppression of neoplastic transformation in vitro by low doses of low LET radiation. For the new studies proposed under Notice 04-21, we intend to follow up on our observation that upregulation of DNA repair may be an important factor and that its importance is dose-dependent. The experimental system will be the human hybrid cell neoplastic transformation assay that we are currently using. We propose to test the following hypothesis: Down-regulation of DNA dsb repair will abrogate the low dose suppression of neoplastic transformation. Using the technique of RNA silencing, it is proposed to test the effect of down-regulation of the two major DNA dsb repair pathways, homologous recombination (HR) and non-homologous end-joining (NHEJ), on the dose response relationship for neoplastic transformation. Based on prior studies, we predict that this will result in abrogation of the suppressive effect at doses in the range 1 to 10 cGy, but not at lower doses. The proposed experiments will also help address the question as to which of the two DNA repair pathways may be the most important in causing suppression of transformation. HR is a pathway that is predominant in S and G2 phase cells and is known to be less error-prone than the NHEJ pathway that is predominant in G1 phase. We hypothesize that down-regulation of HR will result in the most effective abrogation of suppression. An important component of this study will be the determination of the how abrogation of DNA dsb repair impacts the spontaneous transformation frequency, presumably a consequence of endogeneous DNA damage. Experiments will be carried out using partially synchronized populations of cells enriched for G1 and S/G2 respectively. In addition to the endpoint of neoplastic transformation the impact of down-regulation of HR and NHEJ on the formation and disappearance of the DNA dsb marker, gamma-H2AX, will be studied.

  20. Radiation Therapy With Full-Dose Gemcitabine and Oxaliplatin for Unresectable Pancreatic Cancer

    SciTech Connect (OSTI)

    Hunter, Klaudia U.; Feng, Felix Y. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Griffith, Kent A. [Comprehensive Cancer Center Biostatistics Unit, University of Michigan, Ann Arbor, MI (United States); Francis, Isaac R. [Department of Radiology, University of Michigan, Ann Arbor, MI (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Desai, Sameer [Department of Internal Medicine, University of Michigan, Ann Arbor, MI (United States); Murphy, James D. [School of Medicine, University of Michigan, Ann Arbor, MI (United States); Zalupski, Mark M. [Department of Internal Medicine, University of Michigan, Ann Arbor, MI (United States); Ben-Josef, Edgar, E-mail: edgarb@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States)

    2012-07-01T23:59:59.000Z

    Purpose: We completed a Phase I trial of gemcitabine and oxaliplatin with concurrent radiotherapy in patients with previously untreated pancreatic cancer. The results of a subset of patients with unresectable disease who went on to receive planned additional therapy are reported here. Methods and Materials: All patients received two 28-day cycles of gemcitabine (1,000 mg/m{sup 2} on Days 1, 8, and 15) and oxaliplatin (40-85 mg/m{sup 2} on Days 1 and 15, per a dose-escalation schema). Radiation therapy was delivered concurrently with Cycle 1 (27 Gy in 1.8-Gy fractions). At 9 weeks, patients were reassessed for resectability. Those deemed to have unresectable disease were offered a second round of treatment consisting of 2 cycles of gemcitabine and oxaliplatin and 27 Gy of radiation therapy (total, 54 Gy). Radiation was delivered to the gross tumor volume plus 1 cm by use of a three-dimensional conformal technique. We used the Common Terminology Criteria for Adverse Events to assess acute toxicity. Late toxicity was scored per the Radiation Therapy Oncology Group scale. Computed tomography scans were reviewed to determine pattern of failure, local response, and disease progression. Kaplan-Meier methodology and Cox regression models were used to evaluate survival and freedom from failure. Results: Thirty-two patients from the Phase I dose-escalation study had unresectable disease, three of whom had low-volume metastatic disease. Of this group, 16 patients went on to receive additional therapy to complete a total of 4 cycles of chemotherapy and 54 Gy of concurrent radiation. For this subset, 38% had at least a partial tumor response at a median of 3.2 months. Median survival was 11.8 months (range, 4.4-26.3 months). The 1-year freedom from local progression rate was 93.8% (95% confidence interval, 63.2-99.1). Conclusions: Radiation therapy to 54 Gy with concurrent full-dose gemcitabine and oxaliplatin is well tolerated and results in favorable rates of local tumor response and 1-year freedom from local progression.

  1. Hysterosalpingography using a flat panel unit: Evaluation and optimization of ovarian radiation dose

    SciTech Connect (OSTI)

    Messaris, Gerasimos A. T.; Abatzis, Ilias; Kagadis, George C.; Samartzis, Alexandros P.; Athanasopoulou, Panagiota; Christeas, Nikolaos; Katsanos, Konstantinos; Karnabatidis, Dimitrios; Nikiforidis, George C. [Department of Medical Physics, University Hospital of Patras, GR 265 04 Rion (Greece); Department of Medical Physics, School of Medicine, University of Patras, GR 265 04 Rion (Greece); Department of Medical Physics, University Hospital of Patras, GR 265 04 Rion, Greece and Department of Medical Physics, School of Medicine, University of Patras, GR 265 04 Rion (Greece); Department of Medical Physics, 'EVANGELISMOS' General Hospital, 45-47 Ypsilantou Street, GR 106 76 Athens (Greece); Philips Hellas, 44 Kifisias Avenue, GR 151 25 Marousi (Greece); Department of Radiology, School of Medicine, University of Patras, GR 265 04 Rion (Greece); Department of Medical Physics, University Hospital of Patras, GR 265 04 Rion, Greece and Department of Medical Physics, School of Medicine, University of Patras, GR 265 04 Rion (Greece)

    2012-07-15T23:59:59.000Z

    Purpose: The aim of the present study was the evaluation and optimization of radiation dose to the ovaries (D) in hysterosalpingography (HSG). Methods: The study included a phantom study and a clinical one. In the phantom study, we evaluated imaging results for different geometrical setups and irradiation conditions. In the clinical study, 34 women were assigned into three different fluoroscopy modes and D was estimated with direct cervical TLD measurements. Results: In the phantom study, we used a source-to-image-distance (SID) of 110 cm and a field diagonal of 48 cm, and thus decreased air KERMA rate (KR) by 19% and 70%, respectively, for beam filtration: 4 mm Al and 0.9 mm Cu (Low dose). The least radiation exposure was accomplished by using the 3.75 pps fluoroscopy mode in conjunction with beam filtration: Low dose. In the clinical study, D normalized to 50 s of fluoroscopy time with a 3.75 pps fluoroscopy mode reached a value of 0.45 {+-} 0.04 mGy. Observers' evaluation of diagnostic image quality did not significantly differ for the three different modes of acquisition that were compared. Conclusions: Digital spot radiographs could be omitted in modern flat panel systems during HSG. Fluoroscopy image acquisitions in a modern flat panel unit at 3.75 pps and a beam filtration of 4 mm Al and 0.9 mm Cu demonstrate acceptable image quality with an average D equal to 0.45 mGy. This value is lower compared to the studied literature. For these reasons, the proposed method may be recommended for routine HSG examination in order to limit radiation exposure to the ovaries.

  2. The Radiation Dose Measurement System for the BaBar Electromagnetic Calorimeter

    SciTech Connect (OSTI)

    Khan, A.; /Brunel U.; Meyer, W.T.; /Iowa State U.; Stelzer, J.; /Stanford U., Phys. Dept.; Yi, Jong; /Manchester U.

    2006-08-14T23:59:59.000Z

    An array of 116 p-channel radiation sensitive MOSFET transistors (RadFETs) has been operational for the past 6 years at the BaBar experiment at the PEP-II asymmetric B-Factory at the Stanford Linear Accelerator Center (SLAC). This system maps the integrated dose absorbed by different regions of the Electromagnetic Calorimeter (EMC) during the running of the experiment. We report on the design and implementation of the system and finally, the performance of the monitoring system during the last 6 years of BaBar data-taking.

  3. Low Dose Radiation Response Curves, Networks and Pathways in Human Lymphoblastoid Cells Exposed from 1 to 10 cGy of Acute Gamma Radiation

    SciTech Connect (OSTI)

    Wyrobek, A. J.; Manohar, C. F.; Nelson, D. O.; Furtado, M. R.; Bhattacharya, M. S.; Marchetti, F.; Coleman, M.A.

    2011-04-18T23:59:59.000Z

    We investigated the low dose dependency of the transcriptional response of human cells to characterize the shape and biological functions associated with the dose response curve and to identify common and conserved functions of low dose expressed genes across cells and tissues. Human lymphoblastoid (HL) cells from two unrelated individuals were exposed to graded doses of radiation spanning the range of 1-10 cGy were analyzed by transcriptome profiling, qPCR and bioinformatics, in comparison to sham irradiated samples. A set of {approx}80 genes showed consistent responses in both cell lines; these genes were associated with homeostasis mechanisms (e.g., membrane signaling, molecule transport), subcellular locations (e.g., Golgi, and endoplasmic reticulum), and involved diverse signal transduction pathways. The majority of radiation-modulated genes had plateau-like responses across 1-10 cGy, some with suggestive evidence that transcription was modulated at doses below 1 cGy. MYC, FOS and TP53 were the major network nodes of the low-dose response in HL cells. Comparison our low dose expression findings in HL cells with those of prior studies in mouse brain after whole body exposure, in human keratinocyte cultures, and in endothelial cells cultures, indicates that certain components of the low dose radiation response are broadly conserved across cell types and tissues, independent of proliferation status.

  4. Radiation Dose to the Esophagus From Breast Cancer Radiation Therapy, 1943-1996: An International Population-Based Study of 414 Patients

    SciTech Connect (OSTI)

    Lamart, Stephanie, E-mail: stephanie.lamart@nih.gov [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)] [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Stovall, Marilyn [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Simon, Steven L. [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)] [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Smith, Susan A.; Weathers, Rita E.; Howell, Rebecca M. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Curtis, Rochelle E. [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)] [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States); Aleman, Berthe M.P. [Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam (Netherlands)] [Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam (Netherlands); Travis, Lois [Rubin Center for Cancer Survivorship and Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York (United States)] [Rubin Center for Cancer Survivorship and Department of Radiation Oncology, University of Rochester Medical Center, Rochester, New York (United States); Kwon, Deukwoo [Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida (United States)] [Sylvester Comprehensive Cancer Center, University of Miami, Miami, Florida (United States); Morton, Lindsay M. [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)] [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland (United States)

    2013-07-15T23:59:59.000Z

    Purpose: To provide dosimetric data for an epidemiologic study on the risk of second primary esophageal cancer among breast cancer survivors, by reconstructing the radiation dose incidentally delivered to the esophagus of 414 women treated with radiation therapy for breast cancer during 1943-1996 in North America and Europe. Methods and Materials: We abstracted the radiation therapy treatment parameters from each patient’s radiation therapy record. Treatment fields included direct chest wall (37% of patients), medial and lateral tangentials (45%), supraclavicular (SCV, 64%), internal mammary (IM, 44%), SCV and IM together (16%), axillary (52%), and breast/chest wall boosts (7%). The beam types used were {sup 60}Co (45% of fields), orthovoltage (33%), megavoltage photons (11%), and electrons (10%). The population median prescribed dose to the target volume ranged from 21 Gy to 40 Gy. We reconstructed the doses over the length of the esophagus using abstracted patient data, water phantom measurements, and a computational model of the human body. Results: Fields that treated the SCV and/or IM lymph nodes were used for 85% of the patients and delivered the highest doses within 3 regions of the esophagus: cervical (population median 38 Gy), upper thoracic (32 Gy), and middle thoracic (25 Gy). Other fields (direct chest wall, tangential, and axillary) contributed substantially lower doses (approximately 2 Gy). The cervical to middle thoracic esophagus received the highest dose because of its close proximity to the SCV and IM fields and less overlying tissue in that part of the chest. The location of the SCV field border relative to the midline was one of the most important determinants of the dose to the esophagus. Conclusions: Breast cancer patients in this study received relatively high incidental radiation therapy doses to the esophagus when the SCV and/or IM lymph nodes were treated, whereas direct chest wall, tangentials, and axillary fields contributed lower doses.

  5. Natural IAP inhibitor Embelin enhances therapeutic efficacy of ionizing radiation in prostate cancer

    E-Print Network [OSTI]

    Dai, Yao; DeSano, Jeffrey; Qu, Yang; Tang, Wenhua; Meng, Yang; Lawrence, Theodore S.; Xu, Liang

    2011-01-01T23:59:59.000Z

    , Indianapolis, Indiana) was used as a positive control, treating cells at a dose of 1 ?M for 24 h. Data represent one of two independent experiments. B, clonogenic survival curve of cells pretreated with indicated dose of Em, as described in A. Data are shown... as mean ± SD (n=3). C, clonogenic survival curve of cells pretreated with 1 ?M and 2 ?M of Gem for 24 h. Data are shown as mean ± SD (n=3). Radiosensitization of prostate cancer by embelin 134...

  6. A Systems Genetic Approach to Identify Low Dose Radiation-Induced Lymphoma Susceptibility/DOE2013FinalReport

    SciTech Connect (OSTI)

    Balmain, Allan [University of California, San Francisco; Song, Ihn Young [University of California, San Francisco

    2013-05-15T23:59:59.000Z

    The ultimate goal of this project is to identify the combinations of genetic variants that confer an individual's susceptibility to the effects of low dose (0.1 Gy) gamma-radiation, in particular with regard to tumor development. In contrast to the known effects of high dose radiation in cancer induction, the responses to low dose radiation (defined as 0.1 Gy or less) are much less well understood, and have been proposed to involve a protective anti-tumor effect in some in vivo scientific models. These conflicting results confound attempts to develop predictive models of the risk of exposure to low dose radiation, particularly when combined with the strong effects of inherited genetic variants on both radiation effects and cancer susceptibility. We have used a Â?Â?Systems Genetics approach in mice that combines genetic background analysis with responses to low and high dose radiation, in order to develop insights that will allow us to reconcile these disparate observations. Using this comprehensive approach we have analyzed normal tissue gene expression (in this case the skin and thymus), together with the changes that take place in this gene expression architecture a) in response to low or high- dose radiation and b) during tumor development. Additionally, we have demonstrated that using our expression analysis approach in our genetically heterogeneous/defined radiation-induced tumor mouse models can uniquely identify genes and pathways relevant to human T-ALL, and uncover interactions between common genetic variants of genes which may lead to tumor susceptibility.

  7. The oncogenic action of ionizing radiation on rat skin. Final progress report, May 1, 1990--April 30, 1992

    SciTech Connect (OSTI)

    Burns, F.J.; Garte, S.J.

    1992-12-31T23:59:59.000Z

    The multistage theory of carcinogenesis specifies that cells progress to cancer through a series of discrete, irreversible genetic alterations, but data on radiation-induced cancer incidence in rat skin suggests that an intermediate repairable alteration may occur. Data are presented on cancer induction in rat skin exposed to an electron beam (LET=0.34 keV/{mu}), a neon ion beam (LET=45) or an argon ion beam (LET=125). The rats were observed for tumors at least 78 weeks with squamous and basal cell carcinomas observed. The total cancer yield was fitted by the quadratic equation, and the equation parameters were estimated by linear regression for each type of radiation. Analysis of the DNA from the electron-induced carcinomas indicated that K-ras and/or c-myc oncogenes were activated. In situ hybridization indicated that the cancers contain subpopulations of cells with differing amounts of c-myc and H-ras amplification. The results are consistent with the idea that ionizing radiation produces stable, carcinogenically relevant lesions via 2 repairable events at low LET and via a non-repairable linked event pathway at high LET; either pathway may advance the cell by 1 stage. The proliferative response of rat epidermis following exposure to ionizing radiation was quantified by injection of {sup 14}C-thymidine. The return of these cells to S-phase a second time was detected by a second label ({sup 3}H). When the labeled cells were in G1-phase, the dorsal skin was irradiated with X-rays. All labeling indices were determined. The {sup 14}C labeling index was constant and unaffected by the radiation. The proportion of all cells entering S-phase averaged 3.5% at 18 hr and increased after 44, 52 and 75 hr to average levels of 11.8%, 5. 3%, and 6.6% at 0, 10 and 25 Gy respectively. The proportion of S-phase cells labeled with {sup 14}C increased after 42 hr and remained relatively constant thereafter.

  8. MicroShield analysis to calculate external radiation dose rates for several spent fuel casks

    SciTech Connect (OSTI)

    Marincel, M.K. [Missouri Univ., Rolla, MO (United States); Weiner, R.F.; Osborn, D.M. [Sandia National Laboratories, Albuquerque, NM (United States)

    2007-07-01T23:59:59.000Z

    The purpose of this MicroShield analysis is to calculate the external radiation, primarily gamma, dose rate for spent fuel casks. The reason for making this calculation is that currently all analyses of transportation risk assume that this external dose rate is the maximum allowed by regulation, 10 mrem/hr at 2 m from the casks, and the risks of incident-free transportation are thus always overestimated to an unknown extent. In order to do this, the program by Grove Software, MicroShield 7.01, was used to model three Nuclear Regulatory Commission (NRC) approved casks: HI-STAR 100, GA-4, and NAC-STC, loaded with specific source material. Dimensions were obtained from NUREG/CR-6672 and the Certificates of Compliance for each respective cask. Detectors were placed at the axial point at 1 m and 2 m from the outer gamma shielding of the casks. In the April 8, 2004 publication of the Federal Register, a notice of intent to prepare a Supplemental Yucca Mountain Environmental Impact Statement (DOE/EIS-0250F-S1) was published by the Office of Civilian Radioactive Waste Management (OCRWM) in order to consider design, construction, operation, and transportation of spent nuclear fuel to the Yucca Mountain repository [1]. These more accurate estimates of the external dose rates could be used in order to provide a more risk-informed analysis. (authors)

  9. Radiation and Reason Why radiation at modest dose rates is quite harmless and current radiation safety regulations are flawed

    E-Print Network [OSTI]

    CERN. Geneva

    2013-01-01T23:59:59.000Z

    Data on the impact of ionising radiation on life are examined in the light of evolutionary biology. This comparison confirms that fear of nuclear radiation is not justified by science itself; rather it originates in a failure of public trust in nuclear science, a relic of the international politics of the Cold War era. Current ionisation safety regulations appease this fear but without scientific support and they need fundamental reformulation. This should change the reaction to accidents like Fukushima, the cost of nuclear energy and the application of nuclear technology to the supply of food and fresh water. Such a boost to the world economy would require that more citizens study and appreciate the science involved – and then tell others -- not as much fun as the Higgs, perhaps, but no less important! www.radiationandreason.com

  10. Simultaneous reduction of radiation dose and scatter for CBCT by using collimators

    SciTech Connect (OSTI)

    Li, Tianfang; Li, Xiang; Yang, Yong; Zhang, Yongqian; Heron, Dwight E.; Huq, M. Saiful [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States)] [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States)

    2013-12-15T23:59:59.000Z

    Purpose: On-board cone-beam CT (CBCT) imaging has been widely available in radiotherapy clinic for target localization. However, the extra radiation dose from CBCT is always a concern for its frequent use. Additionally, the relatively large scatter in CBCT often degrades the image quality. By using collimators, some of the X-rays can be stopped from reaching the patient and the detectors, hence both the scatter and the patient doses are simultaneously reduced. The authors show in this work that the collimated CBCT data can be reconstructed without any noticeable artifacts for certain collimator blocking ratios and blocking patterns, and the focus of this work is to study the relationship between the image quality and these two collimator factors.Methods: A CBCT system with collimators was simulated following the typical geometry used in clinic. Different collimator designs were tested by varying the size and the number of the collimator slits, and at the same time, the ratio of transmitted beams to total beams was varied from 100% to 10%, resulting in hundreds of different simulation scenarios. Lung and pelvis phantoms created from patients CT images were used in the simulations, and an iterative reconstruction algorithm using the compressed sensing technique was adopted. The image quality was examined by root mean square errors (RMSEs) and compared with the conventional CBCT images.Results: The CBCT image quality increases as the amount of beams passing through the collimators increases, and decreases as the size of the collimator slits increases. With ultra-high resolution collimators, the RMSEs were comparable to the conventional CBCT image quality until the beam transmission rate is reduced below 25%.Conclusions: Collimators can reduce the scatters and radiation dose, however, the collimated CBCT image quality is strongly dependent on both the collimator blocking ratio and the blocking pattern. To achieve image quality comparable to the conventional CBCT, the amount of information and data format must be adequate.

  11. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.

    1992-05-01T23:59:59.000Z

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  12. Peering through the holes: the far UV color of star-forming galaxies at z~3-4 and the escaping fraction of ionizing radiation

    E-Print Network [OSTI]

    Vanzella, E; Castellano, M; Grazian, A; Inoue, A K; Schaerer, D; Guaita, L; Zamorani, G; Giavalisco, M; Siana, B; Pentericci, L; Giallongo, E; Fontana, A; Vignali, C

    2015-01-01T23:59:59.000Z

    We aim to investigate the effect of the escaping ionizing radiation on the color selection of high redshift galaxies and identify candidate Lyman continuum (LyC) emitters. The intergalactic medium prescription of Inoue et al.(2014) and galaxy synthesis models of Bruzual&Charlot (2003) have been used to properly treat the ultraviolet stellar emission, the stochasticity of the intergalactic transmission and mean free path in the ionizing regime. Color tracks are computed by turning on/off the escape fraction of ionizing radiation. At variance with recent studies, a careful treatment of IGM transmission leads to no significant effects on the high-redshift broad-band color selection. The decreasing mean free path of ionizing photons with increasing redshift further diminishes the contribution of the LyC to broad-band colors. We also demonstrate that prominent LyC sources can be selected under suitable conditions by calculating the probability of a null escaping ionizing radiation. The method is applied to a s...

  13. Effects of low levels of radiation on humans

    SciTech Connect (OSTI)

    Auxier, J.A.

    1981-01-01T23:59:59.000Z

    The state of knowledge on effects of low-level ionizing radiations on humans is reviewed. Several problems relating to dose thresholds or lack of thresholds for several types of cancer and high LET radiations and the effects of fractionation and dose protection are discussed. (ACR)

  14. Ionization chamber

    DOE Patents [OSTI]

    Walenta, Albert H. (Port Jefferson Station, NY)

    1981-01-01T23:59:59.000Z

    An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.

  15. Precise method of compensating radiation-induced errors in a hot-cathode-ionization gauge with correcting electrode

    SciTech Connect (OSTI)

    Saeki, Hiroshi, E-mail: saeki@spring8.or.jp; Magome, Tamotsu, E-mail: saeki@spring8.or.jp [Japan Synchrotron Radiation Research Institute, SPring-8, Kohto 1-1-1, Sayo, Hyogo 679-5198 (Japan)

    2014-10-06T23:59:59.000Z

    To compensate pressure-measurement errors caused by a synchrotron radiation environment, a precise method using a hot-cathode-ionization-gauge head with correcting electrode, was developed and tested in a simulation experiment with excess electrons in the SPring-8 storage ring. This precise method to improve the measurement accuracy, can correctly reduce the pressure-measurement errors caused by electrons originating from the external environment, and originating from the primary gauge filament influenced by spatial conditions of the installed vacuum-gauge head. As the result of the simulation experiment to confirm the performance reducing the errors caused by the external environment, the pressure-measurement error using this method was approximately less than several percent in the pressure range from 10{sup ?5} Pa to 10{sup ?8} Pa. After the experiment, to confirm the performance reducing the error caused by spatial conditions, an additional experiment was carried out using a sleeve and showed that the improved function was available.

  16. The privilege to use lasers (non-ionizing radiation) at Stanford University requires each individual user to follow and adhere to the guidelines recommended in the American National Standard Institute

    E-Print Network [OSTI]

    Kay, Mark A.

    Preface The privilege to use lasers (non-ionizing radiation) at Stanford, and the institution. This manual provides an orientation on lasers (non-ionizing radiation.2.2 Engineering Controls 5.2.3 Administrative and Procedural Controls 6.0 PROTECTIVE EQUIPMENT

  17. The prediction of radiation-induced liver dysfunction using a local dose and regional venous perfusion model

    SciTech Connect (OSTI)

    Cao Yue; Platt, Joel F.; Francis, Isaac R; Balter, James M.; Pan, Charlie; Normolle, Daniel; Ben-Josef, Edgar; Haken, Randall K. ten; Lawrence, Theodore S. [Departments of Radiation Oncology and Radiology, University of Michigan, Ann Arbor, Michigan 48109-0010 (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109-0010 (United States); Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan 48109-0010 (United States)

    2007-02-15T23:59:59.000Z

    We have shown that high dose conformal radiation combined with chemotherapy appears to prolong the survival of patients with unresectable intrahepatic cancers. The ability to safely deliver higher doses is primarily limited by the development of radiation-induced liver disease, characterized by venous occlusion. In this study, we investigated whether portal venous perfusion measured prior to the end of radiation therapy (RT) together with dose could predict liver venous perfusion dysfunction after treatment. Ten patients with unresectable intrahepatic cancer participated in an IRB-approved computer tomography (CT) perfusion study. Hepatic arterial and portal vein perfusion distributions were estimated by using dynamic contrast enhanced CT and the single compartmental model. Scans were obtained at four time points: prior to treatment, after 15 and 30 fractions of 1.5 Gy treatments, and one month following the completion of RT. Multivariant linear regression was used to determine covariances among the first three time point measurements plus dose for prediction of the post RT measurement. The reduction in the regional venous perfusion one month following RT was predicted by the local accumulated dose and the change in the regional venous perfusion after {approx}30 fractions (F=90.6,p<0.000 01). Each Gy produced an approximately 1.2% of reduction in the venous perfusion. This local dose and venous perfusion model has the potential to predict individual sensitivity to radiation. This is the first step toward developing a method to deliver higher and potentially more curative radiation doses to the patients who can safely receive these higher doses.

  18. Total Dose Evaluation of Deep Submicron CMOS Imaging Technology Through Elementary Device and

    E-Print Network [OSTI]

    Mailhes, Corinne

    layer. Current-voltage character- istics were carried out at 23 using a low-current ( 10 fA) test bench. Bernard, and G. Rolland Abstract--Ionizing radiation effects on CMOS image sensors (CIS) manufactured to understand ionizing dose effects on devices and then on image sensors. The main degra- dations observed

  19. Long-Term Outcomes After High-Dose Postprostatectomy Salvage Radiation Treatment

    SciTech Connect (OSTI)

    Goenka, Anuj; Magsanoc, Juan Martin; Pei Xin; Schechter, Michael; Kollmeier, Marisa; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Scardino, Peter T.; Eastham, James A. [Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)] [Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2012-09-01T23:59:59.000Z

    Purpose: To review the impact of high-dose radiotherapy (RT) in the postprostatectomy salvage setting on long-term biochemical control and distant metastases-free survival, and to identify clinical and pathologic predictors of outcomes. Methods and Materials: During 1988-2007, 285 consecutive patients were treated with salvage RT (SRT) after radical prostatectomy. All patients were treated with either three-dimensional conformal RT or intensity-modulated RT. Two hundred seventy patients (95%) were treated to a dose {>=}66 Gy, of whom 205 (72%) received doses {>=}70 Gy. Eighty-seven patients (31%) received androgen-deprivation therapy as a component of their salvage treatment. All clinical and pathologic records were reviewed to identify treatment risk factors and response. Results: The median follow-up time after SRT was 60 months. Seven-year actuarial prostate-specific antigen (PSA) relapse-free survival and distant metastases-free survival were 37% and 77%, respectively. Independent predictors of biochemical recurrence were vascular invasion (p < 0.01), negative surgical margins (p < 0.01), presalvage PSA level >0.4 ng/mL (p < 0.01), androgen-deprivation therapy (p = 0.03), Gleason score {>=}7 (p = 0.02), and seminal vesicle involvement (p = 0.05). Salvage RT dose {>=}70 Gy was not associated with improvement in biochemical control. A doubling time <3 months was the only independent predictor of metastatic disease (p < 0.01). There was a trend suggesting benefit of SRT dose {>=}70 Gy in preventing clinical local failure in patients with radiographically visible local disease at time of SRT (7 years: 90% vs. 79.1%, p = 0.07). Conclusion: Salvage RT provides effective long-term biochemical control and freedom from metastasis in selected patients presenting with detectable PSA after prostatectomy. Androgen-deprivation therapy was associated with improvement in biochemical progression-free survival. Clinical local failures were rare but occurred most commonly in patients with greater burden of disease at time of SRT as reflected by either radiographic imaging or a greater PSA level. Salvage radiation doses {>=}70 Gy may ultimately be most beneficial in these patients, but this needs to be further studied.

  20. An Overview of the Regulation of Low Dose Radiation in the Nuclear and Non-nuclear Industries

    SciTech Connect (OSTI)

    Menon, Shankar; Valencia, Luis; Teunckens, Lucien

    2003-02-27T23:59:59.000Z

    Now that increasing numbers of nuclear power stations are reaching the end of their commercially useful lives, the management of the large quantities of very low level radioactive material that arises during their decommissioning has become a major subject of discussion, with very significant economic implications. Much of this material can, in an environmentally advantageous manner, be recycled for reuse without radiological restrictions. Much larger quantities--2-3 orders of magnitude larger--of material, radiologically similar to the candidate material for recycling from the nuclear industry, arise in non-nuclear industries like coal, fertilizer, oil and gas, mining, etc. In such industries, naturally occurring radioactivity is artificially concentrated in products, by-products or waste to form TENORM (Technologically Enhanced Naturally Occurring Radioactive Material). It is only in the last decade that the international community has become aware of the prevalence of TENORM, specially the activity levels and quantities arising in so many non-nuclear industries. The first reaction of international organizations seems to have been to propose different standards for the nuclear and non-nuclear industries, with very stringent release criteria for radioactive material from the regulated nuclear industry and up to thirty to a hundred times more liberal criteria for the release/exemption of TENORM from the as yet unregulated non-nuclear industries. There are significant strategic issues that need to be discussed and resolved. Some examples of these are: - Disposal aspects of long-lived nuclides, - The use of radioactive residues in building materials, - Commercial aspects of differing and discriminating criteria in competing power industries in a world of deregulated electric power production. Of even greater importance is the need for the discussion of certain basic issues, such as - The quantitative risk levels of exposure to ionizing radiation, - The need for in-depth studies on populations of the naturally high background dose level areas of the world, - The validity of the various calculation codes currently used to arrive at mass specific clearance levels for redundant material. The paper discusses these and other strategic issues regarding the management of redundant low radiation material from both the nuclear and non-nuclear industries, underlining the need for consistency in regulatory treatment.

  1. CY 1995 radiation dose reconciliation report and resulting CY 1996 dose estimate for the 324 nuclear facility

    SciTech Connect (OSTI)

    Landsman, S.D.; Thornhill, R.E.; Peterson, C.A.

    1996-04-01T23:59:59.000Z

    In this report, the dose estimate for CY 1995 is reconciled by month wih actual doses received. Results of the reconciliation were used to revise estimates of worker dose for CY 1996. Resulting dose estimate for the facility is also included. Support for two major programs (B-Cell Cleanout and Surveillance and Maintenance) accounts for most of the exposure received by workers in the faility. Most of the expousre received by workers comes from work in the Radiochemical Engineering Complex airlock. In spite of schedule and work scope changes during CY 1995, dose estimates were close to actual exposures received. A number of ALARA measures were taken throughout the year; exposure reduction due to those was 20.6 Man-Rem, a 28% reduction from the CY 1995 estimate. Baseline estimates for various tasks in the facility were used to compile the CY 1996 dose estimate of 45.4 Man-Rem; facility goal for CY 1996 is to reduce worker dose by 20%, to 36.3 Man-Rem.

  2. Nuclear and Non-Ionizing Energy-Loss for Coulomb Scattered Particles from Low Energy up to Relativistic Regime in Space Radiation Environment

    E-Print Network [OSTI]

    M. J. Boschini; C. Consolandi; M. Gervasi; S. Giani; D. Grandi; V. Ivanchenko; S. Pensotti; P. G. Rancoita; M. Tacconi

    2014-01-21T23:59:59.000Z

    In the space environment, instruments onboard of spacecrafts can be affected by displacement damage due to radiation. The differential scattering cross section for screened nucleus--nucleus interactions - i.e., including the effects due to screened Coulomb nuclear fields -, nuclear stopping powers and non-ionization energy losses are treated from about 50 keV/nucleon up to relativistic energies.

  3. 2009 US-Japan Workshop on Advanced Simulation Methods in Plasma Physics MHD Simulations of the Solar Astmosphere: Effects of Weak Ionization and Radiation

    E-Print Network [OSTI]

    Ito, Atsushi

    of the Solar Astmosphere: Effects of Weak Ionization and Radiation Hiroaki Isobe1 1 Unit of Synergetic Studies subject in solar physics is to understand the variety of dynamics and structure formation a key role in many cases. In this talk I will first review the plasma parameters in the solar atmosphere

  4. The degradation of TPX components by oxygen, elevated temperature, and ionizing radiation

    SciTech Connect (OSTI)

    Farmer, J.C.

    1996-05-31T23:59:59.000Z

    TPX is PMP or poly(4-methyl-1-pentene). It has several commercially important characteristics such as high optical transparency, high crystalline melting point, etc., leading to numerous applications including infrared windows, lenses, membranes, food packaging. The life components fabricated from this material may be limited by thermal oxidative and radiation-induced degradation. A preliminary review of the scientific literature was conducted to obtain relevant information on the effects of oxygen, moisture elevated temperature, and radiation on the chemical, thermodynamic, mechanical, and electrical properties of this material. Refs, figs, tabs.

  5. Effects of ionizing radiation on the response of certain photosensitive seeds to red light

    E-Print Network [OSTI]

    Richardson, Billy

    1964-01-01T23:59:59.000Z

    of gamma radiation and red light on the germination of L~t~ua ~tva New York. Data recorded 48 hours after start of imbibition. 18 Gamma-irradiated ~La t~ ~t New York seeds 48 hours after start of imbibition. One hundred (top) and 300 (bottom) K-rads...~nt g, seeds 48 hours after start of imbibition. Top (left to right): 0, 25, 50, 75 K-rads; bottom: 100, 200, 300, 400 K-rads, administered to dry seed. . 26 Effects of gamma radiation and red light on the germination of Lactuca gativa Grand Rapids...

  6. The effects of diet and ionizing radiation on azoxymethane induced colon carcinogenesis 

    E-Print Network [OSTI]

    Mann, John Clifford

    2006-10-30T23:59:59.000Z

    rats were exposed to a single dose of approximately 1 Gy, 1GeV/nucleon Fe-56 ions at the Alternating Gradient Synchrotron/Relativistic Heavy Ion Collider (AGS/RHIC) facility at Brookhaven National Laboratory (Upton, NY). Each rat was immobilized.... 11 CHAPTER II MATERIALS AND METHODS Experimental design. Animal protocols used for this study were approved by the Institutional Animal Care Committees of Texas A&M University and Brookhaven National Laboratory and conform to the guidelines...

  7. Stable Intrachromosomal Biomarkers of Past Exposure to Densely Ionizing Radiation in Several Chromosomes of Exposed Individuals

    E-Print Network [OSTI]

    Brenner, David Jonathan

    , researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive is collaborating with JSTOR to digitize, preserve and extend access to Radiation Research. http://www.jstor.org #12. Brennera aCenterfor Radiological Research, Columbia University, 630 West 168th Street, New York,New York

  8. Normal Liver Tissue Density Dose Response in Patients Treated With Stereotactic Body Radiation Therapy for Liver Metastases

    SciTech Connect (OSTI)

    Howells, Christopher C.; Stinauer, Michelle A.; Diot, Quentin; Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States); Miften, Moyed, E-mail: Moyed.Miften@ucdenver.edu [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)] [Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, Colorado (United States)

    2012-11-01T23:59:59.000Z

    Purpose: To evaluate the temporal dose response of normal liver tissue for patients with liver metastases treated with stereotactic body radiation therapy (SBRT). Methods and Materials: Ninety-nine noncontrast follow-up computed tomography (CT) scans of 34 patients who received SBRT between 2004 and 2011 were retrospectively analyzed at a median of 8 months post-SBRT (range, 0.7-36 months). SBRT-induced normal liver tissue density changes in follow-up CT scans were evaluated at 2, 6, 10, 15, and 27 months. The dose distributions from planning CTs were mapped to follow-up CTs to relate the mean Hounsfield unit change ({Delta}HU) to dose received over the range 0-55 Gy in 3-5 fractions. An absolute density change of 7 HU was considered a significant radiographic change in normal liver tissue. Results: Increasing radiation dose was linearly correlated with lower post-SBRT liver tissue density (slope, -0.65 {Delta}HU/5 Gy). The threshold for significant change (-7 {Delta}HU) was observed in the range of 30-35 Gy. This effect did not vary significantly over the time intervals evaluated. Conclusions: SBRT induces a dose-dependent and relatively time-independent hypodense radiation reaction within normal liver tissue that is characterized by a decrease of >7 HU in liver density for doses >30-35 Gy.

  9. System and method for radiation dose calculation within sub-volumes of a monte carlo based particle transport grid

    DOE Patents [OSTI]

    Bergstrom, Paul M. (Livermore, CA); Daly, Thomas P. (Livermore, CA); Moses, Edward I. (Livermore, CA); Patterson, Jr., Ralph W. (Livermore, CA); Schach von Wittenau, Alexis E. (Livermore, CA); Garrett, Dewey N. (Livermore, CA); House, Ronald K. (Tracy, CA); Hartmann-Siantar, Christine L. (Livermore, CA); Cox, Lawrence J. (Los Alamos, NM); Fujino, Donald H. (San Leandro, CA)

    2000-01-01T23:59:59.000Z

    A system and method is disclosed for radiation dose calculation within sub-volumes of a particle transport grid. In a first step of the method voxel volumes enclosing a first portion of the target mass are received. A second step in the method defines dosel volumes which enclose a second portion of the target mass and overlap the first portion. A third step in the method calculates common volumes between the dosel volumes and the voxel volumes. A fourth step in the method identifies locations in the target mass of energy deposits. And, a fifth step in the method calculates radiation doses received by the target mass within the dosel volumes. A common volume calculation module inputs voxel volumes enclosing a first portion of the target mass, inputs voxel mass densities corresponding to a density of the target mass within each of the voxel volumes, defines dosel volumes which enclose a second portion of the target mass and overlap the first portion, and calculates common volumes between the dosel volumes and the voxel volumes. A dosel mass module, multiplies the common volumes by corresponding voxel mass densities to obtain incremental dosel masses, and adds the incremental dosel masses corresponding to the dosel volumes to obtain dosel masses. A radiation transport module identifies locations in the target mass of energy deposits. And, a dose calculation module, coupled to the common volume calculation module and the radiation transport module, for calculating radiation doses received by the target mass within the dosel volumes.

  10. The degradation of TPX components by oxygen, elevated temperature, and ionizing radiation

    SciTech Connect (OSTI)

    Farmer, J.C.

    1996-09-01T23:59:59.000Z

    Poly(4-methyl-l-pentene), also known as PMP or TPX, has several commercially important characteristics such as high optical transparency, high crystalline melting point, low density, low electrical conductivity, and good heat resistance. Such characteristics have lead to numerous industrial applications including infrared windows, infrared lenses, membranes, and food packaging. The life components fabricated from this material may be limited bv thermal oxidative and radiation-induced degradation. A preliminary review of the scientific literature has been conducted to obtain relevant information on the effects of oxygen, moisture elevated temperature, and radiation on the chemical, thermodynamic, mechanical, and electrical properties of this important construction material. Key information from the literature has become especially important in light of decreased budgets for defense-related research and development, and the prolonged service life of existing systems.

  11. RADIATION RESEARCH 156, 594597 (2001) 0033-7587/01 $5.00

    E-Print Network [OSTI]

    Brenner, David Jonathan

    2001-01-01T23:59:59.000Z

    594 RADIATION RESEARCH 156, 594­597 (2001) 0033-7587/01 $5.00 2001 by Radiation Research Society Doses. Radiat. Res. 156, 594­597 (2001). The patterns of DSBs induced in the genome are different for sparsely and densely ionizing radiations: In the former case, the patterns are well described by a random

  12. SU-E-I-15: Comparison of Radiation Dose for Radiography and EOS in Adolescent Scoliosis Patients

    SciTech Connect (OSTI)

    Schueler, B; Walz-Flannigan, A [Mayo Clinic, Rochester, MN (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To estimate patient radiation dose for whole spine imaging using EOS, a new biplanar slot-scanning radiographic system and compare with standard scoliosis radiography. Methods: The EOS imaging system (EOS Imaging, Paris, France) consists of two orthogonal x-ray fan beams which simultaneously acquire frontal and lateral projection images of a standing patient. The patient entrance skin air kerma was measured for each projection image using manufacturer-recommended exposure parameters for spine imaging. Organ and effective doses were estimated using a commercially-available Monte Carlo simulation program (PCXMC, STUK, Radiation and Nuclear Safety Authority, Helsinki, Finland) for a 15 year old mathematical phantom model. These results were compared to organ and effective dose estimated for scoliosis radiography using computed radiography (CR) with standard exposure parameters obtained from a survey of pediatric radiographic projections. Results: The entrance skin air kerma for EOS was found to be 0.18 mGy and 0.33 mGy for posterior-anterior (PA) and lateral projections, respectively. This compares to 0.76 mGy and 1.4 mGy for CR, PA and lateral projections. Effective dose for EOS (PA and lateral projections combined) is 0.19 mSv compared to 0.51 mSv for CR. Conclusion: The EOS slot-scanning radiographic system allows for reduced patient radiation dose in scoliosis patients as compared to standard CR radiography.

  13. A Phase I Clinical and Pharmacology Study Using Amifostine as a Radioprotector in Dose-escalated Whole Liver Radiation Therapy

    SciTech Connect (OSTI)

    Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Smith, David E. [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States); Normolle, Daniel P. [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States)] [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Knol, James A. [Department of Surgery, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Surgery, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Pan, Charlie C.; Ben-Josef, Edgar [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Lu Zheng; Feng, Meihua R.; Chen Jun [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, Ann Arbor, Michigan (United States); Ensminger, William [Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Internal Medicine, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States); Lawrence, Theodore S. [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, School of Medicine, University of Michigan, Ann Arbor, Michigan (United States)

    2012-08-01T23:59:59.000Z

    Purpose: Diffuse intrahepatic tumors are difficult to control. Whole-liver radiotherapy has been limited by toxicity, most notably radiation-induced liver disease. Amifostine is a prodrug free-radical scavenger that selectively protects normal tissues and, in a preclinical model of intrahepatic cancer, systemic amifostine reduced normal liver radiation damage without compromising tumor effect. We hypothesized that amifostine would permit escalation of whole-liver radiation dose to potentially control microscopic disease. We also aimed to characterize the pharmacokinetics of amifostine and its active metabolite WR-1065 to optimize timing of radiotherapy. Methods and Materials: We conducted a radiation dose-escalation trial for patients with diffuse, intrahepatic cancer treated with whole-liver radiation and intravenous amifostine. Radiation dose was assigned using the time-to-event continual reassessment method. A companion pharmacokinetic study was performed. Results: Twenty-three patients were treated, with a maximum dose of 40 Gy. Using a logistical regression model, compared with our previously treated patients, amifostine increased liver tolerance by 3.3 {+-} 1.1 Gy (p = 0.007) (approximately 10%) with similar response rates. Peak concentrations of WR-1065 were 25 {mu}M with an elimination half-life of 1.5 h; these levels are consistent with radioprotective effects of amifostine in patients. Conclusion: These findings demonstrate for the first time that amifostine is a normal liver radioprotector. They further suggest that it may be useful to combine amifostine with fractionated or stereotactic body radiation therapy for patients with focal intrahepatic cancer.

  14. Identification and Characterization of Soluble Factors Involved in Delayed Effects of Low Dose Radiation. Final report

    SciTech Connect (OSTI)

    Baulch, Janet

    2013-09-11T23:59:59.000Z

    This is a 'glue grant' that was part of a DOE Low Dose project entitled 'Identification and Characterization of Soluble Factors Involved in Delayed Effects of Low Dose Radiation'. This collaborative program has involved Drs. David L. Springer from Pacific Northwest National Laboratory (PNNL), John H. Miller from Washington State University, Tri-cities (WSU) and William F. Morgan then from the University of Maryland, Baltimore (UMB). In July 2008, Dr. Morgan moved to PNNL and Dr. Janet E. Baulch became PI for this project at University of Maryland. In November of 2008, a one year extension with no new funds was requested to complete the proteomic analyses. The project stemmed from studies in the Morgan laboratory demonstrating that genomically unstable cells secret a soluble factor or factors into the culture medium, that cause cytogenetic aberrations and apoptosis in normal parental GM10115 cells. The purpose of this project was to identify the death inducing effect (DIE) factor or factors, estimate their relative abundance, identify the cell signaling pathways involved and finally recapitulate DIE in normal cells by exogenous manipulation of putative DIE factors in culture medium. As reported in detail in the previous progress report, analysis of culture medium from the parental cell line, and stable and unstable clones demonstrated inconsistent proteomic profiles as relate to candidate DIE factors. While the proposed proteomic analyses did not provide information that would allow DIE factors to be identified, the analyses provided another important set of observations. Proteomic analysis suggested that proteins associated with the cellular response to oxidative stress and mitochondrial function were elevated in the medium from unstable clones in a manner consistent with mitochondrial dysfunction. These findings correlate with previous studies of these clones that demonstrated functional differences between the mitochondria of stable and unstable clones. These mitochondrial abnormalities in the unstable clones contributes to oxidative stress.

  15. Quantifying the Impact of Immediate Reconstruction in Postmastectomy Radiation: A Large, Dose-Volume Histogram-Based Analysis

    SciTech Connect (OSTI)

    Ohri, Nisha [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Cordeiro, Peter G. [Department of Plastic Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Plastic Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Keam, Jennifer [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ballangrud, Ase [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shi Weiji; Zhang Zhigang [Department of Biostatistics and Epidemiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Biostatistics and Epidemiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Nerbun, Claire T.; Woch, Katherine M.; Stein, Nicholas F.; Zhou Ying [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); McCormick, Beryl; Powell, Simon N. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ho, Alice Y., E-mail: HoA1234@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-10-01T23:59:59.000Z

    Purpose: To assess the impact of immediate breast reconstruction on postmastectomy radiation (PMRT) using dose-volume histogram (DVH) data. Methods and Materials: Two hundred forty-seven women underwent PMRT at our center, 196 with implant reconstruction and 51 without reconstruction. Patients with reconstruction were treated with tangential photons, and patients without reconstruction were treated with en-face electron fields and customized bolus. Twenty percent of patients received internal mammary node (IMN) treatment. The DVH data were compared between groups. Ipsilateral lung parameters included V20 (% volume receiving 20 Gy), V40 (% volume receiving 40 Gy), mean dose, and maximum dose. Heart parameters included V25 (% volume receiving 25 Gy), mean dose, and maximum dose. IMN coverage was assessed when applicable. Chest wall coverage was assessed in patients with reconstruction. Propensity-matched analysis adjusted for potential confounders of laterality and IMN treatment. Results: Reconstruction was associated with lower lung V20, mean dose, and maximum dose compared with no reconstruction (all P<.0001). These associations persisted on propensity-matched analysis (all P<.0001). Heart doses were similar between groups (P=NS). Ninety percent of patients with reconstruction had excellent chest wall coverage (D95 >98%). IMN coverage was superior in patients with reconstruction (D95 >92.0 vs 75.7%, P<.001). IMN treatment significantly increased lung and heart parameters in patients with reconstruction (all P<.05) but minimally affected those without reconstruction (all P>.05). Among IMN-treated patients, only lower lung V20 in those without reconstruction persisted (P=.022), and mean and maximum heart doses were higher than in patients without reconstruction (P=.006, P=.015, respectively). Conclusions: Implant reconstruction does not compromise the technical quality of PMRT when the IMNs are untreated. Treatment technique, not reconstruction, is the primary determinant of target coverage and normal tissue doses.

  16. Ionization dynamics and radiative behavior of a betatron driven gold atom

    SciTech Connect (OSTI)

    Davis, J.; Petrova, Tz. B.; Whitney, K. G. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)] [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2014-03-15T23:59:59.000Z

    The study of inner-shell transitions induced by an intense (>10{sup 19}?W/cm{sup 2}) ultrashort (?5 fs) x-ray pulse provides a challenging opportunity to investigate the behavior and dynamics of hollow atoms and to explore the feasibility of creating population inversions in some of the inner-shell states that may lead to a variety of amplifications and gains in the x-ray regime. In this paper, we investigate the interaction through inner-shell photoionizations of a spectrally broad femtosecond pulse of betatron x-ray radiation incident on a gold atom. The level populations of Pt-like Au and Ir-like Au are described by non-(local thermodynamic equilibrium) inner-shell dynamics and compared and contrasted with the level populations created by a 'single' frequency x-ray laser pulse. Gain coefficients for a variety of transitions are calculated. It is found that long wavelength x-rays must be filtered from the betatron spectrum before any population inversions can be generated.

  17. Increased Radiation Dose to Overweight and Obese Patients from Radiographic Examinations

    E-Print Network [OSTI]

    Yanch, Jacquelyn C.

    Purpose: To estimate the increase in effective dose from diagnostic x-rays for overweight and obese adult patients compared with „lean? reference phantoms. Materials and Methods: Relative effective doses, E/E[subscript 0], ...

  18. Observation of a Dose-Control Relationship for Lung and Liver Tumors After Stereotactic Body Radiation Therapy

    SciTech Connect (OSTI)

    McCammon, Robert [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States)], E-mail: Robert.mccammon@uchsc.edu; Schefter, Tracey E.; Gaspar, Laurie E.; Zaemisch, Rebekah; Gravdahl, Daniel; Kavanagh, Brian [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States)

    2009-01-01T23:59:59.000Z

    Purpose: To determine prognostic factors for local control of primary or metastatic tumors within the lung or liver treated with stereotactic body radiation therapy (SBRT) within a single institution. Methods and Materials: The records of 141 consecutive patients with 246 lesions treated with three-fraction SBRT from Oct 1999 through Aug 2005 were reviewed. Local control was assessed radiographically. Univariate and multivariate analyses were performed to evaluate the influence of the following factors on local control: total dose, expressed as either nominal prescription dose or equivalent uniform dose (EUD); gross tumor volume; primary site; treatment site (lung vs. other); histologic characteristics (adenocarcinoma vs. other); gender; age; and primary vs. metastatic tumor. Results: On univariate analysis, increased dose (either nominal or EUD) and smaller gross tumor volume were significant predictors of higher local control. Lesions treated to a nominal dose of 54 Gy or greater had a 3-year actuarial local control rate of 89.3% compared with 59.0% and 8.1% for those treated to 36-53.9 Gy and less than 36 Gy. On multivariate analysis, only increased nominal dose and EUD retained statistical significance. Treatment was well tolerated; 5.7% of patients experienced Grade 3 or higher toxicity. Conclusions: This large single-institution series suggests a dose-control relationship within the range of SBRT doses applied. Excellent local control rates are achieved with a nominal dose of 54 Gy or greater, corresponding to an EUD greater than 65.3 Gy. These results support the use of aggressive SBRT regimens when durable tumor control is the primary objective.

  19. Comparison of Kodak EDR2 and Gafchromic EBT film for intensity-modulated radiation therapy dose distribution verification

    SciTech Connect (OSTI)

    Sankar, A. [Department of Radiation Oncology, Apollo Specialty Hospital, Chennai (India) and Department of Physics, Anna University, Chennai (India)]. E-mail: asankar_phy@yahoo.co.in; Ayyangar, Komanduri M. [Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE (United States); Nehru, R. Mothilal [Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE (United States); Gopalakrishna Kurup, P.G. [Department of Radiation Oncology, Apollo Specialty Hospital, Chennai (India); Murali, V. [Department of Radiation Oncology, Apollo Specialty Hospital, Chennai (India); Enke, Charles A. [Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE (United States); Velmurugan, J. [Department of Physics, Anna University, Chennai (India)

    2006-01-01T23:59:59.000Z

    The quantitative dose validation of intensity-modulated radiation therapy (IMRT) plans require 2-dimensional (2D) high-resolution dosimetry systems with uniform response over its sensitive region. The present work deals with clinical use of commercially available self-developing Radio Chromic Film, Gafchromic EBT film, for IMRT dose verification. Dose response curves were generated for the films using a VXR-16 film scanner. The results obtained with EBT films were compared with the results of Kodak extended dose range 2 (EDR2) films. The EBT film had a linear response between the dose range of 0 to 600 cGy. The dose-related characteristics of the EBT film, such as post irradiation color growth with time, film uniformity, and effect of scanning orientation, were studied. There was up to 8.6% increase in the color density between 2 to 40 hours after irradiation. There was a considerable variation, up to 8.5%, in the film uniformity over its sensitive region. The quantitative differences between calculated and measured dose distributions were analyzed using DTA and Gamma index with the tolerance of 3% dose difference and 3-mm distance agreement. The EDR2 films showed consistent results with the calculated dose distributions, whereas the results obtained using EBT were inconsistent. The variation in the film uniformity limits the use of EBT film for conventional large-field IMRT verification. For IMRT of smaller field sizes (4.5 x 4.5 cm), the results obtained with EBT were comparable with results of EDR2 films.

  20. Radiation doses in cone-beam breast computed tomography: A Monte Carlo simulation study

    SciTech Connect (OSTI)

    Yi Ying; Lai, Chao-Jen; Han Tao; Zhong Yuncheng; Shen Youtao; Liu Xinming; Ge Shuaiping; You Zhicheng; Wang Tianpeng; Shaw, Chris C. [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2011-02-15T23:59:59.000Z

    Purpose: In this article, we describe a method to estimate the spatial dose variation, average dose and mean glandular dose (MGD) for a real breast using Monte Carlo simulation based on cone beam breast computed tomography (CBBCT) images. We present and discuss the dose estimation results for 19 mastectomy breast specimens, 4 homogeneous breast models, 6 ellipsoidal phantoms, and 6 cylindrical phantoms. Methods: To validate the Monte Carlo method for dose estimation in CBBCT, we compared the Monte Carlo dose estimates with the thermoluminescent dosimeter measurements at various radial positions in two polycarbonate cylinders (11- and 15-cm in diameter). Cone-beam computed tomography (CBCT) images of 19 mastectomy breast specimens, obtained with a bench-top experimental scanner, were segmented and used to construct 19 structured breast models. Monte Carlo simulation of CBBCT with these models was performed and used to estimate the point doses, average doses, and mean glandular doses for unit open air exposure at the iso-center. Mass based glandularity values were computed and used to investigate their effects on the average doses as well as the mean glandular doses. Average doses for 4 homogeneous breast models were estimated and compared to those of the corresponding structured breast models to investigate the effect of tissue structures. Average doses for ellipsoidal and cylindrical digital phantoms of identical diameter and height were also estimated for various glandularity values and compared with those for the structured breast models. Results: The absorbed dose maps for structured breast models show that doses in the glandular tissue were higher than those in the nearby adipose tissue. Estimated average doses for the homogeneous breast models were almost identical to those for the structured breast models (p=1). Normalized average doses estimated for the ellipsoidal phantoms were similar to those for the structured breast models (root mean square (rms) percentage difference=1.7%; p=0.01), whereas those for the cylindrical phantoms were significantly lower (rms percentage difference=7.7%; p<0.01). Normalized MGDs were found to decrease with increasing glandularity. Conclusions: Our results indicate that it is sufficient to use homogeneous breast models derived from CBCT generated structured breast models to estimate the average dose. This investigation also shows that ellipsoidal digital phantoms of similar dimensions (diameter and height) and glandularity to actual breasts may be used to represent a real breast to estimate the average breast dose with Monte Carlo simulation. We have also successfully demonstrated the use of structured breast models to estimate the true MGDs and shown that the normalized MGDs decreased with the glandularity as previously reported by other researchers for CBBCT or mammography.

  1. Assessment of effectiveness of geologic isolation systems. ARRRG and FOOD: computer programs for calculating radiation dose to man from radionuclides in the environment

    SciTech Connect (OSTI)

    Napier, B.A.; Roswell, R.L.; Kennedy, W.E. Jr.; Strenge, D.L.

    1980-06-01T23:59:59.000Z

    The computer programs ARRRG and FOOD were written to facilitate the calculation of internal radiation doses to man from the radionuclides in the environment and external radiation doses from radionuclides in the environment. Using ARRRG, radiation doses to man may be calculated for radionuclides released to bodies of water from which people might obtain fish, other aquatic foods, or drinking water, and in which they might fish, swim or boat. With the FOOD program, radiation doses to man may be calculated from deposition on farm or garden soil and crops during either an atmospheric or water release of radionuclides. Deposition may be either directly from the air or from irrigation water. Fifteen crop or animal product pathways may be chosen. ARRAG and FOOD doses may be calculated for either a maximum-exposed individual or for a population group. Doses calculated are a one-year dose and a committed dose from one year of exposure. The exposure is usually considered as chronic; however, equations are included to calculate dose and dose commitment from acute (one-time) exposure. The equations for calculating internal dose and dose commitment are derived from those given by the International Commission on Radiological Protection (ICRP) for body burdens and Maximum Permissible Concentration (MPC) of each radionuclide. The radiation doses from external exposure to contaminated farm fields or shorelines are calculated assuming an infinite flat plane source of radionuclides. A factor of two is included for surface roughness. A modifying factor to compensate for finite extent is included in the shoreline calculations.

  2. Lack of benefit of pelvic radiation in prostate cancer patients with a high risk of positive pelvic lymph nodes treated with high-dose radiation

    SciTech Connect (OSTI)

    Vargas, Carlos Enrique [William Beaumont Hospital, Royal Oak, MI (United States); Galalae, Razavan [Kiel University Hospital, Kiel (Germany); Demanes, Jeffrey [California Endocuritherapy Cancer Center, Oakland, CA (United States); Harsolia, Asif [William Beaumont Hospital, Royal Oak, MI (United States); Meldolesi, Elisa [William Beaumont Hospital, Royal Oak, MI (United States); Nuernberg, Nils [Municipal Hospital Kiel, Kiel (Germany); Schour, Lionel [California Endocuritherapy Cancer Center, Oakland, CA (United States); Martinez, Alvaro [William Beaumont Hospital, Royal Oak, MI (United States)]. E-mail: amartinez@beaumont.edu

    2005-12-01T23:59:59.000Z

    Purpose: The use of pelvic radiation for patients with a high risk of lymph node (LN) metastasis (>15%) remains controversial. We reviewed the data at three institutions treating patients with a combination of external-beam radiation therapy and high-dose-rate brachytherapy to address the prognostic implications of the use of the Roach formula and the benefit of pelvic treatment. Methods and Materials: From 1986 to 2003, 1,491 patients were treated with external-beam radiation therapy and high-dose-rate brachytherapy. The Roach formula [2/3 prostate-specific antigen + (Gleason score -6) x 10] could be calculated for 1,357 patients. Group I consisted of patients having a risk of positive LN {<=}15% (n = 761), Group II had a risk >15% and {<=}30% (n = 422), and Group III had a risk of LN disease >30% (n 174). A >15% risk of having positive LN was found in 596 patients and was used to determine the benefit of pelvic radiation. The pelvis was treated at two of the cancer centers (n = 312), whereas at the third center (n = 284) radiation therapy was delivered to the prostate and seminal vesicles alone. Average biologic effective dose was {>=}100 Gy ({alpha}{beta} = 1.2). Biochemical failure was as per the American Society for Therapeutic Radiology and Oncology definition. Statistics included the log-rank test as well as Cox univariate and multivariate analysis. Results: For all 596 patients with a positive LN risk >15%, median follow-up was 4.3 years, with a mean of 4.8 years. For all cases, median follow-up was 4 years and mean follow-up was 4.4 years. Five-year results for the three groups based on their risk of positive LN were significantly different in terms of biochemical failure (p < 0.001), clinical control (p < 0.001), disease-free survival excluding biochemical failure (p < 0.001), cause-specific survival (p < 0.001), and overall survival (p < 0.001). For all patients with a risk of positive LN >15% (n 596), Group II (>15-30% risk), or Group III (>30% risk), no benefit was seen in the 5-year rates of clinical failure, cause-specific survival, or overall survival with pelvic radiation. In the Cox multivariate analysis for cause-specific survival, Gleason score (p = 0.009, hazard ratio [HR] 3.1), T stage (p = 0.03, HR 1.8), and year of treatment (p = 0.05, HR 1.1) were significant. A log-rank test for cause-specific survival for all patients (n = 577) by the use of pelvic radiation was not significant (p = 0.99) accounting for high-dose-rate brachytherapy dose, neoadjuvant hormones, Gleason score, prostate-specific antigen, T stage, and year of treatment as covariates. Conclusions: The use of the Roach formula to stratify patients for clinical and biochemical outcomes is excellent. Pelvic radiation added to high prostate radiation doses did not show a clinical benefit for patients at a high risk of pelvic LN disease (>15%) selected using the Roach formula.

  3. SU-C-12A-03: The Impact of Contrast Medium On Radiation Dose in CT: A Systematic Evaluation Across 58 Patient Models

    SciTech Connect (OSTI)

    Sahbaee, P [NC State University, Raleigh, NC (United States); Samei, E [Duke University Medical Center, Durham, NC (United States); Segars, W [Duke University, Durham, NC (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To assess the effect of contrast medium on radiation dose as a function of time via Monte Carlo simulation from the liver CT scan across a library of 5D XCAT models Methods: A validated Monte Carlo simulation package (PENELOPE) was employed to model a CT system (LightSpeed 64 VCT, GE Healthcare). The radiation dose was estimated from a common abdomen CT examination. The dose estimation was performed on a library of adult extended cardiac-torso (5D XCAT) phantoms (35 male, 23 female, mean age 51.5 years, mean weight 80.2 kg). The 5D XCAT models were created based on patient-specific iodine concentration-time results from our computational contrast medium propagation model for different intravenous injection protocols. To enable a dynamic estimation of radiation dose, each organ in the model was assigned to its own time-concentration curve via the PENELOPE package, material.exe. Using the Monte Carlo, for each scan time point after the injection, 80 million photons were initiated and tracked through the phantoms. Finally, the dose to the liver was tallied from the deposited energy. Results: Monte Carlo simulation results of radiation dose delivered to the liver from the XCAT models indicated up to 30% increase in dose for different time after the administration of contrast medium. Conclusion: The contrast enhancement is employed in over 60% of imaging modalities, which not only remarkably affects the CT image quality, but also increases the radiation dose by as much as 70%. The postinjection multiple acquisition in several enhanced CT protocols, makes the radiation dose increment through the use of contrast medium, an inevitable factor in optimization of these protocols. The relationship between radiation dose and injected contrast medium as a function of time studied in this work allows optimization of contrast administration for vulnerable individuals.

  4. Ionizing Radiation Detector

    DOE Patents [OSTI]

    Wright, Gomez W. (Nashville, TN); James, Ralph B. (Livermore, CA); Burger, Arnold (Nashville, TN); Chinn, Douglas A. (Livermore, CA)

    2003-11-18T23:59:59.000Z

    A CdZnTe (CZT) crystal provided with a native CdO dielectric coating to reduce surface leakage currents and thereby, improve the resolution of instruments incorporating detectors using CZT crystals is disclosed. A two step process is provided for forming the dielectric coating which includes etching the surface of a CZT crystal with a solution of the conventional bromine/methanol etch treatment, and passivating the CZT crystal surface with a solution of 10 w/o NH.sub.4 F and 10 w/o H.sub.2 O.sub.2 in water after attaching electrical contacts to the crystal surface.

  5. Low Dose Suppression of Neoplastic Transformation in Vitro

    SciTech Connect (OSTI)

    John Leslie Redpath

    2012-05-01T23:59:59.000Z

    This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

  6. Biological in situ Dose Painting for Image-Guided Radiation Therapy Using Drug-Loaded Implantable Devices

    SciTech Connect (OSTI)

    Cormack, Robert A. [Department of Radiation Oncology, Dana Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts (United States); Sridhar, Srinivas [Electronics Materials Research Institute, Northeastern University, and Department of Physics, Northeastern University, Boston, Massachusetts (United States); Suh, W. Warren; D'Amico, Anthony V. [Department of Radiation Oncology, Dana Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts (United States); Makrigiorgos, G. Mike, E-mail: mmakrigiorgos@lroc.harvard.ed [Department of Radiation Oncology, Dana Farber Cancer Institute, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts (United States)

    2010-02-01T23:59:59.000Z

    Purpose: Implantable devices routinely used for increasing spatial accuracy in modern image-guided radiation treatments (IGRT), such as fiducials or brachytherapy spacers, encompass the potential for in situ release of biologically active drugs, providing an opportunity to enhance the therapeutic ratio. We model this new approach for two types of treatment. Methods and Materials: Radiopaque fiducials used in IGRT, or prostate brachytherapy spacers ('eluters'), were assumed to be loaded with radiosensitizer for in situ drug slow release. An analytic function describing the concentration of radiosensitizer versus distance from eluters, depending on diffusion-elimination properties of the drug in tissue, was developed. Tumor coverage by the drug was modeled for tumors typical of lung stereotactic body radiation therapy treatments for various eluter dimensions and drug properties. Six prostate {sup 125}I brachytherapy cases were analyzed by assuming implantation of drug-loaded spacers. Radiosensitizer-induced subvolume boost was simulated from which biologically effective doses for typical radiosensitizers were calculated in one example. Results: Drug distributions from three-dimensional arrangements of drug eluters versus eluter size and drug properties were tabulated. Four radiosensitizer-loaded fiducials provide adequate radiosensitization for {approx}4-cm-diameter lung tumors, thus potentially boosting biologically equivalent doses in centrally located stereotactic body treated lesions. Similarly, multiple drug-loaded spacers provide prostate brachytherapy with flexible shaping of 'biologically equivalent doses' to fit requirements difficult to meet by using radiation alone, e.g., boosting a high-risk region juxtaposed to the urethra while respecting normal tissue tolerance of both the urethra and the rectum. Conclusions: Drug loading of implantable devices routinely used in IGRT provides new opportunities for therapy modulation via biological in situ dose painting.

  7. Randomized, Multicenter Trial on the Effect of Radiation Therapy on Plantar Fasciitis (Painful Heel Spur) Comparing a Standard Dose With a Very Low Dose: Mature Results After 12 Months' Follow-Up

    SciTech Connect (OSTI)

    Niewald, Marcus, E-mail: marcus.niewald@uks.eu [Department of Radiation Oncology, Saarland University Medical Center, Homburg/Saar (Germany)] [Department of Radiation Oncology, Saarland University Medical Center, Homburg/Saar (Germany); Seegenschmiedt, M. Heinrich [Radiotherapy Center, Hamburg (Germany)] [Radiotherapy Center, Hamburg (Germany); Micke, Oliver [Franziskus Hospital, Bielefeld (Germany)] [Franziskus Hospital, Bielefeld (Germany); Graeber, Stefan [Institute for Medical Biometry, Epidemiology and Medical Informatics, Saarland University Medical Center, Homburg/Saar (Germany)] [Institute for Medical Biometry, Epidemiology and Medical Informatics, Saarland University Medical Center, Homburg/Saar (Germany); Muecke, Ralf [Lippe Hospital, Lemgo (Germany)] [Lippe Hospital, Lemgo (Germany); Schaefer, Vera; Scheid, Christine; Fleckenstein, Jochen; Licht, Norbert; Ruebe, Christian [Department of Radiation Oncology, Saarland University Medical Center, Homburg/Saar (Germany)] [Department of Radiation Oncology, Saarland University Medical Center, Homburg/Saar (Germany)

    2012-11-15T23:59:59.000Z

    Purpose: To conduct a randomized trial of radiation therapy for painful heel spur, comparing a standard dose with a very low dose. Methods and Materials: Sixty-six patients were randomized to receive radiation therapy either with a total dose of 6.0 Gy applied in 6 fractions of 1.0 Gy twice weekly (standard dose) or with a total dose of 0.6 Gy applied in 6 fractions of 0.1 Gy twice weekly (low dose). In all patients lateral opposing 4- to 6-MV photon beams were used. The results were measured using a visual analogue scale, the Calcaneodynia score, and the SF12 health survey. The fundamental phase of the study ended after 3 months, and the follow-up was continued up to 1 year. Patients with insufficient pain relief after 3 months were offered reirradiation with the standard dosage at any time afterward. Results: Of 66 patients, 4 were excluded because of withdrawal of consent or screening failures. After 3 months the results in the standard arm were highly significantly superior compared with those in the low-dose arm (visual analogue scale, P=.001; Calcaneodynia score, P=.027; SF12, P=.045). The accrual of patients was stopped at this point. Further evaluation after 12 months' follow-up showed the following results: (1) highly significant fewer patients were reirradiated in the standard arm compared with the low-dose arm (P<.001); (2) the results of patients in the low-dose arm who were reirradiated were identical to those in the standard arm not reirradiated (reirradiation as a salvage therapy if the lower dose was ineffective); (3) patients experiencing a favorable result after 3 months showed this even after 12 months, and some results even improved further between 3 and 12 months. Conclusions: This study confirms the superior analgesic effect of radiation therapy with 6-Gy doses on painful heel spur even for a longer time period of at least 1 year.

  8. Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA. Volume 8

    SciTech Connect (OSTI)

    Sullivan, S.G.; Khan, T.A.; Xie, J.W. [Brookhaven National Lab., Upton, NY (United States)

    1995-05-01T23:59:59.000Z

    The ALARA Center at Brookhaven National Laboratory publishes a series of bibliographies of selected readings in radiation protection and ALARA in a continuing effort to collect and disseminate information on radiation dose reduction at nuclear power plants. This volume 8 of the series. The abstracts in this bibliography were selected form proceedings of technical meetings and conference journals, research reports, and searches of the Energy Science and Technology database of the US Department of Energy. The subject material of these abstracts relates to the many aspects of radiation protection and dose reduction, and ranges form use of robotics, to operational health physics, to water chemistry. Material on the design, planning, and management of nuclear power stations is included, as well as information on decommissioning and safe storage efforts. Volume 8 contains 232 abstracts, an author index, and a subject index. The author index is specific for this volume. The subject index is cumulative and lists all abstract numbers from volumes 1 to 8. The numbers in boldface indicate the abstracts in this volume; the numbers not in boldface represent abstracts in previous volumes.

  9. Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA. Volume 7

    SciTech Connect (OSTI)

    Kaurin, D.G.; Khan, T.A.; Sullivan, S.G.; Baum, J.W. [Brookhaven National Lab., Upton, NY (United States)

    1993-07-01T23:59:59.000Z

    The ALARA Center at Brookhaven National Laboratory publishes a series of bibliographies of selected readings in radiation protection and ALARA in the continuing effort to collect and disseminate information on radiation dose reduction at nuclear power plants. This is volume 7 of the series. The abstracts in this bibliography were selected from proceedings of technical meetings and conferences, journals, research reports, and searches of the Energy Science and Technology database of the US Department of Energy. The subject material of these abstracts relates to radiation protection and dose reduction, and ranges from use of robotics to operational health physics, to water chemistry. Material on the design, planning, and management of nuclear power stations is included, as well as information on decommissioning and safe storage efforts. Volume 7 contains 293 abstract, an author index, and a subject index. The author index is specific for this volume. The subject index is cumulative and lists all abstract numbers from volumes 1 to 7. The numbers in boldface indicate the abstracts in this volume; the numbers not in boldface represent abstracts in previous volumes.

  10. Threshold sensor for high-doses of radiation I. Augustyniak, P. Knapkiewicz, J. Dziuban

    E-Print Network [OSTI]

    Boyer, Edmond

    radiation, HDPE degrades and releases atomic hydrogen. The resulting pressure of hydrogen destroys thin are also observed in experimental infrastructures for example LHC where level of radiation is low but long by family of passive thermo- and photoluminescence indicators or hydrogen pressure dosimeters. In situ

  11. Predictive Models for Regional Hepatic Function Based on 99mTc-IDA SPECT and Local Radiation Dose for Physiologic Adaptive Radiation Therapy

    SciTech Connect (OSTI)

    Wang, Hesheng, E-mail: hesheng@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Frey, Kirk A. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Ten Haken, Randall K.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)

    2013-08-01T23:59:59.000Z

    Purpose: High-dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed before and during the course of RT using 99mTc-labeled iminodiacetic acid (IDA) single photon emission computed tomography (SPECT) could predict regional liver function reserve after RT. Methods and Materials: Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans before RT, during, and 1 month after completion of RT. Indocyanine green (ICG) tests, a measure of overall liver function, were performed within 1 day of each scan. Three-dimensional volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After coregistration of the CT/SPECT and the treatment planning CT, HEF dose–response functions during and after RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, dose, priori, and adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function after RT. Results: The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r=?0.80, P<.0001), for all time points. Linear correlations between local doses and regional HEFs 1 month after RT were significant in 12 patients. In the priori model, regional HEF after RT was predicted by the planned dose and regional HEF assessed before RT (R=0.71, P<.0001). In the adaptive model, regional HEF after RT was predicted by regional HEF reassessed during RT and the remaining planned local dose (R=0.83, P<.0001). Conclusions: 99mTc-IDA SPECT obtained during RT could be used to assess regional hepatic function and helped predict post-RT regional liver function reserve. This could support individualized adaptive radiation treatment strategies to maximize tumor control and minimize the risk of liver damage.

  12. Correlation of radiation absorbed dose to the human thyroid using the FBX dosimeter and external probe techniques

    E-Print Network [OSTI]

    Bateman, Sarah Caroline Louisa

    1986-01-01T23:59:59.000Z

    . Nuclear Regulatory Commission provides the criteria under which an in-vivo external probe bioassay program for those occupationally exposed to '- I and '" I should be implemented (USNRC79). This is the basis for the Texas A&M University bioassay program... present in the thyroid. Determination of the radiation absorbed dose to the thyroid gland from a known activity of radioiodine present in the thyroid is necessary from both a safety and regulatory standpoint. Regulatory Guide 8. 20, issued by the U. S...

  13. Radiation Dose Is More Than A Number Workshop 15-16 September 2011

    E-Print Network [OSTI]

    or Water Contamination Nuclear detonation Accident ­ Power Plant Release ­ Sealed radiological sources;Radiation Countermeasure Mission Space Radionuclide Threats ­ Am-241 ­ Co-60 ­ Cs-137 ­ I-131 ­ Ir-192 ­ Po

  14. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, P.B.; Looney, L.D.

    1993-11-30T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  15. Enhanced radiation resistant fiber optics

    DOE Patents [OSTI]

    Lyons, Peter B. (Los Alamos, NM); Looney, Larry D. (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

  16. MEASUREMENT OF THE HIGH GAMMA RADIATION DOSE USING THE MEMS BASED DOSIMETER AND RADIOLISYS EFFECT

    E-Print Network [OSTI]

    Boyer, Edmond

    Power Plants (NPP) and high energy physics facilities as Large Hadron Collider (LHC). All in the world and about 50 under construction, we are all concern about the safety operation of these facilities due to the cumulative absorbed dose. Needless to say that the typical NPP of 3rd generation

  17. Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures

    SciTech Connect (OSTI)

    Scott, Bobby, R., Ph.D.

    2003-06-27T23:59:59.000Z

    OAK - B135 This project final report summarizes modeling research conducted in the U.S. Department of Energy (DOE), Low Dose Radiation Research Program at the Lovelace Respiratory Research Institute from October 1998 through June 2003. The modeling research described involves critically evaluating the validity of the linear nonthreshold (LNT) risk model as it relates to stochastic effects induced in cells by low doses of ionizing radiation and genotoxic chemicals. The LNT model plays a central role in low-dose risk assessment for humans. With the LNT model, any radiation (or genotoxic chemical) exposure is assumed to increase one¡¯s risk of cancer. Based on the LNT model, others have predicted tens of thousands of cancer deaths related to environmental exposure to radioactive material from nuclear accidents (e.g., Chernobyl) and fallout from nuclear weapons testing. Our research has focused on developing biologically based models that explain the shape of dose-response curves for low-dose radiation and genotoxic chemical-induced stochastic effects in cells. Understanding the shape of the dose-response curve for radiation and genotoxic chemical-induced stochastic effects in cells helps to better understand the shape of the dose-response curve for cancer induction in humans. We have used a modeling approach that facilitated model revisions over time, allowing for timely incorporation of new knowledge gained related to the biological basis for low-dose-induced stochastic effects in cells. Both deleterious (e.g., genomic instability, mutations, and neoplastic transformation) and protective (e.g., DNA repair and apoptosis) effects have been included in our modeling. Our most advanced model, NEOTRANS2, involves differing levels of genomic instability. Persistent genomic instability is presumed to be associated with nonspecific, nonlethal mutations and to increase both the risk for neoplastic transformation and for cancer occurrence. Our research results, based on applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always ¡Ý 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR < 1 may be more the rule than the exception. Directly tied to the current RR paradigm are the billion-dollar cleanup costs for radionuclide-contaminated DOE sites. Our research results suggest that continued use of the current RR paradigm for which RR ¡Ý 1 could cause more harm than benefit to society (e.g., by spreading unwarranted fear about phantom excess risks associated with low-dose low-LET radiation). Such phantom risks also may arise from risk assessments conducted for com

  18. Dose-dependent misrejoining of radiation-induced DNA double-strand breaks in human fibroblasts: Experimental and theoretical study for high and low LET radiation

    E-Print Network [OSTI]

    Rydberg, Bjorn; Cooper, Brian; Cooper, Priscilla K.; Holley, William; Chatterjee, Aloke

    2004-01-01T23:59:59.000Z

    S. Kim, and R. M. Myers. Radiation hybrid mapping: a somaticformulation of dual radiation action. Radiat. Res. 75: 471-High-Linear Energy Transfer Radiation in Human Fibroblasts.

  19. Dose reconstruction for the Urals population. Joint Coordinating Committee on Radiation Effects Research, Project 1.1 -- Final report

    SciTech Connect (OSTI)

    Degteva, M.O. [Urals Research Center for Radiation Medicine, Chelyabinsk (Russian Federation)] [Urals Research Center for Radiation Medicine, Chelyabinsk (Russian Federation); Drozhko, E. [Branch 1 of Moscow Biophysics Inst., Ozersk (Russian Federation)] [Branch 1 of Moscow Biophysics Inst., Ozersk (Russian Federation); Anspaugh, L.R. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); Napier, B.A. [Pacific Northwest National Lab., Richland, WA (United States)] [Pacific Northwest National Lab., Richland, WA (United States); Bouville, A.C. [National Cancer Inst., Bethesda, MD (United States)] [National Cancer Inst., Bethesda, MD (United States); Miller, C.W. [Centers for Disease Control and Prevention, Atlanta, GA (United States)] [Centers for Disease Control and Prevention, Atlanta, GA (United States)

    1996-02-01T23:59:59.000Z

    This work is being carried out as a feasibility study to determine if a long-term course of work can be implemented to assess the long-term risks of radiation exposure delivered at low to moderate dose rates to the populations living in the vicinity of the Mayak Industrial Association (MIA). This work was authorized and conducted under the auspices of the US-Russian Joint Coordinating Committee on Radiation Effects Research (JCCRER) and its Executive Committee (EC). The MIA was the first Russian site for the production and separation of plutonium. This plant began operation in 1948, and during its early days there were technological failures that resulted in the release of large amounts of waste into the rather small Techa River. There were also gaseous releases of radioiodines and other radionuclides during the early days of operation. In addition, there was an accidental explosion in a waste storage tank in 1957 that resulted in a significant release. The Techa River Cohort has been studied for several years by scientists from the Urals Research Centre for Radiation Medicine and an increase in both leukemia and solid tumors has been noted.

  20. Radiation dose assessments to support evaluations of radiological control levels for recycling or reuse of materials and equipment

    SciTech Connect (OSTI)

    Hill, R.L.; Aaberg, R.L.; Baker, D.A.; Kennedy, W.E. Jr.

    1995-07-01T23:59:59.000Z

    Pacific Northwest Laboratory is providing Environmental Protection Support and Assistance to the USDOE, Office of Environmental Guidance. Air, Water, and Radiation Division. As part of this effort, PNL is collecting data and conducting technical evaluations to support DOE analyses of the feasibility of developing radiological control levels for recycling or reuse of metals, concrete, or equipment containing residual radioactive contamination from DOE operations. The radiological control levels will be risk-based, as developed through a radiation exposure scenario and pathway analysis. The analysis will include evaluation of relevant radionuclides, potential mechanisms of exposure, and both health and non-health-related impacts. The main objective of this report is to develop a methodology for establishing radiological control levels for recycle or reuse. This report provides the results of the radiation exposure scenario and pathway analyses for 42 key radionuclides generated during DOE operations that may be contained in metals or equipment considered for either recycling or reuse. The scenarios and information developed by the IAEA. Application of Exemption Principles to the Recycle and Reuse of Materials from Nuclear Facilities, are used as the initial basis for this study. The analyses were performed for both selected worker populations at metal smelters and for the public downwind of a smelter facility. Doses to the public downwind were estimated using the US (EPA) CAP88-PC computer code with generic data on atmospheric dispersion and population density. Potential non-health-related effects of residual activity on electronics and on film were also analyzed.

  1. Causes of Mortality After Dose-Escalated Radiation Therapy and Androgen Deprivation for High-Risk Prostate Cancer

    SciTech Connect (OSTI)

    Tendulkar, Rahul D., E-mail: tendulr@ccf.org [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Hunter, Grant K. [Department of Radiation Oncology, Intermountain Healthcare, Salt Lake City, Utah (United States); Reddy, Chandana A.; Stephans, Kevin L.; Ciezki, Jay P.; Abdel-Wahab, May [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Stephenson, Andrew J.; Klein, Eric A. [Department of Urology, Glickman Urological Institute, Cleveland Clinic, Cleveland, Ohio (United States); Mahadevan, Arul [Seacoast Cancer Center New Hampshire, Dover, New Hampshire (United States); Kupelian, Patrick A. [Department of Radiation Oncology, University of California Los Angeles Health System, Los Angeles, California (United States)

    2013-09-01T23:59:59.000Z

    Purpose: Men with high-risk prostate cancer have other competing causes of mortality; however, current risk stratification schema do not account for comorbidities. We aim to identify the causes of death and factors predictive for mortality in this population. Methods and Materials: A total of 660 patients with high-risk prostate cancer were treated with definitive high-dose external beam radiation therapy (?74 Gy) and androgen deprivation (AD) between 1996 and 2009 at a single institution. Cox proportional hazards regression analysis was conducted to determine factors predictive of survival. Results: The median radiation dose was 78 Gy, median duration of AD was 6 months, and median follow-up was 74 months. The 10-year overall survival (OS) was 60.6%. Prostate cancer was the leading single cause of death, with 10-year mortality of 14.1% (95% CI 10.7-17.6), compared with other cancers (8.4%, 95% CI 5.7-11.1), cardiovascular disease (7.3%, 95% CI 4.7-9.9), and all other causes (10.4%, 95% CI 7.2-13.6). On multivariate analysis, older age (HR 1.55, P=.002) and Charlson comorbidity index score (CS) ?1 (HR 2.20, P<.0001) were significant factors predictive of OS, whereas Gleason score, T stage, prostate-specific antigen, duration of AD, radiation dose, smoking history, and body mass index were not. Men younger than 70 years of age with CS = 0 were more likely to die of prostate cancer than any other cause, whereas older men or those with CS ?1 more commonly suffered non-prostate cancer death. The cumulative incidences of prostate cancer-specific mortality were similar regardless of age or comorbidities (P=.60). Conclusions: Men with high-risk prostate cancer are more likely to die of causes other than prostate cancer, except for the subgroup of men younger than 70 years of age without comorbidities. Only older age and presence of comorbidities significantly predicted for OS, whereas prostate cancer- and treatment-related factors did not.

  2. A preliminary model of the circulating blood for use in radiation dose calculations 

    E-Print Network [OSTI]

    Hui, Tsz-Yik Edmond

    1986-01-01T23:59:59.000Z

    . , 1968) "Distribution of Dose in the Body for a Source of Gamma Rays Distributed Uniformly in an Organ, " Oak Rdige National Laboratory, Oak Ridge, TN, ORNL-4168. Folkow B ~ and Neil E ~ g 1971' Circulation (New York: Oxford University Press... Phantom, Oak Ridge National Laboratory, Oak Ridge, TN, ORNL-TM-2250. Wa84 Watson E. E. , Stabin M. G. and Bolch W. E. , 1984, HIRDOSE, Oak Ridge Associated Universities, Oak Ridge/ TN. 53 Va80 van Reenen O. R. , Lotter M. G. , Minnaar P. C. , Heyns A...

  3. I. IONIZATION COOLING A. Introduction

    E-Print Network [OSTI]

    McDonald, Kirk

    ionization cooling techniques to reduce the 6­dimensional phase space emittance. B. Cooling TheoryI. IONIZATION COOLING A. Introduction The muon beam at the end of the decay channel is very intense for beam cooling. Cooling by synchrotron radiation, conventional stochastic cooling and conventional

  4. Amorphous silicon ionizing particle detectors

    DOE Patents [OSTI]

    Street, R.A.; Mendez, V.P.; Kaplan, S.N.

    1988-11-15T23:59:59.000Z

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation. 15 figs.

  5. Amorphous silicon ionizing particle detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Mendez, Victor P. (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    1988-01-01T23:59:59.000Z

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.

  6. Statistical effects of dose deposition in track-structure modelling of radiobiology efficiency

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    : Track-structure model, cell survival, high LET, ions, theory, simulation Abstract: Ion-induced cell. In this paper we focus on two approaches developed and extensively used to predict cell survival in response dose deposition statistics. A INTRODUCTION Cell survival to ionizing radiations is a relevant

  7. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1991--November 30, 1992

    SciTech Connect (OSTI)

    Hall, E.J.

    1992-05-01T23:59:59.000Z

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent.

  8. Experimental and Simulation of Gamma Radiation Dose Rate for High Exposure Building Material

    E-Print Network [OSTI]

    Abbasi, Akbar

    2015-01-01T23:59:59.000Z

    Natural radioactivity concentrations in high exposure building materials are commonly used in Iran, which is measured a direct exposure by using {\\gamma}-ray spectrometry. The values for 226Ra, 232Th and 40K were in the ranges 3.8 - 94.2, 6.5 - 172.2 and 556.9 - 1539.2 Bqkg-1, respectively. The absorbed dose rates in the standard dwelling room due to 238U, 232Th series and 40K were calculated with MCNPX code. The simulation and experimental results were between 7.95 - 41.74 and 8.36 - 39.99 nGy h-1, respectively. These results were compared with experimental outing and there was overlap closely. The simulation results are able to develop for any kind of dwelling places.

  9. Experimental and Simulation of Gamma Radiation Dose Rate for High Exposure Building Material

    E-Print Network [OSTI]

    Akbar Abbasi; Mustfa Hassanzadeh

    2014-10-27T23:59:59.000Z

    Natural radioactivity concentrations in high exposure building materials are commonly used in Iran, which is measured a direct exposure by using {\\gamma}-ray spectrometry. The values for 226Ra, 232Th and 40K were in the ranges 3.8 - 94.2, 6.5 - 172.2 and 556.9 - 1539.2 Bqkg-1, respectively. The absorbed dose rates in the standard dwelling room due to 238U, 232Th series and 40K were calculated with MCNPX code. The simulation and experimental results were between 7.95 - 41.74 and 8.36 - 39.99 nGy h-1, respectively. These results were compared with experimental outing and there was overlap closely. The simulation results are able to develop for any kind of dwelling places.

  10. Radiation Doses to the Public From the Transport of Spent Nuclear Fuel

    SciTech Connect (OSTI)

    Best, R. E.; Maheras, S. J.; Ross, S. S.; Weiner, R.

    2003-02-25T23:59:59.000Z

    This paper reviews issues that have been raised concerning radiological risks and safety of the public exposed to shipments of spent nuclear fuel and high-level radioactive waste to a Yucca Mountain repository. It presents and analyzes the contrasting viewpoints of opponents and proponents, presents facts about radiological exposures and risks, and provides perspective from which to observe the degree of risk that would devolve from the shipments. The paper concludes that the risks to the public's health and safety from being exposed to radiation from the shipments will not be discernable.

  11. Radiation dose delivered to the proximal penis as a predictor of the risk of erectile dysfunction after three-dimensional conformal radiotherapy for localized prostate cancer

    SciTech Connect (OSTI)

    Wernicke, A. Gabriella [Department of Radiation Oncology, Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Valicenti, Richard [Department of Radiation Oncology, Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania (United States)]. E-mail: richard.valicenti@mail.tju.edu; DiEva, Kelly [Department of Radiation Oncology, Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Houser, Christopher [Department of Radiation Oncology, Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Pequignot, Ed [Department of Medicine, Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA (United States)

    2004-12-01T23:59:59.000Z

    Purpose/objective: In this study, we evaluated in a serial manner whether radiation dose to the bulb of the penis is predictive of erectile dysfunction, ejaculatory difficulty (EJ), and overall satisfaction with sex life (quality of life) by using serial validated self-administered questionnaires. Methods and materials: Twenty-nine potent men with AJCC Stage II prostate cancer treated with three-dimensional conformal radiation therapy alone to a median dose 72.0 Gy (range: 66.6-79.2 Gy) were evaluated by determining the doses received by the penile bulb. The penile bulb was delineated volumetrically, and the dose-volume histogram was obtained on each patient. Results: The median follow-up time was 35 months (range, 16-43 months). We found that for D{sub 30}, D{sub 45}, D{sub 60}, and D{sub 75} (doses to a percent volume of PB: 30%, 45%, 60%, and 75%), higher than the corresponding median dose (defined as high-dose group) correlated with an increased risk of impotence (erectile dysfunction firmness score = 0) (odds ratio [OR] = 7.5, p = 0.02; OR = 7.5, p = 0.02; OR = 8.6, p = 0.008; and OR = 6.9, p = 0.015, respectively). Similarly, for EJD D{sub 30}, D{sub 45}, D{sub 60}, and D{sub 75}, doses higher than the corresponding median ones correlated with worsening ejaculatory function score (EJ = 0 or 1) (OR = 8, p = 0.013; OR = 8, p 0.013; OR = 9.2, p = 0.015; and OR = 8, p = 0.026, respectively). For quality of life, low ({<=}median dose) dose groups of patients improve over time, whereas high-dose groups of patients worsen. Conclusions: This study supports the existence of a penile bulb dose-volume relationship underlying the development of radiation-induced erectile dysfunction. Our data may guide the use of inverse treatment planning to maximize the probability of maintaining sexual potency after radiation therapy.

  12. RADIATION SAFETY TRAINING MANUAL Radiation Safety Office

    E-Print Network [OSTI]

    Sibille, Etienne

    protection and the potential risks of ionizing radiation. Radiation Safety Office personnel provide.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 II. OVERVIEW OF REGULATIONS, PROTECTION STANDARDS, AND RADIATION SAFETY ORGANIZATION.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 V. BASIC RADIATION PROTECTION PRINCIPLES

  13. A Phase I/II Trial of Intensity Modulated Radiation (IMRT) Dose Escalation With Concurrent Fixed-dose Rate Gemcitabine (FDR-G) in Patients With Unresectable Pancreatic Cancer

    SciTech Connect (OSTI)

    Ben-Josef, Edgar, E-mail: edgar.ben-josef@uphs.upenn.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Mathew [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Francis, Isaac R. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Hadley, Scott; Ten-Haken, Randall; Lawrence, Theodore; Normolle, Daniel [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Simeone, Diane M.; Sonnenday, Christopher [Department of Surgery, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Surgery, University of Michigan, Ann Arbor, Michigan (United States); Abrams, Ross [Department of Radiation Oncology, Rush Medical Center, Chicago, Illinois (United States)] [Department of Radiation Oncology, Rush Medical Center, Chicago, Illinois (United States); Leslie, William [Division of Hematology Oncology, Department of Internal Medicine, Rush Medical Center, Chicago, Illinois (United States)] [Division of Hematology Oncology, Department of Internal Medicine, Rush Medical Center, Chicago, Illinois (United States); Khan, Gazala; Zalupski, Mark M. [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States)

    2012-12-01T23:59:59.000Z

    Purpose: Local failure in unresectable pancreatic cancer may contribute to death. We hypothesized that intensification of local therapy would improve local control and survival. The objectives were to determine the maximum tolerated radiation dose delivered by intensity modulated radiation with fixed-dose rate gemcitabine (FDR-G), freedom from local progression (FFLP), and overall survival (OS). Methods and Materials: Eligibility included pathologic confirmation of adenocarcinoma, radiographically unresectable, performance status of 0-2, absolute neutrophil count of {>=}1500/mm{sup 3}, platelets {>=}100,000/mm{sup 3}, creatinine <2 mg/dL, bilirubin <3 mg/dL, and alanine aminotransferase/aspartate aminotransferase {<=}2.5 Multiplication-Sign upper limit of normal. FDR-G (1000 mg/m{sup 2}/100 min intravenously) was given on days -22 and -15, 1, 8, 22, and 29. Intensity modulated radiation started on day 1. Dose levels were escalated from 50-60 Gy in 25 fractions. Dose-limiting toxicity was defined as gastrointestinal toxicity grade (G) {>=}3, neutropenic fever, or deterioration in performance status to {>=}3 between day 1 and 126. Dose level was assigned using TITE-CRM (Time-to-Event Continual Reassessment Method) with the target dose-limiting toxicity (DLT) rate set to 0.25. Results: Fifty patients were accrued. DLTs were observed in 11 patients: G3/4 anorexia, nausea, vomiting, and/or dehydration (7); duodenal bleed (3); duodenal perforation (1). The recommended dose is 55 Gy, producing a probability of DLT of 0.24. The 2-year FFLP is 59% (95% confidence interval [CI]: 32-79). Median and 2-year overall survival are 14.8 months (95% CI: 12.6-22.2) and 30% (95% CI 17-45). Twelve patients underwent resection (10 R0, 2 R1) and survived a median of 32 months. Conclusions: High-dose radiation therapy with concurrent FDR-G can be delivered safely. The encouraging efficacy data suggest that outcome may be improved in unresectable patients through intensification of local therapy.

  14. Variations of the hypoxic fraction in the SCC VII tumors after single dose and during fractionated radiation therapy: Assessment without anesthesia or physical restraint of mice

    SciTech Connect (OSTI)

    Kitakabu, Y.; Shibamoto, Y.; Sasai, K.; Ono, K.; Abe, M. (Kyoto Univ. (Japan))

    1991-04-01T23:59:59.000Z

    Variations of the hypoxic fraction (HF) after single dose (13 Gy or 4 Gy) and during fractionated (5 fractions of 4 Gy, 1 or 2 fractions per day) radiation therapy were studied in SCC VII tumors implanted subcutaneously in the hind legs of C3H/He/Jms mice using the paired survival curve method. Whole-body irradiation was delivered to tumor-bearing mice without anesthesia or physical restraint, because both are known to increase the HF artificially. The HF decreased after a single 13 Gy dose in a biphasic fashion: extremely rapidly within 1 hr and comparatively slowly during the following 12-72 hr. On the other hand, nearly no fall of HF was observed in 24 hr following a single 4 Gy dose. Also, reoxygenation was found to occur more rapidly in the interfraction period as the number of fractions of 4 Gy increased irrespective of differences of interfraction time. However, the HF just before each radiation fraction was significantly higher than the pretreatment level for both fractionated regimens. Thus, the reoxygenation patterns observed after single low and high doses of irradiation were different from each other, and reoxygenation in each interfraction period did not always proceed in a similar manner to that after single low dose irradiation. Reoxygenation was facilitated as fractionated radiation therapy proceeded, but it was not sufficient for the HF to remain at a level comparable to that before irradiation.

  15. On the possibility of cosmic ray-induced ionizing radiation-powered life in subsurface environments in the Universe

    E-Print Network [OSTI]

    Atri, Dimitra

    2015-01-01T23:59:59.000Z

    Photosynthesis is a highly efficient mechanism developed by terrestrial life to utilize the energy from photons of solar origin for biological use. Subsurface regions are isolated from the photosphere, and consequently are incapable of utilizing this energy. This opens up the opportunity for life to cultivate alternative mechanisms in order to take advantage of other available energy sources. Studies have shown that in subsurface environments, life can use energy generated from geochemical and geothermal processes to sustain a minimal metabolism. Another mechanism is radiolysis, in which particles emitted by radioactive substances are indirectly utilized for metabolism. One such example is the bacterium fueled by radiation, found 2 miles deep in a South African mine, which consumes hydrogen formed from particles emitted by radioactive U, Th and K present in rock. An additional source of radiation in the subsurface environments is secondary particles, such as muons generated by Galactic Cosmic Rays (GCRs). It ...

  16. Physics of intense, high energy radiation effects.

    SciTech Connect (OSTI)

    Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

    2011-02-01T23:59:59.000Z

    This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic calculations, the continuum calculations and the experiments.

  17. Primate polonium metabolic models and their use in estimation of systemic radiation doses from bioassay data. Final report

    SciTech Connect (OSTI)

    Cohen, N. [New York Univ. Medical Center, Tuxedo, NY (United States). Dept. of Environmental Medicine

    1989-03-15T23:59:59.000Z

    A Polonium metabolic model was derived and incorporated into a Fortran algorithm which estimates the systemic radiation dose from {sup 210}Po when applied to occupational urine bioassay data. The significance of the doses estimated are examined by defining the degree of uncertainty attached to them through comprehensive statistical testing procedures. Many parameters necessary for dosimetry calculations (such as organ partition coefficients and excretion fractions), were evaluated from metabolic studies of {sup 210}Po in non-human primates. Two tamarins and six baboons were injected intravenously with {sup 210}Po citrate. Excreta and blood samples were collected. Five of the baboons were sacrificed at times ranging from 1 day to 3 months post exposure. Complete necropsies were performed and all excreta and the majority of all skeletal and tissue samples were analyzed radiochemically for their {sup 210}Po content. The {sup 210}Po excretion rate in the baboon was more rapid than in the tamarin. The biological half-time of {sup 210}Po excretion in the baboon was approximately 15 days while in the tamarin, the {sup 210}Po excretion rate was in close agreement with the 50 day biological half-time predicted by ICRP 30. Excretion fractions of {sup 210}Po in the non-human primates were found to be markedly different from data reported elsewhere in other species, including man. A thorough review of the Po urinalysis procedure showed that significant recovery losses resulted when metabolized {sup 210}Po was deposited out of raw urine. Polonium-210 was found throughout the soft tissues of the baboon but not with the partition coefficients for liver, kidneys, and spleen that are predicted by the ICRP 30 metabolic model. A fractional distribution of 0.29 for liver, 0.07 for kidneys, and 0.006 for spleen was determined. Retention times for {sup 210}Po in tissues are described by single exponential functions with biological half-times ranging from 15 to 50 days.

  18. Dose profiles through the dermis for on and off-skin hot particle exposures

    E-Print Network [OSTI]

    Shaw, Kimberly Rochelle

    1993-01-01T23:59:59.000Z

    compared to gamma-rays. Gamma-rays are monoenergetic photons with energies ranging from a few keV to several MeV. Unlike beta particles, gamma-rays are indirectly ionizing radiation. Because a gamma-ray is uncharged, it undergoes no direct ionization... detailed data on dose profiles This thesis follows the format of Radiation Protection Dosimetry. through the dermis from fuel fragments or from mixed beta-gamma activation products. The effects of beta-emitting hot particles suspended above skin without...

  19. Prognostic Significance of Carbohydrate Antigen 19-9 in Unresectable Locally Advanced Pancreatic Cancer Treated With Dose-Escalated Intensity Modulated Radiation Therapy and Concurrent Full-Dose Gemcitabine: Analysis of a Prospective Phase 1/2 Dose Escalation Study

    SciTech Connect (OSTI)

    Vainshtein, Jeffrey M., E-mail: jvainsh@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Schipper, Matthew [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Zalupski, Mark M. [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Abrams, Ross [Department of Radiation Oncology, Rush Medical Center, Chicago, Illinois (United States)] [Department of Radiation Oncology, Rush Medical Center, Chicago, Illinois (United States); Francis, Isaac R. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Khan, Gazala [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States)] [Division of Hematology Oncology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan (United States); Leslie, William [Division of Hematology Oncology, Department of Internal Medicine, Rush Medical Center, Chicago, Illinois (United States)] [Division of Hematology Oncology, Department of Internal Medicine, Rush Medical Center, Chicago, Illinois (United States); Ben-Josef, Edgar [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2013-05-01T23:59:59.000Z

    Purpose: Although established in the postresection setting, the prognostic value of carbohydrate antigen 19-9 (CA19-9) in unresectable locally advanced pancreatic cancer (LAPC) is less clear. We examined the prognostic utility of CA19-9 in patients with unresectable LAPC treated on a prospective trial of intensity modulated radiation therapy (IMRT) dose escalation with concurrent gemcitabine. Methods and Materials: Forty-six patients with unresectable LAPC were treated at the University of Michigan on a phase 1/2 trial of IMRT dose escalation with concurrent gemcitabine. CA19-9 was obtained at baseline and during routine follow-up. Cox models were used to assess the effect of baseline factors on freedom from local progression (FFLP), distant progression (FFDP), progression-free survival (PFS), and overall survival (OS). Stepwise forward regression was used to build multivariate predictive models for each endpoint. Results: Thirty-eight patients were eligible for the present analysis. On univariate analysis, baseline CA19-9 and age predicted OS, CA19-9 at baseline and 3 months predicted PFS, gross tumor volume (GTV) and black race predicted FFLP, and CA19-9 at 3 months predicted FFDP. On stepwise multivariate regression modeling, baseline CA19-9, age, and female sex predicted OS; baseline CA19-9 and female sex predicted both PFS and FFDP; and GTV predicted FFLP. Patients with baseline CA19-9 ?90 U/mL had improved OS (median 23.0 vs 11.1 months, HR 2.88, P<.01) and PFS (14.4 vs 7.0 months, HR 3.61, P=.001). CA19-9 progression over 90 U/mL was prognostic for both OS (HR 3.65, P=.001) and PFS (HR 3.04, P=.001), and it was a stronger predictor of death than either local progression (HR 1.46, P=.42) or distant progression (HR 3.31, P=.004). Conclusions: In patients with unresectable LAPC undergoing definitive chemoradiation therapy, baseline CA19-9 was independently prognostic even after established prognostic factors were controlled for, whereas CA19-9 progression strongly predicted disease progression and death. Future trials should stratify by baseline CA19-9 and incorporate CA19-9 progression as a criterion for progressive disease.

  20. 3D radiative transfer simulations of Eta Carinae's inner colliding winds - II: Ionization structure of helium at periastron

    E-Print Network [OSTI]

    Clementel, Nicola; Kruip, Chael J H; Paardekooper, Jan-Pieter

    2015-01-01T23:59:59.000Z

    Spectral observations of the massive colliding wind binary Eta Carinae show phase-dependent variations, in intensity and velocity, of numerous helium emission and absorption lines throughout the entire 5.54-year orbit. Approaching periastron, the 3D structure of the wind-wind interaction region (WWIR) gets highly distorted due to the eccentric ($e \\sim 0.9$) binary orbit. The secondary star ($\\eta_{\\mathrm{B}}$) at these phases is located deep within the primary's dense wind photosphere. The combination of these effects is thought to be the cause of the particularly interesting features observed in the helium lines at periastron. We perform 3D radiative transfer simulations of $\\eta$ Car's interacting winds at periastron. Using the SimpleX radiative transfer algorithm, we post-process output from 3D smoothed particle hydrodynamic simulations of the inner 150 au of the $\\eta$ Car system for two different primary star mass-loss rates ($\\dot{M}_{\\eta_{\\mathrm{A}}}$). Using previous results from simulations at ap...

  1. Tissue responses to low protracted doses of high let radiations or photons: Early and late damage relevant to radio-protective countermeasures

    SciTech Connect (OSTI)

    Ainsworth, E.J.; Afzal, S.M.J.; Crouse, D.A.; Hanson, W.R.; Fry, R.J.M.

    1988-01-01T23:59:59.000Z

    Early and late murine tissue responses to single or fractionated low doses of heavy charged particles, fission-spectrum neutrons or gamma rays are considered. Damage to the hematopoietic system is emphasized, but results on acute lethality, host response to challenge with transplanted leukemia cells and life-shortening are presented. Low dose rates per fraction were used in some neutron experiments. Split-dose lethality studies (LD 50/30) with fission neutrons indicated greater accumulation of injury during a 9 fraction course (over 17 days) than was the case for ..gamma..-radiation. When total doses of 96 or 247 cGy of neutrons or ..gamma.. rays were given as a single dose or in 9 fractions, a significant sparing effect on femur CFU-S depression was observed for both radiation qualities during the first 11 days, but there was not an earlier return to normal with dose fractionation. During the 9 fraction sequence, a significant sparing effect of low dose rate on CFU-S depression was observed in both neutron and ..gamma..-irradiated mice. CFU-S content at the end of the fractionation sequence did not correlate with measured LD 50/30. Sustained depression of femur and spleen CFU-S and a significant thrombocytopenia were observed when a total neutron dose of 240 cGy was given in 72 fractions over 24 weeks at low dose rates. The temporal aspects of CFU-S repopulation were different after a single versus fractionated neutron doses. The sustained reduction in the size of the CFU-S population was accompanied by an increase in the fraction in DNA synthesis. The proliferation characteristics and effects of age were different for radial CFU-S population closely associated with bone, compared with the axial population that can be readily aspirated from the femur. In aged irradiated animals, the CFU-S proliferation/redistribution response to typhoid vaccine showed both an age and radiation effect. 63 refs., 6 figs., 7 tabs.

  2. Patterns of Local Recurrence and Dose Fractionation of Adjuvant Radiation Therapy in 462 Patients With Soft Tissue Sarcoma of Extremity and Trunk Wall

    SciTech Connect (OSTI)

    Jebsen, Nina L., E-mail: nina.louise.jebsen@helse-bergen.no [Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Bergen (Norway); Department of Oncology, Haukeland University Hospital, Bergen (Norway); Engellau, Jacob [Department of Oncology, Skåne University Hospital, Lund (Sweden); Engström, Katarina [Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden); Bauer, Henrik C. [Department of Molecular Medicine and Surgery, Section for Orthopaedics and Sports Medicine, Karolinska University Hospital, Karolinska Institute, Stockholm (Sweden); Monge, Odd R. [Department of Oncology, Haukeland University Hospital, Bergen (Norway); Muren, Ludvig P. [Department of Physics and Technology, University of Bergen, Bergen (Norway); Department of Medical Physics, Aarhus University and Aarhus University Hospital, Aarhus (Denmark); Eide, Geir E. [Centre for Clinical Research, Haukeland University Hospital, Bergen (Norway); Department of Public Health and Primary Health Care, University of Bergen, Bergen (Norway); Trovik, Clement S. [Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Bergen (Norway); Department of Oncology, Haukeland University Hospital, Bergen (Norway); Bruland, Øyvind S. [Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Institute of Clinical Medicine, University of Oslo, Oslo (Norway)

    2013-08-01T23:59:59.000Z

    Purpose: To study the impact of dose fractionation of adjuvant radiation therapy (RT) on local recurrence (LR) and the relation of LR to radiation fields. Methods and Materials: LR rates were analyzed in 462 adult patients with soft tissue sarcoma who underwent surgical excision and adjuvant RT at five Scandinavian sarcoma centers from 1998 to 2009. Medical records were reviewed for dose fractionation parameters and to determine the location of the LR relative to the radiation portals. Results: Fifty-five of 462 patients developed a LR (11.9%). Negative prognostic factors included intralesional surgical margin (hazard ratio [HR]: 7.83, 95% confidence interval [CI]: 3.08-20.0), high malignancy grade (HR: 5.82, 95% CI: 1.31-25.8), age at diagnosis (HR per 10 years: 1.27, 95% CI: 1.03-1.56), and malignant peripheral nerve sheath tumor histological subtype (HR: 6.66, 95% CI: 2.56-17.3). RT dose was tailored to margin status. No correlation between RT dose and LR rate was found in multiple Cox regression analysis. The majority (65%) of LRs occurred within the primary RT volume. Conclusions: No significant dose–response effect of adjuvant RT was demonstrated. Interestingly, patients given 45-Gy accelerated RT (1.8 Gy twice daily/2.5 weeks) had the best local outcome. A total dose of 50 Gy in 25 fractions seemed adequate following wide margin surgery. The risk of LR was associated with histopathologic subtype, which should be included in the treatment algorithm of adjuvant RT in soft tissue sarcoma.

  3. Radiation physics, biophysics, and radiation biology

    SciTech Connect (OSTI)

    Hall, E.J.; Zaider, M.

    1993-05-01T23:59:59.000Z

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  4. Radiation leukaemogenesis at low doses DE-FG02-05 ER 63947 Final Technical Report 15 May 2005 â?? 14 May 2010

    SciTech Connect (OSTI)

    Simon Bouffler; Christophe Badie; Natalie Brown; Rosemary Finnon

    2010-07-28T23:59:59.000Z

    This report provides a full summary of the results obtained under grant DE-FG02-05ER63947, Radiation Leukaemogenesis at low doses. The studies employed an experimental model of radiation leukaemogenesis with the main aim of identifying key events that convert normal cells into leukaemic cells follwoing exposure to radiation. Important aspect of the work was to understand dose-response relationships and time course relationships for leakaemogenis events. The studies performed provided evidence for direct radiation-induced losses of the Sfpi1/PU.1 gene being critical for induction of the disease. No threshold below 0.1 Gy in the induction of the gene losses was observed. The critical cell type in which the myeloid lekaemias arise has been identified and point mutations in the Sfpi1/PU.1 gene are common in leukaemias. The consequences of the genetic losses and mutation have been examined and these provide evidence of a disruption of differentiation in leukaemic cells. Additional pathways to leukaemogenesis have been identified also. Overall the study provides quantitiative data suitable for testing approaches to modelling of leukaemia rosk at low doses.

  5. SU-E-T-96: Demonstration of a Consistent Method for Correcting Surface Dose Measurements Using Both Solid State and Ionization Chamber Detectors

    SciTech Connect (OSTI)

    Reynolds, T; Gerbi, B; Higgins, P [UniversityMinnesota, Minneapolis, MN (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To compare the surface dose (SD) measured using a PTW 30-360 extrapolation chamber with different commonly used dosimeters (Ds): parallel plate ion chambers (ICs): RMI-449 (Attix), Capintec PS-033, PTW 30-329 (Markus) and Memorial; TLD chips (cTLD), TLD powder (pTLD), optically stimulated (OSLs), radiochromic (EXR2) and radiographic (EDR2) films, and to provide an intercomparison correction to Ds for each of them. Methods: Investigations were performed for a 6 MV x-ray beam (Varian Clinac 2300, 10x10 cm{sup 2} open field, SSD = 100 cm). The Ds were placed at the surface of the solid water phantom and at the reference depth dref=1.7cm. The measurements for cTLD, OSLs, EDR2 and EXR2 were corrected to SD using an extrapolation method (EM) indexed to the baseline PTW 30-360 measurements. A consistent use of the EM involved: 1) irradiation of three Ds stacked on top of each other on the surface of the phantom; 2) measurement of the relative dose value for each layer; and, 3) extrapolation of these values to zero thickness. An additional measurement was performed with externally exposed OSLs (eOSLs), that were rotated out of their protective housing. Results: All single Ds measurements overestimated the SD compared with the extrapolation chamber, except for Attix IC. The closest match to the true SD was measured with the Attix IC (? 0.1%), followed by pTLD (0.5%), Capintec (4.5%), Memorial (7.3%), Markus (10%), cTLD (11.8%), eOSL (12.8%), EXR2 (14%), EDR2 (14.8%) and OSL (26%). The EM method of correction for SD worked well for all Ds, except the unexposed OSLs. Conclusion: This EM cross calibration of solid state detectors with an extrapolation or Attix chamber can provide thickness corrections for cTLD, eOSLs, EXR2, and EDR2. Standard packaged OSLs were not found to be simply corrected.

  6. Low Dose Radiation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12electron 9 5LetLooking5investsLouisPrepared:Stability

  7. RADIATION SENSITIVITY & PROCESSING OF DNA DAMAGE FOLLOWING LOW DOSES OF GAMMA-RAY ALPHA PARTICLES & HZE IRRADIATION OF NORMAL DSB REPAIR DEFICIENT CELLS

    SciTech Connect (OSTI)

    O'Neil, Peter

    2009-05-15T23:59:59.000Z

    Non-homologous end joining (NHEJ) predominates in the repair of DNA double strand breaks (DSB) over homologous recombination (HR). NHEJ occurs throughout the cell cycle whereas HR occurs in late S/G2 due to the requirement of a sister chromatid (Rothkamm et al, Mol Cell Biol 23 5706-15 [2003]). To date evidence obtained with DSB repair deficient cells using pulsed-field gel electrophoresis has revealed the major pathway throughout all phases of the cell cycle for processing high dose induced DSBs is NHEJ (Wang et al, Oncogene 20 2212-24 (2001); Pluth et al, Cancer Res. 61 2649-55 [2001]). These findings however were obtained at high doses when on average >> 20-30 DSBs are formed per cell. The contribution of the repair pathways (NHEJ and HR) induced in response to DNA damage during the various phases of the cell cycle may depend upon the dose (the level of initial DSBs) especially since low levels of DSBs are induced at low dose. To date, low dose studies using NHEJ and HR deficient mutants have not been carried out to address this important question with radiations of different quality. The work presented here leads us to suggest that HR plays a relatively minor role in the repair of radiation-induced prompt DSBs. SSBs lead to the induction of DSBs which are associated specifically with S-phase cells consistent with the idea that they are formed at stalled replication forks in which HR plays a major role in repair. That DNA-PKcs is in some way involved in the repair of the precursors to replication-induced DSB remains an open question. Persistent non-DSB oxidative damage also leads to an increase in RAD51 positive DSBs. Both simple and complex non-DSB DNA damage may therefore contribute to indirect DSBs induced by ionising radiation at replication forks.

  8. Determining the effective dose equivalent and effective dose for anthropomorphic phantoms with different torso thicknesses for broad parallel beams of external photon radiation

    E-Print Network [OSTI]

    Chichkov, Igor

    1999-01-01T23:59:59.000Z

    for broad parallel beams of external photon radiation. The mathematical model of the human body that was used for this study was a hermaphroditic phantom developed at the Oak Ridge National Laboratory (Eckerman et at. 1996). Adding a layer of soft tissue...

  9. Determining the effective dose equivalent and effective dose for anthropomorphic phantoms with different torso thicknesses for broad parallel beams of external photon radiation 

    E-Print Network [OSTI]

    Chichkov, Igor

    1999-01-01T23:59:59.000Z

    for broad parallel beams of external photon radiation. The mathematical model of the human body that was used for this study was a hermaphroditic phantom developed at the Oak Ridge National Laboratory (Eckerman et at. 1996). Adding a layer of soft tissue...

  10. American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) Practice Guideline for the Performance of High-Dose-Rate Brachytherapy

    SciTech Connect (OSTI)

    Erickson, Beth A. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Demanes, D. Jeffrey [Department of Radiation Oncology , University of California, Los Angeles, CA (United States); Ibbott, Geoffrey S. [Radiological Physics Center, MD Anderson Cancer Center, Houston, TX (United States); Hayes, John K. [Gamma West Brachytherapy, Salt Lake City, UT (United States); Hsu, I-Chow J. [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States); Morris, David E. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC (United States); Rabinovitch, Rachel A. [Department of Radiation Oncology, University of Colorado Denver, Aurora, CO (United States); Tward, Jonathan D. [Department of Radiation Oncology, Huntsman Cancer Institute, Salt Lake City, UT (United States); Rosenthal, Seth A. [Radiation Oncology Centers, Radiological Associates of Sacramento, Sacramento, CA (United States)

    2011-03-01T23:59:59.000Z

    High-Dose-Rate (HDR) brachytherapy is a safe and efficacious treatment option for patients with a variety of different malignancies. Careful adherence to established standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for HDR brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrists. Review of the leading indications for HDR brachytherapy in the management of gynecologic, thoracic, gastrointestinal, breast, urologic, head and neck, and soft tissue tumors is presented. Logistics with respect to the brachytherapy implant procedures and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful HDR brachytherapy program.

  11. Meeting Report--NASA Radiation Biomarker Workshop

    E-Print Network [OSTI]

    Straume, Tore

    2008-01-01T23:59:59.000Z

    ionizing radiation. In: Advances in Medical Physics (A. B.for medical management of radiation casualties. ADVANCES INMedical Center presented the radiation oncology perspective on biomarkers. Advances

  12. Acute radiation syndrones and their management

    SciTech Connect (OSTI)

    Cronkite, E.P.

    1988-01-01T23:59:59.000Z

    Radiation syndromes produced by large doses of ionizing radiation are divided into three general groups depending on dose of radiation and time after exposure. The CNS syndrome requires many thousands of rad, appears in minutes to hours, and kills within hours to days. The GIS appears after doses of a few hundred to 2000 rad. It is characterized by nausea, vomiting, diarrhea, and disturbances of water and electrolyte metabolism. It has a high mortality in the first week after exposure. Survivors will then experience the HS as a result of marrow aplasia. Depending on dose, survival is possible with antibiotic and transfusion therapy. The relationship of granulocyte depression to mortality in dogs and human beings is illustrated. The role of depth dose pattern of mortality of radiation exposure is described and used as an indication of why air exposure doses may be misleading. The therapy of radiation injury is described based on antibiotics, transfusion therapy, and use of molecular regulators. The limited role of matched allogenic bone marrow transplants is discussed. 52 refs., 13 figs.

  13. A phase I/II trial of stereotactic body radiation therapy (SBRT) for lung metastases: Initial report of dose escalation and early toxicity

    SciTech Connect (OSTI)

    Schefter, Tracey E. [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States)]. E-mail: Tracey.Schefter@uchsc.edu; Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States); Raben, David [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States); Kane, Madeleine [Division of Medical Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States); Chen Changhu [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States); Stuhr, Kelly [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States); Kelly, Karen [Division of Medical Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States); Mitchell, John D. [Section of Thoracic Surgery, University of Colorado Health Sciences Center, Aurora, CO (United States); Bunn, Paul A. [Division of Medical Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States); Gaspar, Laurie E. [Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO (United States)

    2006-11-15T23:59:59.000Z

    Purpose: To determine the maximum tolerated dose (MTD) of stereotactic body radiation therapy (SBRT) for lung metastases. Methods and Materials: A Phase I clinical trial was conducted. Eligible patients had one to three pulmonary metastases from a solid tumor, cumulative tumor diameter <7 cm, and adequate pulmonary function (forced expiratory volume in 1 s {>=}1.0 L). The planning target volume (PTV) was typically constructed from the gross tumor volume (GTV) by adding a 5-mm radial and 10-mm craniocaudal margin. The first cohort received 48 Gy to the PTV in three fractions (F). SBRT dose was escalated in subsequent cohorts up to a preselected maximum of 60 Gy/3 F. The percent of normal lung receiving more than 15 Gy (V{sub 15}) was restricted to less than 35%. Respiratory control and a dynamic conformal arc SBRT technique were used. Dose-limiting toxicity (DLT) included acute Grade 3 lung or esophageal toxicity or any acute Grade 4 toxicity within 3 months. After the Phase I dose escalation, the trial continued as a Phase II study, and patients in this cohort are included to increase the number of patients evaluable for early toxicity assessment. Results: Twenty-five eligible patients have been enrolled to date. In the Phase I component of the trial, there were 12 patients (7 male, 5 female): median age, 55 years (range, 31-83 years); the most common primary site was colorectal (4 patients). Seven patients had two lung lesions, and 1 patient had three lesions. The median aggregate volume of all GTVs was 18.7 mL (range, 2-40 mL). No patient experienced a DLT, and dose was escalated to 60 Gy/3 F without reaching the MTD; including the additional Phase II cohort patients, 16 patients have been treated to a dose of 60 Gy/3F without experiencing a DLT in the first 3 months. The equivalent uniform dose to the GTV in the highest dose group ranged from 66 to 77 Gy in 3 F. Conclusions: In patients with limited pulmonary metastases, radiobiologically potent doses of SBRT are well tolerated with minimal early toxicity. A Phase II SBRT study of 60 Gy/3 F for lung metastases is ongoing to evaluate local tumor control rates with this regimen and continue surveillance for any late effects.

  14. Nuclear apoJ: A low dose radiation inducible regulator of cell death. Final report for period September 15, 1998 - September 14, 2001

    SciTech Connect (OSTI)

    Aronow, Bruce J.

    2002-04-19T23:59:59.000Z

    This project was based on preliminary data that was published by Dr. Boothman (Yang et al. 2000) which indicated a strong induction of apoJ gene expression, increased secretion of the protein, and accumulation of an apparently somewhat different form of the apoJ protein in the nucleus of MCF-7 breast carcinoma cells undergoing response to DNA damage. A clone expressing apoJ protein was isolated that was capable of interacting with Ku80, a component of the double strand break repair complex that is essential for the successful repair of rearranging immunoglobulin and T-cell receptor genes as evidenced by failure to produce mature B and T cells in the absence of Ku70. ApoJ clones isolated and characterized by Dr. Boothman bound strongly to a Ku-70 ''bait'' protein. Over-expression of these same clones in a cell line was capable of killing the cell. ApoJ is very strongly induced in many instances of programmed cell death and has been proposed repeatedly to play some sort of effector role in the process. Our principle hypothesis for this study was that the strong induction of the apoJ gene and the particular expression of a nuclear form of the protein was potentially a causal factor in the decision point made by the cell as it attempts to repair double-strand breakage based DNA damage. The hypothesis was that if sufficiently high damage occurred, it would be deleterious to maintain the cell's viability through continued DNA repair. One method to inhibit DNA repair might be by inhibiting proteins such as Ku-70 that are necessary for double-strand break repair. If apoJ does play a critical role in tipping the decision balance over to cell death, we reasoned that deficiency of apoJ would cause increased accumulation of cells with DNA damage and that this might decrease cell death in response to DNA damage and increase tumor occurrence rates. To test this hypothesis and its potential implications, we exposed wildtype and apoJ deficient animals that we constructed through gene targeting to increasing levels of ionizing radiation from a Cesium source. Data gathered under the support of this grant application initially indicated that apoJ deficient animals were more resistant to radiation, but as we accumulated more and more data points and covered a tighter exposure range, the genotype-based differences became insignificant. However, the possibility existed that because mortality based radiation-resistance could be attributable to mechanism for which nuclear apoJ was not rate determining, we maintained a very large of colony of apoJ knockout and wildtype animals in both the C57/B16 and Cv129 strain backgrounds that were exposed to sub-lethal levels of ionizing radiation to monitor for the occurrence of tumors. These animals were allowed to fully recover and age normally in either germ free or normal animal housing. Our results demonstrated no significant differences between wildtype and apoJ knockout animals over a period that extended up to 30 months for individual animals. We recorded similar weight gain, a relatively low mortality rate, and a similar mixture and rate of sarcoma and adenocarcinomas after surviving the initial ionizing radiation exposures. Thus we conclude that apoJ gene function, which was totally eliminated by our gene targeting, did not influence radiation sensitivity or serve as a tumor suppressor in response to DNA damage.

  15. Postoperative Nomogram Predicting the 9-Year Probability of Prostate Cancer Recurrence After Permanent Prostate Brachytherapy Using Radiation Dose as a Prognostic Variable

    SciTech Connect (OSTI)

    Potters, Louis, E-mail: LPotters@nshs.ed [Department of Radiation Medicine, North Shore Long Island Jewish Health System, New Hyde Park, NY (United States); Roach, Mack [Departments of Radiation Oncology and Urology, University of California at San Francisco, San Francisco, CA (United States); Davis, Brian J. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Stock, Richard G. [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States); Ciezki, Jay P. [Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH (United States); Zelefsky, Michael J. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Stone, Nelson N. [Department of Urology, Mount Sinai School of Medicine, New York, NY (United States); Fearn, Paul A. [Department of Urology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yu Changhong [Glickman Urological Institute and the Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH (United States); Shinohara, Katsuto [Departments of Radiation Oncology and Urology, University of California at San Francisco, San Francisco, CA (United States); Kattan, Michael W. [Glickman Urological Institute and the Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH (United States)

    2010-03-15T23:59:59.000Z

    Purpose: To report a multi-institutional outcomes study on permanent prostate brachytherapy (PPB) to 9 years that includes postimplant dosimetry, to develop a postimplant nomogram predicting biochemical freedom from recurrence. Methods and Materials: Cox regression analysis was used to model the clinical information for 5,931 patients who underwent PPB for clinically localized prostate cancer from six centers. The model was validated against the dataset using bootstrapping. Disease progression was determined using the Phoenix definition. The biological equivalent dose was calculated from the minimum dose to 90% of the prostate volume (D90) and external-beam radiotherapy dose using an alpha/beta of 2. Results: The 9-year biochemical freedom from recurrence probability for the modeling set was 77% (95% confidence interval, 73-81%). In the model, prostate-specific antigen, Gleason sum, isotope, external beam radiation, year of treatment, and D90 were associated with recurrence (each p < 0.05), whereas clinical stage was not. The concordance index of the model was 0.710. Conclusion: A predictive model for a postimplant nomogram for prostate cancer recurrence at 9-years after PPB has been developed and validated from a large multi-institutional database. This study also demonstrates the significance of implant dosimetry for predicting outcome. Unique to predictive models, these nomograms may be used a priori to calculate a D90 that likely achieves a desired outcome with further validation. Thus, a personalized dose prescription can potentially be calculated for each patient.

  16. SU-E-I-82: Improving CT Image Quality for Radiation Therapy Using Iterative Reconstruction Algorithms and Slightly Increasing Imaging Doses

    SciTech Connect (OSTI)

    Noid, G; Chen, G; Tai, A; Li, X [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Iterative reconstruction (IR) algorithms are developed to improve CT image quality (IQ) by reducing noise without diminishing spatial resolution or contrast. For CT in radiation therapy (RT), slightly increasing imaging dose to improve IQ may be justified if it can substantially enhance structure delineation. The purpose of this study is to investigate and to quantify the IQ enhancement as a result of increasing imaging doses and using IR algorithms. Methods: CT images were acquired for phantoms, built to evaluate IQ metrics including spatial resolution, contrast and noise, with a variety of imaging protocols using a CT scanner (Definition AS Open, Siemens) installed inside a Linac room. Representative patients were scanned once the protocols were optimized. Both phantom and patient scans were reconstructed using the Sinogram Affirmed Iterative Reconstruction (SAFIRE) and the Filtered Back Projection (FBP) methods. IQ metrics of the obtained CTs were compared. Results: IR techniques are demonstrated to preserve spatial resolution as measured by the point spread function and reduce noise in comparison to traditional FBP. Driven by the reduction in noise, the contrast to noise ratio is doubled by adopting the highest SAFIRE strength. As expected, increasing imaging dose reduces noise for both SAFIRE and FBP reconstructions. The contrast to noise increases from 3 to 5 by increasing the dose by a factor of 4. Similar IQ improvement was observed on the CTs for selected patients with pancreas and prostrate cancers. Conclusion: The IR techniques produce a measurable enhancement to CT IQ by reducing the noise. Increasing imaging dose further reduces noise independent of the IR techniques. The improved CT enables more accurate delineation of tumors and/or organs at risk during RT planning and delivery guidance.

  17. Saha Ionization Formula and the Voids

    E-Print Network [OSTI]

    Mofazzal Azam

    2002-08-14T23:59:59.000Z

    The ultra-low density limit of Saha ionization formula suggests that, in this limit, matter would prefer to remain ionized.This has a very important implication for cosmic structures known as Voids.These are ultra-low density (much less than average density of matter in the Universe) regions in the galactic clusters and superclusters.The ionization formula implies that matter trapped in the Voids should be ionized.Therefore, we expect a very faint radiation glow from the Voids resulting from the motion of the charged particles.

  18. Relative Biologic Effects of Low-Dose-Rate {alpha}-Emitting {sup 227}Th-Rituximab and {beta}-Emitting {sup 90}Y-Tiuexetan-Ibritumomab Versus External Beam X-Radiation

    SciTech Connect (OSTI)

    Dahle, Jostein [Department of Radiation Biology, Norwegian Radium Hospital, Montebello, Oslo (Norway)], E-mail: jostein.dahle@rr-research.no; Bruland, Oyvind S. [University of Oslo and Department of Oncology, Norwegian Radium Hospital, Montebello, Oslo (Norway); Larsen, Roy H. [Department of Radiation Biology, The Norwegian Radium Hospital, Montebello, Oslo (Norway)

    2008-09-01T23:59:59.000Z

    Purpose: To determine the relative biologic effects (RBE) of {alpha}-particle radiation from {sup 227}Th-rituximab and of {beta}-radiation from {sup 90}Y-tiuexetan-ibritumomab (Zevalin) compared with external beam X-radiation in the Raji lymphoma xenograft model. Methods and Materials: Radioimmunoconjugates were administered intravenously in nude mice with Raji lymphoma xenografts at different levels of activity. Absorbed dose to tumor was estimated by separate biodistribution experiments for {sup 227}Th-rituximab and Zevalin. Tumor growth was measured two to three times per week after injection or X-radiation. Treatment-induced increase in growth delay to reach tumor volumes of 500 and 1,000 mm{sup 3}, respectively, was used as an end point. Results: The absorbed radiation dose-rate in tumor was slightly more than 0.1 Gy/d for the first week following injection of {sup 227}Th-rituximab, and thereafter gradually decreased to 0.03 Gy/d at 21 days after injection. For treatment with Zevalin the maximum dose-rate in tumor was achieved already 6 h after injection (0.2 Gy/d), and thereafter decreased to 0.01 Gy/d after 7 days. The relative biologic effect was between 2.5 and 7.2 for {sup 227}Th-rituximab and between 1 and 1.3 for Zevalin. Conclusions: Both at low doses and low-dose-rates, the {sup 227}Th-rituximab treatment was more effective per absorbed radiation dose unit than the two other treatments. The considerable effect at low doses suggests that the best way to administer low-dose-rates, {alpha}-emitting radioimmunoconjugates is via multiple injections.

  19. Achieving 50% ionization efficiency in sub-ambient pressure ionization...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    50% ionization efficiency in sub-ambient pressure ionization with nanoelectrospray. Achieving 50% ionization efficiency in sub-ambient pressure ionization with nanoelectrospray....

  20. SU-E-I-89: Assessment of CT Radiation Dose and Image Quality for An Automated Tube Potential Selection Algorithm Using Pediatric Anthropomorphic and ACR Phantoms

    SciTech Connect (OSTI)

    Mahmood, U; Erdi, Y; Wang, W [Memorial Sloan Kettering Cancer Center, NY, NY (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To assess the impact of General Electrics automated tube potential algorithm, kV assist (kVa) on radiation dose and image quality, with an emphasis on optimizing protocols based on noise texture. Methods: Radiation dose was assessed by inserting optically stimulated luminescence dosimeters (OSLs) throughout the body of a pediatric anthropomorphic phantom (CIRS). The baseline protocol was: 120 kVp, 80 mA, 0.7s rotation time. Image quality was assessed by calculating the contrast to noise ratio (CNR) and noise power spectrum (NPS) from the ACR CT accreditation phantom. CNRs were calculated according to the steps described in ACR CT phantom testing document. NPS was determined by taking the 3D FFT of the uniformity section of the ACR phantom. NPS and CNR were evaluated with and without kVa and for all available adaptive iterative statistical reconstruction (ASiR) settings, ranging from 0 to 100%. Each NPS was also evaluated for its peak frequency difference (PFD) with respect to the baseline protocol. Results: For the baseline protocol, CNR was found to decrease from 0.460 ± 0.182 to 0.420 ± 0.057 when kVa was activated. When compared against the baseline protocol, the PFD at ASiR of 40% yielded a decrease in noise magnitude as realized by the increase in CNR = 0.620 ± 0.040. The liver dose decreased by 30% with kVa activation. Conclusion: Application of kVa reduces the liver dose up to 30%. However, reduction in image quality for abdominal scans occurs when using the automated tube voltage selection feature at the baseline protocol. As demonstrated by the CNR and NPS analysis, the texture and magnitude of the noise in reconstructed images at ASiR 40% was found to be the same as our baseline images. We have demonstrated that 30% dose reduction is possible when using 40% ASiR with kVa in pediatric patients.

  1. PSA Response to Neoadjuvant Androgen Deprivation Therapy Is a Strong Independent Predictor of Survival in High-Risk Prostate Cancer in the Dose-Escalated Radiation Therapy Era

    SciTech Connect (OSTI)

    McGuire, Sean E., E-mail: semcguir@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas (United States); Lee, Andrew K. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Cerne, Jasmina Z. [Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas (United States)] [Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas (United States); Munsell, Mark F. [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Levy, Lawrence B. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kudchadker, Rajat J. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Choi, Seungtaek L.; Nguyen, Quynh N.; Hoffman, Karen E.; Pugh, Thomas J.; Frank, Steven J. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Corn, Paul G.; Logothetis, Christopher J. [Department of Genitourinary Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Genitourinary Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kuban, Deborah A. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2013-01-01T23:59:59.000Z

    Purpose: The aim of the study was to evaluate the prognostic value of prostate-specific antigen (PSA) response to neoadjuvant androgen deprivation therapy (ADT) prior to dose-escalated radiation therapy (RT) and long-term ADT in high-risk prostate cancer. Methods and Materials: We reviewed the charts of all patients diagnosed with high-risk prostate cancer and treated with a combination of long-term ADT (median, 24 months) and dose-escalated (median, 75.6 Gy) RT between 1990 and 2007. The associations among patient, tumor, and treatment characteristics with biochemical response to neoadjuvant ADT and their effects on failure-free survival (FFS), time to distant metastasis (TDM), prostate cancer-specific mortality (PCSM) and overall survival (OS) were examined. Results: A total of 196 patients met criteria for inclusion. Median follow-up time for patients alive at last contact was 7.0 years (range, 0.5-18.1 years). Multivariate analysis identified the pre-RT PSA concentration (<0.5 vs {>=}0.5 ng/mL) as a significant independent predictor of FFS (P=.021), TDM (P=.009), PCSM (P=.039), and OS (P=.037). On multivariate analysis, pretreatment PSA (iPSA) and African-American race were significantly associated with failure to achieve a pre-RT PSA of <0.5 ng/mL. Conclusions: For high-risk prostate cancer patients treated with long-term ADT and dose-escalated RT, a pre-RT PSA level {>=}0.5 ng/mL after neoadjuvant ADT predicts for worse survival measures. Both elevated iPSA and African-American race are associated with increased risk of having a pre-RT PSA level {>=}0.5 ng/mL. These patients should be considered for clinical trials that test newer, more potent androgen-depleting therapies such as abiraterone and MDV3100 in combination with radiation.

  2. Randomized Noninferiority Trial of Reduced High-Dose Volume Versus Standard Volume Radiation Therapy for Muscle-Invasive Bladder Cancer: Results of the BC2001 Trial (CRUK/01/004)

    SciTech Connect (OSTI)

    Huddart, Robert A., E-mail: robert.huddart@icr.ac.uk [Institute of Cancer Research, Royal Marsden NHSFT (National Health Service Foundation Trust) (United Kingdom); Hall, Emma [Institute of Cancer Research (United Kingdom); Hussain, Syed A. [University of Liverpool (United Kingdom); Jenkins, Peter [Gloucestershire Hospitals NHSFT (United Kingdom); Rawlings, Christine [South Devon Healthcare NHSFT (United Kingdom); Tremlett, Jean [Brighton and Sussex University Hospitals (United Kingdom); Crundwell, Malcolm [Royal Devon and Exeter NHSFT (United Kingdom); Adab, Fawzi A. [University Hospital of North Staffordshire NHS Trust (United Kingdom); Sheehan, Denise [Royal Devon and Exeter NHSFT (United Kingdom); Syndikus, Isabel [Clatterbridge Cancer Centre NHSFT (United Kingdom); Hendron, Carey [University of Birmingham (United Kingdom); Lewis, Rebecca; Waters, Rachel [Institute of Cancer Research (United Kingdom); James, Nicholas D. [University of Birmingham (United Kingdom)

    2013-10-01T23:59:59.000Z

    Purpose: To test whether reducing radiation dose to uninvolved bladder while maintaining dose to the tumor would reduce side effects without impairing local control in the treatment of muscle-invasive bladder cancer. Methods and Materials: In this phase III multicenter trial, 219 patients were randomized to standard whole-bladder radiation therapy (sRT) or reduced high-dose volume radiation therapy (RHDVRT) that aimed to deliver full radiation dose to the tumor and 80% of maximum dose to the uninvolved bladder. Participants were also randomly assigned to receive radiation therapy alone or radiation therapy plus chemotherapy in a partial 2 × 2 factorial design. The primary endpoints for the radiation therapy volume comparison were late toxicity and time to locoregional recurrence (with a noninferiority margin of 10% at 2 years). Results: Overall incidence of late toxicity was less than predicted, with a cumulative 2-year Radiation Therapy Oncology Group grade 3/4 toxicity rate of 13% (95% confidence interval 8%, 20%) and no statistically significant differences between groups. The difference in 2-year locoregional recurrence free rate (RHDVRT ? sRT) was 6.4% (95% confidence interval ?7.3%, 16.8%) under an intention to treat analysis and 2.6% (?12.8%, 14.6%) in the “per-protocol” population. Conclusions: In this study RHDVRT did not result in a statistically significant reduction in late side effects compared with sRT, and noninferiority of locoregional control could not be concluded formally. However, overall low rates of clinically significant toxicity combined with low rates of invasive bladder cancer relapse confirm that (chemo)radiation therapy is a valid option for the treatment of muscle-invasive bladder cancer.

  3. Hypofractionated High-Dose Radiation Therapy for Prostate Cancer: Long-Term Results of a Multi-Institutional Phase II Trial

    SciTech Connect (OSTI)

    Fonteyne, Valerie, E-mail: valerie.fonteyne@uzgent.be [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium)] [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Soete, Guy [Department of Radiotherapy, Universitair Ziekenhuis Brussels, Jette (Belgium)] [Department of Radiotherapy, Universitair Ziekenhuis Brussels, Jette (Belgium); Arcangeli, Stefano [Department of Radiotherapy, Regina Elena National Cancer Institute, Rome (Italy)] [Department of Radiotherapy, Regina Elena National Cancer Institute, Rome (Italy); De Neve, Wilfried [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium)] [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium); Rappe, Bernard [Department of Urology, Algemeen Stedelijk Ziekenhuis, Aalst (Belgium)] [Department of Urology, Algemeen Stedelijk Ziekenhuis, Aalst (Belgium); Storme, Guy [Department of Radiotherapy, Universitair Ziekenhuis Brussels, Jette (Belgium)] [Department of Radiotherapy, Universitair Ziekenhuis Brussels, Jette (Belgium); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy)] [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Arcangeli, Giorgio [Department of Radiotherapy, Regina Elena National Cancer Institute, Rome (Italy)] [Department of Radiotherapy, Regina Elena National Cancer Institute, Rome (Italy); De Meerleer, Gert [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium)] [Department of Radiotherapy, Ghent University Hospital, Ghent (Belgium)

    2012-11-15T23:59:59.000Z

    Purpose: To report late gastrointestinal (GI) and genitourinary (GU) toxicity, biochemical and clinical outcomes, and overall survival after hypofractionated radiation therapy for prostate cancer (PC). Methods and Materials: Three institutions included 113 patients with T1 to T3N0M0 PC in a phase II study. Patients were treated with 56 Gy in 16 fractions over 4 weeks. Late toxicity was scored using Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria extended with additional symptoms. Biochemical outcome was reported according to the Phoenix definition for biochemical failure. Results: The incidence of late GI and GU toxicity was low. The 3-year actuarial risk of developing late GU and GI toxicity of grade {>=}2 was 13% and 8% respectively. Five-year biochemical non-evidence of disease (bNED) was 94%. Risk group, T stage, and deviation from planned hormone treatment were significant predictive factors for bNED. Deviation from hormone treatment remained significant in multivariate analysis. Five-year clinical non evidence of disease and overall survival was 95% and 91% respectively. No patient died from PC. Conclusions: Hypofractionated high-dose radiation therapy is a valuable treatment option for patients with PC, with excellent biochemical and clinical outcome and low toxicity.

  4. Outcome of Patients Treated With a Single-Fraction Dose of Palliative Radiation for Cutaneous T-Cell Lymphoma

    SciTech Connect (OSTI)

    Thomas, Tarita O.; Agrawal, Priya [Department of Radiation Oncology, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States)] [Department of Radiation Oncology, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States); Guitart, Joan [Department of Dermatology, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States)] [Department of Dermatology, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States); Rosen, Steven T. [Division of Hematology/Oncology, Department of Medicine, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States)] [Division of Hematology/Oncology, Department of Medicine, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States); Rademaker, Alfred W. [Department of Preventive Medicine, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States)] [Department of Preventive Medicine, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States); Querfeld, Christiane [Department of Medicine/Dermatology Service, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Medicine/Dermatology Service, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Hayes, John P. [Department of Radiation Oncology, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States)] [Department of Radiation Oncology, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States); Kuzel, Timothy M. [Division of Hematology/Oncology, Department of Medicine, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States)] [Division of Hematology/Oncology, Department of Medicine, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States); Mittal, Bharat B., E-mail: bmittal@nmh.org [Department of Radiation Oncology, Northwestern University, Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois (United States)

    2013-03-01T23:59:59.000Z

    Purpose: Cutaneous T-cell lymphoma (CTCL) is a radiosensitive tumor. Presently, treatment with radiation is given in multiple fractions. The current literature lacks data that support single-fraction treatment for CTCL. This retrospective review assesses the clinical response in patients treated with a single fraction of radiation. Methods and Materials: This study reviewed the records of 58 patients with CTCL, primarily mycosis fungoides, treated with a single fraction of palliative radiation therapy (RT) between October 1991 and January 2011. Patient and tumor characteristics were reviewed. Response rates were compared using Fisher's exact test and multiple logistic regressions. Survival rates were determined using the Kaplan-Meier method. Cost-effectiveness analysis was performed to assess the cost of a single vs a multifractionated treatment regimen. Results: Two hundred seventy individual lesions were treated, with the majority (97%) treated with ?700 cGy; mean follow-up was 41.3 months (range, 3-180 months). Response rate by lesion was assessed, with a complete response (CR) in 255 (94.4%) lesions, a partial response in 10 (3.7%) lesions, a partial response converted to a CR after a second treatment in 4 (1.5%) lesions, and no response in 1 (0.4%) lesion. The CR in lower extremity lesions was lower than in other sites (P=.0016). Lesions treated with photons had lower CR than those treated with electrons (P=.017). Patients with lesions exhibiting large cell transformation and tumor morphology had lower CR (P=.04 and P=.035, respectively). Immunophenotype did not impact response rate (P=.23). Overall survival was significantly lower for patients with Sézary syndrome (P=.0003) and erythroderma (P<.0001). The cost of multifractionated radiation was >200% higher than that for single-fraction radiation. Conclusions: A single fraction of 700 cGy-800 cGy provides excellent palliation for CTCL lesions and is cost effective and convenient for the patient.

  5. Low Dose IR Creates an Oncogenic Microenvironment by Inducing Premature

    SciTech Connect (OSTI)

    Yuan, Zhi-Min [Harvard School of Public Health

    2013-04-28T23:59:59.000Z

    Introduction Much of the work addressing ionizing radiation-induced cellular response has been carried out mainly with the traditional cell culture technique involving only one cell type, how cellular response to IR is influenced by the tissue microenvironment remains elusive. By use of a three-dimensional (3D) co-culture system to model critical interactions of different cell types with their neighbors and with their environment, we recently showed that low-dose IR-induced extracellular signaling via the tissue environment affects profoundly cellular responses. This proposal aims at determining the response of mammary epithelial cells in a tissue-like setting.

  6. Performance parameters of a liquid filled ionization chamber array

    SciTech Connect (OSTI)

    Poppe, B.; Stelljes, T. S.; Looe, H. K.; Chofor, N. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany); Harder, D. [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany)] [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany); Willborn, K. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)] [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)

    2013-08-15T23:59:59.000Z

    Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluated using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The ?-values of the Gaussian dose response function for a single detector of the array were found to be (0.72 ± 0.25) mm at 6 MV and (0.74 ± 0.25) mm at 15 MV and the corresponding low pass cutoff frequencies are 0.22 and 0.21 mm{sup ?1}, respectively. For the inner 5 × 5 cm{sup 2} region and the outer 11 × 11 cm{sup 2} region of the array the Nyquist theorem is fulfilled for maximum sampling frequencies of 0.2 and 0.1 mm{sup ?1}, respectively. An IMRT field verification with a Gamma-Index analysis yielded a passing rate of 95.2% for a 3 mm/3% criterion with a TPS calculation as reference.Conclusions: This study shows the applicability of the Octavius 1000SRS in modern dosimetry. Output factor and dose profile measurements illustrated the applicability of the array in small field and stereotactic dosimetry. The high spatial resolution ensures adequate measurements of dose profiles in regular and intensity modulated photon-beam fields.

  7. SU-E-I-81: Assessment of CT Radiation Dose and Image Quality for An Automated Tube Potential Selection Algorithm Using Adult Anthropomorphic and ACR Phantoms

    SciTech Connect (OSTI)

    Mahmood, U; Erdi, Y; Wang, W [Memorial Sloan Kettering Cancer Center, NY, NY (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To assess the impact of General Electrics (GE) automated tube potential algorithm, kV assist (kVa) on radiation dose and image quality, with an emphasis on optimizing protocols based on noise texture. Methods: Radiation dose was assessed by inserting optically stimulated luminescence dosimeters (OSLs) throughout the body of an adult anthropomorphic phantom (CIRS). The baseline protocol was: 120 kVp, Auto mA (180 to 380 mA), noise index (NI) = 14, adaptive iterative statistical reconstruction (ASiR) of 20%, 0.8s rotation time. Image quality was evaluated by calculating the contrast to noise ratio (CNR) and noise power spectrum (NPS) from the ACR CT accreditation phantom. CNRs were calculated according to the steps described in ACR CT phantom testing document. NPS was determined by taking the 3D FFT of the uniformity section of the ACR phantom. NPS and CNR were evaluated with and without kVa and for all available adaptive iterative statistical reconstruction (ASiR) settings, ranging from 0 to 100%. Each NPS was also evaluated for its peak frequency difference (PFD) with respect to the baseline protocol. Results: The CNR for the adult male was found to decrease from CNR = 0.912 ± 0.045 for the baseline protocol without kVa to a CNR = 0.756 ± 0.049 with kVa activated. When compared against the baseline protocol, the PFD at ASiR of 40% yielded a decrease in noise magnitude as realized by the increase in CNR = 0.903 ± 0.023. The difference in the central liver dose with and without kVa was found to be 0.07%. Conclusion: Dose reduction was insignificant in the adult phantom. As determined by NPS analysis, ASiR of 40% produced images with similar noise texture to the baseline protocol. However, the CNR at ASiR of 40% with kVa fails to meet the current ACR CNR passing requirement of 1.0.

  8. Occupational dose reduction at Department of Energy contractor facilities: Bibliography of selected readings in radiation protection and ALARA; Volume 5

    SciTech Connect (OSTI)

    Dionne, B.J.; Sullivan, S.G.; Baum, J.W. [Brookhaven National Lab., Upton, NY (United States)

    1994-01-01T23:59:59.000Z

    Promoting the exchange of information related to implementation of the As Low as Reasonably Achievable (ALARA) philosophy is a continuing objective for the Department of Energy (DOE). This report was prepared by the Brookhaven National Laboratory (BNL) ALARA Center for the DOE Office of Health. It contains the fifth in a series of bibliographies on dose reduction at DOE facilities. The BNL ALARA Center was originally established in 1983 under the sponsorship of the Nuclear Regulatory Commission to monitor dose-reduction research and ALARA activities at nuclear power plants. This effort was expanded in 1988 by the DOE`s Office of Environment, Safety and Health, to include DOE nuclear facilities. This bibliography contains abstracts relating to various aspects of ALARA program implementation and dose-reduction activities, with a specific focus on DOE facilities. Abstracts included in this bibliography were selected from proceedings of technical meetings, journals, research reports, searches of the DOE Energy, Science and Technology Database (in general, the citation and abstract information is presented as obtained from this database), and reprints of published articles provided by the authors. Facility types and activities covered in the scope of this report include: radioactive waste, uranium enrichment, fuel fabrication, spent fuel storage and reprocessing, facility decommissioning, hot laboratories, tritium production, research, test and production reactors, weapons fabrication and testing, fusion, uranium and plutonium processing, radiography, and accelerators. Information on improved shielding design, decontamination, containments, robotics, source prevention and control, job planning, improved operational and design techniques, as well as on other topics, has been included. In addition, DOE/EH reports not included in previous volumes of the bibliography are in this volume (abstracts 611 to 684). This volume (Volume 5 of the series) contains 217 abstracts.

  9. Real-time Molecular Study of Bystander Effects of Low dose Low LET radiation Using Living Cell Imaging and Nanoparticale Optics

    SciTech Connect (OSTI)

    Natarajan, Mohan [UT Health Science Center at San Antonio; Xu, Nancy R [Old Dominion University; Mohan, Sumathy [UT Health Science Center at San Antonio

    2013-06-03T23:59:59.000Z

    In this study two novel approaches are proposed to investigate precisely the low dose low LET radiation damage and its effect on bystander cells in real time. First, a flow shear model system, which would provide us a near in vivo situation where endothelial cells in the presence of extra cellular matrix experiencing continuous flow shear stress, will be used. Endothelial cells on matri-gel (simulated extra cellular matrix) will be subjected to physiological flow shear (that occurs in normal blood vessels). Second, a unique tool (Single nano particle/single live cell/single molecule microscopy and spectroscopy; Figure A) will be used to track the molecular trafficking by single live cell imaging. Single molecule chemical microscopy allows one to single out and study rare events that otherwise might be lost in assembled average measurement, and monitor many target single molecules simultaneously in real-time. Multi color single novel metal nanoparticle probes allow one to prepare multicolor probes (Figure B) to monitor many single components (events) simultaneously and perform multi-complex analysis in real-time. These nano-particles resist to photo bleaching and hence serve as probes for unlimited timeframe of analysis. Single live cell microscopy allows one to image many single cells simultaneously in real-time. With the combination of these unique tools, we will be able to study under near-physiological conditions the cellular and sub-cellular responses (even subtle changes at one molecule level) to low and very low doses of low LET radiation in real time (milli-second or nano-second) at sub-10 nanometer spatial resolution. This would allow us to precisely identify, at least in part, the molecular mediators that are responsible of radiation damage in the irradiated cells and the mediators that are responsible for initiating the signaling in the neighboring cells. Endothelial cells subjected to flow shear (2 dynes/cm2 or 16 dynes/cm2) and exposed to 0.1, 1 and 10 cGy on coverslips will be examined for (a) low LET radiation-induced alterations of cellular function and its physiological relevance in real time; and (b) radiation damage triggered bystander effect on the neighboring unirradiated cells. First, to determine the low LET radiation induced alteration of cellular function we will examine: (i) the real time transformation of single membrane transporters in single living cells; (ii) the pump efficiency of membrane efflux pump of live cells in real time at the molecular level; (iii) the kinetics of single-ligand receptor interaction on single live cell surface (Figure C); and (iv) alteration in chromosome replication in living cell. Second, to study the radiation triggered bystander responses, we will examine one of the key signaling pathway i.e. TNF- alpha/NF-kappa B mediated signaling. TNF-alpha specific nano particle sensors (green) will be developed to detect the releasing dynamics, transport mechanisms and ligand-receptor binding on live cell surface in real time. A second sensor (blue) will be developed to simultaneously monitor the track of NF-kB inside the cell. The proposed nano-particle optics approach would complement our DOE funded study on biochemical mechanisms of TNF-alpha- NF-kappa B-mediated bystander effect.

  10. 10 CFR 835- Occupational Radiation Protection

    Broader source: Energy.gov [DOE]

    The rules in this part establish radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of DOE activities.

  11. A Multi-institutional Clinical Trial of Rectal Dose Reduction via Injected Polyethylene-Glycol Hydrogel During Intensity Modulated Radiation Therapy for Prostate Cancer: Analysis of Dosimetric Outcomes

    SciTech Connect (OSTI)

    Song, Danny Y., E-mail: dsong2@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland (United States); Herfarth, Klaus K.; Uhl, Matthias [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Eble, Michael J.; Pinkawa, Michael [Department of Radiation Oncology, RWTH Aachen University, Aachen (Germany); Triest, Baukelien van; Kalisvaart, Robin [Department of Radiation Oncology, Netherlands Cancer Institute/Antoni van Leeuwenhoek Ziekenhuis, Amsterdam (Netherlands); Weber, Damien C.; Miralbell, Raymond [Department of Radiation Oncology, Geneva University, Geneva (Switzerland); DeWeese, Theodore L. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland (United States); Ford, Eric C. [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States)

    2013-09-01T23:59:59.000Z

    Purpose: To characterize the effect of a prostate-rectum spacer on dose to rectum during external beam radiation therapy for prostate cancer and to assess for factors correlated with rectal dose reduction. Methods and Materials: Fifty-two patients at 4 institutions were enrolled into a prospective pilot clinical trial. Patients underwent baseline scans and then were injected with perirectal spacing hydrogel and rescanned. Intensity modulated radiation therapy plans were created on both scans for comparison. The objectives were to establish rates of creation of ?7.5 mm of prostate-rectal separation, and decrease in rectal V70 of ?25%. Multiple regression analysis was performed to evaluate the associations between preinjection and postinjection changes in rectal V70 and changes in plan conformity, rectal volume, bladder volume, bladder V70, planning target volume (PTV), and postinjection midgland separation, gel volume, gel thickness, length of PTV/gel contact, and gel left-to-right symmetry. Results: Hydrogel resulted in ?7.5-mm prostate-rectal separation in 95.8% of patients; 95.7% had decreased rectal V70 of ?25%, with a mean reduction of 8.0 Gy. There were no significant differences in preinjection and postinjection prostate, PTV, rectal, and bladder volumes. Plan conformities were significantly different before versus after injection (P=.02); plans with worse conformity indexes after injection compared with before injection (n=13) still had improvements in rectal V70. In multiple regression analysis, greater postinjection reduction in V70 was associated with decreased relative postinjection plan conformity (P=.01). Reductions in V70 did not significantly vary by institution, despite significant interinstitutional variations in plan conformity. There were no significant relationships between reduction in V70 and the other characteristics analyzed. Conclusions: Injection of hydrogel into the prostate-rectal interface resulted in dose reductions to rectum for >90% of patients treated. Rectal sparing was statistically significant across a range of 10 to 75 Gy and was demonstrated within the presence of significant interinstitutional variability in plan conformity, target definitions, and injection results.

  12. Long-term Survival and Toxicity in Patients Treated With High-Dose Intensity Modulated Radiation Therapy for Localized Prostate Cancer

    SciTech Connect (OSTI)

    Spratt, Daniel E.; Pei, Xin; Yamada, Josh; Kollmeier, Marisa A.; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2013-03-01T23:59:59.000Z

    Purpose: To report long-term survival and toxicity outcomes with the use of high-dose intensity modulated radiation therapy (IMRT) to 86.4 Gy for patients with localized prostate cancer. Methods and Materials: Between August 1997 and December 2008, 1002 patients were treated to a dose of 86.4 Gy using a 5-7 field IMRT technique. Patients were stratified by prognostic risk group based on National Comprehensive Cancer Network risk classification criteria. A total of 587 patients (59%) were treated with neoadjuvant and concurrent androgen deprivation therapy. The median follow-up for the entire cohort was 5.5 years (range, 1-14 years). Results: For low-, intermediate-, and high-risk groups, 7-year biochemical relapse-free survival outcomes were 98.8%, 85.6%, and 67.9%, respectively (P<.001), and distant metastasis-free survival rates were 99.4%, 94.1%, and 82.0% (P<.001), respectively. On multivariate analysis, T stage (P<.001), Gleason score (P<.001), and >50% of initial biopsy positive core (P=.001) were predictive for distant mestastases. No prostate cancer-related deaths were observed in the low-risk group. The 7-year prostate cancer-specific mortality (PCSM) rates, using competing risk analysis for intermediate- and high-risk groups, were 3.3% and 8.1%, respectively (P=.008). On multivariate analysis, Gleason score (P=.004), percentage of biopsy core positivity (P=.003), and T-stage (P=.033) were predictive for PCSM. Actuarial 7-year grade 2 or higher late gastrointestinal and genitourinary toxicities were 4.4% and 21.1%, respectively. Late grade 3 gastrointestinal and genitourinary toxicity was experienced by 7 patients (0.7%) and 22 patients (2.2%), respectively. Of the 427 men with full potency at baseline, 317 men (74%) retained sexual function at time of last follow-up. Conclusions: This study represents the largest cohort of patients treated with high-dose radiation to 86.4 Gy, using IMRT for localized prostate cancer, with the longest follow-up to date. Our findings indicate that this treatment results in excellent clinical outcomes with acceptable toxicity.

  13. Prediction of human observer performance in a 2-alternative forced choice low-contrast detection task using channelized Hotelling observer: Impact of radiation dose and reconstruction algorithms

    SciTech Connect (OSTI)

    Yu Lifeng; Leng Shuai; Chen Lingyun; Kofler, James M.; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Carter, Rickey E. [Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota 55905 (United States)

    2013-04-15T23:59:59.000Z

    Purpose: Efficient optimization of CT protocols demands a quantitative approach to predicting human observer performance on specific tasks at various scan and reconstruction settings. The goal of this work was to investigate how well a channelized Hotelling observer (CHO) can predict human observer performance on 2-alternative forced choice (2AFC) lesion-detection tasks at various dose levels and two different reconstruction algorithms: a filtered-backprojection (FBP) and an iterative reconstruction (IR) method. Methods: A 35 Multiplication-Sign 26 cm{sup 2} torso-shaped phantom filled with water was used to simulate an average-sized patient. Three rods with different diameters (small: 3 mm; medium: 5 mm; large: 9 mm) were placed in the center region of the phantom to simulate small, medium, and large lesions. The contrast relative to background was -15 HU at 120 kV. The phantom was scanned 100 times using automatic exposure control each at 60, 120, 240, 360, and 480 quality reference mAs on a 128-slice scanner. After removing the three rods, the water phantom was again scanned 100 times to provide signal-absent background images at the exact same locations. By extracting regions of interest around the three rods and on the signal-absent images, the authors generated 21 2AFC studies. Each 2AFC study had 100 trials, with each trial consisting of a signal-present image and a signal-absent image side-by-side in randomized order. In total, 2100 trials were presented to both the model and human observers. Four medical physicists acted as human observers. For the model observer, the authors used a CHO with Gabor channels, which involves six channel passbands, five orientations, and two phases, leading to a total of 60 channels. The performance predicted by the CHO was compared with that obtained by four medical physicists at each 2AFC study. Results: The human and model observers were highly correlated at each dose level for each lesion size for both FBP and IR. The Pearson's product-moment correlation coefficients were 0.986 [95% confidence interval (CI): 0.958-0.996] for FBP and 0.985 (95% CI: 0.863-0.998) for IR. Bland-Altman plots showed excellent agreement for all dose levels and lesions sizes with a mean absolute difference of 1.0%{+-} 1.1% for FBP and 2.1%{+-} 3.3% for IR. Conclusions: Human observer performance on a 2AFC lesion detection task in CT with a uniform background can be accurately predicted by a CHO model observer at different radiation dose levels and for both FBP and IR methods.

  14. Occupational dose reduction at Department of Energy contractor facilities: Bibliography of selected readings in radiation protection and ALARA

    SciTech Connect (OSTI)

    Dionne, B.J.; Sullivan, S.G.; Baum, J.W.

    1993-12-01T23:59:59.000Z

    This bibliography contains abstracts relating to various aspects of ALARA program implementation and dose reduction activities, with a focus on DOE facilities. Abstracts included in this bibliography were selected from proceedings of technical meetings, journals, research reports, searches of the DOE Energy, Science and Technology Database (in general, the citation and abstract information is presented as obtained from this database), and reprints of published articles provided by the authors. Facility types and activities covered in the scope of this report include: radioactive waste, uranium enrichment, fuel fabrication, spent fuel storage and reprocessing, facility decommissioning, hot laboratories, tritium production, research, test and production reactors, weapons fabrication and testing, fusion, uranium and plutonium processing, radiography, and aocelerators. Information on improved shielding design, decontamination, containments, robotics, source prevention and control, job planning, improved operational and design techniques, as well as on other topics, has been included. In addition, DOE/EH reports not included in previous volumes of the bibliography are in this volume (abstracts 611 to 684). This volume (Volume 5 of the series) contains 217 abstracts. An author index and a subject index are provided to facilitate use. Both indices contain the abstract numbers from previous volumes, as well as the current volume. Information that the reader feels might be included in the next volume of this bibliography should be submitted to the BNL ALARA Center.

  15. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2010-06-15T23:59:59.000Z

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  16. Radiation-resistant microorganism

    DOE Patents [OSTI]

    Fliermans, Carl B.

    2007-01-09T23:59:59.000Z

    An isolated and purified bacterium is provided which was isolated from a high-level radioactive waste site of mixed waste. The isolate has the ability to degrade a wide variety of organic contaminants while demonstrating high tolerance to ionizing radiation. The organism is uniquely suited to bioremediation of a variety or organic contaminants while in the presence of ionizing radiation.

  17. Recoil-Ion Momentum Distributions for Two-Photon Double Ionization of He and Ne by 44 eV Free-Electron Laser Radiation

    SciTech Connect (OSTI)

    Rudenko, A.; Moshammer, R.; Ullrich, J. [Max-Planck Advanced Study Group at CFEL, Notkestrasse 85, 22607 Hamburg (Germany); Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Foucar, L.; Havermeier, T.; Smolarski, M.; Schoessler, S.; Cole, K.; Schoeffler, M.; Doerner, R. [Institut fuer Kernphysik, Universitaet Frankfurt, 60486 Frankfurt (Germany); Kurka, M.; Ergler, Th.; Kuehnel, K. U.; Jiang, Y. H.; Voitkiv, A.; Najjari, B.; Luedemann, S.; Schroeter, C. D. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Kheifets, A. [Research School of Physical Sciences, Australian University, Canberra, ACT 0200 (Australia); Duesterer, S. [DESY, Notkestrasse 85, 22607 Hamburg (Germany)] (and others)

    2008-08-15T23:59:59.000Z

    Recoil-ion momentum distributions for two-photon double ionization of He and Ne (({Dirac_h}/2{pi}){omega}=44 eV) have been recorded with a reaction microscope at FLASH (the free-electron laser at Hamburg) at an intensity of {approx}1x10{sup 14} W/cm{sup 2} exploring the dynamics of the two fundamental two-photon-two-electron reaction pathways, namely, sequential and direct (or nonsequential) absorption of the photons. We find strong differences in the recoil-ion momentum patterns for the two mechanisms pointing to the significantly different two-electron emission dynamics and thus provide serious constraints for theoretical models.

  18. Dose optimization with first-order total-variation minimization for dense angularly sampled and sparse intensity modulated radiation therapy (DASSIM-RT)

    SciTech Connect (OSTI)

    Kim, Hojin; Li Ruijiang; Lee, Rena; Goldstein, Thomas; Boyd, Stephen; Candes, Emmanuel; Xing Lei [Department of Electrical Engineering, Stanford University, Stanford, California 94305-9505 (United States) and Department of Radiation Oncology, Stanford University, Stanford, California 94305-5847 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305-5847 (United States); Department of Radiation Oncology, Ehwa University, Seoul 158-710 (Korea, Republic of); Department of Electrical Engineering, Stanford University, Stanford, California 94305-9505 (United States); Department of Statistics, Stanford University, Stanford, California 94305-4065 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305-5304 (United States)

    2012-07-15T23:59:59.000Z

    Purpose: A new treatment scheme coined as dense angularly sampled and sparse intensity modulated radiation therapy (DASSIM-RT) has recently been proposed to bridge the gap between IMRT and VMAT. By increasing the angular sampling of radiation beams while eliminating dispensable segments of the incident fields, DASSIM-RT is capable of providing improved conformity in dose distributions while maintaining high delivery efficiency. The fact that DASSIM-RT utilizes a large number of incident beams represents a major computational challenge for the clinical applications of this powerful treatment scheme. The purpose of this work is to provide a practical solution to the DASSIM-RT inverse planning problem. Methods: The inverse planning problem is formulated as a fluence-map optimization problem with total-variation (TV) minimization. A newly released L1-solver, template for first-order conic solver (TFOCS), was adopted in this work. TFOCS achieves faster convergence with less memory usage as compared with conventional quadratic programming (QP) for the TV form through the effective use of conic forms, dual-variable updates, and optimal first-order approaches. As such, it is tailored to specifically address the computational challenges of large-scale optimization in DASSIM-RT inverse planning. Two clinical cases (a prostate and a head and neck case) are used to evaluate the effectiveness and efficiency of the proposed planning technique. DASSIM-RT plans with 15 and 30 beams are compared with conventional IMRT plans with 7 beams in terms of plan quality and delivery efficiency, which are quantified by conformation number (CN), the total number of segments and modulation index, respectively. For optimization efficiency, the QP-based approach was compared with the proposed algorithm for the DASSIM-RT plans with 15 beams for both cases. Results: Plan quality improves with an increasing number of incident beams, while the total number of segments is maintained to be about the same in both cases. For the prostate patient, the conformation number to the target was 0.7509, 0.7565, and 0.7611 with 80 segments for IMRT with 7 beams, and DASSIM-RT with 15 and 30 beams, respectively. For the head and neck (HN) patient with a complicated target shape, conformation numbers of the three treatment plans were 0.7554, 0.7758, and 0.7819 with 75 segments for all beam configurations. With respect to the dose sparing to the critical structures, the organs such as the femoral heads in the prostate case and the brainstem and spinal cord in the HN case were better protected with DASSIM-RT. For both cases, the delivery efficiency has been greatly improved as the beam angular sampling increases with the similar or better conformal dose distribution. Compared with conventional quadratic programming approaches, first-order TFOCS-based optimization achieves far faster convergence and smaller memory requirements in DASSIM-RT. Conclusions: The new optimization algorithm TFOCS provides a practical and timely solution to the DASSIM-RT or other inverse planning problem requiring large memory space. The new treatment scheme is shown to outperform conventional IMRT in terms of dose conformity to both the targetand the critical structures, while maintaining high delivery efficiency.

  19. Sexual Functioning Among Endometrial Cancer Patients Treated With Adjuvant High-Dose-Rate Intra-Vaginal Radiation Therapy

    SciTech Connect (OSTI)

    Damast, Shari, E-mail: shari.damast@yale.edu [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Alektiar, Kaled M. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Goldfarb, Shari [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Eaton, Anne; Patil, Sujata [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Mosenkis, Jeffrey [Department of Comparative Human Development, University of Chicago, Chicago, Illinois (United States)] [Department of Comparative Human Development, University of Chicago, Chicago, Illinois (United States); Bennett, Antonia [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Atkinson, Thomas [Department of Psychiatry, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Psychiatry, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Jewell, Elizabeth; Leitao, Mario; Barakat, Richard; Carter, Jeanne [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Basch, Ethan [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-10-01T23:59:59.000Z

    Purpose: We used the Female Sexual Function Index (FSFI) to investigate the prevalence of sexual dysfunction (SD) and factors associated with diminished sexual functioning in early stage endometrial cancer (EC) patients treated with simple hysterectomy and adjuvant brachytherapy. Methods and Materials: A cohort of 104 patients followed in a radiation oncology clinic completed questionnaires to quantify current levels of sexual functioning. The time interval between hysterectomy and questionnaire completion ranged from <6 months to >5 years. Multivariate regression was performed using the FSFI as a continuous variable (score range, 1.2-35.4). SD was defined as an FSFI score of <26, based on the published validation study. Results: SD was reported by 81% of respondents. The mean ({+-} standard deviation) domain scores in order of highest-to-lowest functioning were: satisfaction, 2.9 ({+-}2.0); orgasm, 2.5 ({+-}2.4); desire, 2.4 ({+-}1.3); arousal, 2.2 ({+-}2.0); dryness, 2.1 ({+-}2.1); and pain, 1.9 ({+-}2.3). Compared to the index population in which the FSFI cut-score was validated (healthy women ages 18-74), all scores were low. Compared to published scores of a postmenopausal population, scores were not statistically different. Multivariate analysis isolated factors associated with lower FSFI scores, including having laparotomy as opposed to minimally invasive surgery (effect size, -7.1 points; 95% CI, -11.2 to -3.1; P<.001), lack of vaginal lubricant use (effect size, -4.4 points; 95% CI, -8.7 to -0.2, P=.040), and short time interval (<6 months) from hysterectomy to questionnaire completion (effect size, -4.6 points; 95% CI, -9.3-0.2; P=.059). Conclusions: The rate of SD, as defined by an FSFI score <26, was prevalent. The postmenopausal status of EC patients alone is a known risk factor for SD. Additional factors associated with poor sexual functioning following treatment for EC included receipt of laparotomy and lack of vaginal lubricant use.

  20. Age and Comorbid Illness Are Associated With Late Rectal Toxicity Following Dose-Escalated Radiation Therapy for Prostate Cancer

    SciTech Connect (OSTI)

    Hamstra, Daniel A. [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Stenmark, Matt H.; Ritter, Tim [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States) [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Department of Radiation Oncology, Veterans Affairs Medical Center, Ann Arbor, Michigan (United States); Litzenberg, Dale; Jackson, William; Johnson, Skyler; Albrecht-Unger, Liesel; Donaghy, Alex; Phelps, Laura; Blas, Kevin; Halverson, Schuyler; Marsh, Robin; Olson, Karin [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States); Feng, Felix Y., E-mail: ffeng@med.umich.edu [Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, Michigan (United States)

    2013-04-01T23:59:59.000Z

    Purpose: To assess the impacts of patient age and comorbid illness on rectal toxicity following external beam radiation therapy (EBRT) for prostate cancer and to assess the Qualitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) normal tissue complication probability (NTCP) model in this context. Methods and Materials: Rectal toxicity was analyzed in 718 men previously treated for prostate cancer with EBRT (?75 Gy). Comorbid illness was scored using the Charlson Comorbidity Index (CCMI), and the NTCP was evaluated with the QUANTEC model. The influence of clinical and treatment-related parameters on rectal toxicity was assessed by Kaplan-Meier and Cox proportional hazards models. Results: The cumulative incidence of rectal toxicity grade ?2 was 9.5% and 11.6% at 3 and 5 years and 3.3% and 3.9% at 3 and 5 years for grade ?3 toxicity, respectively. Each year of age predicted an increasing relative risk of grade ?2 (P<.03; hazard ratio [HR], 1.04 [95% confidence interval (CI), 1.01-1.06]) and ?3 rectal toxicity (P<.0001; HR, 1.14 [95% CI,1.07-1.22]). Increasing CCMI predicted rectal toxicity where a history of either myocardial infarction (MI) (P<.0001; HR, 5.1 [95% CI, 1.9-13.7]) or congestive heart failure (CHF) (P<.0006; HR, 5.4 [95% CI, 0.6-47.5]) predicted grade ?3 rectal toxicity, with lesser correlation with grade ?2 toxicity (P<.02 for MI, and P<.09 for CHF). An age comorbidity model to predict rectal toxicity was developed and confirmed in a validation cohort. The use of anticoagulants increased toxicity independent of age and comorbidity. NTCP was prognostic for grade ?3 (P=.015) but not grade ?2 (P=.49) toxicity. On multivariate analysis, age, MI, CHF, and an NTCP >20% all correlated with late rectal toxicity. Conclusions: Patient age and a history of MI or CHF significantly impact rectal toxicity following EBRT for the treatment of prostate cancer, even after controlling for NTCP.

  1. Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. (comps.)

    1991-01-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms; environmental transport environmental monitoring data; demographics, agriculture, food habits; environmental pathways and dose estimates.

  2. Radiation effects in SYNROC-D

    SciTech Connect (OSTI)

    Van Konynenburg, R.A.; Guinan, M.W.

    1981-09-30T23:59:59.000Z

    This paper describes SYNROC-D and the irradiation it will be subjected to over the first million years of storage. This will include about 8 x 10/sup 24/ alpha decays per m/sup 3/ and a total ionization dose of about 1 x 10/sup 11/ rads. Methods of simulating the radiation effects are discussed. Previous work by others is reviewed and compared on a dpa basis. /sup 238/Pu doping experiments to simulate internal alpha decay are described, and the progress is discussed. It is concluded that dose rate effects on swelling and metamictization of perovskite and zirconolite are small over a wide range of dose rate, and that swelling and metamictization in these minerals does not anneal significantly over geological time periods.

  3. Analysis of radiation doses from operation of postulated commercial spent fuel transportation systems: Analysis of a system containing a monitored retrievable storage facility. Addendum 1

    SciTech Connect (OSTI)

    Smith, R.I.; Daling, P.M. [Pacific Northwest Lab., Richland, WA (United States); Faletti, D.W. [Westinghouse Hanford Co., Richland, WA (United States)

    1992-04-01T23:59:59.000Z

    This addendum report extends the original study of the estimated radiation doses to the public and to workers resulting from transporting spent nuclear fuel from commercial nuclear power reactor stations through the federal waste management system (FWMS), to a system that contains a monitored retrievable storage (MRS) facility. The system concepts and designs utilized herein are consistent with those used in the original study (circa 1985--1987). Because the FWMS design is still evolving, the results of these analyses may no longer apply to the design for casks and cask handling systems that are currently being considered. Four system scenarios are examined and compared with the reference No-MRS scenario (all spent fuel transported directly from the reactors to the western repository in standard-capacity truck and rail casks). In Scenarios 1 and 2, an MRS facility is located in eastern United States and ships either intact fuel assemblies or consolidated fuel rods and compacted assembly hardware in canisters. In Scenarios 3 and 4, an MRS facility is located in the western United States and ship either intact fuel assemblies or consolidated fuel rods and compacted assembly hardware in canisters.

  4. Quality Services: Radiation (New York)

    Broader source: Energy.gov [DOE]

    These regulations establish standards for protection against ionizing radiation resulting from the disposal and discharge of radioactive material to the environment. The regulations apply to any...

  5. Multiscale non-adiabatic dynamics with radiative decay, case study on the post-ionization fragmentation of rare-gas tetramers

    E-Print Network [OSTI]

    Ivan Jane?ek; Tomáš Jan?a; Pavel Naar; Frederic Renard; René Kalus; Florent X. Gadéa

    2012-03-08T23:59:59.000Z

    In this supplementary material, we recollect, for reader's convenience, the general scheme of suggested multiscale model (Sec. 1), and basic informations about approaches used for pilot study: a detailed description of the interaction model (Sec. 2) and dynamical methods used for the dark dynamics step (Sec. 3) reported previously in two preceding studies [1, 2]. In addition, a detailed description of the treatment of radiative processes is also given (Sec. 4).

  6. Multiscale non-adiabatic dynamics with radiative decay, case study on the post-ionization fragmentation of rare-gas tetramers

    E-Print Network [OSTI]

    Jane?ek, Ivan; Naar, Pavel; Renard, Frederic; Kalus, René; Gadéa, Florent X

    2012-01-01T23:59:59.000Z

    In this supplementary material, we recollect, for reader's convenience, the general scheme of suggested multiscale model (Sec. 1), and basic informations about approaches used for pilot study: a detailed description of the interaction model (Sec. 2) and dynamical methods used for the dark dynamics step (Sec. 3) reported previously in two preceding studies [1, 2]. In addition, a detailed description of the treatment of radiative processes is also given (Sec. 4).

  7. Analytic 1D pn junction diode photocurrent solutions following ionizing radiation and including time-dependent changes in the carrier lifetime.

    SciTech Connect (OSTI)

    Axness, Carl L.; Keiter, Eric Richard; Kerr, Bert (New Mexico Tech, Socorro, NM)

    2011-04-01T23:59:59.000Z

    Circuit simulation tools (e.g., SPICE) have become invaluable in the development and design of electronic circuits in radiation environments. These codes are often employed to study the effect of many thousands of devices under transient current conditions. Device-scale simulation tools (e.g., MEDICI) are commonly used in the design of individual semiconductor components, but require computing resources that make their incorporation into a circuit code impossible for large-scale circuits. Analytic solutions to the ambipolar diffusion equation, an approximation to the carrier transport equations, may be used to characterize the transient currents at nodes within a circuit simulator. We present new transient 1D excess carrier density and photocurrent density solutions to the ambipolar diffusion equation for low-level radiation pulses that take into account a finite device geometry, ohmic fields outside the depleted region, and an arbitrary change in the carrier lifetime due to neutron irradiation or other effects. The solutions are specifically evaluated for the case of an abrupt change in the carrier lifetime during or after, a step, square, or piecewise linear radiation pulse. Noting slow convergence of the raw Fourier series for certain parameter sets, we use closed-form formulas for some of the infinite sums to produce 'partial closed-form' solutions for the above three cases. These 'partial closed-form' solutions converge with only a few tens of terms, which enables efficient large-scale circuit simulations.

  8. Prediction of proton and neutron absorbed-dose distributions in proton beam radiation therapy using Monte Carlo n-particle transport code (MCNPX)

    E-Print Network [OSTI]

    Massingill, Brian Edward

    2009-05-15T23:59:59.000Z

    The objective of this research was to develop a complex MCNPX model of the human head to predict absorbed dose distributions during proton therapy of ocular tumors. Absorbed dose distributions using the complex geometry were compared to a simple...

  9. Prediction of proton and neutron absorbed-dose distributions in proton beam radiation therapy using Monte Carlo n-particle transport code (MCNPX) 

    E-Print Network [OSTI]

    Massingill, Brian Edward

    2009-05-15T23:59:59.000Z

    The objective of this research was to develop a complex MCNPX model of the human head to predict absorbed dose distributions during proton therapy of ocular tumors. Absorbed dose distributions using the complex geometry were compared to a simple...

  10. Radiation-induced Genomic Instability and Radiation Sensitivity

    SciTech Connect (OSTI)

    Varnum, Susan M.; Sowa, Marianne B.; Kim, Grace J.; Morgan, William F.

    2013-01-19T23:59:59.000Z

    The obvious relationships between reactive oxygen and nitrogen species, mitochondrial dysfunction, inflammatory type responses and reactive chemokines and cytokines suggests a general stress response induced by ionizing radiation most likely leads to the non-targeted effects described after radiation exposure. We argue that true bystander effects do not occur in the radiation therapy clinic. But there is no question that effects outside the target volume do occur. These “out of field effects” are considered very low dose effects in the context of therapy. So what are the implications of non-targeted effects on radiation sensitivity? The primary goal of therapy is to eradicate the tumor. Given the genetic diversity of the human population, lifestyle and environment factors it is likely some combination of these will influence patient outcome. Non-targeted effects may contribute to a greater or lesser extent. But consider the potential situation involving a partial body exposure due to a radiation accident or radiological terrorism. Non-targeted effects suggest that the tissue at risk for demonstrating possible detrimental effects of radiation exposure might be greater than the volume actually irradiated.

  11. Dose rate dependence for different dosimeters and detectors: TLD, OSL, EBT films, and diamond detectors

    SciTech Connect (OSTI)

    Karsch, L.; Beyreuther, E.; Burris-Mog, T.; Kraft, S.; Richter, C.; Zeil, K.; Pawelke, J. [OncoRay-National Center for Radiation Research in Oncology, Technische Universitaet Dresden, Fetscherstr, 74, 01307 Dresden (Germany); Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, P.O. Box 510119, 01314 Dresden (Germany); OncoRay-National Center for Radiation Research in Oncology, Technische Universitaet Dresden, Fetscherstr, 74, 01307 Dresden (Germany) and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, P.O. Box 510119, 01314 Dresden (Germany)

    2012-05-15T23:59:59.000Z

    Purpose: The use of laser accelerators in radiation therapy can perhaps increase the low number of proton and ion therapy facilities in some years due to the low investment costs and small size. The laser-based acceleration technology leads to a very high peak dose rate of about 10{sup 11} Gy/s. A first dosimetric task is the evaluation of dose rate dependence of clinical dosimeters and other detectors. Methods: The measurements were done at ELBE, a superconductive linear electron accelerator which generates electron pulses with 5 ps length at 20 MeV. The different dose rates are reached by adjusting the number of electrons in one beam pulse. Three clinical dosimeters (TLD, OSL, and EBT radiochromic films) were irradiated with four different dose rates and nearly the same dose. A faraday cup, an integrating current transformer, and an ionization chamber were used to control the particle flux on the dosimeters. Furthermore two diamond detectors were tested. Results: The dosimeters are dose rate independent up to 410{sup 9} Gy/s within 2% (OSL and TLD) and up to 1510{sup 9} Gy/s within 5% (EBT films). The diamond detectors show strong dose rate dependence. Conclusions: TLD, OSL dosimeters, and EBT films are suitable for pulsed beams with a very high pulse dose rate like laser accelerated particle beams.

  12. Direct 2-Arm Comparison Shows Benefit of High-Dose-Rate Brachytherapy Boost vs External Beam Radiation Therapy Alone for Prostate Cancer

    SciTech Connect (OSTI)

    Khor, Richard [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia)] [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia); Duchesne, Gillian [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia) [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia); Monash University, Melbourne (Australia); Tai, Keen-Hun; Foroudi, Farshad; Chander, Sarat; Van Dyk, Sylvia; Garth, Margaret [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia)] [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia); Williams, Scott, E-mail: Scott.Williams@petermac.org [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia)] [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, and University of Melbourne, Melbourne (Australia)

    2013-03-01T23:59:59.000Z

    Purpose: To evaluate the outcomes of patients treated for intermediate- and high-risk prostate cancer with a single schedule of either external beam radiation therapy (EBRT) and high-dose-rate brachytherapy (HDRB) boost or EBRT alone. Methods and Materials: From 2001-2006, 344 patients received EBRT with HDRB boost for definitive treatment of intermediate- or high-risk prostate cancer. The prescribed EBRT dose was 46 Gy in 23 fractions, with a HDR boost of 19.5 Gy in 3 fractions. This cohort was compared to a contemporaneously treated cohort who received EBRT to 74 Gy in 37 fractions, using a matched pair analysis. Three-dimensional conformal EBRT was used. Matching was performed using a propensity score matching technique. High-risk patients constituted 41% of the matched cohorts. Five-year clinical and biochemical outcomes were analyzed. Results: Initial significant differences in prognostic indicators between the unmatched treatment cohorts were rendered negligible after matching, providing a total of 688 patients. Median biochemical follow-up was 60.5 months. The 5-year freedom from biochemical failure was 79.8% (95% confidence interval [CI], 74.3%-85.0%) and 70.9% (95% CI, 65.4%-76.0%) for the HDRB and EBRT groups, respectively, equating to a hazard ratio of 0.59 (95% CI, 0.43-0.81, P=.0011). Interaction analyses showed no alteration in HDR efficacy when planned androgen deprivation therapy was administered (P=.95), but a strong trend toward reduced efficacy was shown compared to EBRT in high-risk cases (P=.06). Rates of grade 3 urethral stricture were 0.3% (95% CI, 0%-0.9%) and 11.8% (95% CI, 8.1%-16.5%) for EBRT and HDRB, respectively (P<.0001). No differences in clinical outcomes were observed. Conclusions: This comparison of 2 individual contemporaneously treated HDRB and EBRT approaches showed improved freedom from biochemical progression with the HDR approach. The benefit was more pronounced in intermediate- risk patients but needs to be weighed against an increased risk of urethral toxicity.

  13. Gleason Pattern 5 Is the Greatest Risk Factor for Clinical Failure and Death From Prostate Cancer After Dose-Escalated Radiation Therapy and Hormonal Ablation

    SciTech Connect (OSTI)

    Sabolch, Aaron [University of Michigan Medical School, Ann Arbor, MI (United States); Feng, Felix Y. [University of Michigan Medical School, Ann Arbor, MI (United States); Department of Radiation Oncology, Ann Arbor, MI (United States); Veterans Administration Medical Center, Ann Arbor, MI (United States); Daignault-Newton, Stephanie [University of Michigan Medical School, Ann Arbor, MI (United States); Division of Biostatistics, Ann Arbor, MI (United States); Halverson, Schuyler; Blas, Kevin; Phelps, Laura [University of Michigan Medical School, Ann Arbor, MI (United States); Olson, Karin B. [University of Michigan Medical School, Ann Arbor, MI (United States); Department of Radiation Oncology, Ann Arbor, MI (United States); Sandler, Howard M. [Department of Radiation Oncology, Cedars Sinai Medical Center, Los Angeles, CA (United States); Hamstra, Daniel A., E-mail: dhamm@med.umich.edu [Department of Radiation Oncology, Ann Arbor, MI (United States)

    2011-11-15T23:59:59.000Z

    Purpose: The division of Gleason score (GS) into three categories (2-6, 7, 8-10) may not fully use its prognostic power, as revealed by recent reports demonstrating the presence of Gleason Pattern 5 (GP5) as a strong predictor for biochemical recurrence. Therefore, we analyzed the clinical outcomes in patients treated with dose-escalated radiation therapy (RT) based on the presence or absence of GP5. Methods and Materials: Outcomes were analyzed for 718 men treated for localized prostate cancer with external-beam RT to a minimum planning target volume dose of at least 75 Gy. We assessed the impact of GP5 and that of pretreatment- and treatment-related factors on freedom from biochemical failure, freedom from metastasis (FFM), cause-specific survival (CSS), and overall survival (OS). Results: At biopsy, 89% of patients had no GP5, and 11% (76/718) had GP5. There were no differences in age, comorbid illness, T stage, prostate-specific antigen, or the use or duration of androgen deprivation therapy between GS8 without GP5 and GS8-10 with GP5. The presence of GP5 predicted lower FFM (p < 0.002; hazard ratio [HR] 3.4 [1.7-7.1]); CSS (p < 0.0001; HR 12.9 [5.4-31]); and OS (p < 0.0001; HR 3.6 [2.0-6.5]) in comparison with GS8 (without GP5). The 8-year FFM, CSS, and OS were 89%, 98%, and 57%, respectively, for those with Gleason 8 prostate cancer without GP5 in comparison with 61%, 55%, and 31%, respectively, for those with GP5. In addition, both FFM and CSS were strongly influenced by androgen deprivation therapy given concurrently with RT. On multivariate analysis, GP5 was the strongest prognostic factor for all clinical endpoints, including OS. Conclusion: The presence of GP5 predicts for worse clinical behavior, which therefore needs to be accounted for by risk stratification schemes. Further intensification of local and/or systemic therapy may be appropriate for such patients.

  14. Optical absorption and ionization of silicate glasses Leonid B. Glebov

    E-Print Network [OSTI]

    Glebov, Leon

    Optical absorption and ionization of silicate glasses Leonid B. Glebov School of Optics and hydroxyl), and induced (color centers) absorption of multicomponent silicate glasses in UV, visible-photon ionization was detected in alkaline-silicate glasses exposed to high-power laser radiation in nano

  15. Comparison of secondary neutron dose in proton therapy resulting from the use of a tungsten alloy MLC or a brass collimator system

    SciTech Connect (OSTI)

    Diffenderfer, Eric S.; Ainsley, Christopher G.; Kirk, Maura L.; McDonough, James E.; Maughan, Richard L. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2011-11-15T23:59:59.000Z

    Purpose: To apply the dual ionization chamber method for mixed radiation fields to an accurate comparison of the secondary neutron dose arising from the use of a tungsten alloy multileaf collimator (MLC) as opposed to a brass collimator system for defining the shape of a therapeutic proton field. Methods: Hydrogenous and nonhydrogenous ionization chambers were constructed with large volumes to enable measurements of absorbed doses below 10{sup -4} Gy in mixed radiation fields using the dual ionization chamber method for mixed-field dosimetry. Neutron dose measurements were made with a nominal 230 MeV proton beam incident on a closed tungsten alloy MLC and a solid brass block. The chambers were cross-calibrated against a {sup 60}Co-calibrated Farmer chamber in water using a 6 MV x-ray beam and Monte Carlo simulations were performed to account for variations in ionization chamber response due to differences in secondary neutron energy spectra. Results: The neutron and combined proton plus {gamma}-ray absorbed doses are shown to be nearly equivalent downstream from either a closed tungsten alloy MLC or a solid brass block. At 10 cm downstream from the distal edge of the collimating material the neutron dose from the closed MLC was (5.3 {+-} 0.4) x 10{sup -5} Gy/Gy. The neutron dose with brass was (6.4 {+-} 0.7) x 10{sup -5} Gy/Gy. Further from the secondary neutron source, at 50 cm, the neutron doses remain close for both the MLC and brass block at (6.9 {+-} 0.6) x 10{sup -6} Gy/Gy and (6.3 {+-} 0.7) x 10{sup -6} Gy/Gy, respectively. Conclusions: The dual ionization chamber method is suitable for measuring secondary neutron doses resulting from proton irradiation. The results of measurements downstream from a closed tungsten alloy MLC and a brass block indicate that, even in an overly pessimistic worst-case scenario, secondary neutron production in a tungsten alloy MLC leads to absorbed doses that are nearly equivalent to those seen from brass collimators. Therefore, the choice of tungsten alloy in constructing the leaves of a proton MLC is appropriate, and does not lead to a substantial increase in the secondary neutron dose to the patient compared to that generated in a brass collimator.

  16. THE CONTRIBUTION OF MODERN MEDICAL IMAGING TECHNOLOGY TO RADIATION HEALTH EFFECTS IN EXPOSED POPULATIONS

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01T23:59:59.000Z

    than for radiation and nuclear energy. Furthermore, unlessof ionizing radiation: Implications for nuclear energy andby radiation as a result of exposure from nuclear power

  17. THE BEIR-III REPORT AND THE HEALTH EFFECTS OF LOW-LEVEL RADIATION

    E-Print Network [OSTI]

    Fabrikant, J.I.

    2010-01-01T23:59:59.000Z

    of such risks from radiation in nuclear energy, as is doneof ionizing radiation: Implications for nuclear energy andlevel radiation and linked to public acceptance of nuclear

  18. High-Dose Hypofractionated Proton Beam Radiation Therapy Is Safe and Effective for Central and Peripheral Early-Stage Non-Small Cell Lung Cancer: Results of a 12-Year Experience at Loma Linda University Medical Center

    SciTech Connect (OSTI)

    Bush, David A., E-mail: dbush@llu.edu [Department of Radiation Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Cheek, Gregory [Department of Pulmonary Medicine, Loma Linda University Medical Center, Loma Linda, California (United States); Zaheer, Salman; Wallen, Jason [Department of Thoracic Surgery, Loma Linda University Medical Center, Loma Linda, California (United States); Mirshahidi, Hamid [Department of Medical Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Katerelos, Ari; Grove, Roger; Slater, Jerry D. [Department of Radiation Oncology, Loma Linda University Medical Center, Loma Linda, California (United States)

    2013-08-01T23:59:59.000Z

    Purpose: We update our previous reports on the use of hypofractionated proton beam radiation therapy for early-stage lung cancer patients. Methods and Materials: Eligible subjects had biopsy-proven non-small cell carcinoma of the lung and were medically inoperable or refused surgery. Clinical workup required staging of T1 or T2, N0, M0. Subjects received hypofractionated proton beam therapy to the primary tumor only. The dose delivered was sequentially escalated from 51 to 60 Gy, then to 70 Gy in 10 fractions over 2 weeks. Endpoints included toxicity, pulmonary function, overall survival (OS), disease-specific survival (DSS), and local control (LC). Results: One hundred eleven subjects were analyzed for treatment outcomes. The patient population had the following average characteristics; age 73.2 years, tumor size 3.6 cm, and 1.33 L forced expiratory volume in 1 second. The entire group showed improved OS with increasing dose level (51, 60, and 70 Gy) with a 4-year OS of 18%, 32%, and 51%, respectively (P=.006). Peripheral T1 tumors exhibited LC of 96%, DSS of 88%, and OS of 60% at 4 years. Patients with T2 tumors showed a trend toward improved LC and survival with the 70-Gy dose level. On multivariate analysis, larger tumor size was strongly associated with increased local recurrence and decreased survival. Central versus peripheral location did not correlate with any outcome measures. Clinical radiation pneumonitis was not found to be a significant complication, and no patient required steroid therapy after treatment for radiation pneumonitis. Pulmonary function was well maintained 1 year after treatment. Conclusions: High-dose hypofractionated proton therapy achieves excellent outcomes for lung carcinomas that are peripherally or centrally located. The 70-Gy regimen has been adopted as standard therapy for T1 tumors at our institution. Larger T2 tumors show a trend toward improved outcomes with higher doses, suggesting that better results could be seen with intensified treatment.

  19. Radiation events in astronomical CCD images

    E-Print Network [OSTI]

    2001-01-01T23:59:59.000Z

    268. 10. “On the Rates of Radiation Events in CCD’s (Excerpt23 Jan 2002 LBNL-49316 Radiation events in astronomical CCDof depleted silicon to ionizing radiation is a nuisance to

  20. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1992--November 30, 1993

    SciTech Connect (OSTI)

    Hall, E.J.; Zaider, M.

    1993-05-01T23:59:59.000Z

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ``biological fingerprint`` of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  1. Health effects models for nuclear power plant accident consequence analysis: Modifications of models resulting from recent reports on health effects of ionizing radiation

    SciTech Connect (OSTI)

    Abrahamson, S. (Wisconsin Univ., Madison, WI (United States)); Bender, M.A. (Brookhaven National Lab., Upton, NY (United States)); Boecker, B.B.; Scott, B.R. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.); Gilbert, E.S. (Pacific Northwest Lab., Richland, WA (United States))

    1991-08-01T23:59:59.000Z

    The Nuclear Regulatory Commission has sponsored several studies to identify and quantify the potential health effects of accidental releases of radionuclides from nuclear power plants. The most recent health effects models resulting from these efforts were published in two reports, NUREG/CR-4214, Rev. 1, Part 1 (1990) and Part 2 (1989). Several major health effects reports have been published recently that may impact the health effects models presented in these reports. This addendum to the Part 2 (1989) report, provides a review of the 1986 and 1988 reports by the United Nations Scientific Committee on the Effects of Atomic Radiation, the National Academy of Sciences/National Research Council BEAR 5 Committee report and Publication 60 of the International Commission on Radiological Protection as they relate to this report. The three main sections of this addendum discuss early occurring and continuing effects, late somatic effects, and genetic effects. The major changes to the NUREG/CR-4214 health effects models recommended in this addendum are for late somatic effects. These changes reflect recent changes in cancer risk factors that have come from longer followup and revised dosimetry in major studies like that on the Japanese A-bomb survivors. The results presented in this addendum should be used with the basic NUREG/CR-4214 reports listed above to obtain the most recent views on the potential health effects of radionuclides released accidentally from nuclear power plants. 48 refs., 4 figs., 24 tabs.

  2. (Ionization in liquids)

    SciTech Connect (OSTI)

    Not Available

    1991-01-01T23:59:59.000Z

    This document describes charge transport following ionization of model liquids and how this process may be important in carcinogenesis. 15 refs., 2 figs., 4 tabs. (MHB)

  3. Dose Reduction Techniques

    SciTech Connect (OSTI)

    WAGGONER, L.O.

    2000-05-16T23:59:59.000Z

    As radiation safety specialists, one of the things we are required to do is evaluate tools, equipment, materials and work practices and decide whether the use of these products or work practices will reduce radiation dose or risk to the environment. There is a tendency for many workers that work with radioactive material to accomplish radiological work the same way they have always done it rather than look for new technology or change their work practices. New technology is being developed all the time that can make radiological work easier and result in less radiation dose to the worker or reduce the possibility that contamination will be spread to the environment. As we discuss the various tools and techniques that reduce radiation dose, keep in mind that the radiological controls should be reasonable. We can not always get the dose to zero, so we must try to accomplish the work efficiently and cost-effectively. There are times we may have to accept there is only so much you can do. The goal is to do the smart things that protect the worker but do not hinder him while the task is being accomplished. In addition, we should not demand that large amounts of money be spent for equipment that has marginal value in order to save a few millirem. We have broken the handout into sections that should simplify the presentation. Time, distance, shielding, and source reduction are methods used to reduce dose and are covered in Part I on work execution. We then look at operational considerations, radiological design parameters, and discuss the characteristics of personnel who deal with ALARA. This handout should give you an overview of what it takes to have an effective dose reduction program.

  4. Biological doses with template distribution patterns

    SciTech Connect (OSTI)

    Harrop, R. (Simon Fraer Univ., Burnaby, British Columbia); Haymond, H.R.; Nisar, A.; Syed, A.N.M.; Feder, B.H.; Neblett, D.L.

    1981-02-01T23:59:59.000Z

    Consideration of radiation dose rate effects emphasizes advantages of the template method for lateral distribution of multiple sources in treatment of laterally infiltrating gynecologic cancer, when compared to a conventional technique with colpostats. Biological doses in time dose fractionation (TDF), ret and reu units are calculated for the two treatment methods. With the template method the lateral dose (point B) is raised without significantly increasing the doses to the rectum and bladder, that is, relatively, the calculated biological doses at point A and B are more nearly equivalent and the doses to the rectum and bladder are significantly lower than the dose to point B.

  5. Research priorities for occupational radiation protection

    SciTech Connect (OSTI)

    Not Available

    1994-02-01T23:59:59.000Z

    The Subpanel on Occupational Radiation Protection Research concludes that the most urgently needed research is that leading to the resolution of the potential effects of low-level ionizing radiation. This is the primary driving force in setting appropriate radiation protection standards and in directing the emphasis of radiation protection efforts. Much has already been done in collecting data that represents a compendium of knowledge that should be fully reviewed and understood. It is imperative that health physics researchers more effectively use that data and apply the findings to enhance understanding of the potential health effects of low-level ionizing radiation and improve the risk estimates upon which current occupational radiation protection procedures and requirements depend. Research must be focused to best serve needs in the immediate years ahead. Only then will we get the most out of what is accomplished. Beyond the above fundamental need, a number of applied research areas also have been identified as national priority issues. If effective governmental focus is achieved on several of the most important national priority issues, important occupational radiation protection research will be enhanced, more effectively coordinated, and more quickly applied to the work environment. Response in the near term will be enhanced and costs will be reduced by: developing microprocessor-aided {open_quotes}smart{close_quotes} instruments to simplify the use and processing of radiation data; developing more sensitive, energy-independent, and tissue-equivalent dosimeters to more accurately quantify personnel dose; and developing an improved risk assessment technology base. This can lead to savings of millions of dollars in current efforts needed to ensure personnel safety and to meet new, more stringent occupational guidelines.

  6. Quantitative assessment of the accuracy of dose calculation using pencil beam and Monte Carlo algorithms and requirements for clinical quality assurance

    SciTech Connect (OSTI)

    Ali, Imad, E-mail: iali@ouhsc.edu [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States); Ahmad, Salahuddin [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2013-10-01T23:59:59.000Z

    To compare the doses calculated using the BrainLAB pencil beam (PB) and Monte Carlo (MC) algorithms for tumors located in various sites including the lung and evaluate quality assurance procedures required for the verification of the accuracy of dose calculation. The dose-calculation accuracy of PB and MC was also assessed quantitatively with measurement using ionization chamber and Gafchromic films placed in solid water and heterogeneous phantoms. The dose was calculated using PB convolution and MC algorithms in the iPlan treatment planning system from BrainLAB. The dose calculation was performed on the patient's computed tomography images with lesions in various treatment sites including 5 lungs, 5 prostates, 4 brains, 2 head and necks, and 2 paraspinal tissues. A combination of conventional, conformal, and intensity-modulated radiation therapy plans was used in dose calculation. The leaf sequence from intensity-modulated radiation therapy plans or beam shapes from conformal plans and monitor units and other planning parameters calculated by the PB were identical for calculating dose with MC. Heterogeneity correction was considered in both PB and MC dose calculations. Dose-volume parameters such as V95 (volume covered by 95% of prescription dose), dose distributions, and gamma analysis were used to evaluate the calculated dose by PB and MC. The measured doses by ionization chamber and EBT GAFCHROMIC film in solid water and heterogeneous phantoms were used to quantitatively asses the accuracy of dose calculated by PB and MC. The dose-volume histograms and dose distributions calculated by PB and MC in the brain, prostate, paraspinal, and head and neck were in good agreement with one another (within 5%) and provided acceptable planning target volume coverage. However, dose distributions of the patients with lung cancer had large discrepancies. For a plan optimized with PB, the dose coverage was shown as clinically acceptable, whereas in reality, the MC showed a systematic lack of dose coverage. The dose calculated by PB for lung tumors was overestimated by up to 40%. An interesting feature that was observed is that despite large discrepancies in dose-volume histogram coverage of the planning target volume between PB and MC, the point doses at the isocenter (center of the lesions) calculated by both algorithms were within 7% even for lung cases. The dose distributions measured with EBT GAFCHROMIC films in heterogeneous phantoms showed large discrepancies of nearly 15% lower than PB at interfaces between heterogeneous media, where these lower doses measured by the film were in agreement with those by MC. The doses (V95) calculated by MC and PB agreed within 5% for treatment sites with small tissue heterogeneities such as the prostate, brain, head and neck, and paraspinal tumors. Considerable discrepancies, up to 40%, were observed in the dose-volume coverage between MC and PB in lung tumors, which may affect clinical outcomes. The discrepancies between MC and PB increased for 15 MV compared with 6 MV indicating the importance of implementation of accurate clinical treatment planning such as MC. The comparison of point doses is not representative of the discrepancies in dose coverage and might be misleading in evaluating the accuracy of dose calculation between PB and MC. Thus, the clinical quality assurance procedures required to verify the accuracy of dose calculation using PB and MC need to consider measurements of 2- and 3-dimensional dose distributions rather than a single point measurement using heterogeneous phantoms instead of homogenous water-equivalent phantoms.

  7. Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. Estimation of radiation dose to man resulting from biotic transport: the BIOPORT/MAXI1 software package. Volume 5

    SciTech Connect (OSTI)

    McKenzie, D.H.; Cadwell, L.L.; Gano, K.A.; Kennedy, W.E. Jr.; Napier, B.A.; Peloquin, R.A.; Prohammer, L.A.; Simmons, M.A.

    1985-10-01T23:59:59.000Z

    BIOPORT/MAXI1 is a collection of five computer codes designed to estimate the potential magnitude of the radiation dose to man resulting from biotic transport processes. Dose to man is calculated for ingestion of agricultural crops grown in contaminated soil, inhalation of resuspended radionuclides, and direct exposure to penetrating radiation resulting from the radionuclide concentrations established in the available soil surface by the biotic transport model. This document is designed as both an instructional and reference document for the BIOPORT/MAXI1 computer software package and has been written for two major audiences. The first audience includes persons concerned with the mathematical models of biological transport of commercial low-level radioactive wastes and the computer algorithms used to implement those models. The second audience includes persons concerned with exercising the computer program and exposure scenarios to obtain results for specific applications. The report contains sections describing the mathematical models, user operation of the computer programs, and program structure. Input and output for five sample problems are included. In addition, listings of the computer programs, data libraries, and dose conversion factors are provided in appendices.

  8. The change of radiation doses to the patient when switching from conventional technique to digital technique without films in barium enema and IVU examinations. Final report SSI research project P933

    E-Print Network [OSTI]

    Sjöholm, B

    2003-01-01T23:59:59.000Z

    X-ray examinations of the colon (barium enema) and the kidneys (IVU) are combined with rather high radiation doses to the patients when using analogue technique with film-screen systems. It is therefore of great interest to see if the change from analogue to digital technique involves a reduction of doses. Barium enema and IVU examinations were monitored with DAP-meters before and after the X-ray department changed to digital techniques. For IVU also the change from storage phosphor plates to a Direct Digital detector is included. The study comprises between 53 and 87 patients for each modality of the two examinations. A considerable dose reduction was observed. In barium enema the overview images with large field sizes were omitted when using digital technique. On the other hand the number of spot images was increased from 6 to 22. The fluoroscopy time was increased from 4 minutes to 6 minutes. The DAP value was reduced from 54,3 Gy cm sup 2 to 21,9 Gy cm sup 2. For IVU a dose reduction from 44,5 Gy cm sup 2...

  9. Plasmadynamics and ionization kinetics of thermionic energy conversion

    SciTech Connect (OSTI)

    Lawless, J.L. Jr.; Lam, S.H.

    1982-02-01T23:59:59.000Z

    To reduce the plasma arc-drop, thermionic energy conversion is studied with both analytical and numerical tools. Simplifications are made in both the plasmadynamic and ionization-recombination theories. These are applied to a scheme proposed presently using laser irradiation to enhance the ionization kinetics of the thermionic plasma and thereby reduce the arc-drop. It is also predicted that it is possible to generate the required laser light from a thermionic-type cesium plasma. The analysis takes advantage of theoretical simplifications derived for the ionization-recombination kinetics. It is shown that large laser ionization enhancements can occur and that collisional cesium recombination lasing is expected. To complement the kinetic theory, a numerical method is developed to solve the thermionic plasma dynamics. To combine the analysis of ionization-recombination kinetics with the plasma dynamics of thermionic conversion, a finite difference computer program is constructed. It is capable of solving for both unsteady and steady thermionic converter behavior including possible laser ionization enhancement or atomic recombination lasing. A proposal to improve thermionic converter performance using laser radiation is considered. In this proposed scheme, laser radiation impinging on a thermionic plasma enhances the ionization process thereby raising the plasma density and reducing the plasma arc-drop. A source for such radiation may possibly be a cesium recombination laser operating in a different thermionic converter. The possibility of this being an energy efficient process is discussed. (WHK)

  10. New Insights into Fully-Depleted SOI Transistor Response During Total-Dose Irradiation

    SciTech Connect (OSTI)

    BURNS,J.A.; DODD,PAUL E.; KEAST,C.L.; SCHWANK,JAMES R.; SHANEYFELT,MARTY R.; WYATT,P.W.

    1999-09-14T23:59:59.000Z

    Previous work showed the possible existence of a total-dose latch effect in fully-depleted SOI transistors that could severely limit the radiation hardness of SOI devices. Other work showed that worst-case bias configuration during irradiation was the transmission gate bias configuration. In this work we further explore the effects of total-dose ionizing irradiation on fully-depleted SOI transistors. Closed-geometry and standard transistors fabricated in two fully-depleted processes were irradiated with 10-keV x rays. Our results show no evidence for a total-dose latch effect as proposed by others. Instead, in absence of parasitic trench sidewall leakage, our data suggests that the increase in radiation-induced leakage current is caused by positive charge trapping in the buried oxide inverting the back-channel interface. At moderate levels of trapped charge, the back-channel interface is slightly inverted causing a small leakage current to flow. This leakage current is amplified to considerably higher levels by impact ionization. Because the back-channel interface is in weak inversion, the top-gate bias can modulate the back-channel interface and turn the leakage current off at large, negative voltage levels. At high levels of trapped charge, the back-channel interface is fully inverted and the gate bias has little effect on leakage current. However, it is likely that this current also is amplified by impact ionization. For these transistors, the worst-case bias configuration was determined to be the ''ON'' bias configuration. These results have important implication on hardness assurance.

  11. condmat/0506136 IONIZATION BY IMPACT ELECTRONS IN SOLIDS

    E-Print Network [OSTI]

    for impact ionizations is essential for investigating the radiation damage by energetic photons in solids­ray irradiation has become of significant interest to the research community. Radiation damage is the limiting or with the more accurate optical mod­ els based on the free­electron­gas approximation 5, 6 , and at very low

  12. Radiation-induced gain degradation in lateral PNP BJTs with lightly and heavily doped emitters

    SciTech Connect (OSTI)

    Wu, A. [Univ. of Arizona, Tucson, AZ (United States); Schrimpf, R.D. [Vanderbilt Univ., Nashville, TN (United States); Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); Kosier, S.L. [VTC Inc., Bloomington, MN (United States)

    1997-06-01T23:59:59.000Z

    Ionizing radiation may cause failures in ICs due to gain degradation of individual devices. The base current of irradiated bipolar devices increases with total dose, while the collector current remains relatively constant. This results in a decrease in the current gain. Lateral PNP (LPNP) transistors typically exhibit more degradation than vertical PNP devices at the same total dose, and have been blamed as the cause of early IC failures at low dose rates. It is important to understand the differences in total-dose response between devices with heavily- and lightly-doped emitters in order to compare different technologies and evaluate the applicability of proposed low-dose-rate hardness-assurance methods. This paper addresses these differences by comparing two different LPNP devices from the same process: one with a heavily-doped emitter and one with a lightly-doped emitter. Experimental results demonstrate that the lightly-doped devices are more sensitive to ionizing radiation and simulations illustrate that increased recombination on the emitter side of the junction is responsible for the higher sensitivity.

  13. Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. (comps.)

    1992-06-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

  14. Radiation Sources and Radioactive Materials (Connecticut)

    Broader source: Energy.gov [DOE]

    These regulations apply to persons who receive, transfer, possess, manufacture, use, store, handle, transport or dispose of radioactive materials and/or sources of ionizing radiation. Some...

  15. Radiation detector

    DOE Patents [OSTI]

    Fultz, Brent T. (Berkeley, CA)

    1983-01-01T23:59:59.000Z

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  16. Radiation detector

    DOE Patents [OSTI]

    Fultz, B.T.

    1980-12-05T23:59:59.000Z

    Apparatus is provided for detecting radiation such as gamma rays and x-rays generated in backscatter Moessbauer effect spectroscopy and x-ray spectrometry, which has a large window for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  17. Improvement of a portable pressurized ionization chamber with the addition of a microprocessor datalogger

    SciTech Connect (OSTI)

    Van Etten, D.; Olsen, B.

    1987-07-01T23:59:59.000Z

    A measurement system was necessary to monitor low-level external radiation levels along a boundary section of the Los Alamos National Laboratory. High pressure ionization chambers were selected to monitor the radiation levels caused by a plume of air activation products generated by a linear proton accelerator. The data are used for evaluation of an atmospheric dispersion model and for boundary dose calculations. The model compares the pressure ionization chamber (PIC) data with the predicted values based on meteorological wind data measured by two meteorological towers and source term data from the discharge stack. The PIC monitoring system required continuous remote (no ac power) battery-only operation, reliability, and data processing capability. The data processing capability simplified calibration and provided fine time resolution for comparison with other logged data. The sensor head of a Reuter-Stokes RSS-111 was used as the detector and an improved electronic control package was developed to operate the detector and to process and log the data.

  18. A surface ionization source 

    E-Print Network [OSTI]

    Buzatu, Daniel J.

    1995-01-01T23:59:59.000Z

    The main part of the work described herein is the development and testing of a surface ionization source for use on a collinear fast beam laser spectroscopy apparatus. A description of the previously existing fast beam apparatus is given...

  19. A surface ionization source

    E-Print Network [OSTI]

    Buzatu, Daniel J.

    1995-01-01T23:59:59.000Z

    The main part of the work described herein is the development and testing of a surface ionization source for use on a collinear fast beam laser spectroscopy apparatus. A description of the previously existing fast beam apparatus is given...

  20. Lesson 4 - Ionizing Radiation | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreaking ofOil & Gas »of EnergyLearning &LegacySecurityLeslie3 - Atoms4

  1. Integer Programs for High Dose Rate Brachytherapy Needle and Dose Planning that Directly Optimize Clinical Objectives

    E-Print Network [OSTI]

    Siauw, Ko-Ay Timmy

    2012-01-01T23:59:59.000Z

    radiation received by the bulb of the penis correlates withof radiation dose to the bulb of the penis in men with andavoided puncturing the penile bulb; the average number of

  2. Considerations of beta and electron transport in internal dose calculations

    SciTech Connect (OSTI)

    Bolch, W.E.; Poston, J.W. Sr.

    1990-12-01T23:59:59.000Z

    Ionizing radiation has broad uses in modern science and medicine. These uses often require the calculation of energy deposition in the irradiated media and, usually, the medium of interest is the human body. Energy deposition from radioactive sources within the human body and the effects of such deposition are considered in the field of internal dosimetry. In July of 1988, a three-year research project was initiated by the Nuclear Engineering Department at Texas A M University under the sponsorship of the US Department of Energy. The main thrust of the research was to consider, for the first time, the detailed spatial transport of electron and beta particles in the estimation of average organ doses under the Medical Internal Radiation Dose (MIRD) schema. At the present time (December of 1990), research activities are continuing within five areas. Several are new initiatives begun within the second or third year of the current contract period. They include: (1) development of small-scale dosimetry; (2) development of a differential volume phantom; (3) development of a dosimetric bone model; (4) assessment of the new ICRP lung model; and (5) studies into the mechanisms of DNA damage. A progress report is given for each of these tasks within the Comprehensive Report. In each case, preliminary results are very encouraging and plans for further research are detailed within this document.

  3. Anastomotic Complications After Ivor Lewis Esophagectomy in Patients Treated With Neoadjuvant Chemoradiation Are Related to Radiation Dose to the Gastric Fundus

    SciTech Connect (OSTI)

    Vande Walle, Caroline [Department of Gastrointestinal Surgery, University Hospital, Ghent (Belgium); Ceelen, Wim P., E-mail: wim.ceelen@ugent.be [Department of Gastrointestinal Surgery, University Hospital, Ghent (Belgium); Boterberg, Tom [Department of Radiation Oncology, University Hospital, Ghent (Belgium); Vande Putte, Dirk; Van Nieuwenhove, Yves; Varin, Oswald; Pattyn, Piet [Department of Gastrointestinal Surgery, University Hospital, Ghent (Belgium)

    2012-03-01T23:59:59.000Z

    Purpose: Neoadjuvant chemoradiation (CRT) is increasingly used in locally advanced esophageal cancer. Some studies have suggested that CRT results in increased surgical morbidity. We assessed the influence of CRT on anastomotic complications in a cohort of patients who underwent CRT followed by Ivor Lewis esophagectomy. Patients and Methods: Clinical and pathologic data were collected from all patients treated with neoadjuvant CRT (36 Gy combined with 5-fluorouracil and cisplatin) followed by Ivor Lewis esophagectomy. On the radiotherapy (RT) planning computed tomography scans, normal tissue volumes were drawn encompassing the proximal esophageal region and the gastric fundus. Within these volumes, dose-volume histograms were analyzed to generate the total dose to 50% of the volume (D{sub 50}). We studied the ability of the D{sub 50} to predict anastomotic complications (leakage, ischemia, or stenosis). Dose limits were derived using receiver operating characteristics analysis. Results: Fifty-four patients were available for analysis. RT resulted in either T or N downstaging in 51% of patients; complete pathologic response was achieved in 11%. In-hospital mortality was 5.4%, and major morbidity occurred in 36% of patients. Anastomotic complications (AC) developed in 7 patients (13%). No significant influence of the D{sub 50} on the proximal esophagus was noted on the anastomotic complication rate. The median D{sub 50} on the gastric fundus, however, was 33 Gy in patients with AC and 18 Gy in patients without AC (p = 0.024). Using receiver operating characteristics analysis, the D{sub 50} limit on the gastric fundus was defined as 29 Gy. Conclusions: In patients undergoing neoadjuvant CRT followed by Ivor Lewis esophagectomy, the incidence of AC is related to the RT dose on the gastric fundus but not to the dose received by the proximal esophagus. When planning preoperative RT, efforts should be made to limit the median dose on the gastric fundus to 29 Gy with a V{sub 30} below 40%.

  4. A VUV Photoionization and Ab Initio Determination of the Ionization Energy of a Gas Phase Sugar (Deoxyribose).

    E-Print Network [OSTI]

    Ghosh, Debashree

    2012-01-01T23:59:59.000Z

    electronic structure calculations of vertical and adiabatic ionization energies. Ab initio molecular dynamics (dynamics snapshots along the reaction coordinate. Keywords: sugars, synchrotron radiation, electronic structure calculations,

  5. A Reanalysis of Curvature in the Dose Response for Cancer and Modifications by Age at Exposure Following Radiation Therapy for Benign Disease

    SciTech Connect (OSTI)

    Little, Mark P., E-mail: mark.little@nih.gov [Radiation Epidemiology Branch, National Cancer Institute, Rockville, Maryland (United States); Stovall, Marilyn; Smith, Susan A. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Kleinerman, Ruth A. [Radiation Epidemiology Branch, National Cancer Institute, Rockville, Maryland (United States)] [Radiation Epidemiology Branch, National Cancer Institute, Rockville, Maryland (United States)

    2013-02-01T23:59:59.000Z

    Purpose: To assess the shape of the dose response for various cancer endpoints and modifiers by age and time. Methods and Materials: Reanalysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by cancer endpoint (stomach, pancreas, lung, leukemia, all other). Results: There are statistically significant (P<.05) excess risks for all cancer and for lung cancer and borderline statistically significant risks for stomach cancer (P=.07), and leukemia (P=.06), with excess relative risks Gy{sup -1} of 0.024 (95% confidence interval [CI] 0.011, 0.039), 0.559 (95% CI 0.221, 1.021), 0.042 (95% CI -0.002, 0.119), and 1.087 (95% CI -0.018, 4.925), respectively. There is statistically significant (P=.007) excess risk of pancreatic cancer when adjusted for dose-response curvature. General downward curvature is apparent in the dose response, statistically significant (P<.05) for all cancers, pancreatic cancer, and all other cancers (ie, other than stomach, pancreas, lung, leukemia). There are indications of reduction in relative risk with increasing age at exposure (for all cancers, pancreatic cancer), but no evidence for quadratic variations in relative risk with age at exposure. If a linear-exponential dose response is used, there is no significant heterogeneity in the dose response among the 5 endpoints considered or in the speed of variation of relative risk with age at exposure. The risks are generally consistent with those observed in the Japanese atomic bomb survivors and in groups of nuclear workers. Conclusions: There are excess risks for various malignancies in this data set. Generally there is a marked downward curvature in the dose response and significant reduction in relative risk with increasing age at exposure. The consistency of risks with those observed in the Japanese atomic bomb survivors and in groups of nuclear workers implies that there may be little sparing effect of fractionation of dose or low-dose-rate exposure.

  6. Intensity-modulated radiotherapy improves lymph node coverage and dose to critical structures compared with three-dimensional conformal radiation therapy in clinically localized prostate cancer

    SciTech Connect (OSTI)

    Wang-Chesebro, Alice [Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States)]. E-mail: awang@radonc17.ucsf.edu; Xia Ping [Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States); Coleman, Joy [Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States); Akazawa, Clayton C. [Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States); Roach, Mack [Radiation Oncology, University of California-San Francisco, San Francisco, CA (United States)

    2006-11-01T23:59:59.000Z

    Purpose: The aim of this study was to quantify gains in lymph node coverage and critical structure dose reduction for whole-pelvis (WP) and extended-field (EF) radiotherapy in prostate cancer using intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3DCRT) for the first treatment phase of 45 Gy in the concurrent treatment of lymph nodes and prostate. Methods and Materials: From January to August 2005, 35 patients with localized prostate cancer were treated with pelvic IMRT; 7 had nodes defined up to L5-S1 (Group 1), and 28 had nodes defined above L5-S1 (Group 2). Each patient had 2 plans retrospectively generated: 1 WP 3DCRT plan using bony landmarks, and 1 EF 3DCRT plan to cover the vascular defined volumes. Dose-volume histograms for the lymph nodes, rectum, bladder, small bowel, and penile bulb were compared by group. Results: For Group 1, WP 3DCRT missed 25% of pelvic nodes with the prescribed dose 45 Gy and missed 18% with the 95% prescribed dose 42.75 Gy, whereas WP IMRT achieved V{sub 45Gy} = 98% and V{sub 42.75Gy} = 100%. Compared with WP 3DCRT, IMRT reduced bladder V{sub 45Gy} by 78%, rectum V{sub 45Gy} by 48%, and small bowel V{sub 45Gy} by 232 cm{sup 3}. EF 3DCRT achieved 95% coverage of nodes for all patients at high cost to critical structures. For Group 2, IMRT decreased bladder V{sub 45Gy} by 90%, rectum V{sub 45Gy} by 54% and small bowel V{sub 45Gy} by 455 cm{sup 3} compared with EF 3DCRT. Conclusion: In this study WP 3DCRT missed a significant percentage of pelvic nodes. Although EF 3DCRT achieved 95% pelvic nodal coverage, it increased critical structure doses. IMRT improved pelvic nodal coverage while decreasing dose to bladder, rectum, small bowel, and penile bulb. For patients with extended node involvement, IMRT especially decreases small bowel dose.

  7. Cross sections for short pulse single and double ionization ofhelium

    SciTech Connect (OSTI)

    Palacios, Alicia; Rescigno, Thomas N.; McCurdy, C. William

    2007-11-27T23:59:59.000Z

    In a previous publication, procedures were proposed for unambiguously extracting amplitudes for single and double ionization from a time-dependent wavepacket by effectively propagating for an infinite time following a radiation pulse. Here we demonstrate the accuracy and utility of those methods for describing two-photon single and one-photon double ionization of helium. In particular it is shown how narrow features corresponding to autoionizing states are easily resolved with these methods.

  8. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect (OSTI)

    Cannon, S.D.; Finch, S.M. [comps.

    1992-10-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  9. Hanford Environmental Dose Reconstruction Project Monthly Report

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. (comps.)

    1992-03-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  10. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. [comps.

    1992-04-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates.

  11. Cellular and molecular research to reduce uncertainties in estimates of health effects from low-level radiation

    SciTech Connect (OSTI)

    Elkind, M.M.; Bedford, J.; Benjamin, S.A.; Waldren, C.A. (Colorado State Univ., Fort Collins, CO (USA)); Gotchy, R.L. (Science Applications International Corp., McLean, VA (USA))

    1990-10-01T23:59:59.000Z

    A study was undertaken by five radiation scientists to examine the feasibility of reducing the uncertainties in the estimation of risk due to protracted low doses of ionizing radiation. In addressing the question of feasibility, a review was made by the study group: of the cellular, molecular, and mammalian radiation data that are available; of the way in which altered oncogene properties could be involved in the loss of growth control that culminates in tumorigenesis; and of the progress that had been made in the genetic characterizations of several human and animal neoplasms. On the basis of this analysis, the study group concluded that, at the present time, it is feasible to mount a program of radiation research directed at the mechanism(s) of radiation-induced cancer with special reference to risk of neoplasia due to protracted, low doses of sparsely ionizing radiation. To implement a program of research, a review was made of the methods, techniques, and instruments that would be needed. This review was followed by a survey of the laboratories and institutions where scientific personnel and facilities are known to be available. A research agenda of the principal and broad objectives of the program is also discussed. 489 refs., 21 figs., 14 tabs.

  12. Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    McMakin, A.H.; Cannon, S.D.; Finch, S.M. (comps.)

    1992-07-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon, Washington, and Idaho, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates. Progress is discussed.

  13. A Monte Carlo Study of the Relationship between the Time Structures of Prompt Gammas and in vivo Radiation Dose in Proton Therapy

    E-Print Network [OSTI]

    Shin, Wook-Geun; Shin, Jae-Ik; Jeong, Jong Hwi; Lee, Se Byeong

    2015-01-01T23:59:59.000Z

    For the in vivo range verification in proton therapy, it has been tried to measure the spatial distribution of the prompt gammas generated by the proton-induced interactions with the close relationship with the proton dose distribution. However, the high energy of the prompt gammas and background gammas are still problematic in measuring the distribution. In this study, we suggested a new method determining the in vivo range by utilizing the time structure of the prompt gammas formed with the rotation of a range modulation wheel (RMW) in the passive scattering proton therapy. To validate the Monte Carlo code simulating the proton beam nozzle, axial percent depth doses (PDDs) were compared with the measured PDDs with the varying beam range of 4.73-24.01 cm. And the relationship between the proton dose rate and the time structure of the prompt gammas was assessed and compared in the water phantom. The results of the PDD showed accurate agreement within the relative errors of 1.1% in the distal range and 2.9% in...

  14. Retrospective Evaluation Reveals That Long-term Androgen Deprivation Therapy Improves Cause-Specific and Overall Survival in the Setting of Dose-Escalated Radiation for High-Risk Prostate Cancer

    SciTech Connect (OSTI)

    Feng, Felix Y., E-mail: ffeng@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiation Oncology, Veterans Affairs Medical Center, Ann Arbor, Michigan (United States); Blas, Kevin; Olson, Karin; Stenmark, Matthew [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Sandler, Howard [Cedars Sinai Medical Center, Los Angeles, California (United States)] [Cedars Sinai Medical Center, Los Angeles, California (United States); Hamstra, Daniel A. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2013-05-01T23:59:59.000Z

    Purpose: To evaluate the role of androgen deprivation therapy (ADT) and duration for high-risk prostate cancer patients treated with dose-escalated radiation therapy (RT). Methods and Materials: A retrospective analysis of high-risk prostate cancer patients treated with dose-escalated RT (minimum 75 Gy) with or without ADT was performed. The relationship between ADT use and duration with biochemical failure (BF), metastatic failure (MF), prostate cancer-specific mortality (PCSM), non-prostate cancer death (NPCD), and overall survival (OS) was assessed as a function of pretreatment characteristics, comorbid medical illness, and treatment using Fine and Gray's cumulative incidence methodology. Results: The median follow-up time was 64 months. In men with National Comprehensive Cancer Network defined high-risk prostate cancer treated with dose-escalated RT, on univariate analysis, both metastasis (P<.0001; hazard ratio 0.34; 95% confidence interval 0.18-0.67; cumulative incidence at 60 months 13% vs 35%) and PCSM (P=.015; hazard ratio 0.41; 95% confidence interval 0.2-1.0; cumulative incidence at 60 months 6% vs 11%) were improved with the use of ADT. On multivariate analysis for all high-risk patients, Gleason score was the strongest negative prognostic factor, and long-term ADT (LTAD) improved MF (P=.002), PCSM (P=.034), and OS (P=.001). In men with prostate cancer and Gleason scores 8 to 10, on multivariate analysis after adjustment for other risk features, there was a duration-dependent improvement in BF, metastasis, PCSM, and OS, all favoring LTAD in comparison with STAD or RT alone. Conclusion: For men with high-risk prostate cancer treated with dose-escalated EBRT, this retrospective study suggests that the combination of LTAD and RT provided a significant improvement in clinical outcome, which was especially true for those with Gleason scores of 8 to 10.

  15. DOE 2010 Occupational Radiation Exposure November 2011

    SciTech Connect (OSTI)

    U.S. Department of Energy, Office of Health, Safety and Security, Office of Analysis

    2011-11-11T23:59:59.000Z

    This report discusses radiation protection and dose reporting requirements, presents the 2010 occupational radiation dose data trended over the past 5 years, and includes instructions to submit successful ALARA projects.

  16. RADIATION RESEARCH 161, 451457 (2004) 0033-7587/04 $15.00

    E-Print Network [OSTI]

    Stewart, Robert D.

    2004-01-01T23:59:59.000Z

    451 RADIATION RESEARCH 161, 451­457 (2004) 0033-7587/04 $15.00 2004 by Radiation Research Society of DNA Damages Formed by Ionizing Radiation V. A. Semenenko and R. D. Stewart1 Purdue University, School Carlo Algorithm to Simulate the Spectrum of DNA Damages Formed by Ionizing Radiation. Radiat. Res. 161

  17. X-band EPR imaging as a tool for gradient dose reconstruction in irradiated bones

    SciTech Connect (OSTI)

    Leveque, Philippe; Godechal, Quentin; Bol, Anne; Trompier, Francois; Gallez, Bernard [Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Institut de Surete Nucleaire et de Radioprotection, F-92262 Fontenay-aux-Roses (France); Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium)

    2009-09-15T23:59:59.000Z

    Purpose: Various tools are currently available for dose reconstruction in individuals after accidental exposure to ionizing radiation. Among the available biological analyses, Monte Carlo simulations, and biophysical methods, such as electron paramagnetic resonance (EPR), the latter has proved its usefulness for retrospective dosimetry. Although EPR spectroscopy is probably the most sensitive technique, it does not provide spatial dosimetric data. This information is, however, highly desirable when steep dose gradient irradiations are involved. The purpose of this work was to explore the possibilities of EPR imaging (EPRI) for spatial dose reconstruction in irradiated biological material. Methods: X-band EPRI was used to reconstruct ex vivo the relative dose distribution in human bone samples and hydroxyapatite phantoms after irradiation with brachytherapy seeds or x rays. Three situations were investigated: Homogeneous, stepwise gradient, and continuous gradient irradiation. Results: EPRI gave a faithful relative spin density distribution in bone samples and in hydroxyapatite phantoms. Measured dose ratios were in close agreement with the actual delivered dose ratios. EPRI was able to distinguish the dose gradients induced by two different sources ({sup 125}I and {sup 192}Ir). However, the measured spatial resolution of the system was 1.9 mm and this appeared to be a limiting factor. The method could be improved by using new signal postprocessing strategies. Conclusions: This study demonstrates that EPRI can be used to assess the regional relative dose distribution in irradiated bone samples. The method is currently applicable to ex vivo measurements of small size samples with low variation in tissue density but is likely to be adapted for in vivo application using L-band EPRI.

  18. Alkali ionization detector

    DOE Patents [OSTI]

    Hrizo, John (Monroeville, PA); Bauerle, James E. (Plum Borough, PA); Witkowski, Robert E. (West Mifflin, PA)

    1982-01-01T23:59:59.000Z

    A calibration filament containing a sodium-bearing compound is included in combination with the sensing filament and ion collector plate of a sodium ionization detector to permit periodic generation of sodium atoms for the in-situ calibration of the detector.

  19. VOLUME 80, NUMBER 12 P H Y S I C A L R E V I E W L E T T E R S 23 MARCH 1998 Tunable Radiation Source through Upshifting without Ionization

    E-Print Network [OSTI]

    electric field is converted into radiation by rapidly changing the number of free carriers. In a gaseousVOLUME 80, NUMBER 12 P H Y S I C A L R E V I E W L E T T E R S 23 MARCH 1998 Tunable Radiation for generating electromagnetic wakes of infrared radiation by a short laser pulse, propagating through

  20. A physical model of the photo- and radiation-induced degradation of ytterbium-doped silica optical fibres

    SciTech Connect (OSTI)

    Mady, Franck, E-mail: franck.mady@unice.fr; Duchez, Jean-Bernard, E-mail: franck.mady@unice.fr; Mebrouk, Yasmine, E-mail: franck.mady@unice.fr; Benabdesselam, Mourad, E-mail: franck.mady@unice.fr [University of Nice Sophia Antipolis, Laboratoire de Physique de la Matière Condensée (LPMC), CNRS UMR 7336, Parc Valrose, 06108 Nice cedex 2 (France)

    2014-10-21T23:59:59.000Z

    We propose a model to describe the photo- or/and the radiation-induced darkening of ytterbium-doped silica optical fibers. This model accounts for the well-established experimental features of photo-darkening. Degradation behaviors predicted for fibers pumped in harsh environments are also fully confirmed by experimental data reported in the work by Duchez et al. (this proceeding), which gives a detailed characterization of the interplay between the effects of the pump and those of a superimposed ionizing irradiation (actual operation conditions in space-based applications for instance). In particular, dependences of the darkening build-up on the pump power, the total ionizing dose and the dose rate are all correctly reproduced. The presented model is a ‘sufficient’ one, including the minimal physical ingredients required to reproduce experimental features. Refinements could be proposed to improve, e.g., quantitative kinetics.

  1. Evaluation of commercial ADC radiation tolerance for accelerator experiments

    E-Print Network [OSTI]

    Kai Chen; Hucheng Chen; James Kierstead; Helio Takai; Sergio Rescia; Xueye Hu; Hao Xu; Joseph Mead; Francesco Lanni; Marena Minelli

    2014-11-25T23:59:59.000Z

    Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detector front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on radiation effects tests conducted on 17 commercially available analog to digital converters and extensive single event effect measurements on specific twelve and fourteen bit ADCs that presented high tolerance to ionizing dose. Mitigation strategies for single event effects (SEE) are discussed for their use in the large hadron collider environment.

  2. Pharmacological Protection From Radiation {+-} Cisplatin-Induced Oral Mucositis

    SciTech Connect (OSTI)

    Cotrim, Ana P. [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Yoshikawa, Masanobu [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Department of Clinical Pharmacology, Tokai University School of Medicine, Kanagawa (Japan); Sunshine, Abraham N.; Zheng Changyu [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Sowers, Anastasia L.; Thetford, Angela D.; Cook, John A.; Mitchell, James B. [Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Baum, Bruce J., E-mail: bbaum@dir.nidcr.nih.gov [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States)

    2012-07-15T23:59:59.000Z

    Purpose: To evaluate if two pharmacological agents, Tempol and D-methionine (D-met), are able to prevent oral mucositis in mice after exposure to ionizing radiation {+-} cisplatin. Methods and Materials: Female C3H mice, {approx}8 weeks old, were irradiated with five fractionated doses {+-} cisplatin to induce oral mucositis (lingual ulcers). Just before irradiation and chemotherapy, mice were treated, either alone or in combination, with different doses of Tempol (by intraperitoneal [ip] injection or topically, as an oral gel) and D-met (by gavage). Thereafter, mice were sacrificed and tongues were harvested and stained with a solution of Toluidine Blue. Ulcer size and tongue epithelial thickness were measured. Results: Significant lingual ulcers resulted from 5 Multiplication-Sign 8 Gy radiation fractions, which were enhanced with cisplatin treatment. D-met provided stereospecific partial protection from lingual ulceration after radiation. Tempol, via both routes of administration, provided nearly complete protection from lingual ulceration. D-met plus a suboptimal ip dose of Tempol also provided complete protection. Conclusions: Two fairly simple pharmacological treatments were able to markedly reduce chemoradiation-induced oral mucositis in mice. This proof of concept study suggests that Tempol, alone or in combination with D-met, may be a useful and convenient way to prevent the severe oral mucositis that results from head-and-neck cancer therapy.

  3. Electrospray Ionization Mass Spectrometry

    SciTech Connect (OSTI)

    Kelly, Ryan T.; Marginean, Ioan; Tang, Keqi

    2014-06-13T23:59:59.000Z

    Electrospray Ionization (ESI) is a process whereby gas phase ions are created from molecules in solution. As a solution exits a narrow tube in the presence of a strong electric field, an aerosol of charged droplets are is formed that produces gas phase ions as they it desolvates. ESI-MS comprises the creation of ions by ESI and the determination of their mass to charge ratio (m/z) by MS.

  4. RADIATION EFFECTS ON EPOXY/CARBON FIBER COMPOSITE

    SciTech Connect (OSTI)

    Hoffman, E; Eric Skidmore, E

    2008-12-12T23:59:59.000Z

    The Department of Energy Savannah River Site vitrifies nuclear waste incident to defense programs through its Defense Waste Processing Facility (DWPF). The piping in the DWPF seal pot jumper configuration must withstand the stresses during an unlikely but potential deflagration event, and maintain its safety function for a 20-year service life. Carbon fiber-reinforced epoxy composites (CFR) were proposed for protection and reinforcement of piping during such an event. The proposed CFR materials have been ASME-approved (Section XI, Code Case N-589-1) for post-construction maintenance and is DOT-compliant per 49CFR 192 and 195. The proposed carbon fiber/epoxy composite reinforcement system was originally developed for pipeline rehabilitation and post-construction maintenance in petrochemical, refineries, DOT applications and other industries. The effects of ionizing radiation on polymers and organic materials have been studied for many years. The majority of available data are based on traditional exposures to gamma irradiation at high dose rates ({approx}10,000 Gy/hr) allowing high total dose within reasonable test periods and general comparison of different materials exposed at such conditions. However, studies in recent years have shown that degradation of many polymers are sensitive to dose rate, with more severe degradation often observed at similar or even lower total doses when exposed to lower dose rates. This behavior has been primarily attributed to diffusion-limited oxidation which is minimized during very high dose rate exposures. Most test standards for accelerated aging and nuclear qualification of components acknowledge these limitations. The results of testing to determine the radiation resistance and microstructural effects of gamma irradiation exposure on a bisphenol-A based epoxy matrix composite reinforced with carbon fibers are presented. This work provides a foundation for a more extensive evaluation of dose rate effects on advanced epoxy reinforced composites.

  5. Method for microbeam radiation therapy

    DOE Patents [OSTI]

    Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

    1994-08-16T23:59:59.000Z

    A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

  6. Plasmadynamics and ionization kinetics of thermionic energy conversion

    SciTech Connect (OSTI)

    Lawless, J.L. Jr.

    1981-01-01T23:59:59.000Z

    To reduce the plasma arc-drop, thermionic energy conversion is studied with both analytical and numerical tools. Simplifications are made in both the plasmadynamic and ionization-recombination theories. These are applied to a scheme proposed presently using laser irradiation to enhance the ionization kinetics of the thermionic plasma and thereby reduce the arc-drop. It is also predicted that it is possible to generate the required laser light from a thermionic-type Cesium plasma. The analysis takes advantage of theoretical simplifications derived for the ionization-recombination kinetics. It is shown that large laser ionization enhancements can occur and that collisional Cesium recombination lasing is expected. To complement the kinetic theory, a numerical method is developed to solve the thermionic plasma dynamics. The effects of the complete system of electron-atom inelastic collisions on the ionization-recombination problem are shown to reduce to a system nearly as simple as the well-known one-quantum approximation. To combine the above analysis of ionization-recombination kinetics with the plasma dynamics of thermionic conversion, a finite difference computer program is constructed. Using the above developments, a proposal to improve thermionic converter performance using laser radiation is considered. In this proposed scheme, laser radiation impinging on a thermionic plasma enhances the ionization process thereby raising the plasma density and reducing the plasma arc-drop. A source for such radiation may possibly be a Cesium recombination laser operating in a different thermionic converter. The possibility of this being an energy efficient process is discussed.

  7. Neurodegeneration and adaptation in response to low-dose photon irradiation

    SciTech Connect (OSTI)

    Limoli, Charles L. [UCI

    2014-10-27T23:59:59.000Z

    Neural stem and precursor cells (i.e. multipotent neural cells) are concentrated in the neurogenic regions of the brain (hippocampal dentate gyrus, subventricular zones), and considerable evidence suggests that these cells are important in mediating the stress response of the CNS after damage from ionizing radiation. The capability of these cells to proliferate, migrate and differentiate (i.e. to undergo neurogenesis) suggests they can participate in the repair and maintenance of CNS functions by replacing brain cells damaged or depleted due to irradiation. Importantly, we have shown that multipotent neural cells are markedly sensitive to irradiation and oxidative stress, insults that compromise neurogenesis and hasten the onset and progression of degenerative processes that are likely to have an adverse impact on cognition. Our past and current work has demonstrated that relatively low doses of radiation cause a persistent (weeks-months) oxidative stress in multipotent neural cells that can elicit a range of degenerative sequelae in the CNS. Therefore, our project is focused on determining the extent that endogenous and redox sensitive multipotent neural cells represent important radioresponsive targets for low dose radiation effects. We hypothesize that the activation of redox sensitive signaling can trigger radioadaptive changes in these cells that can be either harmful or beneficial to overall cognitive health.

  8. SM22{alpha}-induced activation of p16{sup INK4a}/retinoblastoma pathway promotes cellular senescence caused by a subclinical dose of {gamma}-radiation and doxorubicin in HepG2 cells

    SciTech Connect (OSTI)

    Kim, Tae Rim; Lee, Hee Min; Lee, So Yong; Kim, Eun Jin; Kim, Kug Chan [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Paik, Sang Gi [Department of Biology, School of Biosciences and Biotechnology, Chungnam National University, Daejeon (Korea, Republic of)] [Department of Biology, School of Biosciences and Biotechnology, Chungnam National University, Daejeon (Korea, Republic of); Cho, Eun Wie, E-mail: ewcho@kribb.re.kr [Daejeon-KRIBB-FHCRC Cooperation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Kim, In Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-09-10T23:59:59.000Z

    Research highlights: {yields} SM22{alpha} overexpression in HepG2 cells leads cells to a growth arrest state, and the treatment of a subclinical dose of {gamma}-radiation or doxorubicin promotes cellular senescence. {yields} SM22{alpha} overexpression elevates p16{sup INK4a} followed by pRB activation, but there are no effects on p53/p21{sup WAF1/Cip1} pathway. {yields} SM22{alpha}-induced MT-1G activates p16{sup INK4a}/pRB pathway, which promotes cellular senescence by damaging agents. -- Abstract: Smooth muscle protein 22-alpha (SM22{alpha}) is known as a transformation- and shape change-sensitive actin cross-linking protein found in smooth muscle tissue and fibroblasts; however, its functional role remains uncertain. We reported previously that SM22{alpha} overexpression confers resistance against anti-cancer drugs or radiation via induction of metallothionein (MT) isozymes in HepG2 cells. In this study, we demonstrate that SM22{alpha} overexpression leads cells to a growth arrest state and promotes cellular senescence caused by treatment with a subclinical dose of {gamma}-radiation (0.05 and 0.1 Gy) or doxorubicin (0.01 and 0.05 {mu}g/ml), compared to control cells. Senescence growth arrest is known to be controlled by p53 phosphorylation/p21{sup WAF1/Cip1} induction or p16{sup INK4a}/retinoblastoma protein (pRB) activation. SM22{alpha} overexpression in HepG2 cells elevated p16{sup INK4a} followed by pRB activation, but did not activate the p53/p21{sup WAF1/Cip1} pathway. Moreover, MT-1G, which is induced by SM22{alpha} overexpression, was involved in the activation of the p16{sup INK4a}/pRB pathway, which led to a growth arrest state and promoted cellular senescence caused by damaging agents. Our findings provide the first demonstration that SM22{alpha} modulates cellular senescence caused by damaging agents via regulation of the p16{sup INK4a}/pRB pathway in HepG2 cells and that these effects of SM22{alpha} are partially mediated by MT-1G.

  9. acute radiation syndrones: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Apoptosis MIT - DSpace Summary: Acute exposure to ionizing radiation can cause lethal damage to the gastrointestinal (GI) tract, a condition called the GI syndrome. Whether the...

  10. arrbod acute radiation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Apoptosis MIT - DSpace Summary: Acute exposure to ionizing radiation can cause lethal damage to the gastrointestinal (GI) tract, a condition called the GI syndrome. Whether the...

  11. Plasma Production via Field Ionization

    SciTech Connect (OSTI)

    O'Connell, C.L.; Barnes, C.D.; Decker, F.; Hogan, M.J.; Iverson, R.; Krejcik, P.; Siemann, R.; Walz, D.R.; /SLAC; Clayton, C.E.; Huang, C.; Johnson, D.K.; Joshi, C.; Lu,; Marsh, K.A.; Mori, W.; Zhou, M.; /UCLA; Deng, S.; Katsouleas, T.; Muggli, P.; Oz, E.; /Southern California U.

    2007-01-02T23:59:59.000Z

    Plasma production via field ionization occurs when an incoming particle beam is sufficiently dense that the electric field associated with the beam ionizes a neutral vapor or gas. Experiments conducted at the Stanford Linear Accelerator Center explore the threshold conditions necessary to induce field ionization by an electron beam in a neutral lithium vapor. By independently varying the transverse beam size, number of electrons per bunch or bunch length, the radial component of the electric field is controlled to be above or below the threshold for field ionization. Additional experiments ionized neutral xenon and neutral nitric oxide by varying the incoming beam's bunch length. A self-ionized plasma is an essential step for the viability of plasma-based accelerators for future high-energy experiments.

  12. Radiation Safety Manual Dec 2012 Page 1 RADIATION SAFETY

    E-Print Network [OSTI]

    Grishok, Alla

    of External and Internal Doses E. Reports and Notices to Workers Chapter VII: Radiation ProtectionRadiation Safety Manual ­ Dec 2012 Page 1 RADIATION SAFETY MANUAL For Columbia University NewYork-Presbyterian Hospital New York State Psychiatric Institute Barnard College December 2012 #12;Radiation Safety Manual

  13. The effects of cooking, storage, and ionizing irradiation on carotenoids, antioxidant activity, and phenolics in potato (Solanum tuberosum L.)

    E-Print Network [OSTI]

    Blessington, Tyann

    2005-11-01T23:59:59.000Z

    on these levels. Therefore, the changes in carotenoid content, antioxidant activity, and phenolic content were investigated using combinations of cultivars, cooking methods, storage treatments, and low-dose ionizing irradiation. Carotenoid content was measured via...

  14. AGING FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect (OSTI)

    R.L. Thacker

    2005-03-24T23:59:59.000Z

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Aging Facility performing operations to transfer aging casks to the aging pads for thermal and logistical management, stage empty aging casks, and retrieve aging casks from the aging pads for further processing in other site facilities. Doses received by workers due to aging cask surveillance and maintenance operations are also included. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation. There are no Category 1 event sequences associated with the Aging Facility (BSC 2004 [DIRS 167268], Section 7.2.1). The results of this calculation will be used to support the design of the Aging Facility and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in Environmental and Nuclear Engineering.

  15. Heating and Ionization of the Primordial Intergalactic Medium by High Mass X-ray Binaries

    E-Print Network [OSTI]

    Knevitt, Gillian; Power, Chris; Bolton, James

    2014-01-01T23:59:59.000Z

    We investigate the influence of High Mass X-ray Binaries on their high redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main sequence stars and HMXBs, at various times after its formation. We consider both uniform density surroundings, and a cluster embedded in a 10^8 solar mass NFW halo. HMXBs in a constant density environment produce negligible enhanced ionization because of their high-energy SEDs and short lifetimes. In this case, HMXBs only marginally contribute to the local heating rate. For NFW profiles, radiation from main sequence stars cannot prevent the initially ionized volume from recombining since it is unable to penetrate the high density galactic core. However, HMXB photons stall recombinations behind the front, keeping it partially ionized for longer. The increased electron density in these partially ionized regions promotes further cooling, resulting in lower IGM temp...

  16. RADIATION CONTROL GUIDE rev 12/99 1-1 RADIATION PROTECTION PROGRAM

    E-Print Network [OSTI]

    Wu, Dapeng Oliver

    RADIATION CONTROL GUIDE rev 12/99 1-1 CHAPTER 1 RADIATION PROTECTION PROGRAM I. INTRODUCTION In view of increased utilization of ionizing and nonionizing radiation at the University of Florida, a university-wide radiation control program was established in September, l960. The primary responsibilities

  17. RADIATION CONTROL GUIDE 2/97 3-1 RADIATION PRODUCING DEVICES

    E-Print Network [OSTI]

    Wu, Dapeng Oliver

    the device. This proposal should point out radiation safety precautions which will be taken to protectRADIATION CONTROL GUIDE 2/97 3-1 CHAPTER 3 RADIATION PRODUCING DEVICES I. AUTHORIZATION TO USE RADIATION PRODUCING DEVICES All devices and apparatus capable of producing ionizing and nonionizing

  18. Ionization front-driven turbulence in the clumpy interstellar medium

    E-Print Network [OSTI]

    Thomas Peters; Robi Banerjee; Ralf S. Klessen

    2008-08-20T23:59:59.000Z

    We present 3D radiation-gasdynamical simulations of an ionization front running into a dense clump. In our setup, a B0 star irradiates an overdensity which is at a distance of 10 pc and modelled as a supercritical 100 M_sol Bonnor-Ebert sphere. The radiation from the star heats up the gas and creates a shock front that expands into the interstellar medium. The shock compresses the clump material while the ionizing radiation heats it up. The outcome of this "cloud-crushing" process is a fully turbulent gas in the wake of the clump. In the end, the clump entirely dissolves. We propose that this mechanism is very efficient in creating short-living supersonic turbulence in the vicinity of massive stars.

  19. Hanford Environmental Dose Reconstruction Project Monthly Report

    SciTech Connect (OSTI)

    Finch, S.M. (comp.)

    1990-01-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Pacific Northwest Laboratory (PNL) under the direction of an independent Technical Steering Panel (TSP). The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demographics; agriculture; food habits; and environmental pathways and dose estimates. 3 figs.

  20. Changes in optically stimulated luminescent dosimeter (OSLD) dosimetric characteristics with accumulated dose

    SciTech Connect (OSTI)

    Jursinic, Paul A. [West Michigan Cancer Center, 200 North Park St., Kalamazoo, Michigan 49007 (United States)

    2010-01-15T23:59:59.000Z

    Purpose: A new type of in vivo dosimeter, an optically stimulated luminescent dosimeter (OSLD), has now become commercially available for clinical use. The OSLD is a plastic disk infused with aluminum oxide doped with carbon (Al{sub 2}O{sub 3}:C). Crystals of Al{sub 2}O{sub 3}:C, when exposed to ionizing radiation, store energy that is released as luminescence (420 nm) when the OSLD is illuminated with stimulation light (540 nm). The intensity of the luminescence depends on the dose absorbed by the OSLD and the intensity of the stimulation light. The effects of accumulated dose on OSLD response were investigated. Methods: The OSLDs used in this work were nanodot dosimeters, which were read with a MicroStar reader (Landauer, Inc., Glenwood, IL). Dose to the OSLDs was delivered by 6 MV x rays and gamma rays from Co-60 and Ir-192. The signal on the OSLDs after irradiation is removed by optical annealing with a 150 W tungsten-halogen lamp or a 14 W compact fluorescent lamp was investigated. Results: It was found that OSLD response to dose was supralinear and this response was altered with the amount of accumulated dose to the OSLD. The OSLD response can be modeled by a quadratic and an exponential equation. For accumulated doses up to 60 Gy, the OSLD sensitivity (counts/dose) decreases and the extent of supralinear increases. Above 60 Gy of accumulated dose the sensitivity increases and the extent of supralinearity decreases or reaches a plateau, depending on how the OSLDs were optically annealed. With preirradiation of OSLDs with greater than 1 kGy, it is found that the sensitivity reaches a plateau 2.5 folds greater than that of an OSLD with no accumulated dose and the supralinearity disappears. A regeneration of the luminescence signal in the dark after full optical annealing occurs with a half time of about two days. The extent of this regeneration signal depends on the amount of accumulated dose. Conclusions: For in vivo dosimetric measurements, a precision of {+-}0.5% can be achieved if the sensitivity and extent of supralinearity is established for each OSLD and use. Methods are presented for accomplishing this task.

  1. Weldon Spring historical dose estimate

    SciTech Connect (OSTI)

    Meshkov, N.; Benioff, P.; Wang, J.; Yuan, Y.

    1986-07-01T23:59:59.000Z

    This study was conducted to determine the estimated radiation doses that individuals in five nearby population groups and the general population in the surrounding area may have received as a consequence of activities at a uranium processing plant in Weldon Spring, Missouri. The study is retrospective and encompasses plant operations (1957-1966), cleanup (1967-1969), and maintenance (1969-1982). The dose estimates for members of the nearby population groups are as follows. Of the three periods considered, the largest doses to the general population in the surrounding area would have occurred during the plant operations period (1957-1966). Dose estimates for the cleanup (1967-1969) and maintenance (1969-1982) periods are negligible in comparison. Based on the monitoring data, if there was a person residing continually in a dwelling 1.2 km (0.75 mi) north of the plant, this person is estimated to have received an average of about 96 mrem/yr (ranging from 50 to 160 mrem/yr) above background during plant operations, whereas the dose to a nearby resident during later years is estimated to have been about 0.4 mrem/yr during cleanup and about 0.2 mrem/yr during the maintenance period. These values may be compared with the background dose in Missouri of 120 mrem/yr.

  2. Multiple anatomy optimization of accumulated dose

    SciTech Connect (OSTI)

    Watkins, W. Tyler, E-mail: watkinswt@virginia.edu; Siebers, Jeffrey V. [Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22908 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Moore, Joseph A. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Gordon, James [Henry Ford Health System, Detroit, Michigan 48202 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Hugo, Geoffrey D. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: To investigate the potential advantages of multiple anatomy optimization (MAO) for lung cancer radiation therapy compared to the internal target volume (ITV) approach. Methods: MAO aims to optimize a single fluence to be delivered under free-breathing conditions such that the accumulated dose meets the plan objectives, where accumulated dose is defined as the sum of deformably mapped doses computed on each phase of a single four dimensional computed tomography (4DCT) dataset. Phantom and patient simulation studies were carried out to investigate potential advantages of MAO compared to ITV planning. Through simulated delivery of the ITV- and MAO-plans, target dose variations were also investigated. Results: By optimizing the accumulated dose, MAO shows the potential to ensure dose to the moving target meets plan objectives while simultaneously reducing dose to organs at risk (OARs) compared with ITV planning. While consistently superior to the ITV approach, MAO resulted in equivalent OAR dosimetry at planning objective dose levels to within 2% volume in 14/30 plans and to within 3% volume in 19/30 plans for each lung V20, esophagus V25, and heart V30. Despite large variations in per-fraction respiratory phase weights in simulated deliveries at high dose rates (e.g., treating 4/10 phases during single fraction beams) the cumulative clinical target volume (CTV) dose after 30 fractions and per-fraction dose were constant independent of planning technique. In one case considered, however, per-phase CTV dose varied from 74% to 117% of prescription implying the level of ITV-dose heterogeneity may not be appropriate with conventional, free-breathing delivery. Conclusions: MAO incorporates 4DCT information in an optimized dose distribution and can achieve a superior plan in terms of accumulated dose to the moving target and OAR sparing compared to ITV-plans. An appropriate level of dose heterogeneity in MAO plans must be further investigated.

  3. Extreme ultraviolet ionization of pure He nanodroplets: Mass-correlated photoelectron imaging, Penning ionization, and electron energy-loss spectra

    SciTech Connect (OSTI)

    Buchta, D.; Stienkemeier, F.; Mudrich, M. [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany)] [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany); Krishnan, S. R.; Moshammer, R. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany)] [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Brauer, N. B.; Drabbels, M. [Laboratoire de Chimie Physique Moléculaire, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland)] [Laboratoire de Chimie Physique Moléculaire, Swiss Federal Institute of Technology Lausanne (EPFL), 1015 Lausanne (Switzerland); O’Keeffe, P.; Coreno, M. [CNR Istituto di Metodologie Inorganiche e dei Plasmi, CP10, 00016 Monterotondo Scalo (Italy)] [CNR Istituto di Metodologie Inorganiche e dei Plasmi, CP10, 00016 Monterotondo Scalo (Italy); Devetta, M. [CIMAINA and Dipartimento di Fisica, Università di Milano, 20133 Milano (Italy)] [CIMAINA and Dipartimento di Fisica, Università di Milano, 20133 Milano (Italy); Di Fraia, M. [Department of Physics, University of Trieste, 34128 Trieste (Italy)] [Department of Physics, University of Trieste, 34128 Trieste (Italy); Callegari, C.; Richter, R.; Prince, K. C. [Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste (Italy)] [Elettra-Sincrotrone Trieste, 34149 Basovizza, Trieste (Italy); Ullrich, J. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany) [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, D-38116 Braunschweig (Germany)

    2013-08-28T23:59:59.000Z

    The ionization dynamics of pure He nanodroplets irradiated by Extreme ultraviolet radiation is studied using Velocity-Map Imaging PhotoElectron-PhotoIon COincidence spectroscopy. We present photoelectron energy spectra and angular distributions measured in coincidence with the most abundant ions He{sup +}, He{sub 2}{sup +}, and He{sub 3}{sup +}. Surprisingly, below the autoionization threshold of He droplets, we find indications for multiple excitation and subsequent ionization of the droplets by a Penning-like process. At high photon energies we observe inelastic collisions of photoelectrons with the surrounding He atoms in the droplets.

  4. ORISE: Health Physics in Radiation Emergencies | REAC/TS Continuing...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (HP), Medical Physicists (MP), Radiation Safety Officers (RSO) and others who have radiation dose assessment andor radiological control responsibilities. The course...

  5. Molecular dissection of the roles of the SOD genes in mammalian response to low dose irradiation

    SciTech Connect (OSTI)

    Eric Y. Chuang

    2006-08-31T23:59:59.000Z

    It has been long recognized that a significant fraction of the radiation-induced genetic damage to cells are caused by secondary oxidative species. Internal cellular defense systems against oxidative stress play significant roles in countering genetic damage induced by ionizing radiation. The role of the detoxifying enzymes may be even more prominent in the case of low-dose, low-LET irradiation, as the majority of genetic damage may be caused by secondary oxidative species. In this study we have attempted to decipher the roles of the superoxide dismutase (SOD) genes, which are responsible for detoxifying the superoxide anions. We used adenovirus vectors to deliver RNA interference (RNAi or siRNA) technology to down-regulate the expression levels of the SOD genes. We have also over-expressed the SOD genes by use of recombinant adenovirus vectors. Cells infected with the vectors were then subjected to low dose ?-irradiation. Total RNA were extracted from the exposed cells and the expression of 9000 genes were profiled by use of cDNA microarrays. The result showed that low dose radiation had clear effects on gene expression in HCT116 cells. Both over-expression and down-regulation of the SOD1 gene can change the expression profiles of sub-groups of genes. Close to 200 of the 9000 genes examined showed over two-fold difference in expression under various conditions. Genes with changed expression pattern belong to many categories that include: early growth response, DNA-repair, ion transport, apoptosis, and cytokine response.

  6. Proton radiation damage in P-channel CCDs fabricated on high-resistivity silicon

    E-Print Network [OSTI]

    2002-01-01T23:59:59.000Z

    Proton Radiation Damage in P-Channel CCDs Fabricated onmeasured as a function of radiation dose. These CCDs werecurrent vs. 1/kT after a radiation dose of 5 × 10 9 protons/

  7. Radiation Testing of Electronics for the CMS Endcap Muon System

    E-Print Network [OSTI]

    B. Bylsma; D. Cady; A. Celik; L. S. Durkin; J. Gilmore; J. Haley; V. Khotilovich; S. Lakdawala; J. Liu; M. Matveev; B. P. Padley; J. Roberts; J. Roe; A. Safonov; I. Suarez; D. Wood; I. Zawisza

    2012-08-20T23:59:59.000Z

    The electronics used in the data readout and triggering system for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) particle accelerator at CERN are exposed to high radiation levels. This radiation can cause permanent damage to the electronic circuitry, as well as temporary effects such as data corruption induced by Single Event Upsets. Once the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will have five times higher instantaneous luminosity than LHC, allowing for detection of rare physics processes, new particles and interactions. Tests have been performed to determine the effects of radiation on the electronic components to be used for the Endcap Muon electronics project currently being designed for installation in the CMS experiment in 2013. During these tests the digital components on the test boards were operating with active data readout while being irradiated with 55 MeV protons. In reactor tests, components were exposed to 30 years equivalent levels of neutron radiation expected at the HL-LHC. The highest total ionizing dose (TID) for the muon system is expected at the inner-most portion of the CMS detector, with 8900 rad over ten years. Our results show that Commercial Off-The-Shelf (COTS) components selected for the new electronics will operate reliably in the CMS radiation environment.

  8. High pressure xenon ionization detector

    DOE Patents [OSTI]

    Markey, John K. (New Haven, CT)

    1989-01-01T23:59:59.000Z

    A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0.degree. to 30.degree. C.

  9. Comparison of radiation exposure and associated radiation-induced cancer risks from mammography and molecular imaging of the breast

    SciTech Connect (OSTI)

    O'Connor, Michael K.; Li Hua; Rhodes, Deborah J.; Hruska, Carrie B.; Clancy, Conor B.; Vetter, Richard J. [Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Department of Medicine, Mayo Clinic, Rochester, Minnesota 55905 (United States); Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905 (United States); Department of Medical Physics, St. James's Hospital, Dublin (Ireland); Radiation Safety, Mayo Clinic, Rochester, Minnesota 55905 (United States)

    2010-12-15T23:59:59.000Z

    Purpose: Recent studies have raised concerns about exposure to low-dose ionizing radiation from medical imaging procedures. Little has been published regarding the relative exposure and risks associated with breast imaging techniques such as breast specific gamma imaging (BSGI), molecular breast imaging (MBI), or positron emission mammography (PEM). The purpose of this article was to estimate and compare the risks of radiation-induced cancer from mammography and techniques such as PEM, BSGI, and MBI in a screening environment. Methods: The authors used a common scheme for all estimates of cancer incidence and mortality based on the excess absolute risk model from the BEIR VII report. The lifetime attributable risk model was used to estimate the lifetime risk of radiation-induced breast cancer incidence and mortality. All estimates of cancer incidence and mortality were based on a population of 100 000 females followed from birth to age 80 and adjusted for the fraction that survives to various ages between 0 and 80. Assuming annual screening from ages 40 to 80 and from ages 50 to 80, the cumulative cancer incidence and mortality attributed to digital mammography, screen-film mammography, MBI, BSGI, and PEM was calculated. The corresponding cancer incidence and mortality from natural background radiation was calculated as a useful reference. Assuming a 15%-32% reduction in mortality from screening, the benefit/risk ratio for the different imaging modalities was evaluated. Results: Using conventional doses of 925 MBq Tc-99m sestamibi for MBI and BSGI and 370 MBq F-18 FDG for PEM, the cumulative cancer incidence and mortality were found to be 15-30 times higher than digital mammography. The benefit/risk ratio for annual digital mammography was >50:1 for both the 40-80 and 50-80 screening groups, but dropped to 3:1 for the 40-49 age group. If the primary use of MBI, BSGI, and PEM is in women with dense breast tissue, then the administered doses need to be in the range 75-150 MBq for Tc-99m sestamibi and 35 MBq-70 MBq for F-18 FDG in order to obtain benefit/risk ratios comparable to those of mammography in these age groups. These dose ranges should be achievable with enhancements to current technology while maintaining a reasonable examination time. Conclusions: The results of the dose estimates in this study clearly indicate that if molecular imaging techniques are to be of value in screening for breast cancer, then the administered doses need to be substantially reduced to better match the effective doses of mammography.

  10. An Introduction to Multiphoton Ionization and Study of Ionization Rate of Hydrogen Atom

    SciTech Connect (OSTI)

    Shrestha, N.; Nakarmi, J. J.; Jha, L. N. [Central Department of Physics, Tribhuvan University, Kirtipur (Nepal)

    2009-04-19T23:59:59.000Z

    From a semiclassical point of view, we discuss the problem of nonlinear interaction between electromagnetic radiation and atoms. The time-dependent Schroedinger equation for single electron systems is solved using perturbative technique to obtain transition probability. We also discuss higher order perturbation used in multiple processes where two or more quanta are emitted instead of a single photon. The approach is based on the assumption that the perturbation is small. From the transition probability ionization rate and absorption, the cross-section of hydrogen atoms is calculated. Variation in photon energy and field strength is analyzed. Variation of cross-section with photon energy is discussed.

  11. The Relationship between Organ Dose and Patients Size in Multidetector Computed Tomography (MDCT) Scans Utilizing Tube Current Modulation (TCM)

    E-Print Network [OSTI]

    Khatonabadi, Maryam

    2013-01-01T23:59:59.000Z

    and radiation dose using Siemens Care Dose 4D. Radiation2 Adj. R 2 Adj. R 2 Predictors WED R 2 Siemens Toshiba PedsKidneys WED Siemens Spleen WED GE Liver WED Interaction WED

  12. Pulsed helium ionization detection system

    DOE Patents [OSTI]

    Ramsey, R.S.; Todd, R.A.

    1985-04-09T23:59:59.000Z

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  13. Pulsed helium ionization detection system

    DOE Patents [OSTI]

    Ramsey, Roswitha S. (Knoxville, TN); Todd, Richard A. (Knoxville, TN)

    1987-01-01T23:59:59.000Z

    A helium ionization detection system is provided which produces stable operation of a conventional helium ionization detector while providing improved sensitivity and linearity. Stability is improved by applying pulsed dc supply voltage across the ionization detector, thereby modifying the sampling of the detectors output current. A unique pulse generator is used to supply pulsed dc to the detector which has variable width and interval adjust features that allows up to 500 V to be applied in pulse widths ranging from about 150 nsec to about dc conditions.

  14. Optical ionization detector

    DOE Patents [OSTI]

    Wuest, Craig R. (Danville, CA); Lowry, Mark E. (Castro Valley, CA)

    1994-01-01T23:59:59.000Z

    An optical ionization detector wherein a beam of light is split so that one arm passes through a fiber optics and the other arm passes through a gas-filled region, and uses interferometry to detect density changes in a gas when charged particles pass through it. The gas-filled region of the detector is subjected to a high electric field and as a charged particle traverses this gas region electrons are freed from the cathode and accelerated so as to generate an electron avalanche which is collected on the anode. The gas density is effected by the electron avalanche formation and if the index or refraction is proportional to the gas density the index will change accordingly. The detector uses this index change by modulating the one arm of the split light beam passing through the gas, with respect to the other arm that is passed through the fiber optic. Upon recombining of the beams, interference fringe changes as a function of the index change indicates the passage of charged particles through the gaseous medium.

  15. Standoff alpha radiation detection via excited state absorption of air

    SciTech Connect (OSTI)

    Yao, Jimmy; Yin, Stuart Shizhuo [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Brenizer, Jack [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Hui, Rongqing [Department of Electrical Engineering and Computer Science, The University of Kansas, Lawrence, Kansas 66045 (United States)] [Department of Electrical Engineering and Computer Science, The University of Kansas, Lawrence, Kansas 66045 (United States)

    2013-06-24T23:59:59.000Z

    A standoff alpha radiation detection technique based on the physical mechanism of excited state absorption of air molecules was explored and is presented in this paper. Instead of directly detecting the radiation via measuring the intensity of radiation induced air fluorescence, the radiation is detected via the excited state absorption of alpha radiation excited/ionized air molecules. Both theoretical analyses and experimental verifications were conducted. The experimental results confirmed that the radiation could be detected via excited state absorption of radiation excited/ionized air molecules at a 10 m standoff distance, which was consistent with the theoretical analyses.

  16. Differential Gene Expression Profiles of Radioresistant Non-Small-Cell Lung Cancer Cell Lines Established by Fractionated Irradiation: Tumor Protein p53-Inducible Protein 3 Confers Sensitivity to Ionizing Radiation

    SciTech Connect (OSTI)

    Lee, Young Sook; Oh, Jung-Hwa; Yoon, Seokjoo; Kwon, Myung-Sang [Toxicogenomics Team, Korea Institute of Toxicology, Daejeon (Korea, Republic of)

    2010-07-01T23:59:59.000Z

    Purpose: Despite the widespread use of radiotherapy as a local and regional modality for the treatment of cancer, some non-small-cell lung cancers commonly develop resistance to radiation. We thus sought to clarify the molecular mechanisms underlying resistance to radiation. Methods and Materials: We established the radioresistant cell line H460R from radiosensitive parental H460 cells. To identify the radioresistance-related genes, we performed microarray analysis and selected several candidate genes. Results: Clonogenic and MTT assays showed that H460R was 10-fold more resistant to radiation than H460. Microarray analysis indicated that the expression levels of 1,463 genes were altered more than 1.5-fold in H460R compared with parental H460. To evaluate the putative functional role, we selected one interesting gene tumor protein p53-inducible protein 3 (TP53I3), because that this gene was significantly downregulated in radioresistant H460R cells and that it was predicted to link p53-dependent cell death signaling. Interestingly, messenger ribonucleic acid expression of TP53I3 differed in X-ray-irradiated H460 and H460R cells, and overexpression of TP53I3 significantly affected the cellular radiosensitivity of H460R cells. Conclusions: These results show that H460R may be useful in searching for candidate genes that are responsible for radioresistance and elucidating the molecular mechanism of radioresistance.

  17. ORISE Video: What is radiation dose?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire3627 FederalTransformers1 DIRECTORJoe Lake One-Timemeasuring

  18. Radiation delivery system and method

    DOE Patents [OSTI]

    Sorensen, Scott A. (Overland Park, KS); Robison, Thomas W. (Los Alamos, NM); Taylor, Craig M. V. (Jemez Springs, NM)

    2002-01-01T23:59:59.000Z

    A radiation delivery system and method are described. The system includes a treatment configuration such as a stent, balloon catheter, wire, ribbon, or the like, a portion of which is covered with a gold layer. Chemisorbed to the gold layer is a radiation-emitting self-assembled monolayer or a radiation-emitting polymer. The radiation delivery system is compatible with medical catheter-based technologies to provide a therapeutic dose of radiation to a lesion following an angioplasty procedure.

  19. Field ionization from carbon nanofibers

    E-Print Network [OSTI]

    Adeoti, Bosun J

    2008-01-01T23:59:59.000Z

    The Micro Gas Analyzer project aims to develop power-efficient, high resolution, high sensitivity, portable and real-time gas sensors. We developed a field ionizer array based on gated CNTs. Arrays of CNTs are used because ...

  20. Hanford Environmental Dose Reconstruction Project monthly report, February 1993

    SciTech Connect (OSTI)

    Cannon, S.D.; Finch, S.M. (comps.)

    1993-01-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project Is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source Terms; Environmental Transport; Environmental Monitoring Data; Demography, Food Consumption, and Agriculture; and Environmental Pathways and Dose Estimates.

  1. Hanford Environmental Dose Reconstruction Project monthly report, February 1993

    SciTech Connect (OSTI)

    Cannon, S.D.; Finch, S.M. [comps.

    1993-03-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project Is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source Terms; Environmental Transport; Environmental Monitoring Data; Demography, Food Consumption, and Agriculture; and Environmental Pathways and Dose Estimates.

  2. Hanford Environmental Dose Reconstruction Project. Monthly report, November 1991

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. [comps.

    1991-12-31T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms; environmental transport environmental monitoring data; demographics, agriculture, food habits; environmental pathways and dose estimates.

  3. Hanford Environmental Dose Reconstruction Project monthly report, May 1992

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. [comps.

    1992-08-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These task correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates.

  4. Hanford Environmental Dose Reconstruction Project monthly report, May 1992

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. (comps.)

    1992-01-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These task correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates.

  5. Resonance ionization for analytical spectroscopy

    DOE Patents [OSTI]

    Hurst, George S. (Oak Ridge, TN); Payne, Marvin G. (Harriman, TN); Wagner, Edward B. (Burchfield Heights, TN)

    1976-01-01T23:59:59.000Z

    This invention relates to a method for the sensitive and selective analysis of an atomic or molecular component of a gas. According to this method, the desired neutral component is ionized by one or more resonance photon absorptions, and the resultant ions are measured in a sensitive counter. Numerous energy pathways are described for accomplishing the ionization including the use of one or two tunable pulsed dye lasers.

  6. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect (OSTI)

    McMakin, A.H.; Cannon, S.D.; Finch, S.M. [comps.

    1992-07-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon, Washington, and Idaho, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates. Progress is discussed.

  7. Determination of radionuclides and pathways contributing to cumulative dose. Hanford Environmental Dose Reconstruction Project: Dose code recovery activities, Calculation 004

    SciTech Connect (OSTI)

    Napier, B.A.

    1992-12-01T23:59:59.000Z

    A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 004) examined the contributions of numerous radionuclides to cumulative dose via environmental exposures and accumulation in foods. Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows` milk from Feeding Regime 1, as described in calculation 002. This calculation specifically addresses cumulative radiation doses to infants and adults resulting from releases occurring over the period 1945 through 1972.

  8. Fluid description of multi-component solar partially ionized plasma

    SciTech Connect (OSTI)

    Khomenko, E., E-mail: khomenko@iac.es; Collados, M.; Vitas, N. [Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife (Spain); Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Tenerife (Spain); Díaz, A. [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)

    2014-09-15T23:59:59.000Z

    We derive self-consistent formalism for the description of multi-component partially ionized solar plasma, by means of the coupled equations for the charged and neutral components for an arbitrary number of chemical species, and the radiation field. All approximations and assumptions are carefully considered. Generalized Ohm's law is derived for the single-fluid and two-fluid formalism. Our approach is analytical with some order-of-magnitude support calculations. After general equations are developed, we particularize to some frequently considered cases as for the interaction of matter and radiation.

  9. Multicriteria optimization of the spatial dose distribution

    SciTech Connect (OSTI)

    Schlaefer, Alexander [Medical Robotics Group, Universität zu Lübeck, Lübeck 23562, Germany and Institute of Medical Technology, Hamburg University of Technology, Hamburg 21073 (Germany)] [Medical Robotics Group, Universität zu Lübeck, Lübeck 23562, Germany and Institute of Medical Technology, Hamburg University of Technology, Hamburg 21073 (Germany); Viulet, Tiberiu [Medical Robotics Group, Universität zu Lübeck, Lübeck 23562 (Germany)] [Medical Robotics Group, Universität zu Lübeck, Lübeck 23562 (Germany); Muacevic, Alexander; Fürweger, Christoph [European CyberKnife Center Munich, Munich 81377 (Germany)] [European CyberKnife Center Munich, Munich 81377 (Germany)

    2013-12-15T23:59:59.000Z

    Purpose: Treatment planning for radiation therapy involves trade-offs with respect to different clinical goals. Typically, the dose distribution is evaluated based on few statistics and dose–volume histograms. Particularly for stereotactic treatments, the spatial dose distribution represents further criteria, e.g., when considering the gradient between subregions of volumes of interest. The authors have studied how to consider the spatial dose distribution using a multicriteria optimization approach.Methods: The authors have extended a stepwise multicriteria optimization approach to include criteria with respect to the local dose distribution. Based on a three-dimensional visualization of the dose the authors use a software tool allowing interaction with the dose distribution to map objectives with respect to its shape to a constrained optimization problem. Similarly, conflicting criteria are highlighted and the planner decides if and where to relax the shape of the dose distribution.Results: To demonstrate the potential of spatial multicriteria optimization, the tool was applied to a prostate and meningioma case. For the prostate case, local sparing of the rectal wall and shaping of a boost volume are achieved through local relaxations and while maintaining the remaining dose distribution. For the meningioma, target coverage is improved by compromising low dose conformality toward noncritical structures. A comparison of dose–volume histograms illustrates the importance of spatial information for achieving the trade-offs.Conclusions: The results show that it is possible to consider the location of conflicting criteria during treatment planning. Particularly, it is possible to conserve already achieved goals with respect to the dose distribution, to visualize potential trade-offs, and to relax constraints locally. Hence, the proposed approach facilitates a systematic exploration of the optimal shape of the dose distribution.

  10. Mechanisms of Low Dose Radio-Suppression of Genomic Instability

    SciTech Connect (OSTI)

    Engelward, Bevin P

    2009-09-16T23:59:59.000Z

    The major goal of this project is to contribute toward the elucidation of the impact of long term low dose radiation on genomic stability. We have created and characterized novel technologies for delivering long term low dose radiation to animals, and we have studied genomic stability by applying cutting edge molecular analysis technologies. Remarkably, we have found that a dose rate that is 300X higher than background radiation does not lead to any detectable genomic damage, nor is there any significant change in gene expression for genes pertinent to the DNA damage response. These results point to the critical importance of dose rate, rather than just total dose, when evaluating public health risks and when creating regulatory guidelines. In addition to these studies, we have also further developed a mouse model for quantifying cells that have undergone a large scale DNA sequence rearrangement via homologous recombination, and we have applied these mice in studies of both low dose radiation and space radiation. In addition to more traditional approaches for assessing genomic stability, we have also explored radiation and possible beneficial effects (adaptive response), long term effects (persistent effects) and effects on communication among cells (bystander effects), both in vitro and in vivo. In terms of the adaptive response, we have not observed any significant induction of an adaptive response following long term low dose radiation in vivo, delivered at 300X background. In terms of persistent and bystander effects, we have revealed evidence of a bystander effect in vivo and with researchers at and demonstrated for the first time the molecular mechanism by which cells “remember” radiation exposure. Understanding the underlying molecular mechanisms by which radiation can induce genomic instability is fundamental to our ability to assess the biological impact of low dose radiation. Finally, in a parallel set of studies we have explored the effects of heavy iron particle radiation on large scale sequence rearrangements and we have discovered tissue specific differences in sensitivity to homologous recombination. DOE support has given rise to critical new knowledge about the biological impact of low dose rate radiation and about the underlying mechanisms that govern genomic stability in response to radiation exposure. This work has spurred interest in radiation among MIT scientists, and has fostered ongoing research projects that will continue to contribute toward our understanding of the biological effects of low dose radiation exposure.

  11. Hanford Environmental Dose Reconstruction Project Monthly Report

    SciTech Connect (OSTI)

    Finch, S.M. (comp.)

    1990-05-01T23:59:59.000Z

    This monthly report summarizes the technical progress and project status for the Hanford Environmental Dose Reconstruction (HEDR) Project being conducted at Pacific Northwest Laboratory (PNL) under the direction of a Technical Steering Panel (TSP). The TSP is composed of experts in numerous technical fields related to this project and represents the interests of the public. The US Department of Energy (DOE) funds the project. The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks address each of the primary steps in the path from radioactive releases to dose estimates source terms, environmental transport, environmental monitoring data, demographics, agriculture, and food habits, and environmental pathways and dose estimates.

  12. Internal dose following a major nuclear war

    SciTech Connect (OSTI)

    Peterson, K.R.; Shapiro, C.S. (Lawrence Livermore National Laboratory, Livermore, CA (Unites States))

    1992-01-01T23:59:59.000Z

    The PATHWAY model results were used, in conjunction with a hypothetical major nuclear attack on the U.S., to arrive at the ratio of internal to external dose for humans from early (48 h) fallout. Considered were the four nuclides (137Cs, 89Sr, 90Sr, 131I) that account for most of the reconstructed whole-body committed equivalent dose from internal radiation in people who lived downwind of the Nevada Test Site during atmospheric tests. Effects of climate perturbations (the 'nuclear winter' effect) on food crops were considered. These could increase internal dose estimates, depending on the severity of the climate perturbations. Internal and external doses to humans for 10 locations within the U.S. have been calculated, with varying local conditions and varying assumption about their shelters. The estimated 50-y internal dose commitment ranged from 0.0-0.17 Sv, the 48-h external dose from 0.15-4.6 Sv. The resultant ratios of internal to external committed dose received in the first months (until food transport was restored) varied from less than 0.01 to about 0.2. In all cases examined, the total dose from early fallout was found to be dominated by the external dose.

  13. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, James E. (Knoxville, TN)

    1989-01-01T23:59:59.000Z

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiation events, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible "chirp". The rate of the "chirps" is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field.

  14. Life-span effects of ionizing radiation in the beagle dog: A summary account of four decades of research funded by the US Department of Energy and its predecessor agencies

    SciTech Connect (OSTI)

    Thompson, R.C.

    1989-01-01T23:59:59.000Z

    Nearly 40 years ago, the US Atomic Energy Commission made a far- reaching commitment to the support of life-span radiation-effects studies in a relatively long-lived animal, the beagle dog. Something in the range of 200 million dollars has already been spent on a group of closely related experiments, many of which are only now coming to fruition. Responsible fiscal management of these studies, directed toward securing an optimum return from past investments, and toward creative planning of future directions, requires a comprehensive view of this total effort. This report is designed to provide that comprehensive view. This is primarily intended as a research management document. Evaluation and interpretation are tasks for those directly involved in conducting these experiments. The limited objective of the present document is to describe what has been done, to give some of the background for why it was done, to describe results already realized and applications that have been made of these results -- all in a manner designed to display the total effort rather than piecemeal details. While proposing no specific answers to the questions ''Where do we go from here.''it is hoped that the document will provide a basis for approaching that question in an informed manner. The maintenance of a continuity of scientific understanding and direction in these experiments, which often continue beyond the initiating investigators' working life, is no small part of the problem involved in conducting these experiments.

  15. Non-Invasive Early Detection and Molecular Analysis of Low X-ray Dose Effects in the Lens

    SciTech Connect (OSTI)

    Goldstein, Lee [Boston University] [Boston University

    2014-07-02T23:59:59.000Z

    This is the Final Progress Report for DOE-funded research project DE-PS02-08ER08-01 titled “Non-Invasive Early Detection and Molecular Analysis of Low X-ray Dose Effects in the Lens”. The project focuses on the effects of low-linear energy transfer (LET) radiation on the ocular lens. The lens is an exquisitely radiosensitive tissue with a highly-ordered molecular structure that is amenable to non-invasive optical study from the periphery. These merits point to the lens as an ideal target for laser-based molecular biodosimetry (MBD). Following exposure to different types of ionizing radiations, the lens demonstrates molecular changes (e.g., oxidation, racemization, crosslinkage, truncation, aggregation, etc.) that impact the structure and function of the long-lived proteins in the cytosol of lens fiber cells. The vast majority of proteins in the lens comprise the highly-ordered crystallins. These highly conserved lens proteins are amongst the most concentrated and stable in the body. Once synthesized, the crystallins are retained in the fiber cell cytoplasm for life. Taken together, these properties point to the lens as an ideal system for quantitative in vivo MBD assessment using quasi-elastic light scattering (QLS) analysis. In this project, we deploy a purpose-designed non-invasive infrared laser QLS instrument as a quantitative tool for longitudinal assessment of pre-cataractous molecular changes in the lenses of living mice exposed to low-dose low-LET radiation compared to non-irradiated sham controls. We hypothesize that radiation exposure will induce dose-dependent changes in the molecular structure of matrix proteins in the lens. Mechanistic assays to ascertain radiation-induced molecular changes in the lens focus on protein aggregation and gene/protein expression patterns. We anticipate that this study will contribute to our understanding of early molecular changes associated with radiation-induced tissue pathology. This study also affords potential for translational development of molecular biodosimetry instrumentation to assess human exposure to mixed radiation fields.

  16. Radiation Environments and Exposure Considerations for the Multi-Mission Radioisotope Thermoelectric Generator

    SciTech Connect (OSTI)

    Kelly, William M.; Low, Nora M.; Zillmer, Andrew; Johnson, Gregory A. [Pratt and Whitney Rocketdyne, 6633 Canoga Avenue, Canoga Park, CA 91309 (United States); Normand, Eugene [Boeing Radiation Effects Laboratory, P.O. Box 3707, M/S 2T-50, Seattle, WA 98124-22079 (United States)

    2006-01-20T23:59:59.000Z

    The Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) is the next generation (RTG) being developed by DOE to provide reliable, long-life electric power for NASA's planetary exploration programs. The MMRTG is being developed by Pratt and Whitney Rocketdyne and Teledyne Energy Systems Incorporated (TESI) for use on currently planned and projected flyby, orbital and planet landing missions. This is a significant departure from the design philosophy of the past which was to match specific mission requirements to RTG design capabilities. Undefined mission requirements provide a challenge to system designers by forcing them to put a design envelope around 'all possible missions'. These multi-mission requirements include internal and external radiation sources. Internal sources include the particles ejected by decaying Pu-238 and its daughters plus particles resulting from the interaction of these particles with other MMRTG materials. External sources include the full spectrum of charged particle radiation surrounding planets with magnetic fields and the surfaces of extraterrestrial objects not shielded by magnetic fields. The paper presents the results of investigations into the environments outlined above and the impact of radiation exposure on potential materials to be used on MMRTG and ground support personnel. Mission requirements were also reviewed to evaluate total integrated dose and to project potential shielding requirements for materials. Much of the information on mission shielding requirements was provided by NASA's Jet Propulsion Laboratory. The primary result is an ionizing radiation design curve which indicates the limits to which a particular mission can take the MMRTG in terms of ionizing radiation exposure. Estimates of personnel radiation exposure during ground handling are also provided.

  17. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect (OSTI)

    Finch, S. M.; McMakin, A. H.

    1991-09-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation dose that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into five technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (i.e., dose estimates). The Source Terms Task develops estimates of radioactive emissions from Hanford facilities since 1944. The Environmental Transport Task reconstructs the movements of radioactive particles from the areas of release to populations. The Environmental Monitoring Data Task assemblies, evaluates and reports historical environmental monitoring data. The Demographics, Agriculture and Food Habits Task develops the data needed to identify the populations that could have been affected by the releases. The Environmental Pathways and Dose Estimates Task used the information derived from the other Tasks to estimate the radiation doses individuals could have received from Hanford radiation. This document lists the progress on this project as of September 1991. 3 figs., 2 tabs.

  18. Topographic Effects on Ambient Dose Equivalent Rates from Radiocesium Fallout

    E-Print Network [OSTI]

    Malins, Alex; Machida, Masahiko; Saito, Kimiaki

    2015-01-01T23:59:59.000Z

    Land topography can affect air radiation dose rates by locating radiation sources closer to, or further, from detector locations when compared to perfectly flat terrain. Hills and slopes can also shield against the propagation of gamma rays. To understand the possible magnitude of topographic effects on air dose rates, this study presents calculations for ambient dose equivalent rates at a range of heights above the ground for varying land topographies. The geometries considered were angled ground at the intersection of two planar surfaces, which is a model for slopes neighboring flat land, and a simple conical geometry, representing settings from hilltops to valley bottoms. In each case the radiation source was radioactive cesium fallout, and the slope angle was varied systematically to determine the effect of topography on the air dose rate. Under the assumption of homogeneous fallout across the land surface, and for these geometries and detector locations, the dose rates at high altitudes are more strongly...

  19. Carbon nanotube-based field ionization vacuum

    E-Print Network [OSTI]

    Jang, Daniel, M. Eng. Massachusetts Institute of Technology

    2012-01-01T23:59:59.000Z

    We report the development of a novel micropump architecture that uses arrays of isolated vertical carbon nanotubes (CNT) to field ionize gas particles. The ionized gas molecules are accelerated to and implanted into a ...

  20. Scientific innovation and resonance ionization spectroscopy

    SciTech Connect (OSTI)

    Richmond, C.R.

    1981-01-01T23:59:59.000Z

    An account is presented of the development and appliations of resonance ionization spectroscopy and one atom detection.

  1. Packet personal radiation monitor

    DOE Patents [OSTI]

    Phelps, J.E.

    1988-03-31T23:59:59.000Z

    A personal radiation monitor of the chirper type is provided for detecting ionizing radiation. A battery powered high voltage power supply is used to generate and apply a high voltage bias to a G-M tube radiation sensor. The high voltage is monitored by a low-loss sensing network which generates a feedback signal to control the high voltage power supply such that the high voltage bias is recharged to +500 VDC when the current pulses of the sensor, generated by the detection of ionizing radiatonevents, discharges the high voltage bias to +450 VDC. During the high voltage recharge period an audio transducer is activated to produce an audible ''chirp''. The rate of the ''chirps'' is controlled by the rate at which the high voltage bias is recharged, which is proportional to the radiation field intensity to which the sensor is exposed. The chirp rate sensitivity is set to be approximately 1.5 (chirps/min/MR/hr.). The G-M tube sensor is used in a current sensing mode so that the device does not paralyze in a high radiation field. 2 figs.

  2. Dose response of selected ion chambers in applied homogeneous transverse and longitudinal magnetic fields

    SciTech Connect (OSTI)

    Reynolds, M. [Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Fallone, B. G. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Departments of Oncology and Physics, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Rathee, S. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Department of Oncology, Medical Physics Division, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

    2013-04-15T23:59:59.000Z

    Purpose: The magnetic fields of an integrated MR-Linac system will alter the paths of electrons that produce ions in the ionization chambers. The dose response of selected ion chambers is evaluated in the presence of varying transverse and longitudinal magnetic fields. The investigation is useful in calibration of therapeutic x-ray beams associated with MR-Linac systems. Methods: The Monte Carlo code PENELOPE was used to model the irradiation of NE2571, and PR06C ionization chambers in the presence of a transverse and longitudinal (with respect to the photon beam) magnetic fields of varying magnitude. The long axis of each chamber was simulated both parallel and perpendicular to the incident photon beam for each magnetic field case. The dose deposited in each chamber for each case was compared to the case with zero magnetic field by means of a ratio. The PR06C chamber's response was measured in the presence of a transverse magnetic field with field strengths ranging from 0.0 to 0.2 T to compare to simulated results. Results: The simulations and measured data show that in the presence of a transverse magnetic field there is a considerable dose response (maximum of 11% near 1.0 T in the ion chambers investigated, which depends on the magnitude of magnetic field, and relative orientation of the magnetic field, radiation beam, and ion chamber. Measurements made with the PR06C chamber verify these results in the region of measurement. In contrast, a longitudinal magnetic field produces only a slight increase in dose response (2% at 1.5 T) that rises slowly with increasing magnetic field and is seemingly independent of chamber orientation. Response trends were similar for the two ion chambers and relative orientations considered, but slight variations are present from chamber to chamber. Conclusions: Care must be taken when making ion chamber measurements in a transverse magnetic field. Ion chamber responses vary not only with transverse field strength, but with chamber orientation and type, and can be considerable. Longitudinal magnetic fields influence ion chamber responses relatively little (2% at 1.5 T), and only at field strengths in excess of 1.0 T.

  3. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, Robert A. (Palo Alto, CA); Perez-Mendez, Victor (Berkeley, CA); Kaplan, Selig N. (El Cerrito, CA)

    1992-01-01T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification.

  4. Amorphous silicon radiation detectors

    DOE Patents [OSTI]

    Street, R.A.; Perez-Mendez, V.; Kaplan, S.N.

    1992-11-17T23:59:59.000Z

    Hydrogenated amorphous silicon radiation detector devices having enhanced signal are disclosed. Specifically provided are transversely oriented electrode layers and layered detector configurations of amorphous silicon, the structure of which allow high electric fields upon application of a bias thereby beneficially resulting in a reduction in noise from contact injection and an increase in signal including avalanche multiplication and gain of the signal produced by incoming high energy radiation. These enhanced radiation sensitive devices can be used as measuring and detection means for visible light, low energy photons and high energy ionizing particles such as electrons, x-rays, alpha particles, beta particles and gamma radiation. Particular utility of the device is disclosed for precision powder crystallography and biological identification. 13 figs.

  5. Gamma Radiation Dose Rate in Air due to Terrestrial Radionuclides in Southern Brazil: Synthesis by Geological Units and Lithotypes Covered by the Serra do Mar Sul Aero-Geophysical Project

    SciTech Connect (OSTI)

    Bastos, Rodrigo O.; Appoloni, Carlos R. [Applied Nuclear Physics Laboratory-Department of Physics-CCE State University of Londrina Campus Universitario-Rodovia Celso Garcia Cid s/n, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil); Pinese, Jose P. P. [Department of Geosciences-CCE State University of Londrina Campus Universitario-Rodovia Celso Garcia Cid s/n, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil)

    2008-08-07T23:59:59.000Z

    The absorbed dose rates in air due to terrestrial radionuclides were estimated from aerial gamma spectrometric data for an area of 48,600 km{sup 2} in Southern Brazil. The source data was the Serra do Mar Sul Aero-Geophysical Project back-calibrated in a cooperative work among the Geological Survey of Brazil, the Geological Survey of Canada, and Paterson, Grant and Watson Ltd. The concentrations of eU (ppm), eTh (ppm) and K (%) were converted to dose rates in air (nGy{center_dot}h{sup -1}) by accounting for the contribution of each element's concentration. Regional variation was interpreted according to lithotypes and a synthesis was performed according to the basic geological units present in the area. Higher values of total dose were estimated for felsic igneous and metamorphic rocks, with average values varying up to 119{+-}24 nGy{center_dot}h{sup -1}, obtained by Anitapolis syenite body. Sedimentary, metasedimentary and metamafic rocks presented the lower dose levels, and some beach deposits reached the lowest average total dose, 18.5{+-}8.2 nGy{center_dot}h{sup -1}. Thorium gives the main average contribution in all geological units, the highest value being reached by the nebulitic gneisses of Atuba Complex, 71{+-}23 nGy{center_dot}h{sup -1}. Potassium presents the lowest average contribution to dose rate in 53 of the 72 units analyzed, the highest contribution being obtained by intrusive alkaline bodies (28{+-}12 nGy{center_dot}h{sup -1}). The general pattern of geographic dose distribution respects well the hypotheses on geo-physicochemical behavior of radioactive elements.

  6. Experimental analysis of general ion recombination in a liquid-filled ionization chamber in high-energy photon beams

    SciTech Connect (OSTI)

    Chung, Eunah; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal General Hospital (L5-113), 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Davis, Stephen [Department of Medical Physics, McGill University Health Centre, Montreal General Hospital (L5-112), 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada)

    2013-06-15T23:59:59.000Z

    Purpose: To study experimentally the general ion recombination effect in a liquid-filled ionization chamber (LIC) in high-energy photon beams. Methods: The general ion recombination effect on the response of a micro liquid ion chamber (microLion) was investigated with a 6 MV photon beam in normal and SRS modes produced from a Varian{sup Registered-Sign} Novalis Tx{sup TM} linear accelerator. Dose rates of the linear accelerator were set to 100, 400, and 1000 MU/min, which correspond to pulse repetition frequencies of 60, 240, and 600 Hz, respectively. Polarization voltages applied to the microLion were +800 and +400 V. The relative collection efficiency of the microLion response as a function of dose per pulse was experimentally measured with changing polarization voltage and pulse repetition frequencies and was compared with the theoretically calculated value. Results: For the 60 Hz pulse repetition frequency, the experimental relative collection efficiency was not different from the theoretical one for a pulsed beam more than 0.3% for both polarization voltages. For a pulsed radiation beam with a higher pulse repetition frequency, the experimental relative collection efficiency converged to the theoretically calculated efficiency for continuous beams. This result indicates that the response of the microLion tends toward the response to a continuous beam with increasing pulse repetition frequency of a pulsed beam because of low ion mobility in the liquid. Conclusions: This work suggests an empirical method to correct for differences in general ion recombination of a LIC between different radiation fields. More work is needed to quantitatively explain the LIC general ion recombination behavior in pulsed beams generated from linear accelerators.

  7. DOE/OR-1066R5/02-03 6-1 6. DOSE CALCULATIONS

    E-Print Network [OSTI]

    Pennycook, Steve

    receive external radiation doses through direct external irradiation by radiations emanating from mechanisms that apply to emissions from ORR. Sections 6.3 and 6.4 discuss the environmental transport, food

  8. New Easy-to-Use Medical Field Guide for Radiation Emergencies...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    radiation dose Delayed effects of radiation exposure, and Psychological considerations "Health care providers are expected to treat patients injured in a multitude of possible...

  9. Total dose and dose rate models for bipolar transistors in circuit simulation.

    SciTech Connect (OSTI)

    Campbell, Phillip Montgomery; Wix, Steven D.

    2013-05-01T23:59:59.000Z

    The objective of this work is to develop a model for total dose effects in bipolar junction transistors for use in circuit simulation. The components of the model are an electrical model of device performance that includes the effects of trapped charge on device behavior, and a model that calculates the trapped charge densities in a specific device structure as a function of radiation dose and dose rate. Simulations based on this model are found to agree well with measurements on a number of devices for which data are available.

  10. Tolerance doses for treatment planning

    SciTech Connect (OSTI)

    Lyman, J.T.

    1985-10-01T23:59:59.000Z

    Data for the tolerance of normal tissues or organs to (low-LET) radiation has been compiled from a number of sources which are referenced at the end of this document. This tolerance dose data are ostensibly for uniform irradiation of all or part of an organ, and are for either 5% (TD/sub 5/) or 50% (TD/sub 50/) complication probability. The ''size'' of the irradiated organ is variously stated in terms of the absolute volume or the fraction of the organ volume irradiated, or the area or the length of the treatment field. The accuracy of these data is questionable. Much of the data represents doses that one or several experienced therapists have estimated could be safely given rather than quantitative analyses of clinical observations. Because these data have been obtained from multiple sources with possible different criteria for the definition of a complication, there are sometimes different values for what is apparently the same endpoint. The data from some sources shows a tendancy to be quantized in 5 Gy increments. This reflects the size of possible round off errors. It is believed that all these data have been accumulated without the benefit of 3-D dose distributions and therefore the estimates of the size of the volume and/or the uniformity of the irradiation may be less accurate than is now possible. 19 refs., 4 figs.

  11. The Ionizing Continuum of Quasars

    E-Print Network [OSTI]

    Ari Laor

    1998-10-15T23:59:59.000Z

    The ionizing continuum shape of quasars is generally not directly observable, but indirect arguments, based on photoionization models and thin accretion disk models suggest that it should peak in the extreme UV, and drop steeply into the soft X-ray regime. However, recent observations of very soft X-ray emission in low z quasars, and far UV emission of high z quasars, suggest that the ionizing continuum of quasars does not peak in the extreme UV, and may extend as a single power law from ~1000 A to ~1 keV. If true, that has interesting implications for photoionization models and for accretion disk models. The proposed revised continuum shape will be tested directly in the near future with FUSE.

  12. STORAGE RING CROSS-SECTION MEASUREMENTS FOR ELECTRON IMPACT SINGLE AND DOUBLE IONIZATION OF Fe{sup 9+} AND SINGLE IONIZATION OF Fe{sup 10+}

    SciTech Connect (OSTI)

    Hahn, M.; Novotny, O.; Savin, D. W. [Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Becker, A.; Grieser, M.; Krantz, C.; Wolf, A. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Lestinsky, M.; Repnow, R. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, D-64291 Darmstadt (Germany); Mueller, A.; Schippers, S.; Spruck, K. [Institut fuer Atom- und Molekuelphysik, Justus-Liebig-Universitaet Giessen, Leihgesterner Weg 217, D-35392 Giessen (Germany)

    2012-11-20T23:59:59.000Z

    We have measured electron impact ionization from the ground state of Fe{sup 9+} and Fe{sup 10+} over the relative electron-ion collision energy ranges 200-1900 eV and 250-1800 eV, respectively. The ions were confined in an ion storage ring long enough for essentially all metastable levels to radiatively relax to the ground state. For single ionization, we find a number of discrepancies between the existing theoretical cross sections and our results. The calculations appear to neglect some excitation-autoionization (EA) channels, particularly from n = 3 to n' excitations, which are important near threshold, and those from n = 2 {yields} 3 excitations, which contribute at about 650 eV. Conversely, at higher energies the calculations appear to overestimate the importance of EA channels due to excitation into levels where n {>=} 4. The resulting experimental rate coefficients agree with the most recent theory for Fe{sup 9+} to within 16% and for Fe{sup 10+} to within 19% at temperatures where these ions are predicted to form in collisional ionization equilibrium. We have also measured double ionization of Fe{sup 9+} forming Fe{sup 11+} in the energy range 450-3000 eV and found that although there is an appreciable cross section for direct double ionization, the dominant mechanism appears to be through direct ionization of an inner shell electron producing an excited state that subsequently stabilizes through autoionization.

  13. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1997

    SciTech Connect (OSTI)

    Davis, M.G.; Flotard, R.D.; Fontana, C.A.; Hennessey, P.A.; Maunu, H.K.; Mouck, T.L.; Mullen, A.A.; Sells, M.D.

    1999-01-01T23:59:59.000Z

    This report describes the Offsite Radiological Environmental Monitoring Program (OREMP) conducted during 1997 by the US Environmental Protection Agency`s (EPAs), Radiation and Indoor Environments National Laboratory, Las Vegas, Nevada. This laboratory operated an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling and analyzing milk, water, and air; by deploying and reading thermoluminescent dosimeters (TLDs); and using pressurized ionization chambers (PICs) to measure ambient gamma exposure rates with a sensitivity capable of detecting low level exposures not detected by other monitoring methods.

  14. Offsite environmental monitoring report: Radiation monitoring around United States nuclear test areas, calendar year 1993

    SciTech Connect (OSTI)

    Chaloud, D.J; Daigler, D.M.; Davis, M.G. [and others

    1996-06-01T23:59:59.000Z

    This report describes the Offsite Radiation Safety Program conducted during 1993 by the Environmental Protection Agency`s (EPA`s) Environmental Monitoring Systems Laboratory - Las Vegas (EMSL-LV). This laboratory operates an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs) and using pressurized ionization chambers (PICs); by biological monitoring of foodstuffs including animal tissues and food crops; and by measurement of radioactive material deposited in humans.

  15. Occupational dose estimates for a monitored retrievable storage facility

    SciTech Connect (OSTI)

    Harty, R.; Stoetzel, G.A.

    1986-06-01T23:59:59.000Z

    Occupational doses were estimated for radiation workers at the monitored retrievable storage (MRS) facility. This study provides an estimate of the occupational dose based on the current MRS facility design, examines the extent that various design parameters and assumptions affect the dose estimates, and identifies the areas and activities where exposures can be reduced most effectively. Occupational doses were estimated for both the primary storage concept and the alternate storage concept. The dose estimates indicate the annual dose to all radiation workers will be below the 5 rem/yr federal dose equivalent limit. However, the estimated dose to most of the receiving and storage crew (the workers responsible for the receipt, storage, and surveillance of the spent fuel and its subsequent retrieval), to the crane maintenance technicians, and to the cold and remote maintenance technicians is above the design objective of 1 rem/yr. The highest annual dose is received by the riggers (4.7 rem) in the receiving and storage crew. An indication of the extent to which various design parameters and assumptions affect the dose estimates was obtained by changing various design-based assumptions such as work procedures, background dose rates in radiation zones, and the amount of fuel received and stored annually. The study indicated that a combination of remote operations, increased shielding, and additional personnel (for specific jobs) or changes in operating procedures will be necessary to reduce worker doses below 1.0 rem/yr. Operations that could be made at least partially remote include the removal and replacement of the tiedowns, impact limiters, and personnel barriers from the shipping casks and the removal or installation of the inner closure bolts. Reductions of the background dose rates in the receiving/shipping and the transfer/discharge areas may be accomplished with additional shielding.

  16. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre; Zeeb, Hajo

    2015-03-23T23:59:59.000Z

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takesmore »up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope ? is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of ?) is biased for ?6¼0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the MayakWorker Cohort, and the U.S. Atomic Veterans Study, is discussed.« less

  17. Effect of gamma radiation on groundwater chemistry and glass leaching as related to the NNWSI repository site

    SciTech Connect (OSTI)

    Abrajano, T.; Bates, J.; Ebert, W.; Gerding, T.

    1986-05-01T23:59:59.000Z

    To address the effect of ionizing radiation on groundwater chemistry and waste form durability, NNWSI is performing an extensive set of experiments as a function of dose rate (2 x 10{sup 5}, 1 x 10{sup 4}, 1 x 10{sup 3}, and 0 rad/h). The results of the tests done at 2 x 10{sup 5} rad/h have been reported, while the 1 x 10{sup 3} and 0 rad/h tests are in progress. This paper presents an overview of the results of the tests done at 1 x 10{sup 4} rad/h and discusses the relevance of these tests to repository conditions. An interpretation of the results relating to the manner by which the glass waste form corrodes is presented elsewhere. A complete discussion of the effect of gamma radiation on groundwater chemistry and waste form durability will be presented when the series of experiments are complete.

  18. 7th International Workshop on Microbeam Probes of Cellular Radiation Response

    SciTech Connect (OSTI)

    Brenner, David J.

    2009-07-21T23:59:59.000Z

    The extended abstracts that follow present a summary of the Proceedings of the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, held at Columbia University’s Kellogg Center in New York City on March 15–17, 2006. These International Workshops on Microbeam Probes of Cellular Radiation Response have been held regularly since 1993 (1–5). Since the first workshop, there has been a rapid growth (see Fig. 1) in the number of centers developing microbeams for radiobiological research, and worldwide there are currently about 30 microbeams in operation or under development. Single-cell/single-particle microbeam systems can deliver beams of different ionizing radiations with a spatial resolution of a few micrometers down to a few tenths of a micrometer. Microbeams can be used to addressquestions relating to the effects of low doses of radiation (a single radiation track traversing a cell or group of cells), to probe subcellular targets (e.g. nucleus or cytoplasm), and to address questions regarding the propagation of information about DNA damage (for example, the radiation-induced bystander effect). Much of the recent research using microbeams has been to study low-dose effects and ‘‘non-targeted’’ responses such as bystander effects, genomic instability and adaptive responses. This Workshop provided a forum to assess the current state of microbeam technology and current biological applications and to discuss future directions for development, both technological and biological. Over 100 participants reviewed the current state of microbeam research worldwide and reported on new technological developments in the fields of both physics and biology.

  19. Neutron dose equivalent meter

    DOE Patents [OSTI]

    Olsher, Richard H. (Los Alamos, NM); Hsu, Hsiao-Hua (Los Alamos, NM); Casson, William H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM); Kleck, Jeffrey H. (Menlo Park, CA); Beverding, Anthony (Foster City, CA)

    1996-01-01T23:59:59.000Z

    A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

  20. DRY TRANSFER FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect (OSTI)

    J.S. Tang

    2004-09-23T23:59:59.000Z

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Dry Transfer Facility No.1 (DTF-1) performing operations to receive transportation casks, transfer wastes, prepare waste packages, and ship out loaded waste packages and empty casks. Doses received by workers due to maintenance operations are also included in this revision. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation, excluding the remediation area of the building. The results of this calculation will be used to support the design of the DTF-1 and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in the Environmental and Nuclear Engineering.

  1. Misonidazole with dexamethasone rescue: an escalating dose toxicity study

    SciTech Connect (OSTI)

    Tanasichuk, H.; Urtasun, R.C.; Fulton, D.S.; Raleigh, J.

    1984-09-01T23:59:59.000Z

    Neurotoxicity induced by misonidazole (MISO) and desmethylmisonidazole (DMM) has become the dose limiting factor in clinical work. In 1981, the authors reported a preliminary study suggestive that Dexamethasone (DEXA) does have a protective effect against peripheral neuropathies (PN) resulting from toxicity of misonidazole. The authors are presently investigating the use of DEXA, with escalating doses of MISO in an attempt to modify its neurotoxicity. To date, 16 patients have been registered to receive total doses of MISO given in 9 equally divided doses over 3 weeks. DEXA is given 3 days prior to the first dose and continues for the duration of therapy. All patients receive palliative radiation. No toxicity was seen at the total dose of 13.5 gm/M/sub 2/. One grade I PN occurred in the first four patients receiving 15.5 gm/M/sub 2/. Six additional patients were entered at this dose level and no further incidence of PN was observed.

  2. alpha radiation effectively: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    perturbations at the heliospheric boundaries and local (i.e. within 10-20 AU from the Sun) effects of the solar ionization, charge exchange, solar gravitation and radiation...

  3. Radiation effects on the blood-brain barrier

    E-Print Network [OSTI]

    Raabe, Rebecca L

    2007-01-01T23:59:59.000Z

    Selective vascular irradiation enables the critical examination of the vasculature and its role in the onset of late radiation effects. It is a novel approach to expose the endothelial cells to much higher levels of ionizing ...

  4. SU-C-18C-04: Evaluation of Effective Dose During Ureteroscopy for Obese and Non-Obese Patients

    SciTech Connect (OSTI)

    Wang, C; Nguyen, G; Chung, Y; Yoshizumi, T [Duke University, Durham, NC (United States); Cabrera, F; Lipkin, M [Duke University Medical Center, Durham, NC (United States); Shin, R [Duke University Medical Center, Durham, North Carolina (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Ureteroscopy involves fluoroscopy which potentially results in considerable amount of radiation dose to the patient. Purpose of this study was two-fold: (a) to develop the effective dose computational model for obese and non-obese patients undergoing left and right ureteroscopy, and (b) to evaluate the utility of a commercial Monte Carlo software for dose assessment in ureteroscopy. Methods: Organ dose measurements were performed on an adult male anthropomorphic phantom, representing the non-obese patients, with 20 high-sensitivity MOSFET detectors and two 0.18cc ionization chambers placed in selected organs. Fat-equivalent paddings were placed around the abdominal region to simulate for obese patients. Effective dose (ED) was calculated using ICRP 103 tissue weighting factors and normalized to the effective dose rate in miliSivert per second (mSv/s). In addition, a commercial Monte Carlo (MC) dose estimation program was used to estimate ED for the non-obese model, with table attenuation correction applied to simulate clinical procedure. Results: For the equipment and protocols involved in this study, the MOSFETderived ED rates for the obese patient model (‘Left’: 0.0092±0.0004 mSv/s; ‘Right’: 0.0086±0.0004 mSv/s) was found to be more than twice as much as that to the non-obese patient model (‘Left’: 0.0041±0.0003 mSv/s; ‘Right’: 0.0036±0.0007 mSv/s). The MC-derived ED rates for the non-obese patient model (‘Left’: 0.0041 mSv/s; ‘Right’: 0.0036 mSv/s; with statistical uncertainty of 1%) showed a good agreement with the MOSFET method. Conclusion: The significant difference in ED rate between the obese and non-obese patient models shows the limitation of directly applying commercial softwares for obese patients and leading to considerable underestimation of ED. Although commercial softwares offer a convenient means of dose estimation, but the utility may be limited to standard-man geometry as the software does not account for table attenuation, obese patient geometry, and differences between the anthropomorphic phantom and MC mathematical phantom.

  5. Ionization Cluster Size Distributions Created by Low Energy Electrons and Alpha Particles in Nanometric Track Segment in Gases

    E-Print Network [OSTI]

    Bantsar, Aliaksandr

    2012-01-01T23:59:59.000Z

    The interaction of ionizing radiation with nanometric targets is a field of interest for many branches of science such as: radiology, oncology, radiation protection and nanoelectronics. A new experimental technique known as nanodosimetry has been developed for the qualitative as well as quantitative description of these types of interactions. The work presented here is a contribution to this development, namely by further improvement of the new experimental technique called the Jet Counter, originally developed at the Andrzej So{\\l}tan Institute for Nuclear Studies. The Jet Counter is a unique device in the world for studying the interaction of low energy electrons with nanometer targets in the range 2-10 nm (in unit density). The basic experimental result is the frequency distribution of ionization cluster size produced by ionizing particles in a gaseous (nitrogen or propane) nanometric track segment. The first experimental data on the frequency distribution of ionization cluster size produced by low energy ...

  6. SU-E-T-79: Comparison of Doses Received by the Hippocampus in Patients Treated with Single Vs Multiple Isocenter Based Stereotactic Radiation Therapy to the Brain for Multiple Brain Metastases

    SciTech Connect (OSTI)

    Algan, O; Giem, J; Young, J; Ali, I; Ahmad, S; Hossain, S [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To investigate the doses received by the hippocampus and normal brain tissue during a course of stereotactic radiotherapy utilizing a single isocenter (SI) versus multiple isocenter (MI) in patients with multiple intracranial metastases. Methods: Seven patients imaged with MRI including SPGR sequence and diagnosed with 2–3 brain metastases were included in this retrospective study. Two sets of stereotactic IMRT treatment plans, (MI vs SI), were generated. The hippocampus was contoured on SPGR sequences and doses received by the hippocampus and whole brain were calculated. The prescribed dose was 25Gy in 5 fractions. The two groups were compared using t-test analysis. Results: There were 17 lesions in 7 patients. The median tumor, right hippocampus, left hippocampus and brain volumes were: 3.37cc, 2.56cc, 3.28cc, and 1417cc respectively. In comparing the two treatment plans, there was no difference in the PTV coverage except in the tail of the DVH curve. All tumors had V95 > 99.5%. The only statistically significant parameter was the V100 (72% vs 45%, p=0.002, favoring MI). All other evaluated parameters including the V95 and V98 did not reveal any statistically significant differences. None of the evaluated dosimetric parameters for the hippocampus (V100, V80, V60, V40, V20, V10, D100, D90, D70, D50, D30, D10) revealed any statistically significant differences (all p-values > 0.31) between MI and SI plans. The total brain dose was slightly higher in the SI plans, especially in the lower dose regions, although this difference was not statistically significant. Utilizing brain-sub-PTV volumes did not change these results. Conclusion: The use of SI treatment planning for patients with up to 3 brain metastases produces similar PTV coverage and similar normal tissue doses to the hippocampus and the brain compared to MI plans. SI treatment planning should be considered in patients with multiple brain metastases undergoing stereotactic treatment.

  7. Radiation dosimeters

    DOE Patents [OSTI]

    Hoelsher, James W. (Pullman, WA); Hegland, Joel E. (Pullman, WA); Braunlich, Peter F. (Pullman, WA); Tetzlaff, Wolfgang (Pullman, WA)

    1992-01-01T23:59:59.000Z

    Radiation dosimeters and dosimeter badges. The dosimeter badges include first and second parts which are connected to join using a securement to produce a sealed area in which at least one dosimeter is held and protected. The badge parts are separated to expose the dosimeters to a stimulating laser beam used to read dose exposure information therefrom. The badge is constructed to allow automated disassembly and reassembly in a uniquely fitting relationship. An electronic memory is included to provide calibration and identification information used during reading of the dosimeter. Dosimeter mounts which reduce thermal heating requirements are shown. Dosimeter constructions and production methods using thin substrates and phosphor binder-layers applied thereto are also taught.

  8. Los Alamos Science Number 23 1995 Ionizing Radiation

    E-Print Network [OSTI]

    Massey, Thomas N.

    . "Except we're using modern film--high-speed PolaroidTM." Irene removes the film from under the uranium ore're repeating Becquerel's experiment with uranium minerals in which he discovered radioactivity," Carl answers the uranium passed into the film except where it was partly blocked by the metal paper clip and the nickel we

  9. atmospheric ionizing radiation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and photoabsorption. Incident spectra from parent star flares, supernovae, and gamma-ray bursts are modeled and compared to energetic particles in importance. We find that...

  10. acute ionizing radiation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Japanese government acts on this presumption in responding to the nuclear reactor damage from the March 2011 earthquake and tsunami at Fukushima, Japans already reeling...

  11. Hanford Environmental Dose Reconstruction Project. Monthly report, June 1992

    SciTech Connect (OSTI)

    Finch, S.M.; McMakin, A.H. [comps.

    1992-06-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

  12. Atmospheric sampling glow discharge ionization source

    DOE Patents [OSTI]

    McLuckey, S.A.; Glish, G.L.

    1989-07-18T23:59:59.000Z

    An atmospheric sampling glow discharge ionization source that can be used in combination with an analytical instrument which operates at high vacuum, such as a mass spectrometer. The atmospheric sampling glow discharge ionization source comprises a chamber with at least one pair of electrodes disposed therein, an inlet for a gaseous sample to be analyzed and an outlet communicating with an analyzer which operates at subatmospheric pressure. The ionization chamber is maintained at a pressure below atmospheric pressure, and a voltage difference is applied across the electrodes to induce a glow discharge between the electrodes, so that molecules passing through the inlet are ionized by the glow discharge and directed into the analyzer. The ionization source accepts the sample under atmospheric pressure conditions and processes it directly into the high vacuum instrument, bridging the pressure gap and drawing off unwanted atmospheric gases. The invention also includes a method for analyzing a gaseous sample using the glow discharge ionization source described above. 3 figs.

  13. The effect of microhydration on ionization energies of thymine

    SciTech Connect (OSTI)

    Khistyev, Kirill; Bravaya, Ksenia B.; Kamarchik, Eugene; Kostko, Oleg; Ahmed, Musahid; Krylov, Anna I.

    2011-01-03T23:59:59.000Z

    A combined theoretical and experimental study of the effect of microhydration on ionization energies (IEs) of thymine is presented. The experimental IEs are derived from photoionization efficiency curves recorded using tunable synchrotron VUV radiation. The onsets of the PIE curves are 8.85+-0.05, 8.60+-0.05, 8.55+-0.05, and 8.40+-0.05 eV for thymine, thymine mono-, di-, and tri-hydrates, respectively. The computed (EOM-IP-CCSD/cc-pVTZ) AIEs are 8.90, 8.51, 8.52, and 8.35 eV for thymine and the lowest isomers of thymine mono-, di-, and tri-hydrates. Due to large structural relaxation, the Franck-Condon factors for the 0<-- 0 transitions are very small shifting the apparent PIE onsets to higher energies. Microsolvation strongly affects IEs of thymine -- addition of each water molecule reduces the first vertical IE by 0.10-0.15 eV. The adiabatic IE decreases even more (up to 0.4 eV). The magnitude of the effect varies for different ionized states and for different isomers. For the ionized states that are localized on thymine the dominant contribution to the IE reduction is the electrostatic interaction between the delocalized positive charge on thymine and the dipole moment of the water molecule.

  14. High-resolution ionization detector and array of such detectors

    DOE Patents [OSTI]

    McGregor, Douglas S. (Ypsilanti, MI); Rojeski, Ronald A. (Pleasanton, CA)

    2001-01-16T23:59:59.000Z

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

  15. Activity concentrations and dose rates from decorative granite countertops W.J. Llope*

    E-Print Network [OSTI]

    Llope, William J.

    Activity concentrations and dose rates from decorative granite countertops W.J. Llope* Rice 19 April 2011 Keywords: Granite Gamma radiation Dose Human phantom a b s t r a c t The gamma radiation emitted from a variety of commercial decorative granites available for use in U.S. homes has been

  16. Comparative study of ionization chamber detectors vis-a-vis a CCD detector for dispersive XAS measurement in transmission geometry

    SciTech Connect (OSTI)

    Poswal, A. K.; Agrawal, A.; Bhattachryya, D.; Jha, S. N.; Sahoo, N. K. [Applied Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai -400 085 (India)

    2013-02-05T23:59:59.000Z

    We have designed and fabricated parallel plate ionization chamber detectors and voltage vs. current characteristics (V-I curve) of the detectors were recorded with synchrotron radiation to qualify for use in X-ray Absorption Spectroscopy (XAS) measurements. After qualifying the ionization chambers, the detectors were used in the dispersive EXAFS beamline (BL-08) at INDUS-2 SRS in Turbo-XAS geometry. Using the same setup and under the same setting, XAS spectra were also recorded with a CCD detector and the observation on relative performance of the ionization chamber vis-a-vis the CCD detector is presented in this paper.

  17. Hall Magnetohydrodynamics of weakly-ionized plasma

    E-Print Network [OSTI]

    B. P. Pandey; Mark Wardle

    2006-08-02T23:59:59.000Z

    We show that the Hall scale in a weakly ionized plasma depends on the fractional ionization of the medium and, Hall MHD description becomes important whenever the ion-neutral collision frequency is comparable to the ion-gyration frequency, or, the ion-neutral collisional mean free path is smaller than the ion gyro-radius. Wave properties of a weakly-ionized plasma also depends on the fractional ionization and plasma Hall parameters, and whistler mode is the most dominant mode in such a medium. Thus Hall MHD description will be important in astrophysical disks, dark molecular clouds, neutron star crusts, and, solar and planetary atmosphere.

  18. Nanospray Desorption Electrospray Ionization: an Ambient Method...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    signal as compared to the traditional DESI and discuss imaging applications. Citation: Roach PJ, J Laskin, and A Laskin.2010."Nanospray Desorption Electrospray Ionization: an...

  19. Ionization probes of molecular structure and chemistry

    SciTech Connect (OSTI)

    Johnson, P.M. [State Univ. of New York, Stony Brook (United States)

    1993-12-01T23:59:59.000Z

    Various photoionization processes provide very sensitive probes for the detection and understanding of the spectra of molecules relevant to combustion processes. The detection of ionization can be selective by using resonant multiphoton ionization or by exploiting the fact that different molecules have different sets of ionization potentials. Therefore, the structure and dynamics of individual molecules can be studied even in a mixed sample. The authors are continuing to develop methods for the selective spectroscopic detection of molecules by ionization, and to use these methods for the study of some molecules of combustion interest.

  20. Theory of multiphoton and tunnel ionization in a bichromatic field

    SciTech Connect (OSTI)

    Bagulov, D. S., E-mail: bagulov-denis@yandex.ru [Novosibirsk State University (Russian Federation); Kotelnikov, I. A., E-mail: I.A.Kotelnikov@inp.nsk.ru [Russian Academy of Sciences, Siberian Branch, Budger Institute of Nuclear Physics (Russian Federation)

    2013-01-15T23:59:59.000Z

    The imaginary-time method [6, 7] is used to calculate the multiphoton and tunnel ionization probabilities for atoms in a laser radiation field part of which is converted into the second harmonic. We assume that the first harmonic has a linear or elliptical polarization and the second harmonic is polarized linearly, with its polarization vector making an arbitrary angle with that of the first harmonic. The mean momentum of the photoelectrons knocked out from atoms is shown to depend on the phase shift between the first and second harmonics and their mutual polarization and to be identically equal to zero for a monochromatic field. An important difference between the case of elliptical polarization and the case of linear polarization of both harmonics is the absence of conditions under which the conditions for dominance of one of the two generation mechanisms considered here can be identified during the generation of terahertz radiation from the region of optical breakdown in a gas.

  1. Technical Reports Ultra-low Dose Lung CT Perfusion Regularized by

    E-Print Network [OSTI]

    Virginia Tech

    Technical Reports Ultra-low Dose Lung CT Perfusion Regularized by a Previous Scan1 Hengyong Yu, Ph­regularized reconstruction (PSRR) method was proposed to reduce radiation dose and applied to lung perfusion studies. Normal and ultra-low-dose lung computed tomographic perfusion studies were compared in terms of the estimation

  2. RADIATION RESEARCH 156, 612617 (2001) 0033-7587/01 $5.00

    E-Print Network [OSTI]

    Brenner, David Jonathan

    2001-01-01T23:59:59.000Z

    612 RADIATION RESEARCH 156, 612­617 (2001) 0033-7587/01 $5.00 2001 by Radiation Research Society on Radiation Risks in a Mars Mission D. J. Brenner1 and C. D. Elliston Center for Radiological Research of Bystander Effects on Radiation Risks in a Mars Mission. Ra- diat. Res. 156, 612­617 (2001). Densely ionizing

  3. Genomic instability and bystander effects induced by high-LET radiation Eric J Hall*,1

    E-Print Network [OSTI]

    of the radiobiological effects of high- linear energy transfer (LET) radiation is essential for radiation protectionGenomic instability and bystander effects induced by high-LET radiation Eric J Hall*,1 and Tom K, it has always been accepted that the deleterious effects of ionizing radiation, such as mutation

  4. Method for the depth corrected detection of ionizing events from a co-planar grids sensor

    DOE Patents [OSTI]

    De Geronimo, Gianluigi (Syosset, NY); Bolotnikov, Aleksey E. (South Setauket, NY); Carini, Gabriella (Port Jefferson, NY)

    2009-05-12T23:59:59.000Z

    A method for the detection of ionizing events utilizing a co-planar grids sensor comprising a semiconductor substrate, cathode electrode, collecting grid and non-collecting grid. The semiconductor substrate is sensitive to ionizing radiation. A voltage less than 0 Volts is applied to the cathode electrode. A voltage greater than the voltage applied to the cathode is applied to the non-collecting grid. A voltage greater than the voltage applied to the non-collecting grid is applied to the collecting grid. The collecting grid and the non-collecting grid are summed and subtracted creating a sum and difference respectively. The difference and sum are divided creating a ratio. A gain coefficient factor for each depth (distance between the ionizing event and the collecting grid) is determined, whereby the difference between the collecting electrode and the non-collecting electrode multiplied by the corresponding gain coefficient is the depth corrected energy of an ionizing event. Therefore, the energy of each ionizing event is the difference between the collecting grid and the non-collecting grid multiplied by the corresponding gain coefficient. The depth of the ionizing event can also be determined from the ratio.

  5. Optical Spectroscopy of Diffuse Ionized Gas in M31

    E-Print Network [OSTI]

    B. Greenawalt; R. A. M. Walterbos; R. Braun

    1997-01-27T23:59:59.000Z

    We have obtained sensitive long-slit spectra of Diffuse Ionized Gas (DIG) in the Andromeda Galaxy, M31, covering the wavelength range of 3550-6850 Angs. By co-adding extracted DIG spectra, we reached a 1 sigma uncertainty of 9.3E-19 ergs/s/cm^{2}/arcsec^{2} corresponding to .46 pc/cm^{6} in Emission Measure. We present average spectra of DIG at four brightness levels with Emission Measures ranging from 9 to 59 pc/cm^{6}. We present the first measurements of [OII]\\lambda3727 and [OIII]\\lambda5007 of the truly diffuse ionized medium in the disk of an external spiral galaxy. We find that I_[OII]/I_H\\alpha=.9-1.4. The [OIII] line is weak (I_[OIII]/I_H\\beta = .5), but stronger than in the Galactic DIG. Measurements of [NII]\\lambda6583 and [SII](\\lambda6717+\\lambda6731) are also presented. The [SII] lines are clearly stronger than typical HII regions (I_[SII]/I_H\\alpha = .5 compared to .2). Overall, the line ratios are in agreement with predictions of photoionization models for diffuse gas exposed to a dilute stellar radiation field, but the line ratios of the DIG in M31 are somewhat different than observed for Galactic DIG. The differences indicate a less diluted radiation field in the DIG of M31's spiral arms compared to DIG in the Solar Neighborhood of the Milky Way. We have also detected HeI\\lambda5876 emission from the brightest DIG in M31. The HeI line appears to be stronger than in the Galactic DIG, possibly indicating that most of the Helium in the bright DIG in M31 is fully ionized. However, this result is somewhat tentative.

  6. Systems Biology Model of Interactions Between Tissue Growth Factors and DNA Damage Pathways: Low Dose Response and Cross-Talk in TGFbeta and ATM Signaling

    SciTech Connect (OSTI)

    O'Neill, Peter [University of Oxford; Anderson, Jennifer [University of Oxford

    2014-10-02T23:59:59.000Z

    The etiology of radiation carcinogenesis has been described in terms of aberrant changes that span several levels of biological organization. Growth factors regulate many important cellular and tissue functions including apoptosis, differentiation and proliferation. A variety of genetic and epigenetic changes of growth factors have been shown to contribute to cancer initiation and progression. It is known that cellular and tissue damage to ionizing radiation is in part initiated by the production of reactive oxygen species, which can activate cytokine signaling, and the DNA damage response pathways, most notably the ATM signaling pathway. Recently the transforming growth factor ? (TGF?) pathway has been shown to regulate or directly interact with the ATM pathway in the response to radiation. The relevance of this interaction with the ATM pathway is not known although p53 becomes phosphorylated and DNA damage responses are involved. However, growth factor interactions with DNA damage responses have not been elucidated particularly at low doses and further characterization of their relationship to cancer processes is warranted. Our goal will be to use a systems biology approach to mathematically and experimentally describe the low dose responses and cross-talk between the ATM and TGF? pathways initiated by low and high LET radiation. We will characterize ATM and TGF? signaling in epithelial and fibroblast cells using 2D models and ultimately extending to 3D organotypic cell culture models to begin to elucidate possible differences that may occur for different cell types and/or inter-cellular communication. We will investigate the roles of the Smad and Activating transcription factor 2 (ATF2) proteins as the potential major contributors to cross- talk between the TGF? and ATM pathways, and links to cell cycle control and/or the DNA damage response, and potential differences in their responses at low and high doses. We have developed various experimental approaches to apply to these problems using confocal microscopy and flow cytometry to detail changes at low dose/dose-rate in order to understand individual cell responses, and will establish our mathematical models based on the experimental findings resulting from changes in DNA repair, apoptosis and proliferation.

  7. Geant4 applications in the heliospheric radiation environment

    E-Print Network [OSTI]

    Pedro Brogueira; Patrícia Gonçalves; Ana Keating; Dalmiro Maia; Mário Pimenta; Bernardo Tomé

    2007-09-11T23:59:59.000Z

    The high energy ionizing radiation environment in the solar system consists of three main sources: the radiation belts, galactic cosmic rays and solar energetic particles. Geant4 is a Monte Carlo radiation transport simulation toolkit, with applications in areas as high energy physics, nuclear physics, astrophysics or medical physics research. In this poster, Geant4 applications to model and study the effects of the heliospheric radiation environment are presented. Specific applications are being developed to study the effect of the radiation environment on detector components, to describe the response and to optimise the design of radiation monitors for future space missions and to predict the radiation environment in Mars surface, orbits and moons.

  8. Ionization of Water Clusters is Mediated by Exciton Energy Transfer from Argon Clusters

    SciTech Connect (OSTI)

    Golan, Amir; Ahmed, Musahid

    2012-01-25T23:59:59.000Z

    The exciton energy deposited in an argon cluster, (Arn ,< n=20>) using VUV radiation is transferred to softly ionize doped water clusters, ((H2O)n, n=1-9) leading to the formation of non-fragmented clusters. Following the initial excitation, electronic energy is channeled to ionize the doped water cluster while evaporating the Ar shell, allowing identification of fragmented and complete water cluster ions. Examination of the photoionization efficiency curve shows that cluster evaporation from excitons located above 12.6 eV are not enough to cool the energized water cluster ion, and leads to their dissociation to (H2O)n-2H+ (protonated) clusters.

  9. Characterization of irradiation cell dose rates at the Nuclear Science Center

    E-Print Network [OSTI]

    Jeffords, Eugene Lamarr

    1987-01-01T23:59:59.000Z

    -filled proportional counter. The high-range ionization 3 chamber was used to measure the gamma-ray component while the BF -filled proportional counter measured the thermal and 3 fast neutron components. The TLD chips utilized were the TLD-100, TLD-600... with a Keithley Model-6014 electrometer to measure the current response of the chamber when exposed to gamma radiation. Ionization chambers have a response magnitude directly proportional to the rate of energy absorption and are widely used in making...

  10. Abdominal radiation causes bacterial translocation

    SciTech Connect (OSTI)

    Guzman-Stein, G.; Bonsack, M.; Liberty, J.; Delaney, J.P.

    1989-02-01T23:59:59.000Z

    The purpose of this study was to determine if a single dose of radiation to the rat abdomen leads to bacterial translocation into the mesenteric lymph nodes (MLN). A second issue addressed was whether translocation correlates with anatomic damage to the mucosa. The radiated group (1100 cGy) which received anesthesia also was compared with a control group and a third group which received anesthesia alone but no abdominal radiation. Abdominal radiation lead to 100% positive cultures of MLN between 12 hr and 4 days postradiation. Bacterial translocation was almost nonexistent in the control and anesthesia group. Signs of inflammation and ulceration of the intestinal mucosa were not seen until Day 3 postradiation. Mucosal damage was maximal by Day 4. Bacterial translocation onto the MLN after a single dose of abdominal radiation was not apparently dependent on anatomical, histologic damage of the mucosa.

  11. Radiation damage by neutrons to plastic scintillators

    SciTech Connect (OSTI)

    Buss, G.; Dannemann, A.; Holm, U.; Wick, K. [Univ. Hamburg (Germany). Inst. fuer Experimentalphysik] [Univ. Hamburg (Germany). Inst. fuer Experimentalphysik

    1995-08-01T23:59:59.000Z

    Polystyrene based scintillator SCSN38, wavelength shifter Y7 with polymethylmethacrylate matrix and pure PM-MA light guide GS218 have been irradiated in the mixed radiation field of a pool reactor. About 77% of the dose released in SCSN38 was caused by the {gamma}-field, 23% by fast neutrons. The total dose ranged from 2 to 105 kGy. The dose measurements were made using alanine dosimeters. Transmission and fluorescence of the samples have been measured before and several times after irradiation. The radiation damage results shown o differences to irradiations in pure {gamma}-fields with corresponding released doses.

  12. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, Jr., Robert F. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  13. Ionization tube simmer current circuit

    DOE Patents [OSTI]

    Steinkraus, R.F. Jr.

    1994-12-13T23:59:59.000Z

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

  14. Phase 1 of the Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    Not Available

    1991-08-01T23:59:59.000Z

    The work described in this report was prompted by the public's concern about potential effect from the radioactive materials released from the Hanford Site. The Hanford Environmental Dose Reconstruction (HEDR) Project was established to estimate radiation dose the public might have received from the Hanford Site since 1944, when facilities began operating. Phase 1 of the HEDR Project is a pilot'' or demonstration'' phase. The objectives of this initial phase were to determine whether enough historical information could be found or reconstructed to be used for dose estimation and develop and test conceptual and computational models for calculating credible dose estimates. Preliminary estimates of radiation doses were produced in Phase 1 because they are needed to achieve these objectives. The reader is cautioned that the dose estimates provided in this and other Phase 1 HEDR reports are preliminary. As the HEDR Project continues, the dose estimates will change for at least three reasons: more complete input information for models will be developed; the models themselves will be refined; and the size and shape of the geographic study area will change. This is one of three draft reports that summarize the first phase of the four-phased HEDR Project. This, the Summary Report, is directed to readers who want a general understanding of the Phase 1 work and preliminary dose estimates. The two other reports -- the Air Pathway Report and the Columbia River Pathway Report -- are for readers who understand the radiation dose assessment process and want to see more technical detail. Detailed descriptions of the dose reconstruction process are available in more than 20 supporting reports listed in Appendix A. 32 refs., 46 figs.

  15. SU-E-J-36: Combining CBCT Dose Into IMRT Treatment Planning

    SciTech Connect (OSTI)

    Grelewicz, Z; Wiersma, R [The University of Chicago, Chicago, IL (United States)

    2014-06-01T23:59:59.000Z

    Purpose: Cone beam CT (CBCT) is increasingly used in patient setup for IMRT. Daily CBCT may provide effective localization, however, it introduces concern over excessive imaging dose. Previous studies investigated the calculation of excess CBCT dose, however, no study has yet treated this dose as a source of therapeutic radiation, optimized in consideration of PTV and OARs constrains. Here we present a novel combined MV+kV inverse optimization engine to weave the CBCT and MV dose together such that CBCT dose is used for both imaging and therapeutic purposes. This may mitigate some of the excess imaging dose effects of daily CBCT and allow complete evaluation of the CBCT dose prior to treatment. Methods: The EGSnrc Monte Carlo system was used to model a Varian Trilogy CBCT system and 6 MV treatment beam. Using the model, the dose to patient from treatment beam and imaging beam was calculated for ten patients. The standard IMRT objective function was modified to include CBCT dose. Treatment plan optimization using the MOSEK optimization tool was performed retrospectively with and without assuming kV radiation dose from CBCT, assuming one CBCT per fraction. Results: Across ten patients, the CBCT delivered peaks of between .4% and 3.0% of the prescription dose to the PTV, with average CBCT dose to the PTV between .3% and .8%. By including CBCT dose to skin as a constraint during optimization, peak skin dose is reduced by between 1.9% and 7.4%, and average skin dose is reduced by .2% to 3.3%. Conclusions: Pre-treatment CBCT may deliver a substantial amount of radiation dose to the target volume. By considering CBCT dose to skin at the point of treatment planning, it is possible to reduce patient skin dose from current clinical levels, and to provide patient treatment with the improved accuracy that daily CBCT provides.

  16. Hanford Environmental Dose Reconstruction Project, Quarterly report, September--November 1993

    SciTech Connect (OSTI)

    Cannon, S.D.; Finch, S.M. [comps.

    1993-12-31T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates); Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  17. Hanford Environmental Dose Reconstruction Project. Quarterly report, June--August 1993

    SciTech Connect (OSTI)

    Cannon, S.D.; Finch, S.M. [comps.

    1993-10-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  18. Applications of High-Resolution Electrospray Ionization Mass...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Applications of High-Resolution Electrospray Ionization Mass...

  19. Nevada Test Site Radiation Protection Program

    SciTech Connect (OSTI)

    Radiological Control Managers' Council, Nevada Test Site

    2007-08-09T23:59:59.000Z

    Title 10 Code of Federal Regulations (CFR) 835, 'Occupational Radiation Protection', establishes radiation protection standards, limits, and program requirements for protecting individuals from ionizing radiation resulting from the conduct of U.S. Department of Energy (DOE) activities. 10 CFR 835.101(a) mandates that DOE activities be conducted in compliance with a documented Radiation Protection Program (RPP) as approved by DOE. This document promulgates the RPP for the Nevada Test Site (NTS), related (onsite or offsite) DOE National Nuclear Security Administration Nevada Site Office (NNSA/NSO) operations, and environmental restoration offsite projects.

  20. Remote radiation dosimetry

    DOE Patents [OSTI]

    Braunlich, P.F.; Tetzlaff, W.; Hegland, J.E.; Jones, S.C.

    1991-03-12T23:59:59.000Z

    Disclosed are methods and apparatus for remotely measuring radiation levels. Such are particularly useful for measuring relatively high levels or dosages of radiation being administered in radiation therapy. They are also useful for more general radiation level measurements where remote sensing from the remaining portions of the apparatus is desirable. The apparatus uses a beam generator, such as a laser beam, to provide a stimulating beam. The stimulating beam is preferably of wavelengths shorter than 6 microns, or more advantageously less than 2 microns. The stimulating beam is used to stimulate a remote luminescent sensor mounted in a probe which emits stored luminescent energy resulting from exposure of the sensor to ionizing radiation. The stimulating beam is communicated to the remote luminescent sensor via a transmissive fiber which also preferably serves to return the emission from the luminescent sensor. The stimulating beam is advantageously split by a beam splitter to create a detector beam which is measured for power during a reading period during which the luminescent phosphor is read. The detected power is preferably used to control the beam generator to thus produce desired beam power during the reading period. The luminescent emission from the remote sensor is communicated to a suitable emission detector, preferably after filtering or other selective treatment to better isolate the luminescent emission. 8 figures.

  1. Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations

    SciTech Connect (OSTI)

    Granero, Domingo, E-mail: dgranero@eresa.com [Department of Radiation Physics, ERESA, Hospital General Universitario, 46014 Valencia (Spain)] [Department of Radiation Physics, ERESA, Hospital General Universitario, 46014 Valencia (Spain); Perez-Calatayud, Jose [Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain)] [Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia 46026 (Spain); Vijande, Javier [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and IFIC (UV-CSIC), Paterna 46980 (Spain)] [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and IFIC (UV-CSIC), Paterna 46980 (Spain); Ballester, Facundo [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain)] [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)] [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States)

    2014-02-15T23:59:59.000Z

    Purpose: In skin high-dose-rate (HDR) brachytherapy, sources are located outside, in contact with, or implanted at some depth below the skin surface. Most treatment planning systems use the TG-43 formalism, which is based on single-source dose superposition within an infinite water medium without accounting for the true geometry in which conditions for scattered radiation are altered by the presence of air. The purpose of this study is to evaluate the dosimetric limitations of the TG-43 formalism in HDR skin brachytherapy and the potential clinical impact. Methods: Dose rate distributions of typical configurations used in skin brachytherapy were obtained: a 5 cm × 5 cm superficial mould; a source inside a catheter located at the skin surface with and without backscatter bolus; and a typical interstitial implant consisting of an HDR source in a catheter located at a depth of 0.5 cm. Commercially available HDR{sup 60}Co and {sup 192}Ir sources and a hypothetical {sup 169}Yb source were considered. The Geant4 Monte Carlo radiation transport code was used to estimate dose rate distributions for the configurations considered. These results were then compared to those obtained with the TG-43 dose calculation formalism. In particular, the influence of adding bolus material over the implant was studied. Results: For a 5 cm × 5 cm{sup 192}Ir superficial mould and 0.5 cm prescription depth, dose differences in comparison to the TG-43 method were about ?3%. When the source was positioned at the skin surface, dose differences were smaller than ?1% for {sup 60}Co and {sup 192}Ir, yet ?3% for {sup 169}Yb. For the interstitial implant, dose differences at the skin surface were ?7% for {sup 60}Co, ?0.6% for {sup 192}Ir, and ?2.5% for {sup 169}Yb. Conclusions: This study indicates the following: (i) for the superficial mould, no bolus is needed; (ii) when the source is in contact with the skin surface, no bolus is needed for either {sup 60}Co and {sup 192}Ir. For lower energy radionuclides like {sup 169}Yb, bolus may be needed; and (iii) for the interstitial case, at least a 0.1 cm bolus is advised for {sup 60}Co to avoid underdosing superficial target layers. For {sup 192}Ir and {sup 169}Yb, no bolus is needed. For those cases where no bolus is needed, its use might be detrimental as the lack of radiation scatter may be beneficial to the patient, although the 2% tolerance for dose calculation accuracy recommended in the AAPM TG-56 report is not fulfilled.

  2. X-ray induced Sm{sup 3+} to Sm{sup 2+} conversion in fluorophosphate and fluoroaluminate glasses for the monitoring of high-doses in microbeam radiation therapy

    SciTech Connect (OSTI)

    Vahedi, Shahrzad; Okada, Go; Morrell, Brian; Muzar, Edward; Koughia, Cyril; Kasap, Safa [Department of Electrical and Computer Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A9 (Canada); Edgar, Andy; Varoy, Chris [School of Chemical and Physical Sciences and MacDiarmid Institute, Victoria University of Wellington, Kelburn Parade (New Zealand); Belev, George; Wysokinski, Tomasz [Canadian Light Source, Inc., University of Saskatchewan, Saskatoon, Saskatchewan S7N 0X4 (Canada); Chapman, Dean [Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5 (Canada)

    2012-10-01T23:59:59.000Z

    Fluorophosphate and fluoroaluminate glasses doped with trivalent samarium were evaluated as sensors of x-ray radiation for microbeam radiation therapy at the Canadian Light Source using the conversion of trivalent Sm{sup 3+} to the divalent form Sm{sup 2+}. Both types of glasses show similar conversion rates and may be used as a linear sensor up to {approx}150 Gy and as a nonlinear sensor up to {approx}2400 Gy, where saturation is reached. Experiments with a multi-slit collimator show high spatial resolution of the conversion pattern; the pattern was acquired by a confocal fluorescence microscopy technique. The effects of previous x-ray exposure may be erased by annealing at temperatures exceeding the glass transition temperature T{sub g} while annealing at T{sub A} < T{sub g} enhances the Sm conversion. This enhancement is explained by a thermally stimulated relaxation of host glass ionic matrix surrounding x-ray induced Sm{sup 2+} ions. In addition, some of the Sm{sup 3+}-doped glasses were codoped with Eu{sup 2+}-ions but the results show that there is no marked improvement in the conversion efficiency by the introduction of Eu{sup 2+}.

  3. Laser-induced ionization of Na vapor

    SciTech Connect (OSTI)

    Wu, R.C.Y.; Judge, D.L.; Roussel, F.; Carre, B.; Breger, P.; Spiess, G.

    1982-01-01T23:59:59.000Z

    The production of Na/sub 2//sup +/ ions by off-resonant laser excitation in the 5800-6200A region mainly results from two-photon absorption by the Na/sub 2/ molecule to highly excited gerade states followed by (a) direct ionization by absorbing a third photon or (b) coupling to the molecular Na/sub 2/ D/sup 1/PI..mu.. Rydberg state which is subsequently ionized by absorbing a third photon. This mechanism, i.e., a two-photon resonance three photon ionization process, explains a recent experimental observation of Roussel et al. It is suggested that the very same mechanism is also responsible for a similar observation reported by Polak-Dingels et al in their work using two crossed Na beams. In the latter two studies the laser-induced associative ionization processes were reported to be responsible for producing the Na/sub 2//sup +/ ion. From the ratio of molecular to atomic concentration in the crossed beam experiment of Polak-Dingels et al we estimate that the cross section for producing Na/sub 2//sup +/ through laser-induced associative ionization is at least four orders of magnitude smaller than ionization through the two-photon resonance three photon ionization process in Na/sub 2/ molecules.

  4. Variations of dose rate observed by MSL/RAD in transit to Mars

    E-Print Network [OSTI]

    Guo, Jingnan; Wimmer-Schweingruber, Robert F; Hassler, Donald M; Posner, Arik; Heber, Bernd; Köhler, Jan; Rafkin, Scot; Ehresmann, Bent; Appel, Jan K; Böhm, Eckart; Böttcher, Stephan; Burmeister, Sönke; Brinza, David E; Lohf, Henning; Martin, Cesar; Reitz, Günther

    2015-01-01T23:59:59.000Z

    Aims: To predict the cruise radiation environment related to future human missions to Mars, the correlation between solar modulation potential and the dose rate measured by the Radiation Assessment Detector (RAD) has been analyzed and empirical models have been employed to quantify this correlation. Methods: The instrument RAD, onboard Mars Science Laboratory's (MSL) rover Curiosity, measures a broad spectrum of energetic particles along with the radiation dose rate during the 253-day cruise phase as well as on the surface of Mars. With these first ever measurements inside a spacecraft from Earth to Mars, RAD observed the impulsive enhancement of dose rate during solar particle events as well as a gradual evolution of the galactic cosmic ray (GCR) induced radiation dose rate due to the modulation of the primary GCR flux by the solar magnetic field, which correlates with long-term solar activities and heliospheric rotation. Results: We analyzed the dependence of the dose rate measured by RAD on solar modulatio...

  5. Radiation: Radiation Control (Indiana)

    Broader source: Energy.gov [DOE]

    It is the policy of the state to encourage the constructive uses of radiation and to control its harmful effects. This section contains regulations pertaining to the manufacture, use,...

  6. Serum Amyloid A as a Predictive Marker for Radiation Pneumonitis in Lung Cancer Patients

    SciTech Connect (OSTI)

    Wang, Yu-Shan [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China) [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Department of Animal Science, National Ilan University, Ilan, Taiwan (China); Chang, Heng-Jui [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China)] [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Chang, Yue-Cune [Department of Mathematics, Tamkang University, Taipei, Taiwan (China)] [Department of Mathematics, Tamkang University, Taipei, Taiwan (China); Huang, Su-Chen; Ko, Hui-Ling; Chang, Chih-Chia [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China)] [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Yeh, Yu-Wung; Jiang, Jiunn-Song [Department of Chest Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China)] [Department of Chest Medicine, Shin-Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Lee, Cheng-Yen; Chi, Mau-Shin [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China)] [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Chi, Kwan-Hwa, E-mail: M006565@ms.skh.org.tw [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China) [Department of Radiation Therapy and Oncology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Institute of Radiation Science and School of Medicine, National Yang-Ming University, Taipei, Taiwan (China)

    2013-03-01T23:59:59.000Z

    Purpose: To investigate serum markers associated with radiation pneumonitis (RP) grade ?3 in patients with lung cancer who were treated with radiation therapy. Methods and Materials: Pretreatment serum samples from patients with stage Ib-IV lung cancer who developed RP within 1 year after radiation therapy were analyzed to identify a proteome marker able to stratify patients prone to develop severe RP by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). Dosimetric parameters and 3 biological factors were compared. Results: Serum samples from 16 patients (28%) with severe RP (grade 3-4) and 42 patients (72%) with no or mild RP (grade 0-2) were collected for analysis. All patients received a median of 54 Gy (range, 42-70 Gy) of three-dimensional conformal radiation therapy with a mean lung dose (MLD) of 1502 cGy (range, 700-2794 cGy). An m/z peak of 11,480 Da was identified by SELDI-TOF-MS, and serum amyloid A (SAA) was the primary splitter serum marker. The receiver operating characteristic area under the curve of SAA (0.94; 95% confidence interval [CI], 0.87-1.00) was higher than those of C-reactive protein (0.83; 95% CI, 0.72-0.94), interleukin-6 (0.79; 95% CI, 0.65-0.94), and MLD (0.57; 95% CI, 0.37-0.77). The best sensitivity and specificity of combined SAA and MLD for predicting RP were 88.9% and 96.0%, respectively. Conclusions: Baseline SAA could be used as an auxiliary marker for predicting severe RP. Extreme care should be taken to limit the lung irradiation dose in patients with high SAA.

  7. DOE 2012 Occupational Radiation Exposure October 2013

    SciTech Connect (OSTI)

    none,

    2012-02-02T23:59:59.000Z

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2012 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past 5-year period, the occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site. As an indicator of the overall amount of radiation dose received during the conduct of operations at DOE, the report includes information on collective total effective dose (TED). The TED is comprised of the effective dose (ED) from external sources, which includes neutron and photon radiation, and the internal committed effective dose (CED), which results from the intake of radioactive material into the body. The collective ED from photon exposure decreased by 23% between 2011 and 2012, while the neutron dose increased by 5%. The internal dose components of the collective TED decreased by 7%. Over the past 5-year period, 99.99% of the individuals receiving measurable TED have received doses below the 2 roentgen equivalent in man (rems) (20 millisievert [mSv]) TED administrative control level (ACL), which is well below the DOE regulatory limit of 5 rems (50 mSv) TED annually. The occupational radiation exposure records show that in 2012, DOE facilities continued to comply with DOE dose limits and ACLs and worked to minimize exposure to individuals. The DOE collective TED decreased 17.1% from 2011 to 2012. The collective TED decreased at three of the five sites with the largest collective TED. u Idaho Site – Collective dose reductions were achieved as a result of continuing improvements at the Advanced Mixed Waste Treatment Project (AMWTP) through the planning of drum movements that reduced the number of times a container is handled; placement of waste containers that created highradiation areas in a centralized location; and increased worker awareness of high-dose rate areas. In addition, Idaho had the largest decrease in the total number of workers with measurable TED (1,143 fewer workers). u Hanford Site (Hanford) – An overall reduction of decontamination and decommissioning (D&D) activities at the Plutonium Finishing Plant (PFP) and Transuranic (TRU) retrieval activities resulted in collective dose reductions. u Savannah River Site (SRS) – Reductions were achieved through ALARA initiatives employed site wide. The Solid Waste Management Facility used extended specialty tools, cameras and lead shield walls to facilitate removal of drums. These tools and techniques reduce exposure time through improved efficiency, increase distance from the source of radiation by remote monitoring, shield the workers to lower the dose rate, and reduce the potential for contamination and release of material through repacking of waste. Overall, from 2011 to 2012, there was a 19% decrease in the number of workers with measurable dose. Furthermore, due to a slight decrease in both the DOE workforce (7%) and monitored workers (10%), the ratio of workers with measurable doses to monitored workers decreased to 13%. Another primary indicator of the level of radiation exposure covered in this report is the average measurable dose, which normalizes the collective dose over the population of workers who actually received a measurable dose. The average measurable TED in

  8. Dose reduction improvements in storage basins of spent nuclear fuel

    SciTech Connect (OSTI)

    Huang, Fan-Hsiung F.

    1997-08-13T23:59:59.000Z

    Spent nuclear fuel in storage basins at the Hanford Site has corroded and contaminated basin water, which has leaked into the soil; the fuel also had deposited a layer of radioactive sludge on basin floors. The SNF is to be removed from the basins to protect the nearby Columbia River. Because the radiation level is high, measures have been taken to reduce the background dose rate to as low as reasonably achievable (ALARA) to prevent radiation doses from becoming the limiting factor for removal of the SW in the basins to long-term dry storage. All activities of the SNF Project require application of ALARA principles for the workers. On the basis of these principles dose reduction improvements have been made by first identifying radiological sources. Principal radiological sources in the basin are basin walls, basin water, recirculation piping and equipment. Dose reduction activities focus on cleaning and coating basin walls to permit raising the water level, hydrolasing piping, and placing lead plates. In addition, the transfer bay floor will be refinished to make decontamination easier and reduce worker exposures in the radiation field. The background dose rates in the basin will be estimated before each task commences and after it is completed; these dose reduction data will provide the basis for cost benefit analysis.

  9. Depth absorbed dose and LET distributions of therapeutic {sup 1}H, {sup 4}He, {sup 7}Li, and {sup 12}C beams

    SciTech Connect (OSTI)

    Kempe, Johanna; Gudowska, Irena; Brahme, Anders [Division of Medical Radiation Physics, Department of Oncology-Pathology, Karolinska Institutet and Stockholm University, Box 260, SE-171 76 Stockholm (Sweden)

    2007-01-15T23:59:59.000Z

    The depth absorbed dose and LET (linear energy transfer) distribution of different ions of clinical interest such as {sup 1}H, {sup 4}He, {sup 7}Li, and {sup 12}C ions have been investigated using the Monte Carlo code SHIELD-HIT. The energies of the projectiles correspond to ranges in water and soft tissue of approximately 260 mm. The depth dose distributions of the primary particles and their secondaries have been calculated and separated with regard to their low and high LET components. A LET value below 10 eV/nm can generally be regarded as low LET and sparsely ionizing like electrons and photons. The high LET region may be assumed to start at 20 eV/nm where on average two double-strand breaks can be formed when crossing the periphery of a nucleosome, even though strictly speaking the LET limits are not sharp and ought to vary with the charge and mass of the ion. At the Bragg peak of a monoenergetic high energy proton beam, less than 3% of the total absorbed dose is comprised of high LET components above 20 eV/nm. The high LET contribution to the total absorbed dose in the Bragg peak is significantly larger with increasing ion charge as a natural result of higher stopping power and lower range straggling. The fact that the range straggling and multiple scattering are reduced by half from hydrogen to helium increases the possibility to accurately deposit only the high LET component in the tumor with negligible dose to organs at risk. Therefore, the lateral penumbra is significantly improved and the higher dose gradients of {sup 7}Li and {sup 12}C ions both longitudinally and laterally will be of major advantage in biological optimized radiation therapy. With increasing charge of the ion, the high LET absorbed dose in the beam entrance and the plateau regions where healthy normal tissues are generally located is also increased. The dose distribution of the high LET components in the {sup 7}Li beam is only located around the Bragg peak, characterized by a Gaussian-type distribution. Furthermore, the secondary particles produced by high energy {sup 7}Li ions in tissuelike media have mainly low LET character both in front of and beyond the Bragg peak.

  10. Non-equilibrium hydrogen ionization in 2D simulations of the solar atmosphere

    E-Print Network [OSTI]

    J. Leenaarts; M. Carlsson; V. Hansteen; R. J. Rutten

    2007-09-24T23:59:59.000Z

    The ionization of hydrogen in the solar chromosphere and transition region does not obey LTE or instantaneous statistical equilibrium because the timescale is long compared with important hydrodynamical timescales, especially of magneto-acoustic shocks. We implement an algorithm to compute non-equilibrium hydrogen ionization and its coupling into the MHD equations within an existing radiation MHD code, and perform a two-dimensional simulation of the solar atmosphere from the convection zone to the corona. Analysis of the simulation results and comparison to a companion simulation assuming LTE shows that: a) Non-equilibrium computation delivers much smaller variations of the chromospheric hydrogen ionization than for LTE. The ionization is smaller within shocks but subsequently remains high in the cool intershock phases. As a result, the chromospheric temperature variations are much larger than for LTE because in non-equilibrium, hydrogen ionization is a less effective internal energy buffer. The actual shock temperatures are therefore higher and the intershock temperatures lower. b) The chromospheric populations of the hydrogen n = 2 level, which governs the opacity of Halpha, are coupled to the ion populations. They are set by the high temperature in shocks and subsequently remain high in the cool intershock phases. c) The temperature structure and the hydrogen level populations differ much between the chromosphere above photospheric magnetic elements and above quiet internetwork. d) The hydrogen n = 2 population and column density are persistently high in dynamic fibrils, suggesting that these obtain their visibility from being optically thick in Halpha also at low temperature.

  11. Overview of the Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    Shipler, D.B.; Napier, B.A.; Ikenberry, T.A.

    1992-04-01T23:59:59.000Z

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that specific and representative individuals and populations may have received as a result of releases of radioactive materials from historical operations at the Hanford Site. These dose estimates would account for the uncertainties of information regarding facilities operations, environmental monitoring, demography, food consumption and lifestyles, and the variability of natural phenomena. Other objectives of the HEDR Project include: supporting the Hanford Thyroid Disease Study (HTDS), declassifying Hanford-generated information and making it available to the public, performing high-quality, credible science, and conducting the project in an open, public forum. The project is briefly described.

  12. Nanodosimetry-based quality factors for radiation protection Reinhard W. Schulte1,2,, Andrew J. Wroe2

    E-Print Network [OSTI]

    Nanodosimetry-based quality factors for radiation protection in space Reinhard W. Schulte1,2,Ã with radiation of low ionization density. Currently, quality factors of radiation both on the ground and in space. This approach makes the determination of the average quality factor of a given radiation field a rather complex

  13. Offsite environmental monitoring report; radiation monitoring around United States nuclear test areas, Calendar Year 1996

    SciTech Connect (OSTI)

    Davis, M.G.; Flotard, R.D.; Fontana, C.A.; Huff, P.A.; Maunu, H.K.; Mouck, T.L.; Mullen, A.A.; Sells, M.D.

    1997-08-01T23:59:59.000Z

    This report describes the Offsite Radiation Safety Program. This laboratory operated an environmental radiation monitoring program in the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi, Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity, if present, in the environment surrounding testing areas to ascertain whether current radiation levels and associated doses to the general public are in compliance with existing radiation protection standards. The surveillance program additionally has the responsibility to take action to protect the health and well being of the public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and radioactivity are assessed by sampling milk, water, and air; by deploying thermoluminescent dosimeters (TLDs); and using pressurized ionization chambers (PICs). No nuclear weapons testing was conducted in 1996 due to the continuing nuclear test moratorium. During this period, R and IE personnel maintained readiness capability to provide direct monitoring support if testing were to be resumed and ascertained compliance with applicable EPA, DOE, state, and federal regulations and guidelines. Comparison of the measurements and sample analysis results with background levels and with appropriate standards and regulations indicated that there was no airborne radioactivity from diffusion or resuspension detected by the various EPA monitoring networks surrounding the NTS. There was no indication of potential migration of radioactivity to the offsite area through groundwater and no radiation exposure above natural background was received by the offsite population. All evaluated data were consistent with previous data history.

  14. Determination of radionuclides and pathways contributing to cumulative dose

    SciTech Connect (OSTI)

    Napier, B.A.

    1992-12-01T23:59:59.000Z

    A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 004) examined the contributions of numerous radionuclides to cumulative dose via environmental exposures and accumulation in foods. Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows' milk from Feeding Regime 1, as described in calculation 002. This calculation specifically addresses cumulative radiation doses to infants and adults resulting from releases occurring over the period 1945 through 1972.

  15. GENII. Environmental Radiation Dosimetry Suite

    SciTech Connect (OSTI)

    Napier, B.A. [Pacific Northwest Lab., Richland, WA, (United States)

    1988-12-01T23:59:59.000Z

    GENII was developed to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) into the environmental pathway analysis models used at Hanford. GENII is a coupled system of seven programs and the associated data libraries that comprise the Hanford Dosimetry System (Generation II) to estimate potential radiation doses to individuals or populations from both routine and accidental releases of radionuclides to air or water and residual contamination from spills or decontamination operations. The GENII system includes interactive menu-driven programs to assist the user with scenario generation and data input,internal and external dose factor generators, and environmental dosimetry programs. The programs analyze environmental contamination resulting from both far-field and near-field scenarios. A far-field scenario focuses outward from a source, while a near-field scenario focuses in toward a receptor. GENII can calculate annual dose, committed dose, and accumulated dose from acute and chronic releases from ground or elevated sources to air or water and from initial contamination of soil or surfaces and can evaluate exposure pathways including direct exposure via water, soil, air, inhalation pathways, and ingestion pathways. In addition, GENII can perform 10,000 years migration analyses and can be used for retrospective calculations of potential radiation doses resulting from routine emissions and for prospective dose calculations for purposes such as siting facilities, environmental impact statements, and safety analysis reports.

  16. X-ray survival characteristics and genetic analysis for nine saccharomyces deletion mutants that show altered radiation sensitivity

    SciTech Connect (OSTI)

    Game, John C.; Williamson, Marsha S.; Baccari, Clelia

    2004-01-07T23:59:59.000Z

    The availability of a genome-wide set of Saccharomyces deletion mutants provides a chance to identify all the yeast genes involved in DNA repair. Using X-rays, we are screening these mutants to identify additional genes that show increased sensitivity to the lethal effects of ionizing radiation. For each mutant identified as sensitive, we are confirming that the sensitivity phenotype co-segregates with the deletion allele and are obtaining multipoint survival-versus-dose assays in at least two haploid and one homozygous diploid strains. We present data for deletion mutants involving the genes DOT1, MDM20, NAT3, SPT7, SPT20, GCN5, HFI1, DCC1 and VID21/EAF1, and discuss their potential roles in repair. Eight of these genes have a clear radiation-sensitive phenotype when deleted, but the ninth, GCN5, has at most a borderline phenotype. None of the deletions confer substantial sensitivity to ultra-violet radiation, although one or two may confer marginal sensitivity. The DOT1 gene is of interest because its only known function is to methylate one lysine residue in the core of the histone H3 protein. We find that histone H3 mutants (supplied by K. Struhl) in which this residue is replaced by other amino-acids are also X-ray sensitive, seeming to confirm that methylation of the lysine-79 residue is required for effective repair of radiation damage.

  17. Quantification of radiation induced crosslinking in a commercial, toughened silicone rubber, TR-55, by 1H MQ-NMR

    SciTech Connect (OSTI)

    Maxwell, R; Chinn, S; Alviso, C; Harvey, C A; Giuliani, J; Wilson, T; Cohenour, R

    2008-11-10T23:59:59.000Z

    Radiation induced degradation in a commercial, filled silicone composite has been studied by SPME/GC-MS, DMA, DSC, swelling, and Multiple Quantum NMR. Analysis of volatile and semivolatile species indicates degradation via decomposition of the peroxide curing catalyst and radiation induced backbiting reactions. DMA, swelling, and spin-echo NMR analysis indicate a increase in crosslink density of near 100% upon exposure to a cumulative dose of 250 kGray. Analysis of the sol-fraction via Charlseby-Pinner analysis indicates a ratio of chain scission to crosslinking yields of 0.38, consistent with the dominance of the crosslinking observed by DMA, swelling and spin-echo NMR and the chain scissioning reactions observed by MS analysis. Multiple Quantum NMR has revealed a bimodal distribution of residual dipolar couplings near 1 krad/sec and 5 krad/sec in an approximately 90:10 ratio, consistent with bulk network chains and chains associated with the filler surface. Upon exposure to radiation, the mean {Omega}{sub d} for both domains and the width of both domains both increased. The MQ NMR analysis provided increase insight into the effects of ionizing radiation on the network structure of silicone polymers.

  18. Effect of primordial magnetic fields on the ionization history

    E-Print Network [OSTI]

    Chluba, Jens; Finelli, Fabio; Rubino-Martin, Jose-Alberto

    2015-01-01T23:59:59.000Z

    Primordial magnetic fields (PMF) damp at scales smaller than the photon diffusion and free-streaming scale. This leads to heating of ordinary matter (electrons and baryons), which affects both the thermal and ionization history of our Universe. Here, we study the effect of heating due to ambipolar diffusion and decaying magnetic turbulence. We find that changes to the ionization history computed with recfast are significantly overestimated when compared with CosmoRec. The main physical reason for the difference is that the photoionization coefficient has to be evaluated using the radiation temperature rather than the matter temperature. A good agreement with CosmoRec is found after changing this aspect. Using Planck 2013 data and considering only the effect of PMF-induced heating, we find an upper limit on the r.m.s. magnetic field amplitude of B0 < 1.1 nG (95% c.l.) for a stochastic background of PMF with a nearly scale-invariant power spectrum. We also discuss uncertainties related to the approximations ...

  19. Radiation-Associated Liver Injury

    SciTech Connect (OSTI)

    Pan, Charlie C., E-mail: cpan@umich.ed [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States); Kavanagh, Brian D. [Department of Radiation Oncology, University of Colorado, Aurora, CO (United States); Dawson, Laura A. [Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Das, Shiva K. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Miften, Moyed [Department of Radiation Oncology, University of Colorado, Aurora, CO (United States); Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, MI (United States)

    2010-03-01T23:59:59.000Z

    The liver is a critically important organ that has numerous functions including the production of bile, metabolism of ingested nutrients, elimination of many waste products, glycogen storage, and plasma protein synthesis. The liver is often incidentally irradiated during radiation therapy (RT) for tumors in the upper- abdomen, right lower lung, distal esophagus, or during whole abdomen or whole body RT. This article describes the endpoints, time-course, and dose-volume effect of radiation on the liver.

  20. DOE 2011 Occupational Radiation Exposure report, _Prepared for the U.S. Department of Energy, Office of Health, Safety and Security. December 2012

    SciTech Connect (OSTI)

    Derek Hagemeyer, Yolanda McCormick

    2012-12-12T23:59:59.000Z

    This report discusses radiation protection and dose reporting requirements, presents the 2011 occupational radiation dose data along with trends over the past 5 years, and provides instructions to submit successful as low as reasonably achievable (ALARA) projects.

  1. DOE Radiation Exposure Monitoring System (REMS) Data Update

    SciTech Connect (OSTI)

    Rao, Nimi; Hagemeyer, Derek

    2012-05-05T23:59:59.000Z

    This slide show presents the 2011 draft data for DOE occupational radiation exposure.Clarification is given on Reporting Data regarding: reporting Total Organ Dose (TOD); reporting Total Skin Dose (TSD), and Total Extremity Dose (TExD) ; and Special individuals reporting.

  2. GROUND-WATER CONTRIBUTION TO DOSE FROM PAST HANFORD OPERATIONS

    SciTech Connect (OSTI)

    Freshley, M. D.; Thorne, P. D.

    1992-01-01T23:59:59.000Z

    The Hanford Environmental Dose Reconstruction (HEOR) Project is being conducted to estimate radiation doses that populations and individuals could have received from Hanford Site operations from 1944 to the present. Four possible pathways by which radionuclides originating in ground water on the Hanford Site could have reached the public have been identified: 1) through contaminated ground water migrating to the Columbia River; 2) through wells on or adjacent to the Hanford Site; 3) through wells that draw some or all of their water from the Columbia River (riparian wells); and 4) through atmospheric deposition resulting in the contamination of a small watershed that, in turn, results in contamination of a shallow well or spring. These four pathways make up the "ground-water pathway ," which is the subject of this study. The objective of the study was to assess the extent to which the groundwater pathway contributed to radiation doses that populations or individuals may have received from past operations at Hanford. The assessment presented in this report was performed by 1) reviewing the extensive ?literature on ground water and ground-water monitoring at Hanford and 2) performing simple calculations to estimate radionuclide concentrations in ground water and the Columbia River resulting from ground-water discharge. Radiation doses that would result from exposure to this ground water and surface water were calculated. The study conclusion is that the ground-water pathways did not contribute significantly to dose. Compared with background radiation in the TriCities {300 mrem/yr), estimated doses are small: 0.02 mrem/yr effective dose equivalent from discharge of contaminated ground water to the Columbia River; 1 mrem/yr effective dose equivalent from Hanford Site wells; 11 mrem/yr effective dose equivalent from riparian wells; and 1 mrem/yr effective dose equivalent from the watershed. Because the estimated doses are so small, the recommendation is that further work on the ground-water pathway be limited to tracking ongoing ground-water studies at the Hanford Site.

  3. RADIATION RESEARCH 169, 17 (2008) 0033-7587/08 $15.00

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    1 RADIATION RESEARCH 169, 1­7 (2008) 0033-7587/08 $15.00 2008 by Radiation Research Society. All and Double-Strand Breaks ­ All's Well that ``Ends'' Well. . . . Radiat. Res. 169, 1­7 (2008). Sometimes one--they protected the physical ends of chromosomes from interaction with broken DNA ends created by ionizing radi

  4. Repression of ATR pathway by miR-185 enhances radiation-induced apoptosis and proliferation

    E-Print Network [OSTI]

    Cai, Long

    of miR-34a expression may be responsible for important protective mechanisms counteracting radiationOPEN Repression of ATR pathway by miR-185 enhances radiation-induced apoptosis and proliferation of a human microRNA (miRNA), hsa-miR-185, is downregulated in response to ionizing radiation. Elevation of mi

  5. Effects of exogenous carbon monoxide on radiation-induced bystander effect in zebrafish embryos in vivo

    E-Print Network [OSTI]

    Yu, K.N.

    -no-threshed (LNT) model widely accepted for radiation protection saying that biological effects caused by ionizingEffects of exogenous carbon monoxide on radiation-induced bystander effect in zebrafish embryos) on the radiation induced bystander effect (RIBE) in vivo between embryos of the zebrafish was studied. RIBE

  6. Large-Area Plasma-Panel Radiation Detectors for Nuclear Medicine Imaging to Homeland Security and the Super Large Hadron Collider

    E-Print Network [OSTI]

    Peter S. Friedman; Robert Ball; J. Wehrley Chapman; Daniel S. Levin; Curtis Weaverdyck; Bing Zhou; Yan Benhammou; Erez Etzion; M. Ben Moshe; Yiftah Silver; James R. Beene; Robert L. Varner Jr.

    2010-07-03T23:59:59.000Z

    A new radiation sensor derived from plasma panel display technology is introduced. It has the capability to detect ionizing and non-ionizing radiation over a wide energy range and the potential for use in many applications. The principle of operation is described and some early results presented.

  7. Whole-body radiation dosimetry of 2-[F-18]fluoro-A-85380 in human PET imaging studies

    E-Print Network [OSTI]

    Obrzut, S L; Koren, A O; Mandelkern, M A; Brody, A L; Hoh, C K; London, E D

    2005-01-01T23:59:59.000Z

    body biodistribution, radiation absorbed dose, and brainM. Biodistribution and radiation dosimetry of 18 F-fluoro-A-Whole-Body Radiation Dosimetry of 2-[ 18 F]Fluoro-A-85380 in

  8. How to move ionized gas: an introduction to the dynamics of HII regions

    E-Print Network [OSTI]

    William J. Henney

    2006-02-28T23:59:59.000Z

    This review covers the dynamic processes that are important in the evolution and structure of galactic HII regions, concentrating on an elementary presentation of the physical concepts and recent numerical simulations of HII region evolution in a non-uniform medium. The contents are as follows: (1) The equations (Euler equations; Radiative transfer; Rate equations; How to avoid the dynamics; How to avoid the atomic physics). (2) Physical concepts (Static photoionization equilibrium; Ionization front propagation; Structure of a D-type front; Photoablation flows; Other ingredients - Stellar winds, Radiation pressure, Magnetic fields, Instabilities). (3) HII region evolution (Early phases: hypercompact and ultracompact regions; Later phases: compact and extended regions; Clumps and turbulence).

  9. Pediatric radiation oncology

    SciTech Connect (OSTI)

    Halperin, E.C.; Kun, L.E.; Constine, L.S.; Tarbell, N.J.

    1989-01-01T23:59:59.000Z

    This text covers all aspects of radiation therapy for treatment of pediatric cancer. The book describes the proper use of irradiation in each of the malignancies of childhood, including tumors that are rarely encountered in adult practice. These include acute leukemia; supratentorial brain tumors; tumors of the posterior fossa of the brain and spinal canal; retinoblastoma and optic nerve glioma; neuroblastoma; Hodgkin's disease; malignant lymphoma; Ewing's sarcoma; osteosarcoma; rhabdomyosarcoma; Desmoid tumor; Wilms' tumor; liver and biliary tumors; germ cell and stromal cell tumors of the gonads; endocrine, aerodigestive tract, and breast tumors; Langerhans' cell histiocytosis; and skin cancer and hemangiomas. For each type of malignancy, the authors describe the epidemiology, common presenting signs and symptoms, staging, and proper diagnostic workup. Particular attention is given to the indications for radiation therapy and the planning of a course of radiotherapy, including the optimal radiation dose, field size, and technique.

  10. Calculation of external dose from distributed source

    SciTech Connect (OSTI)

    Kocher, D.C.

    1986-01-01T23:59:59.000Z

    This paper discusses a relatively simple calculational method, called the point kernel method (Fo68), for estimating external dose from distributed sources that emit photon or electron radiations. The principles of the point kernel method are emphasized, rather than the presentation of extensive sets of calculations or tables of numerical results. A few calculations are presented for simple source geometries as illustrations of the method, and references and descriptions are provided for other caluclations in the literature. This paper also describes exposure situations for which the point kernel method is not appropriate and other, more complex, methods must be used, but these methods are not discussed in any detail.

  11. The NCI Radiation Research Program: Grant portfolio and radiation

    E-Print Network [OSTI]

    models (89 animals no human subject material, 21 use both) ­ 109 utilize rodent models ­ 2 have canine and R37s). Of those that utilize radiation: · 6 use tissue culture models only · 110 utilize animal subjects · 39 use human subjects or human subject materials only. #12;Dose and Dosimetry · The majority

  12. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1993--November 30, 1994

    SciTech Connect (OSTI)

    Hall, E.J.; Zaider, M.

    1994-05-01T23:59:59.000Z

    Research at the Center for Radiological Research is a blend of physics, chemistry and biology and epitomizes the multidisciplinary approach towards understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. To an increasing extent, the focus of attention is on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights from the past year are briefly described.

  13. A Theoretical Approach for the Determination and Mechanistic Interpretation of Radiation D10-value

    E-Print Network [OSTI]

    Ekpanyaskun, Nont

    2010-07-14T23:59:59.000Z

    , and the number of genome equivalents were hypothetically investigated. The developed computational methodology as well as the results presented can be used as an analytical tool to evaluate the impact of ionizing radiation on cell survival....

  14. FY 1992 revised task plans for the Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    Shipler, D.B.

    1992-04-01T23:59:59.000Z

    The purpose of the Hanford Environmental Dose Rec