Sample records for radiation dose equivalent

  1. 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

  2. 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

  3. 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.

  4. Dose-equivalent neutron dosimeter

    DOE Patents [OSTI]

    Griffith, R.V.; Hankins, D.E.; Tomasino, L.; Gomaa, M.A.M.

    1981-01-07T23:59:59.000Z

    A neutron dosimeter is disclosed which provides a single measurement indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer contaning conversion material such as /sup 6/Li and /sup 10/B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet.

  5. 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...

  6. 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...

  7. 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...

  8. 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

  9. Measurement of neutron dose equivalent outside and inside of the treatment vault of GRID therapy

    SciTech Connect (OSTI)

    Wang, Xudong; Charlton, Michael A.; Esquivel, Carlos; Eng, Tony Y.; Li, Ying; Papanikolaou, Nikos [University of Texas Health Science Center, San Antonio, Texas 78229 (United States)] [University of Texas Health Science Center, San Antonio, Texas 78229 (United States)

    2013-09-15T23:59:59.000Z

    Purpose: To evaluate the neutron and photon dose equivalent rates at the treatment vault entrance (H{sub n,D} and H{sub G}), and to study the secondary radiation to the patient in GRID therapy. The radiation activation on the grid was studied.Methods: A Varian Clinac 23EX accelerator was working at 18 MV mode with a grid manufactured by .decimal, Inc. The H{sub n,D} and H{sub G} were measured using an Andersson–Braun neutron REM meter, and a Geiger Müller counter. The radiation activation on the grid was measured after the irradiation with an ion chamber ?-ray survey meter. The secondary radiation dose equivalent to patient was evaluated by etched track detectors and OSL detectors on a RANDO{sup ®} phantom.Results: Within the measurement uncertainty, there is no significant difference between the H{sub n,D} and H{sub G} with and without a grid. However, the neutron dose equivalent to the patient with the grid is, on average, 35.3% lower than that without the grid when using the same field size and the same amount of monitor unit. The photon dose equivalent to the patient with the grid is, on average, 44.9% lower. The measured average half-life of the radiation activation in the grid is 12.0 (±0.9) min. The activation can be categorized into a fast decay component and a slow decay component with half-lives of 3.4 (±1.6) min and 15.3 (±4.0) min, respectively. There was no detectable radioactive contamination found on the surface of the grid through a wipe test.Conclusions: This work indicates that there is no significant change of the H{sub n,D} and H{sub G} in GRID therapy, compared with a conventional external beam therapy. However, the neutron and scattered photon dose equivalent to the patient decrease dramatically with the grid and can be clinical irrelevant. Meanwhile, the users of a grid should be aware of the possible high dose to the radiation worker from the radiation activation on the surface of the grid. A delay in handling the grid after the beam delivery is suggested.

  10. Calculation of extremity neutron fluence-to-dose equivalent conversion factors

    E-Print Network [OSTI]

    Wood-Zika, Annmarie Ruth

    1997-01-01T23:59:59.000Z

    surface fluence spectra 45 LIST OF TABLES TABLE Page Properties of commercially available TLDs . . PNNL dose equivalent averaged quality factors . 16 3 MCNP input deck geometries Phantoms modeled in MCNP input decks . . Comparison of calculated..., PNNL and DOELAP fluence-to-dose equivalent conversion factors for bare '"Cf . . . . 37 Comparison of calculated, PNNL and DOELAP fluence-to-dose equivalent conversion factors for D, O moderated '"Cf. 37 Fluence-to-dose equivalent conversion factors...

  11. Total effective dose equivalent associated with fixed uranium surface contamination

    SciTech Connect (OSTI)

    Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

    1997-04-01T23:59:59.000Z

    This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm{sup 2} and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels.

  12. Equivalent Neutrinos, Light WIMPs, and the Chimera of Dark Radiation

    E-Print Network [OSTI]

    Gary Steigman

    2013-03-18T23:59:59.000Z

    According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu equivalent neutrinos (or dark radiation), Neff is generally >3. The canonical results are reconsidered here, revealing that a measurement of Neff>3 can be consistent with DeltaNnu=0 (dark radiation without dark radiation). Conversely, a measurement consistent with Neff=3 is not inconsistent with the presence of dark radiation (DeltaNnu>0). In particular, if there is a light WIMP that annihilates to photons after the SM neutrinos have decoupled, the photons are heated beyond their usual heating from e+- annihilation, reducing the late time ratio of neutrino and photon temperatures (and number densities), leading to Neff3 even in the absence of equivalent neutrinos or dark radiation. A measurement of Neff>3 is thus no guarantee of the presence of equivalent neutrinos or dark radiation. In the presence of light WIMPs and/or equivalent neutrinos there are degeneracies among the light WIMP mass and its nature (fermion or boson, as well as its couplings to neutrinos or photons), the number and nature (fermion or boson) of the equivalent neutrinos, and their decoupling temperature (the strength of their interactions with the SM particles). There's more to a measurement of Neff than meets the eye.

  13. 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 ...

  14. 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...

  15. Equivalent Neutrinos, Light WIMPs, and the Chimera of Dark Radiation

    E-Print Network [OSTI]

    Steigman, Gary

    2013-01-01T23:59:59.000Z

    According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu equivalent neutrinos (or dark radiation), Neff is generally >3. The canonical results are reconsidered here, revealing that a measurement of Neff>3 can be consistent with DeltaNnu=0 (dark radiation without dark radiation). Conversely, a measurement consistent with Neff=3 is not inconsistent with the presence of dark radiation (DeltaNnu>0). In particular, if there is a light WIMP that annihilates to photons after the SM neutrinos have decoupled, the photons are heated beyond their usual heating from e+- annihilation, reducing the late time ratio of neutrino and photon temperatures (and number densities), leading to Neff3 even in the absence of equivalent neutrinos or dark radiation. A measurement of Neff>3 is thus no guarantee of the presence of equivalent neutrinos or dark ra...

  16. 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.

  17. 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.

  18. 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

  19. Measurements of neutron dose equivalent for a proton therapy center using uniform scanning proton beams

    SciTech Connect (OSTI)

    Zheng Yuanshui; Liu Yaxi; Zeidan, Omar; Schreuder, Andries Niek; Keole, Sameer [ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); INTEGRIS Cancer Insititute, 5911 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States); ProCure Treatment Centers, 420 North Walnut Street, Bloomington, Indiana 47404 (United States); ProCure Proton Therapy Center, 5901 West Memorial Road, Oklahoma City, Oklahoma 73142 (United States)

    2012-06-15T23:59:59.000Z

    Purpose: Neutron exposure is of concern in proton therapy, and varies with beam delivery technique, nozzle design, and treatment conditions. Uniform scanning is an emerging treatment technique in proton therapy, but neutron exposure for this technique has not been fully studied. The purpose of this study is to investigate the neutron dose equivalent per therapeutic dose, H/D, under various treatment conditions for uniform scanning beams employed at our proton therapy center. Methods: Using a wide energy neutron dose equivalent detector (SWENDI-II, ThermoScientific, MA), the authors measured H/D at 50 cm lateral to the isocenter as a function of proton range, modulation width, beam scanning area, collimated field size, and snout position. They also studied the influence of other factors on neutron dose equivalent, such as aperture material, the presence of a compensator, and measurement locations. They measured H/D for various treatment sites using patient-specific treatment parameters. Finally, they compared H/D values for various beam delivery techniques at various facilities under similar conditions. Results: H/D increased rapidly with proton range and modulation width, varying from about 0.2 mSv/Gy for a 5 cm range and 2 cm modulation width beam to 2.7 mSv/Gy for a 30 cm range and 30 cm modulation width beam when 18 Multiplication-Sign 18 cm{sup 2} uniform scanning beams were used. H/D increased linearly with the beam scanning area, and decreased slowly with aperture size and snout retraction. The presence of a compensator reduced the H/D slightly compared with that without a compensator present. Aperture material and compensator material also have an influence on neutron dose equivalent, but the influence is relatively small. H/D varied from about 0.5 mSv/Gy for a brain tumor treatment to about 3.5 mSv/Gy for a pelvic case. Conclusions: This study presents H/D as a function of various treatment parameters for uniform scanning proton beams. For similar treatment conditions, the H/D value per uncollimated beam size for uniform scanning beams was slightly lower than that from a passive scattering beam and higher than that from a pencil beam scanning beam, within a factor of 2. Minimizing beam scanning area could effectively reduce neutron dose equivalent for uniform scanning beams, down to the level close to pencil beam scanning.

  20. A new online detector for estimation of peripheral neutron equivalent dose in organ

    SciTech Connect (OSTI)

    Irazola, L., E-mail: leticia@us.es; Sanchez-Doblado, F. [Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Sevilla 41009, Spain and Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla 41007 (Spain); Lorenzoli, M.; Pola, A. [Departimento di Ingegneria Nuclear, Politecnico di Milano, Milano 20133 (Italy); Bedogni, R. [Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare (INFN), Frascati Roma 00044 (Italy); Terrón, J. A. [Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla 41007 (Spain); Sanchez-Nieto, B. [Instituto de Física, Pontificia Universidad Católica de Chile, Santiago 4880 (Chile); Expósito, M. R. [Departamento de Física, Universitat Autònoma de Barcelona, Bellaterra 08193 (Spain); Lagares, J. I.; Sansaloni, F. [Centro de Investigaciones Energéticas y Medioambientales y Tecnológicas (CIEMAT), Madrid 28040 (Spain)

    2014-11-01T23:59:59.000Z

    Purpose: Peripheral dose in radiotherapy treatments represents a potential source of secondary neoplasic processes. As in the last few years, there has been a fast-growing concern on neutron collateral effects, this work focuses on this component. A previous established methodology to estimate peripheral neutron equivalent doses relied on passive (TLD, CR39) neutron detectors exposed in-phantom, in parallel to an active [static random access memory (SRAMnd)] thermal neutron detector exposed ex-phantom. A newly miniaturized, quick, and reliable active thermal neutron detector (TNRD, Thermal Neutron Rate Detector) was validated for both procedures. This first miniaturized active system eliminates the long postprocessing, required for passive detectors, giving thermal neutron fluences in real time. Methods: To validate TNRD for the established methodology, intrinsic characteristics, characterization of 4 facilities [to correlate monitor value (MU) with risk], and a cohort of 200 real patients (for second cancer risk estimates) were evaluated and compared with the well-established SRAMnd device. Finally, TNRD was compared to TLD pairs for 3 generic radiotherapy treatments through 16 strategic points inside an anthropomorphic phantom. Results: The performed tests indicate similar linear dependence with dose for both detectors, TNRD and SRAMnd, while a slightly better reproducibility has been obtained for TNRD (1.7% vs 2.2%). Risk estimates when delivering 1000 MU are in good agreement between both detectors (mean deviation of TNRD measurements with respect to the ones of SRAMnd is 0.07 cases per 1000, with differences always smaller than 0.08 cases per 1000). As far as the in-phantom measurements are concerned, a mean deviation smaller than 1.7% was obtained. Conclusions: The results obtained indicate that direct evaluation of equivalent dose estimation in organs, both in phantom and patients, is perfectly feasible with this new detector. This will open the door to an easy implementation of specific peripheral neutron dose models for any type of treatment and facility.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Method for detecting water equivalent of snow using secondary cosmic gamma radiation

    DOE Patents [OSTI]

    Condreva, K.J.

    1997-01-14T23:59:59.000Z

    Water equivalent of accumulated snow determination by measurement of secondary background cosmic radiation attenuation by the snowpack. By measuring the attenuation of 3-10 MeV secondary gamma radiation it is possible to determine the water equivalent of snowpack. The apparatus is designed to operate remotely to determine the water equivalent of snow in areas which are difficult or hazardous to access during winter, accumulate the data as a function of time and transmit, by means of an associated telemetry system, the accumulated data back to a central data collection point for analysis. The electronic circuitry is designed so that a battery pack can be used to supply power. 4 figs.

  6. Method for detecting water equivalent of snow using secondary cosmic gamma radiation

    DOE Patents [OSTI]

    Condreva, Kenneth J. (1420 Fifth St., Livermore, Alameda County, CA 94550)

    1997-01-01T23:59:59.000Z

    Water equivalent of accumulated snow determination by measurement of secondary background cosmic radiation attenuation by the snowpack. By measuring the attentuation of 3-10 MeV secondary gamma radiation it is possible to determine the water equivalent of snowpack. The apparatus is designed to operate remotely to determine the water equivalent of snow in areas which are difficult or hazardous to access during winter, accumulate the data as a function of time and transmit, by means of an associated telemetry system, the accumulated data back to a central data collection point for analysis. The electronic circuitry is designed so that a battery pack can be used to supply power.

  7. 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.

  8. Method to determine the position-dependant metal correction factor for dose-rate equivalent laser testing of semiconductor devices

    DOE Patents [OSTI]

    Horn, Kevin M.

    2013-07-09T23:59:59.000Z

    A method reconstructs the charge collection from regions beneath opaque metallization of a semiconductor device, as determined from focused laser charge collection response images, and thereby derives a dose-rate dependent correction factor for subsequent broad-area, dose-rate equivalent, laser measurements. The position- and dose-rate dependencies of the charge-collection magnitude of the device are determined empirically and can be combined with a digital reconstruction methodology to derive an accurate metal-correction factor that permits subsequent absolute dose-rate response measurements to be derived from laser measurements alone. Broad-area laser dose-rate testing can thereby be used to accurately determine the peak transient current, dose-rate response of semiconductor devices to penetrating electron, gamma- and x-ray irradiation.

  9. 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

  10. 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: ...

  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. 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

  13. 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.

  14. 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, ...

  15. 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:

  16. Development of an optimal anisotropic responding (OAR) dosimeter for two-dosimeter dosimetry for better estimation of effective dose equivalent (He) and the impact of dosimeter misposition on estimating effective dose equivalent using isotropic dosimeters

    E-Print Network [OSTI]

    Han, Hsiang-Jung

    1998-01-01T23:59:59.000Z

    exposure, the U. S. Nuclear Regulatory Commission (NRC) added the "whole body" as an organ in the table of organ dose weighting factors. The statement, published in the Title 10 Code of Federal Regulations Part 20 (10 CFR20), was as follows: "For...). This report, ICRP Publication 26, initiated a major change from the Commission's recommendations in the past. ICRP Publication 26 indicated that radiation protection is concerned with the protection of individuals, their pregnancy and mankind as a whole...

  17. 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.

  18. 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.

  19. 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.

  20. R1S-M-2322 TABLE OF EXPOSURE RATE CONSTANTS AND DOSE EQUIVALENT

    E-Print Network [OSTI]

    a point source . 4 5. DOSE BUILD-UP FACTORS 7 6. MASS ENERGY ABSORPTION COEFFICIENTS AND LINEAR in units of MeV/photon , (pen/p)air in cm2 /g gives r in R»m2 /Ci«h if the following conversion factors, the contributions from photon energies below 30 keV and X-rays are omitted. (Continue on next page) December 1982

  1. 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...

  2. 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...

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Plutonium 239 Equivalency Calculations

    SciTech Connect (OSTI)

    Wen, J

    2011-05-31T23:59:59.000Z

    This document provides the basis for converting actual weapons grade plutonium mass to a plutonium equivalency (PuE) mass of Plutonium 239. The conversion can be accomplished by performing calculations utilizing either: (1) Isotopic conversions factors (CF{sub isotope}), or (2) 30-year-old weapons grade conversion factor (CF{sub 30 yr}) Both of these methods are provided in this document. Material mass and isotopic data are needed to calculate PuE using the isotopic conversion factors, which will provide the actual PuE value at the time of calculation. PuE is the summation of the isotopic masses times their associated isotopic conversion factors for plutonium 239. Isotopic conversion factors are calculated by a normalized equation, relative to Plutonium 239, of specific activity (SA) and cumulated dose inhalation affects based on 50-yr committed effective dose equivalent (CEDE). The isotopic conversion factors for converting weapons grade plutonium to PuE are provided in Table-1. The unit for specific activity (SA) is curies per gram (Ci/g) and the isotopic SA values come from reference [1]. The cumulated dose inhalation effect values in units of rem/Ci are based on 50-yr committed effective dose equivalent (CEDE). A person irradiated by gamma radiation outside the body will receive a dose only during the period of irradiation. However, following an intake by inhalation, some radionuclides persist in the body and irradiate the various tissues for many years. There are three groups CEDE data representing lengths of time of 0.5 (D), 50 (W) and 500 (Y) days, which are in reference [2]. The CEDE values in the (W) group demonstrates the highest dose equivalent value; therefore they are used for the calculation.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Monte Carlo Simulations of Grid Walled Proportional Counters with Different Site Sizes for HZE Radiation

    E-Print Network [OSTI]

    Liu, Haifeng

    2012-07-16T23:59:59.000Z

    Tissue-equivalent proportional counters are frequently used to measure dose and dose equivalent in cosmic radiation fields that include high-Z, high-energy (HZE) particles. The fact that particles with different stopping powers can produce the same...

  15. 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.

  16. 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.

  17. 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

  18. Estimating Radiation Risk from Total Effective Dose Equivalent (TEDE) ISCORS Technical Report No. 1

    National Nuclear Security Administration (NNSA)

    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 for4,645 3,625 1,006 492 742EnergyOn AprilA Approved:AdministrationAnalysisDarby/%2AO 474.2 ChgQuestionsReporting

  19. Estimating Radiation Risk from Total Effective Dose Equivalent (TEDE) ISCORS Technical Report No. 1

    National Nuclear Security Administration (NNSA)

    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 for4,645 3,625 1,006 492 742EnergyOn AprilA Approved:AdministrationAnalysisDarby/%2AO 474.2 ChgQuestionsReportingan 0 Tw

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Monte Carlo simulations of solid walled proportional counters with different site size for HZE radiation 

    E-Print Network [OSTI]

    Wang, Xudong

    2009-05-15T23:59:59.000Z

    Characterizing high z high energy (HZE) particles in cosmic radiation is of importance for the study of the equivalent dose to astronauts. Low pressure, tissue equivalent proportional counters (TEPC) are routinely used to evaluate radiation...

  5. Monte Carlo simulations of solid walled proportional counters with different site size for HZE radiation

    E-Print Network [OSTI]

    Wang, Xudong

    2009-05-15T23:59:59.000Z

    Characterizing high z high energy (HZE) particles in cosmic radiation is of importance for the study of the equivalent dose to astronauts. Low pressure, tissue equivalent proportional counters (TEPC) are routinely used to evaluate radiation...

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Gravitational radiation fields in teleparallel equivalent of general relativity and their energies

    E-Print Network [OSTI]

    G. G. L. Nashed

    2011-01-05T23:59:59.000Z

    We derive two new retarded solutions in the teleparallel theory equivalent to general relativity (TEGR). One of these solutions gives a divergent energy. Therefore, we used the regularized expression of the gravitational energy-momentum tensor, which is a coordinate dependent. A detailed analysis of the loss of the mass of Bondi space-time is carried out using the flux of the gravitational energy-momentum.

  3. 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

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  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. 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

  13. 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.

  14. Determination of the transuranic dose equivalent to the Rongelapese from urinary output analyzed by the fission track method

    E-Print Network [OSTI]

    Taylor, George Anthony

    1989-01-01T23:59:59.000Z

    materials and fission products, 2s9Pu is the major radionuclide of concern in the contamination of the environment (Sun 1984). Internally deposited plutonium is extremely hazardous to man, mainly because of its long effective half-life. It has been... Background Transuranic Dose MATERIAL AND METHODS Plutonium In Man . Urinalysis . Whole Body Counting (WBC) . Computer Programs Data Analysis . . . . . RESULTS AND DISCUSSION . CONCLUSIONS RECOMMENDATIONS ON FURTHER WORK REFERENCES VITA . Page Vl...

  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. 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.

  18. 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.

  19. 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.

  20. 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...

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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)

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. An assessment of current and proposed methodologies for estimating effective dose equivalent from non-uniform external photon radiation

    E-Print Network [OSTI]

    Hay, Michael Charles

    1997-01-01T23:59:59.000Z

    of Federal Regulations) Part 20 with the results obtained from using recommended methodologies from the scientific community. These recommendations are discussed in detail in NCRP Report 122 (1995), ANSI 13.41 (1997), and EPRI Reports TR-101909 Volumes 1...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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], ...

  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. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Helical Tomotherapy vs. Intensity-Modulated Proton Therapy for Whole Pelvis Irradiation in High-Risk Prostate Cancer Patients: Dosimetric, Normal Tissue Complication Probability, and Generalized Equivalent Uniform Dose Analysis

    SciTech Connect (OSTI)

    Widesott, Lamberto, E-mail: widesott@yahoo.it [Agenzia Provinciale per la Protonterapia, Trento (Italy); Pierelli, Alessio; Fiorino, Claudio [Department of Medical Physics, St. Raffaele Scientific Institute, Milan (Italy); Lomax, Antony J. [Paul Scherrer Institut, Villigen (Switzerland); Amichetti, Maurizio [Agenzia Provinciale per la Protonterapia, Trento (Italy); Cozzarini, Cesare [Department of Radiotherapy, St. Raffaele Scientific Institute, Milan (Italy); Soukup, Martin [Section for Biomedical Physics, Universitatsklinik fur Radioonkologie, Tubingen (Germany); Schneider, Ralf; Hug, Eugen [Paul Scherrer Institut, Villigen (Switzerland); Di Muzio, Nadia [Department of Radiotherapy, St. Raffaele Scientific Institute, Milan (Italy); Calandrino, Riccardo [Department of Medical Physics, St. Raffaele Scientific Institute, Milan (Italy); Schwarz, Marco [Agenzia Provinciale per la Protonterapia, Trento (Italy)

    2011-08-01T23:59:59.000Z

    Purpose: To compare intensity-modulated proton therapy (IMPT) and helical tomotherapy (HT) treatment plans for high-risk prostate cancer (HRPCa) patients. Methods and Materials: The plans of 8 patients with HRPCa treated with HT were compared with IMPT plans with two quasilateral fields set up (-100{sup o}; 100{sup o}) and optimized with the Hyperion treatment planning system. Both techniques were optimized to simultaneously deliver 74.2 Gy/Gy relative biologic effectiveness (RBE) in 28 fractions on planning target volumes (PTVs)3-4 (P + proximal seminal vesicles), 65.5 Gy/Gy(RBE) on PTV2 (distal seminal vesicles and rectum/prostate overlapping), and 51.8 Gy/Gy(RBE) to PTV1 (pelvic lymph nodes). Normal tissue calculation probability (NTCP) calculations were performed for the rectum, and generalized equivalent uniform dose (gEUD) was estimated for the bowel cavity, penile bulb and bladder. Results: A slightly better PTV coverage and homogeneity of target dose distribution with IMPT was found: the percentage of PTV volume receiving {>=}95% of the prescribed dose (V{sub 95%}) was on average >97% in HT and >99% in IMPT. The conformity indexes were significantly lower for protons than for photons, and there was a statistically significant reduction of the IMPT dosimetric parameters, up to 50 Gy/Gy(RBE) for the rectum and bowel and 60 Gy/Gy(RBE) for the bladder. The NTCP values for the rectum were higher in HT for all the sets of parameters, but the gain was small and in only a few cases statistically significant. Conclusions: Comparable PTV coverage was observed. Based on NTCP calculation, IMPT is expected to allow a small reduction in rectal toxicity, and a significant dosimetric gain with IMPT, both in medium-dose and in low-dose range in all OARs, was observed.

  6. 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 ...

  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. Equivalence and Order Section 1: Equivalence

    E-Print Network [OSTI]

    Bernstein, Daniel

    Unit EO Equivalence and Order Section 1: Equivalence The concept of an equivalence relation to us, as "equivalence relation" turns out to be just another name for "partition of a set." Our start with the definition. Definition 1 (Equivalence relation) An equivalence relation on a set

  14. 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

  15. 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

  16. 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.

  17. Basis for radiation protection of the nuclear worker

    SciTech Connect (OSTI)

    Guevara, F.A.

    1982-01-01T23:59:59.000Z

    A description is given of the standards for protection of persons who work in areas that have a potential for radiation exposure. A review is given of the units of radiation exposure and dose equivalent and of the value of the maximum permissible dose limits for occupational exposure. Federal Regulations and Regulatory Guides for radiation protection are discussed. Average occupational equivalent doses experienced in several operations typical of the United States Nuclear Industry are presented and shown to be significantly lower than the maximum permissible. The concept of maintaining radiation doses to As-Low-As-Reasonably-Achievable is discussed and the practice of imposing engineering and administrative controls to provide effective radiation protection for the nuclear worker is described.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Parameterized algorithms for quantitative differentials in spectrally equivalent medical diagnostic x-ray beams

    SciTech Connect (OSTI)

    Okunade, Akintunde Akangbe [Department of Physics, Obafemi Awolowo University, Ile-Ife, Osun State (Nigeria)

    2005-06-15T23:59:59.000Z

    Qualitative and quantitative equivalence of spectra transmitted by two different elemental filters require a good match in terms of shape and size over the entire energy range of 0-150 keV used in medical diagnostic radiology. However, the photoelectric absorptions and Compton scattering involved in the interaction of x rays with matter at these relatively low photon energies differ in a nonuniform manner with energy and atomic number. By careful choice of thicknesses for filter materials with an atomic number between 12 and 39, when compared with aluminum, it is possible to obtain transmitted beams of the same shape (quality) but not of the same size (quantity). In this paper, calculations have been carried out for the matching of the shapes and sizes of beams transmitted through specified thicknesses of aluminium filter and spectrally equivalent thicknesses of other filter materials (different from aluminium) using FORTRAN source codes traceable to the American Association of Physics in Medicine (AAPM), College Park, MD, USA. Parametrized algorithms for the evaluation of quantitative differentials (deficit or surplus) in radiation output (namely, photon fluence, exposure, kerma, energy imparted, absorbed dose, and effective dose) from these transmitted spectrally equivalent beams were developed. These differentials range between 1%, and 4% at 1 mm Al filtration and between 8%, and 25% for filtration of 6 mm Al for different filter materials in comparison with aluminum. Also developed were models for factors for converting measures of photon fluence, exposure-area product, (EAP), and kerma-area product (KAP) to risk related quantities such as energy imparted, absorbed dose, and effective dose from the spectrally equivalent beams. The thicknesses of other filter materials that are spectrally equivalent to given thicknesses of aluminum filter were characterized using polynomial functions. The fact that the use of equivalent spectra in radiological practice can provide means of ranking the differentials in radiographic image quality and stochastic risk is discussed.

  1. Effect of Fractionation in Stereotactic Body Radiation Therapy Using the Linear Quadratic Model

    SciTech Connect (OSTI)

    Yang, Jun, E-mail: JunBME@yahoo.com [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States) [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States); Philadelphia Cyberknife, Havertown, Pennsylvania (United States); Lamond, John [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States) [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States); Philadelphia Cyberknife, Havertown, Pennsylvania (United States); Fowler, Jack [Department of Radiation Oncology, University of Wisconsin, Madison, Wisconsin (United States)] [Department of Radiation Oncology, University of Wisconsin, Madison, Wisconsin (United States); Lanciano, Rachelle [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States) [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States); Philadelphia Cyberknife, Havertown, Pennsylvania (United States); Feng, Jing [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States); Brady, Luther [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States) [Department of Radiation Oncology, Drexel University, Philadelphia, Pennsylvania (United States); Philadelphia Cyberknife, Havertown, Pennsylvania (United States)

    2013-05-01T23:59:59.000Z

    Purpose: To examine the fractionation effect of stereotactic body radiation therapy with a heterogeneous dose distribution. Methods: Derived from the linear quadratic formula with measurements from a hypothetical 2-cm radiosurgical tumor, the threshold percentage was defined as (?/?{sub tissue}/?/?{sub tumor}), the balance ?/? ratio was defined as (prescription dose/tissue tolerance*?/?{sub tumor}), and the balance dose was defined as (tissue tolerance/threshold percentage). Results: With increasing fractions and equivalent peripheral dose to the target, the biological equivalent dose of “hot spots” in a target decreases. The relative biological equivalent doses of serial organs decrease only when the relative percentage of its dose to the prescription dose is above the threshold percentage. The volume of parallel organs at risk decreases only when the tumor's ?/? ratio is above the balance ?/? ratio and the prescription dose is lower than balance dose. Conclusions: The potential benefits of fractionation in stereotactic body radiation therapy depend on the complex interplay between the total dose, ?/? ratios, and dose differences between the target and the surrounding normal tissues.

  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. 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.

  4. Laser-based irradiation apparatus and method to measure the functional dose-rate response of semiconductor devices

    DOE Patents [OSTI]

    Horn, Kevin M. (Albuquerque, NM)

    2008-05-20T23:59:59.000Z

    A broad-beam laser irradiation apparatus can measure the parametric or functional response of a semiconductor device to exposure to dose-rate equivalent infrared laser light. Comparisons of dose-rate response from before, during, and after accelerated aging of a device, or from periodic sampling of devices from fielded operational systems can determine if aging has affected the device's overall functionality. The dependence of these changes on equivalent dose-rate pulse intensity and/or duration can be measured with the apparatus. The synchronized introduction of external electrical transients into the device under test can be used to simulate the electrical effects of the surrounding circuitry's response to a radiation exposure while exposing the device to dose-rate equivalent infrared laser light.

  5. 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.

  6. 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.

  7. 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.

  8. Clinical prototype of a plastic water-equivalent scintillating fiber dosimeter array for QA applications

    SciTech Connect (OSTI)

    Lacroix, Frederic; Archambault, Louis; Gingras, Luc; Guillot, Mathieu; Beddar, A. Sam; Beaulieu, Luc [Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec, G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec, Quebec G1R2J6 (Canada); Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030 (United States); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec, Quebec G1R2J6 (Canada); Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030 (United States); Departement de Physique, de Genie Physique et d'Optique, Universite Laval, Quebec, Quebec, G1K 7P4 (Canada) and Departement de Radio-Oncologie, Hotel-Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec, Quebec G1R2J6 (Canada)

    2008-08-15T23:59:59.000Z

    A clinical prototype of a scintillating fiber dosimeter array for quality assurance applications is presented. The array consists of a linear array of 29 plastic scintillation detectors embedded in a water-equivalent plastic sheet coupled to optical fibers used to guide optical photons to a charge coupled device (CCD) camera. The CCD is packaged in a light-tight, radiation-shielded housing designed for convenient transport. A custom designed connector is used to ensure reproducible mechanical positioning of the optical fibers relative to the CCD. Profile and depth dose characterization measurements are presented and show that the prototype provides excellent dose measurement reproducibility ({+-}0.8%) in-field and good accuracy ({+-}1.6% maximum deviation) relative to the dose measured with an IC10 ionization chamber.

  9. 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.

  10. Testing Model Nesting and Equivalence

    E-Print Network [OSTI]

    Peter M. Bentler; Albert Satorra

    2011-01-01T23:59:59.000Z

    sense of observational equivalence, implying that theirModel Nesting and Equivalence* Peter M. Bentler UniversityModel Nesting and Equivalence Using existing technology, it

  11. Testing Model Nesting and Equivalence

    E-Print Network [OSTI]

    Bentler, Peter M.; Satorra, Albert

    2008-01-01T23:59:59.000Z

    sense of observational equivalence, implying that theirModel Nesting and Equivalence* Peter M. Bentler UniversityModel Nesting and Equivalence Using existing technology, it

  12. 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.

  13. 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.

  14. On the Sensitivity of ?/? Prediction to Dose Calculation Methodology in Prostate Brachytherapy

    SciTech Connect (OSTI)

    Afsharpour, Hossein [Centre de Recherche sur le Cancer, Université Laval and Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, QC (Canada); Centre Intégré de Cancérologie de la Montérégie, Hôpital Charles-LeMoyne, Greenfield Park, QC (Canada); Walsh, Sean [Department of Radiation Oncology Maastricht Radiation Oncology (MAASTRO), GROW, University Hospital Maastricht, Maastricht (Netherlands); Gray Institute for Radiation Oncology and Biology, The University of Oxford, The United Kingdom (United Kingdom); Collins Fekete, Charles-Antoine; Vigneault, Eric [Centre de Recherche sur le Cancer, Université Laval and Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, QC (Canada); Verhaegen, Frank [Department of Radiation Oncology Maastricht Radiation Oncology (MAASTRO), GROW, University Hospital Maastricht, Maastricht (Netherlands); Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec (Canada); Beaulieu, Luc, E-mail: Luc.Beaulieu@phy.ulaval.ca [Centre de Recherche sur le Cancer, Université Laval and Département de Radio-Oncologie, Centre Hospitalier Universitaire de Québec, Québec, QC (Canada)

    2014-02-01T23:59:59.000Z

    Purpose: To study the relationship between the accuracy of the dose calculation in brachytherapy and the estimations of the radiosensitivity parameter, ?/?, for prostate cancer. Methods and Materials: In this study, Monte Carlo methods and more specifically the code ALGEBRA was used to produce accurate dose calculations in the case of prostate brachytherapy. Equivalent uniform biologically effective dose was calculated for these dose distributions and was used in an iso-effectiveness relationship with external beam radiation therapy. Results: By considering different levels of detail in the calculations, the estimation for the ?/? parameter varied from 1.9 to 6.3 Gy, compared with a value of 3.0 Gy suggested by the American Association of Physicists in Medicine Task Group 137. Conclusions: Large variations of the ?/? show the sensitivity of this parameter to dose calculation modality. The use of accurate dose calculation engines is critical for better evaluating the biological outcomes of treatments.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. Causal equivalence of frames

    E-Print Network [OSTI]

    Henderson, Troy Lee, IV

    2006-10-30T23:59:59.000Z

    Major Subject: Mathematics August 2005 DOCTOR OF PHILOSOPHY in partial fulfillment of the requirements for the degree of Texas A&M University Submitted to the Office of Graduate Studies of TROY LEE HENDERSON, IV by A Dissertation CAUSAL EQUIVALENCE... to the Office of Graduate Studies of TROY LEE HENDERSON, IV by A Dissertation CAUSAL EQUIVALENCE OF FRAMES iii ABSTRACT Causal Equivalence of Frames. (August 2005) Troy Lee Henderson, IV, B.S., The University of Alabama; M.A., The University of Alabama Chair...

  2. Nonequivalence of equivalence principles

    E-Print Network [OSTI]

    Eolo Di Casola; Stefano Liberati; Sebastiano Sonego

    2015-03-18T23:59:59.000Z

    Equivalence principles played a central role in the development of general relativity. Furthermore, they have provided operative procedures for testing the validity of general relativity, or constraining competing theories of gravitation. This has led to a flourishing of different, and inequivalent, formulations of these principles, with the undesired consequence that often the same name, "equivalence principle", is associated with statements having a quite different physical meaning. In this paper we provide a precise formulation of the several incarnations of the equivalence principle, clarifying their uses and reciprocal relations. We also discuss their possible role as selecting principles in the design and classification of viable theories of gravitation.

  3. Beyond Network Equivalence

    E-Print Network [OSTI]

    Koetter, Ralf

    In earlier work, we described an equivalence result for network capacity. Roughly, that result is as follows. Given a network of noisy, memoryless, point-to-point channels, replace each channel by a noiseless, memoryless ...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Equivalence of Real Elliptic CurvesEquivalence of Real Elliptic Curves Part 2Part 2 --Birational EquivalenceBirational Equivalence

    E-Print Network [OSTI]

    Broughton, S. Allen

    1 Equivalence of Real Elliptic CurvesEquivalence of Real Elliptic Curves Part 2Part 2 -- Birational EquivalenceBirational Equivalence Allen Broughton Rose-Hulman Institute of Technology #12;2 CreditsCredits Discussion with Ken McMurdy #12;3 OutlineOutline -- 11 Recap of linear equivalence Complex elliptic curves

  9. Equivalence and Strong Equivalence between Sparsest and Least ...

    E-Print Network [OSTI]

    2013-12-15T23:59:59.000Z

    Equivalence and Strong Equivalence between. Sparsest and Least l1-Norm Nonnegative Solutions of. Linear Systems and Their Application. YUN-BIN ZHAO ?.

  10. Confounding Equivalence in Causal Inference

    E-Print Network [OSTI]

    Pearl, Judea; Paz, Azaria

    2010-01-01T23:59:59.000Z

    July 2010 Confounding Equivalence in Causal Inference Judeawise process of testing c-equivalence, T ? T 1 ? T 2 ? . . .wish to assess, using c-equivalence tests, whether a given

  11. 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.

  12. 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.

  13. 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.

  14. Design, construction and implementation of spherical tissue equivalent proportional counter

    E-Print Network [OSTI]

    Perez Nunez, Delia Josefina

    2009-05-15T23:59:59.000Z

    Tissue equivalent proportional counters (TEPC) are used for medical and space activities whenever a combination of high and low LET (lineal energy transfer) radiations are present. With the frequency and duration of space activities increasing...

  15. Free products, Orbit Equivalence and Measure Equivalence Rigidity

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Free products, Orbit Equivalence and Measure Equivalence Rigidity Aur´elien Alvarez and Damien Gaboriau February 18, 2009 Abstract We study the analogue in orbit equivalence of free product decomposition and free indecomposability for countable groups. We introduce the (orbit equivalence invariant

  16. Equivalence relations which reduce all Borel equivalence relations

    E-Print Network [OSTI]

    Clemens, John D.

    Equivalence relations which reduce all Borel equivalence relations John D. Clemens June 25, 2007 Abstract We study equivalence relations E such that every Borel equiva- lence relation is Borel reducible of equality of Borel sets, and show that this is not a minimal such re- lation among co-analytic equivalence

  17. Equivalence Principle and Clocks

    E-Print Network [OSTI]

    T. Damour

    1999-04-14T23:59:59.000Z

    String theory suggests the existence of gravitational-strength scalar fields ("dilaton" and "moduli") whose couplings to matter violate the equivalence principle. This provides a new motivation for high-precision clock experiments, as well as a generic theoretical framework for analyzing their significance.

  18. 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.

  19. 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.

  20. The effect of a paraffin screen on the neutron dose at the maze door of a 15 MV linear accelerator

    SciTech Connect (OSTI)

    Krmar, M.; Kuzmanovi?, A. [Physics Department, Faculty of Science, University of Novi Sad, Novi Sad 21000 (Serbia)] [Physics Department, Faculty of Science, University of Novi Sad, Novi Sad 21000 (Serbia); Nikoli?, D. [National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada)] [National Institute for Nanotechnology, Edmonton, Alberta T6G 2M9 (Canada); Kuzmanovi?, Z. [International Medical Centers, Banja Luka 78000, Republika Srpska, Bosnia and Herzegovina (Bosnia and Herzegowina)] [International Medical Centers, Banja Luka 78000, Republika Srpska, Bosnia and Herzegovina (Bosnia and Herzegowina); Ganezer, K. [Physics Department, California State University Dominguez Hills, Carson, California 90747 (United States)] [Physics Department, California State University Dominguez Hills, Carson, California 90747 (United States)

    2013-08-15T23:59:59.000Z

    Purpose: The purpose of this study was to explore the effects of a paraffin screen located at various positions in the maze on the neutron dose equivalent at the maze door.Methods: The neutron dose equivalent was measured at the maze door of a room containing a 15 MV linear accelerator for x-ray therapy. Measurements were performed for several positions of the paraffin screen covering only 27.5% of the cross-sectional area of the maze. The neutron dose equivalent was also measured at all screen positions. Two simple models of the neutron source were considered in which the first assumed that the source was the cross-sectional area at the inner entrance of the maze, radiating neutrons in an isotropic manner. In the second model the reduction in the neutron dose equivalent at the maze door due to the paraffin screen was considered to be a function of the mean values of the neutron fluence and energy at the screen.Results: The results of this study indicate that the equivalent dose at the maze door was reduced by a factor of 3 through the use of a paraffin screen that was placed inside the maze. It was also determined that the contributions to the dosage from areas that were not covered by the paraffin screen as viewed from the dosimeter, were 2.5 times higher than the contributions from the covered areas. This study also concluded that the contributions of the maze walls, ceiling, and floor to the total neutron dose equivalent were an order of magnitude lower than those from the surface at the far end of the maze.Conclusions: This study demonstrated that a paraffin screen could be used to reduce the neutron dose equivalent at the maze door by a factor of 3. This paper also found that the reduction of the neutron dose equivalent was a linear function of the area covered by the maze screen and that the decrease in the dose at the maze door could be modeled as an exponential function of the product ?·E at the screen.

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. Laser-based irradiation apparatus and methods for monitoring the dose-rate response of semiconductor devices

    DOE Patents [OSTI]

    Horn, Kevin M. (Albuquerque, NM)

    2006-03-28T23:59:59.000Z

    A scanned, pulsed, focused laser irradiation apparatus can measure and image the photocurrent collection resulting from a dose-rate equivalent exposure to infrared laser light across an entire silicon die. Comparisons of dose-rate response images or time-delay images from before, during, and after accelerated aging of a device, or from periodic sampling of devices from fielded operational systems allows precise identification of those specific age-affected circuit structures within a device that merit further quantitative analysis with targeted materials or electrical testing techniques. Another embodiment of the invention comprises a broad-beam, dose rate-equivalent exposure apparatus. The broad-beam laser irradiation apparatus can determine if aging has affected the device's overall functionality. This embodiment can be combined with the synchronized introduction of external electrical transients into a device under test to simulate the electrical effects of the surrounding circuitry's response to a radiation exposure.

  6. 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.

  7. ambient dose equivalent: Topics by E-print Network

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

    describing semiclassically and quantum mechanically various systems such as the hydrogen atom, a particle on the surface of a sphere, and a spinning top. It is also...

  8. GENERATING EQUIVALENCE RELATIONS BY HOMEOMORPHISMS

    E-Print Network [OSTI]

    Clemens, John D.

    GENERATING EQUIVALENCE RELATIONS BY HOMEOMORPHISMS JOHN D. CLEMENS Abstract. We give a construction of a single homeomorphism of 2N which generates the equivalence relation E0. We then consider ways of generating this equivalence relation using homeomorphisms with nicer structural properties, and show

  9. 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.

  10. Use of 4-Dimensional Computed Tomography-Based Ventilation Imaging to Correlate Lung Dose and Function With Clinical Outcomes

    SciTech Connect (OSTI)

    Vinogradskiy, Yevgeniy, E-mail: yevgeniy.vinogradskiy@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); Castillo, Richard [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Castillo, Edward [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States) [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Computational and Applied Mathematics, Rice University, Houston, Texas (United States); Tucker, Susan L. [Departments of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Departments of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao, Zhongxing [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Guerrero, Thomas [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States) [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Computational and Applied Mathematics, Rice University, Houston, Texas (United States); Martel, Mary K. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)] [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2013-06-01T23:59:59.000Z

    Purpose: Four-dimensional computed tomography (4DCT)-based ventilation is an emerging imaging modality that can be used in the thoracic treatment planning process. The clinical benefit of using ventilation images in radiation treatment plans remains to be tested. The purpose of the current work was to test the potential benefit of using ventilation in treatment planning by evaluating whether dose to highly ventilated regions of the lung resulted in increased incidence of clinical toxicity. Methods and Materials: Pretreatment 4DCT data were used to compute pretreatment ventilation images for 96 lung cancer patients. Ventilation images were calculated using 4DCT data, deformable image registration, and a density-change based algorithm. Dose–volume and ventilation-based dose function metrics were computed for each patient. The ability of the dose–volume and ventilation-based dose–function metrics to predict for severe (grade 3+) radiation pneumonitis was assessed using logistic regression analysis, area under the curve (AUC) metrics, and bootstrap methods. Results: A specific patient example is presented that demonstrates how incorporating ventilation-based functional information can help separate patients with and without toxicity. The logistic regression significance values were all lower for the dose–function metrics (range P=.093-.250) than for their dose–volume equivalents (range, P=.331-.580). The AUC values were all greater for the dose–function metrics (range, 0.569-0.620) than for their dose–volume equivalents (range, 0.500-0.544). Bootstrap results revealed an improvement in model fit using dose–function metrics compared to dose–volume metrics that approached significance (range, P=.118-.155). Conclusions: To our knowledge, this is the first study that attempts to correlate lung dose and 4DCT ventilation-based function to thoracic toxicity after radiation therapy. Although the results were not significant at the .05 level, our data suggests that incorporating ventilation-based functional imaging can improve prediction for radiation pneumonitis. We present an important first step toward validating the use of 4DCT-based ventilation imaging in thoracic treatment planning.

  11. 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.

  12. The Dosimetric Impact of Prostate Rotations During Electromagnetically Guided External-Beam Radiation Therapy

    SciTech Connect (OSTI)

    Amro, Hanan, E-mail: hanan.amro@gmail.com [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Hamstra, Daniel A.; Mcshan, Daniel L. [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 [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California (United States)] [Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California (United States); Vineberg, Karen; Hadley, Scott; Litzenberg, Dale [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States)

    2013-01-01T23:59:59.000Z

    Purpose: To study the impact of daily rotations and translations of the prostate on dosimetric coverage during radiation therapy (RT). Methods and Materials: Real-time tracking data for 26 patients were obtained during RT. Intensity modulated radiation therapy plans meeting RTOG 0126 dosimetric criteria were created with 0-, 2-, 3-, and 5-mm planning target volume (PTV) margins. Daily translations and rotations were used to reconstruct prostate delivered dose from the planned dose. D{sub 95} and V{sub 79} were computed from the delivered dose to evaluate target coverage and the adequacy of PTV margins. Prostate equivalent rotation is a new metric introduced in this study to quantify prostate rotations by accounting for prostate shape and length of rotational lever arm. Results: Large variations in prostate delivered dose were seen among patients. Adequate target coverage was met in 39%, 65%, and 84% of the patients for plans with 2-, 3-, and 5-mm PTV margins, respectively. Although no correlations between prostate delivered dose and daily rotations were seen, the data showed a clear correlation with prostate equivalent rotation. Conclusions: Prostate rotations during RT could cause significant underdosing even if daily translations were managed. These rotations should be managed with rotational tolerances based on prostate equivalent rotations.

  13. Influence of Gravitation on Mass-Energy Equivalence Relation

    E-Print Network [OSTI]

    R. V. R. Pandya

    2005-07-01T23:59:59.000Z

    We study influence of gravitational field on the mass-energy equivalence relation by incorporating gravitation in the physical situation considered by Einstein (Ann. Physik, 17, 1905, English translation in ref. [1]) for his first derivation of mass-energy equivalence. In doing so, we also refine Einstein's expression (Ann. Physik, 35, 1911, English translation in ref. [3]) for increase in gravitational mass of the body when it absorbs E amount of radiation energy.

  14. Equivalence in Ventilation and Indoor Air Quality

    E-Print Network [OSTI]

    Sherman, Max

    2012-01-01T23:59:59.000Z

    Equivalence in Ventilation and Indoor Air Quality M. H.have a method for determining equivalence in terms of eitherwe need to establish an equivalence principle that allows

  15. Recursion theory and countable Borel equivalence relations

    E-Print Network [OSTI]

    Marks, Andrew

    2012-01-01T23:59:59.000Z

    and countable Borel equivalence ii 2 Overture 2.1 A simplecountable Borel equivalence relations 3.1 Consequences ofof arithmetic equivalence . . . . . . . . . . 3.2 Ergodicity

  16. Expression equivalence checking using interval analysis

    E-Print Network [OSTI]

    Ghodrat, Mohammad Ali; Givargis, Tony; Nicolau, Alex

    2006-01-01T23:59:59.000Z

    Z. Zhou and W. Burleson, “Equivalence checking of datapathsusing combinational equivalence for extensible processor,”et al. : EXPRESSION EQUIVALENCE CHECKING USING INTERVAL

  17. Equivalence Principle and Gravitational Redshift

    SciTech Connect (OSTI)

    Hohensee, Michael A.; Chu, Steven; Mueller, Holger [Department of Physics, University of California, Berkeley, California 94720 (United States); Peters, Achim [Institut fuer Physik, Humboldt-Universitaet zu Berlin, Newtonstrasse 15, 12489 Berlin (Germany)

    2011-04-15T23:59:59.000Z

    We investigate leading order deviations from general relativity that violate the Einstein equivalence principle in the gravitational standard model extension. We show that redshift experiments based on matter waves and clock comparisons are equivalent to one another. Consideration of torsion balance tests, along with matter-wave, microwave, optical, and Moessbauer clock tests, yields comprehensive limits on spin-independent Einstein equivalence principle-violating standard model extension terms at the 10{sup -6} level.

  18. 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...

  19. 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.

  20. SAPONIFICATION EQUIVALENT OF DASAMULA TAILA

    E-Print Network [OSTI]

    R. B. Saxena

    1994-01-01T23:59:59.000Z

    ABSTRACT: Saponification equivalent values of Dasamula taila are very useful for the technical and analytical work. It gives the mean molecular weight of the glycerides and acids present in Dasamula Taila. Saponification equivalent values of Dasamula taila are reported in different packings.

  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. 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%.

  3. 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.

  4. Mathematical Equivalence vs. Physical Equivalence between Extended Theories of Gravitations

    E-Print Network [OSTI]

    L. Fatibene; M. Francaviglia

    2013-02-12T23:59:59.000Z

    We shall show that although Palatini f(R)-theories are equivalent to Brans-Dicke theories, still the first pass the Mercury precession of perihelia test, while the second do not. We argue that the two models are not physically equivalent due to a different assumptions about free fall. We shall also go through perihelia test without fixing a conformal gauge (clocks or rulers) in order to highlight what can be measured in a conformal invariant way and what cannot. We shall argue that the conformal gauge is broken by choosing a definition of clock, rulers or, equivalently, of masses.

  5. Radionuclides in the terrestrial ecosystem near a Canadian uranium mill -- Part 1: Distribution and doses

    SciTech Connect (OSTI)

    Thomas, P.A.

    2000-06-01T23:59:59.000Z

    Soils, vegetation, small mammals, and birds were measured for uranium series radionuclides at three sites near the operating Key Lake uranium mill in northern Saskatchewan. Sites, impacted by windblown tailings and mill dust, had significantly higher concentrations of uranium, {sup 226}Ra, {sup 210}Pb, and {sup 210}Po in soils, litter, vegetation, tree needles and twigs, small mammals, and birds, compared to a control site. Samples were collected from both upland jackpine and black spruce bog habitats in triplicate at each site. Both habitats were similar in radionuclide accumulation. Absorbed doses averaged 0.92, 8.4, and 4.9 mGy y{sup {minus}1} to small mammals and 2.0, 5.8, and 2.8 mGy y{sup {minus}1} to Lincoln's sparrows at the control, tailings, and mill sites, respectively. These doses do not include doses from short-lived radon progeny. The majority of the dose increment at the tailings and mill sites was due to {sup 226}Ra, whereas it was {sup 210}Po at the control site. Thus, use of a radiation weighting factor of 20 for alpha radiation raised equivalent doses (in mSv y{sup {minus}1}) by nearly a factor of 20.

  6. Specific gamma-ray dose constants for nuclides important to dosimetry and radiological assessment

    SciTech Connect (OSTI)

    Unger, L.M.; Trubey, D.K.

    1981-09-01T23:59:59.000Z

    Tables of specific gamma-ray dose constants (the unshielded gamma-ray dose equivalent rate at 1 m from a point source) have been computed for approximately 500 nuclides important to dosimetry and radiological assessment. The half life, the mean attenuation coefficient, and thickness for a lead shield providing 95% dose equivalent attenuation are also listed.

  7. Specific gamma-ray dose constants for nuclides important to dosimetry and radiological assessment

    SciTech Connect (OSTI)

    Unger, L.M.; Trubey, D.K.

    1982-05-01T23:59:59.000Z

    Tables of specific gamma-ray dose constants (the unshielded gamma-ray dose equivalent rate at 1 m from a point source) have been computed for approximately 500 nuclides important to dosimetry and radiological assessment. The half life, the mean attenuation coefficient, and thickness for a lead shield providing 95% dose equivalent attenuation are also listed.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Potential Offsite Radiological Doses Estimated for the Proposed Divine Strake Experiment, Nevada Test Site

    SciTech Connect (OSTI)

    Ron Warren

    2006-12-01T23:59:59.000Z

    An assessment of the potential radiation dose that residents offsite of the Nevada Test Site (NTS) might receive from the proposed Divine Strake experiment was made to determine compliance with Subpart H of Part 61 of Title 40 of the Code of Federal Regulations, National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities. The Divine Strake experiment, proposed by the Defense Threat Reduction Agency, consists of a detonation of 700 tons of heavy ammonium nitrate fuel oil-emulsion above the U16b Tunnel complex in Area 16 of the NTS. Both natural radionuclides suspended, and historic fallout radionuclides resuspended from the detonation, have potential to be transported outside the NTS boundary by wind. They may, therefore, contribute radiological dose to the public. Subpart H states ''Emissions of radionuclides to the ambient air from Department of Energy facilities shall not exceed those amounts that would cause any member of the public to receive in any year an effective dose equivalent of 10 mrem/yr'' (Title 40 of the Code of Federal Regulations [CFR] 61.92) where mrem/yr is millirem per year. Furthermore, application for U.S. Environmental Protection Agency (EPA) approval of construction of a new source or modification of an existing source is required if the effective dose equivalent, caused by all emissions from the new construction or modification, is greater than or equal to 0.1 mrem/yr (40 CFR 61.96). In accordance with Section 61.93, a dose assessment was conducted with the computer model CAP88-PC, Version 3.0. In addition to this model, a dose assessment was also conducted by the National Atmospheric Release Advisory Center (NARAC) at the Lawrence Livermore National Laboratory. This modeling was conducted to obtain dose estimates from a model designed for acute releases and which addresses terrain effects and uses meteorology from multiple locations. Potential radiation dose to a hypothetical maximally exposed individual at the closest NTS boundary to the proposed Divine Strake experiment, as estimated by the CAP88-PC model, was 0.005 mrem with wind blowing directly towards that location. Boundary dose, as modeled by NARAC, ranged from about 0.006 to 0.007 mrem. Potential doses to actual offsite populated locations were generally two to five times lower still, or about 40 to 100 times lower then the 0.1 mrem level at which EPA approval is required pursuant to Section 61.96.

  13. SU-E-T-130: Dosimetric Evaluation of Tissue Equivalent Gel Dosimeter Using Saccharide in Radiotherapy System

    SciTech Connect (OSTI)

    Cho, Y [Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul (Korea, Republic of); Lee, D; Jung, H; Ji, Y; Kim, K; Chang, U [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Kwon, S [Kyonggi University, Suwon-si, Gyeonggi-do (Korea, Republic of)

    2014-06-01T23:59:59.000Z

    Purpose: In this study, the dose responses of the MAGIC gel with various concentrations and type of saccharide are examined to clarify the roles of mono and disaccharide in the polymerization process. Then we focused on the tissue equivalence and dose sensitivity of MAGIC gel dosimeters. Methods: The gel is composed of HPLC, 8% gelatin, 2 × 10-3 M L-ascorbic acid, 1.8 × 10-2 M hydroquinone, 8 × 10-5 M copper(II)sulfate and 9% methacrylic acid, new polymer gels are synthesized by adding glucose(monosaccharide), sucrose(disaccharide) and urea in the concentration range of 5?35%. For irradiation of the gel, cesium-137 gamma-ray irradiator was used, radiation dose was delivered from 5?50 Gy. MRI images of the gel were acquired by using a 3.0 T MRI system. Results: When saccharide and urea were added, the O/C, O/N and C/N ratios agreed with those of soft tissue with 1.7%. The dose-response of glucose and sucrose gel have slope-to-intercept ratio of 0.044 and 0.283 respectively. The slope-to-ratio is one important determinant of gel sensitivity. R-square values of glucose and sucrose gel dosimeters were 0.984 and 0.994 respectively. Moreover when urea were added, the slope-to-intercept ratio is 0.044 and 0.073 respectively. R-square values of mono and disaccharide gel were 0.973 and 0.989 respectively. When a saccharide is added into the MAGIC gel dosimeter, dose sensitivity is increased. However when urea were added, dose sensitivity is slightly decreased. Conclusion: In this study, it was possible to obtain the following conclusions by looking at the dose response characteristics after adding mono-, di-saccharide and urea to a MAGIC gel dosimeter. Saccharide was a tendency of increasing dose sensitivity with disaccharide. Sa.ccharide is cost effective, safe, soft tissue equivalent, and can be used under various experimental conditions, making it a suitable dosimeter for some radiotherapy applications.

  14. 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.

  15. Measurement of Radiation Damage on Silica Aerogel Cerenkov Radiator

    E-Print Network [OSTI]

    Belle Preprint; Sahu Wang; M. Z. Wang; R. Suda; R. Enomoto; K. C. Peng; C. H. Wang; I. Adachi; M. Amami

    We measured the radiation damage on silica aerogel Cerenkov radiators originally developed for the B-factory experiment at KEK. Refractive index of the aerogel samples ranged from 1.012 to 1.028. The samples were irradiated up to 9.8 MRad of equivalent dose. Measurements of transmittance and refractive index were carried out and these samples were found to be radiation hard. Deteriorations in transparency and changes of refractive index were observed to be less than 1.3% and 0.001 at 90% confidence level, respectively. Prospects of using aerogels under high-radiation environment are discussed. 1 Introduction Silica aerogels(aerogels) are a colloidal form of glass, in which globules of silica are connected in three dimensional networks with siloxan bonds. They are solid, very light, transparent and their refractive index can be controlled in the production process. Many high energy and nuclear physics experiments have used aerogels instead of pressurized gas for their Cerenkov coun...

  16. External dose-rate conversion factors for calculation of dose to the public

    SciTech Connect (OSTI)

    Not Available

    1988-07-01T23:59:59.000Z

    This report presents a tabulation of dose-rate conversion factors for external exposure to photons and electrons emitted by radionuclides in the environment. This report was prepared in conjunction with criteria for limiting dose equivalents to members of the public from operations of the US Department of Energy (DOE). The dose-rate conversion factors are provided for use by the DOE and its contractors in performing calculations of external dose equivalents to members of the public. The dose-rate conversion factors for external exposure to photons and electrons presented in this report are based on a methodology developed at Oak Ridge National Laboratory. However, some adjustments of the previously documented methodology have been made in obtaining the dose-rate conversion factors in this report. 42 refs., 1 fig., 4 tabs.

  17. 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...

  18. 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.

  19. Analytic equivalence relations and bi-embeddability

    E-Print Network [OSTI]

    Ros, Luca Motto

    Analytic equivalence relations and bi-embeddability Luca Motto Ros Kurt G¨odel Research Center Analytic equivalence relations and bi-embeddability #12;Analytic equivalence relations A subset of a Polish Analytic equivalence relations and bi-embeddability #12;Analytic equivalence relations A subset of a Polish

  20. 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.

  1. Morita Equivalence in Deformation Quantization Henrique Bursztyn

    E-Print Network [OSTI]

    Bursztyn, Henrique

    Morita Equivalence in Deformation Quantization by Henrique Bursztyn Engineer (Universidade Federal at Berkeley Spring 2001 #12;Morita Equivalence in Deformation Quantization Copyright 2001 by Henrique Bursztyn #12;1 Abstract Morita Equivalence in Deformation Quantization by Henrique Bursztyn Doctor

  2. 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

  3. Dosimetry in Mammography: Average Glandular Dose Based on Homogeneous Phantom

    SciTech Connect (OSTI)

    Benevides, Luis A. [Naval Sea Systems Command,1333 Isaac Hull Avenue, Washington Navy Yard, DC 20376 (United States); Hintenlang, David E. [University of Florida, 202 Nuclear Sciences Center, P.O. Box 1183, Gainesville Florida 32611 (United States)

    2011-05-05T23:59:59.000Z

    The objective of this study was to demonstrate that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 and 46 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. The clinical dosimetry protocol developed in this study can reliably predict the AGD imparted to an individual patient during a routine screening mammogram.

  4. Occupational dose reduction at Department of Energy contractor facilities: Study of ALARA programs. Status 1990

    SciTech Connect (OSTI)

    Dionne, B.J.; Meinhold, C.B.; Khan, T.A.; Baum, J.W.

    1992-08-01T23:59:59.000Z

    This report provides the US Department of Energy (DOE) and its contractors with information that will be useful for reducing occupational radiation doses at DOE`s nuclear facilities. In 1989 and 1990, health physicists from the Brookhaven National Laboratory`s (BNL) ALARA Center visited twelve DOE contractor facilities with annual collective dose equivalents greater than 100 person-rem (100 person-cSv). The health physicists interviewed radiological safety staff, engineers, and training personnel who were responsible for dose control. The status of ALARA practices at the major contractor facilities was compared with the requirements and recommendation in DOE Order 5480.11 ``Radiation Protection for Occupational Workers`` and PNL-6577 ``Health Physics Manual of Good Practices for Reducing Radiation Exposure to Levels that are as Low as Reasonably Achievable.`` The information and data collected are described and examples of successful practices are presented. The findings on the status of the DOE Contractor ALARA Programs are summarized and evaluated. In addition, the supplement to this report contains examples of good-practice documents associated with implementing the major elements of a formally documented ALARA program for a major DOE contractor facility.

  5. Analytic equivalence of geometric transitions

    E-Print Network [OSTI]

    Michele Rossi

    2014-08-28T23:59:59.000Z

    In this paper \\emph{analytic equivalence} of geometric transition is defined in such a way that equivalence classes of geometric transitions turn out to be the \\emph{arrows} of the \\cy web. Then it seems natural and useful, both from the mathematical and physical point of view, look for privileged arrows' representatives, called \\emph{canonical models}, laying the foundations of an \\emph{analytic} classification of geometric transitions. At this purpose a numerical invariant, called \\emph{bi--degree}, summarizing the topological, geometric and physical changing properties of a geometric transition, is defined for a large class of geometric transitions.

  6. A filter for compensation of the angular dependence of LiF: Mg,Ti(TLD-100) for beta radiation

    E-Print Network [OSTI]

    Akabani Hneide, Gamal

    1987-01-01T23:59:59.000Z

    . INTRODUCTION Since the intmduction of thermoluminescent (TL) techniques in radiation dosimetry, the phosphor lithium fluorid has ieceived considerable attention. Because of its approximate tissue equivalence and useful dosimetric properties, namely, high... thermoluminescent dosimeter. For personnel dosimetry puxposes the angular and energy dependence are important factors to be considered to assess the dose under normal wearing conditions. The normal pxocedute for calibrating a TL dosimeter is by using...

  7. 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.

  8. Normal Tissue Complication Probability Modeling of Radiation-Induced Hypothyroidism After Head-and-Neck Radiation Therapy

    SciTech Connect (OSTI)

    Bakhshandeh, Mohsen [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Hashemi, Bijan, E-mail: bhashemi@modares.ac.ir [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mahdavi, Seied Rabi Mehdi [Department of Medical Physics, Faculty of Medical Sciences, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)] [Department of Medical Physics, Faculty of Medical Sciences, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Nikoofar, Alireza; Vasheghani, Maryam [Department of Radiation Oncology, Hafte-Tir Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)] [Department of Radiation Oncology, Hafte-Tir Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Kazemnejad, Anoshirvan [Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)] [Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2013-02-01T23:59:59.000Z

    Purpose: To determine the dose-response relationship of the thyroid for radiation-induced hypothyroidism in head-and-neck radiation therapy, according to 6 normal tissue complication probability models, and to find the best-fit parameters of the models. Methods and Materials: Sixty-five patients treated with primary or postoperative radiation therapy for various cancers in the head-and-neck region were prospectively evaluated. Patient serum samples (tri-iodothyronine, thyroxine, thyroid-stimulating hormone [TSH], free tri-iodothyronine, and free thyroxine) were measured before and at regular time intervals until 1 year after the completion of radiation therapy. Dose-volume histograms (DVHs) of the patients' thyroid gland were derived from their computed tomography (CT)-based treatment planning data. Hypothyroidism was defined as increased TSH (subclinical hypothyroidism) or increased TSH in combination with decreased free thyroxine and thyroxine (clinical hypothyroidism). Thyroid DVHs were converted to 2 Gy/fraction equivalent doses using the linear-quadratic formula with {alpha}/{beta} = 3 Gy. The evaluated models included the following: Lyman with the DVH reduced to the equivalent uniform dose (EUD), known as LEUD; Logit-EUD; mean dose; relative seriality; individual critical volume; and population critical volume models. The parameters of the models were obtained by fitting the patients' data using a maximum likelihood analysis method. The goodness of fit of the models was determined by the 2-sample Kolmogorov-Smirnov test. Ranking of the models was made according to Akaike's information criterion. Results: Twenty-nine patients (44.6%) experienced hypothyroidism. None of the models was rejected according to the evaluation of the goodness of fit. The mean dose model was ranked as the best model on the basis of its Akaike's information criterion value. The D{sub 50} estimated from the models was approximately 44 Gy. Conclusions: The implemented normal tissue complication probability models showed a parallel architecture for the thyroid. The mean dose model can be used as the best model to describe the dose-response relationship for hypothyroidism complication.

  9. 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.

  10. Section 3.3 Equivalence Relations1 Section 3.3 Equivalence RelationSection 3.3 Equivalence RelationSection 3.3 Equivalence RelationSection 3.3 Equivalence Relationssss

    E-Print Network [OSTI]

    Farlow, Jerry

    Section 3.3 Equivalence Relations1 Section 3.3 Equivalence RelationSection 3.3 Equivalence RelationSection 3.3 Equivalence RelationSection 3.3 Equivalence Relationssss Purpose of SectionPurpose of SectionPurpose of SectionPurpose of Section To introduce the concept of an equivalence relationequivalence

  11. 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

  12. 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.

  13. Equivalence of Learning Algorithms Julien Audiffren1

    E-Print Network [OSTI]

    Equivalence of Learning Algorithms Julien Audiffren1 and Hachem Kadri2 1 CMLA, ENS Cachan is to introduce a concept of equivalence between machine learn- ing algorithms. We define two notions of algorithmic equivalence, namely, weak and strong equivalence. These notions are of paramount importance

  14. 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...

  15. Derivation of Accident-Specific Material-at-Risk Equivalency Factors

    SciTech Connect (OSTI)

    Jason P. Andrus; Dr. Chad L. Pope

    2012-05-01T23:59:59.000Z

    A novel method for calculating material at risk (MAR) dose equivalency developed at the Idaho National Laboratory (INL) now allows for increased utilization of dose equivalency for facility MAR control. This method involves near-real time accounting for the use of accident and material specific release and transport. It utilizes all information from the committed effective dose equation and the five factor source term equation to derive dose equivalency factors which can be used to establish an overall facility or process MAR limit. The equivalency factors allow different nuclide spectrums to be compared for their respective dose consequences by relating them to a specific quantity of an identified reference nuclide. The ability to compare spectrums to a reference limit ensures that MAR limits are in fact bounding instead of attempting to establish a representative or bounding spectrum which may lead to unintended or unanalyzed configurations. This methodology is then coupled with a near real time material tracking system which allows for accurate and timely material composition information and corresponding MAR equivalency values. The development of this approach was driven by the complex nature of processing operations in some INL facilities. This type of approach is ideally suited for facilities and processes where the composition of the MAR and possible release mechanisms change frequently but in well defined fashions and in a batch-type nature.

  16. Analysis of high–dose rate brachytherapy dose distribution resemblance in CyberKnife hypofractionated treatment plans of localized prostate cancer

    SciTech Connect (OSTI)

    Sudahar, H., E-mail: h.sudahar@gmail.com [Department of Radiotherapy, Apollo Speciality Hospital, Chennai (India); Kurup, P.G.G.; Murali, V.; Mahadev, P. [Department of Radiotherapy, Apollo Speciality Hospital, Chennai (India); Velmurugan, J. [Department of Medical Physics, Anna University, Chennai (India)

    2013-01-01T23:59:59.000Z

    The present study is to analyze the CyberKnife hypofractionated dose distribution of localized prostate cancer in terms of high–dose rate (HDR) brachytherapy equivalent doses to assess the degree of HDR brachytherapy resemblance of CyberKnife dose distribution. Thirteen randomly selected localized prostate cancer cases treated using CyberKnife with a dose regimen of 36.25 Gy in 5 fractions were considered. HDR equivalent doses were calculated for 30 Gy in 3 fractions of HDR brachytherapy regimen. The D{sub 5%} of the target in the CyberKnife hypofractionation was 41.57 ± 2.41 Gy. The corresponding HDR fractionation (3 fractions) equivalent dose was 32.81 ± 1.86 Gy. The mean HDR fractionation equivalent dose, D{sub 98%}, was 27.93 ± 0.84 Gy. The V{sub 100%} of the prostate target was 95.57% ± 3.47%. The V{sub 100%} of the bladder and the rectum were 717.16 and 79.6 mm{sup 3}, respectively. Analysis of the HDR equivalent dose of CyberKnife dose distribution indicates a comparable resemblance to HDR dose distribution in the peripheral target doses (D{sub 98%} to D{sub 80%}) reported in the literature. However, there is a substantial difference observed in the core high-dose regions especially in D{sub 10%} and D{sub 5%}. The dose fall-off within the OAR is also superior in reported HDR dose distribution than the HDR equivalent doses of CyberKnife.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. EQUIVARIANT FLOW EQUIVALENCE FOR SHIFTS OF FINITE TYPE, BY MATRIX EQUIVALENCE OVER

    E-Print Network [OSTI]

    Boyle, Mike

    EQUIVARIANT FLOW EQUIVALENCE FOR SHIFTS OF FINITE TYPE, BY MATRIX EQUIVALENCE OVER GROUP RINGS MIKE equivalence of nontrivial irreducible shifts of finite type in terms of (i) elementary equivalence of matrices. In the case G = Z/2, we have the classification for twistwise flow equivalence. We include some algebraic

  3. EQUIVARIANT FLOW EQUIVALENCE FOR SHIFTS OF FINITE TYPE, BY MATRIX EQUIVALENCE OVER

    E-Print Network [OSTI]

    Sullivan, Michael

    EQUIVARIANT FLOW EQUIVALENCE FOR SHIFTS OF FINITE TYPE, BY MATRIX EQUIVALENCE OVER GROUP RINGS MIKE equivalence of nontrivial irreducible shifts of #12;nite type in terms of (i) elementary equivalence vertex. In the case G = Z=2, we have the classi#12;cation for twistwise ow equivalence. We include some

  4. 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.

  5. 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.

  6. Dose reduction at nuclear power plants

    SciTech Connect (OSTI)

    Baum, J.W.; Dionne, B.J.

    1983-01-01T23:59:59.000Z

    The collective dose equivalent at nuclear power plants increased from 1250 rem in 1969 to nearly 54,000 rem in 1980. This rise is attributable primarily to an increase in nuclear generated power from 1289 MW-y to 29,155 MW-y; and secondly, to increased average plant age. However, considerable variation in exposure occurs from plant to plant depending on plant type, refueling, maintenance, etc. In order to understand the factors influencing these differences, an investigation was initiated to study dose-reduction techniques and effectiveness of as low as reasonably achievable (ALARA) planning at light water plants. Objectives are to: identify high-dose maintenance tasks and related dose-reduction techniques; investigate utilization of high-reliability, low-maintenance equipment; recommend improved radioactive waste handling equipment and procedures; examine incentives for dose reduction; and compile an ALARA handbook.

  7. Whole Brain Irradiation With Hippocampal Sparing and Dose Escalation on Multiple Brain Metastases: A Planning Study on Treatment Concepts

    SciTech Connect (OSTI)

    Prokic, Vesna, E-mail: vesna.prokic@uniklinik-freiburg.de [Department of Radiation Oncology, University Medical Center Freiburg, Freiburg (Germany)] [Department of Radiation Oncology, University Medical Center Freiburg, Freiburg (Germany); Wiedenmann, Nicole; Fels, Franziska; Schmucker, Marianne [Department of Radiation Oncology, University Medical Center Freiburg, Freiburg (Germany)] [Department of Radiation Oncology, University Medical Center Freiburg, Freiburg (Germany); Nieder, Carsten [Department of Oncology and Palliative Medicine, Nordland Hospital, Bodo (Norway) [Department of Oncology and Palliative Medicine, Nordland Hospital, Bodo (Norway); Institute of Clinical Medicine, Faculty of Health Sciences, University of Tromso, Tromso (Norway); Grosu, Anca-Ligia [Department of Radiation Oncology, University Medical Center Freiburg, Freiburg (Germany)] [Department of Radiation Oncology, University Medical Center Freiburg, Freiburg (Germany)

    2013-01-01T23:59:59.000Z

    Purpose: To develop a new treatment planning strategy in patients with multiple brain metastases. The goal was to perform whole brain irradiation (WBI) with hippocampal sparing and dose escalation on multiple brain metastases. Two treatment concepts were investigated: simultaneously integrated boost (SIB) and WBI followed by stereotactic fractionated radiation therapy sequential concept (SC). Methods and Materials: Treatment plans for both concepts were calculated for 10 patients with 2-8 brain metastases using volumetric modulated arc therapy. In the SIB concept, the prescribed dose was 30 Gy in 12 fractions to the whole brain and 51 Gy in 12 fractions to individual brain metastases. In the SC concept, the prescription was 30 Gy in 12 fractions to the whole brain followed by 18 Gy in 2 fractions to brain metastases. All plans were optimized for dose coverage of whole brain and lesions, simultaneously minimizing dose to the hippocampus. The treatment plans were evaluated on target coverage, homogeneity, and minimal dose to the hippocampus and organs at risk. Results: The SIB concept enabled more successful sparing of the hippocampus; the mean dose to the hippocampus was 7.55 {+-} 0.62 Gy and 6.29 {+-} 0.62 Gy, respectively, when 5-mm and 10-mm avoidance regions around the hippocampus were used, normalized to 2-Gy fractions. In the SC concept, the mean dose to hippocampus was 9.8 {+-} 1.75 Gy. The mean dose to the whole brain (excluding metastases) was 33.2 {+-} 0.7 Gy and 32.7 {+-} 0.96 Gy, respectively, in the SIB concept, for 5-mm and 10-mm hippocampus avoidance regions, and 37.23 {+-} 1.42 Gy in SC. Conclusions: Both concepts, SIB and SC, were able to achieve adequate whole brain coverage and radiosurgery-equivalent dose distributions to individual brain metastases. The SIB technique achieved better sparing of the hippocampus, especially when a10-mm hippocampal avoidance region was used.

  8. 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.

  9. Optimization Online - Equivalence of Convex Problem Geometry ...

    E-Print Network [OSTI]

    Robert Freund

    2009-02-07T23:59:59.000Z

    Feb 7, 2009 ... Equivalence of Convex Problem Geometry and Computational Complexity in the Separation Oracle Model. Robert Freund (rfreund ***at*** ...

  10. Snow water equivalent estimation using blackbox optimization

    E-Print Network [OSTI]

    Alarie et al.

    2011-02-23T23:59:59.000Z

    Feb 23, 2011 ... Abstract: Accurate measurements of snow water equivalent (SWE) is an ... managing water resources for hydroelectric power generation.

  11. 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.

  12. EQUIVALENCE RELATIONS ON ALGEBRAIC CYCLES UWE JANNSEN

    E-Print Network [OSTI]

    EQUIVALENCE RELATIONS ON ALGEBRAIC CYCLES UWE JANNSEN Mathematisches Institut Universit¨at zu K, and it is common to study the groups of algebraic cycles via so­called adequate equivalence relations. For example, the basic Chow groups are defined by considering cycles modulo rational equivalence. Rational, algebraic

  13. Characterizing Contextual Equivalence in Calculi with Passivation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Characterizing Contextual Equivalence in Calculi with Passivation Sergue¨i Lengleta , Alan Schmittb We study the problem of characterizing contextual equivalence in higher-order languages of contextual equivalence in the HOP calculus, an extension of the higher-order -calculus with passivation

  14. ACQUIRED EQUIVALENCE CHANGES STIMULUS REPRESENTATIONS , D. SHOHAMY

    E-Print Network [OSTI]

    Shohamy, Daphna

    ACQUIRED EQUIVALENCE CHANGES STIMULUS REPRESENTATIONS M. MEETER 1 , D. SHOHAMY 2 , AND C.E. MYERS 3 UNIVERSITY 3 DEPT. OF PSYCHOLOGY, RUTGERS UNIVERSITY Acquired equivalence is a paradigm in which of feature salience. A different way of conceptualizing acquired equivalence is in terms of strategic

  15. Operational Equivalence of Graph Transformation Systems

    E-Print Network [OSTI]

    Sarna-Starosta, Beata

    Operational Equivalence of Graph Transformation Systems Frank Raiser and Thom Fr¨uhwirth Faculty. With the growing number of GTS- based applications the comparison of operational equivalence of two GTS becomes an important area of research. This work introduces a notion of operational equivalence for graph

  16. Categorical Equivalence of Varieties and Invariant Relations

    E-Print Network [OSTI]

    Jipsen, Peter

    Categorical Equivalence of Varieties and Invariant Relations K. Denecke and O. Lders August 21. In applications the weaker concept of an equivalence between categories is used more often than the concept is equivalent with the category of all vector spaces which are dual to the vector spaces from C. For two

  17. 8 Equivalence Relations 8.1 Relations

    E-Print Network [OSTI]

    Gera, Ralucca

    8 Equivalence Relations 8.1 Relations 1. for sets A and B we define a relation from A to B have that if (a, b) R and (b, c) R then (a, c) R 8.3 Equivalence Relations 1. a relation is an equivalence relation if it is reflexive, symmetric and transitive 2. if a relation R on a set

  18. Equivalence of Julesz Ensembles and Frame Models

    E-Print Network [OSTI]

    Ying Nian Wu; Song Chun Zhu; Xiu Wen Liu

    2011-01-01T23:59:59.000Z

    o f , A . 1979. " T h e equivalence of ensembles a n d G i bEquivalence of Julesz Ensembles and F R A M E Models Y i n gr i n c i p l e of equivalence of ensembles i n statistical

  19. Orbit equivalence for Cantor minimal Zd

    E-Print Network [OSTI]

    Putnam, Ian F.

    Orbit equivalence for Cantor minimal Zd -systems Thierry Giordano Department of Mathematics on the Cantor set is (topologically) orbit equivalent to an AF relation. As a consequence, this extends the classification up to orbit equivalence of minimal dynamical systems on the Cantor set to include AF relations

  20. 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.

  1. 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...

  2. 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.

  3. An analytical method to calculate equivalent fields to irregular symmetric and asymmetric photon fields

    SciTech Connect (OSTI)

    Tahmasebi Birgani, Mohamad J. [Department of Radiation Therapy, Golestan Hospital, JondiShapour University of Medical Science, Ahvaz (Iran, Islamic Republic of); Department of Medical Physics, JondiShapour University of Medical Sciences, Ahvaz (Iran, Islamic Republic of); Chegeni, Nahid, E-mail: nchegen@yahoo.com [Department of Medical Physics, JondiShapour University of Medical Sciences, Ahvaz (Iran, Islamic Republic of); Zabihzadeh, Mansoor; Hamzian, Nima [Department of Medical Physics, JondiShapour University of Medical Sciences, Ahvaz (Iran, Islamic Republic of)

    2014-04-01T23:59:59.000Z

    Equivalent field is frequently used for central axis depth-dose calculations of rectangular- and irregular-shaped photon beams. As most of the proposed models to calculate the equivalent square field are dosimetry based, a simple physical-based method to calculate the equivalent square field size was used as the basis of this study. The table of the sides of the equivalent square or rectangular fields was constructed and then compared with the well-known tables by BJR and Venselaar, et al. with the average relative error percentage of 2.5 ± 2.5% and 1.5 ± 1.5%, respectively. To evaluate the accuracy of this method, the percentage depth doses (PDDs) were measured for some special irregular symmetric and asymmetric treatment fields and their equivalent squares for Siemens Primus Plus linear accelerator for both energies, 6 and 18 MV. The mean relative differences of PDDs measurement for these fields and their equivalent square was approximately 1% or less. As a result, this method can be employed to calculate equivalent field not only for rectangular fields but also for any irregular symmetric or asymmetric field.

  4. 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/

  5. Radiation levels in the SSC interaction regions

    SciTech Connect (OSTI)

    Groom, D.E. [ed.

    1988-06-10T23:59:59.000Z

    The radiation environment in a typical SSC detector has been evaluated using the best available particle production models coupled with Monte Carlo simulations of hadronic and electromagnetic cascades. The problems studied include direct charged particle dose, dose inside a calorimeter from the cascades produced by incident photons and hadrons, the flux of neutrons and photons backscattered from the calorimeter into a central cavity, and neutron flux in the calorimeter. The luminosity lifetime at the SSC is dominated by collision losses in the interaction regions, where the luminosity is equivalent to losing an entire full-energy proton beam into the apparatus every six days. The result of an average p-p collision can be described quite simply. The mean charged multiplicity is about 110, and the particles are distributed nearly uniformly in pseudorapidity ({eta}) over all the angles of interest. The transverse momentum distribution is independent of angle, and for our purposes may be written as p{perpendicular}exp(-p{perpendicular}/{beta}). The mean value of p{perpendicular} may be as high as 0.6 GeV/c. Most of the radiation is produced by the very abundant low-p{perpendicular} particles. The dose or neutron fluence produced by individual particles in this energy region are simulated over a wide variety of conditions, and several measurements serve to confirm the simulation results. In general, the response (a dose, fluence, the number of backscattered neutrons, etc.) for an incident particle of momentum p can be parameterized in the form Np{sup {alpha}}, where 0.5 < {alpha}< 1.0. The authors believe most of their results to be accurate to within a factor of two or three, sufficiently precise to serve as the basis for detailed designs.

  6. 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

  7. 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

  8. The Non-Equivalence of Empirically Equivalent Theories: The Case of Hidden Variables in

    E-Print Network [OSTI]

    Chopra, Samir

    The Non-Equivalence of Empirically Equivalent Theories: The Case of Hidden Variables in Quantum 43rd Street New York, NY 10036 schopra@broadway.gc.cuny.edu September 28, 2000 1 #12; The Non-Equivalence of Empirically Equivalent Theories: The Case of Hidden Variables in Quantum Mechanics 1 Introduction The problem

  9. Dosimetric Analysis of Radiation-induced Gastric Bleeding

    SciTech Connect (OSTI)

    Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Normolle, Daniel [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States)] [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Pan, Charlie C. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Amarnath, Sudha [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Ensminger, William D. [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Lawrence, Theodore S.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)

    2012-09-01T23:59:59.000Z

    Purpose: Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy. Methods and Materials: The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of {>=}grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models. Results: Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n=0.10 and m=0.21 and with TD{sub 50} (normal) = 56 Gy and TD{sub 50} (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD{sub 50} value for the cirrhosis patients points out their greater sensitivity. Conclusions: This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation.

  10. Evaluation of the accuracy of 3DVH software estimates of dose to virtual ion chamber and film in composite IMRT QA

    SciTech Connect (OSTI)

    Olch, Arthur J. [University of Southern California Keck School of Medicine and Children's Hospital Los Angeles, Radiation Oncology Program, Los Angeles, California 90027 (United States)

    2012-01-15T23:59:59.000Z

    Purpose: A novel patient-specific intensity modulated radiation therapy (IMRT) QA system, 3DVH software and mapcheck 2, purports to be able to use diode array-measured beam doses and the patient's DICOM RT plan, structure set, and dose files to predict the delivered 3D dose distribution in the patient for comparison to the treatment planning system (TPS) calculated doses. In this study, the composite dose to an ion chamber and film in phantom predicted by the 3DVH and mapcheck 2 system is compared to the actual measured chamber and film doses. If validated in this context, then 3DVH can be used to perform an equivalent dose analysis as that obtained with film dosimetry and ion chamber-based composite IMRT QA. This is important for those losing their ability to perform film dosimetry for true composite IMRT QA and provides a measure of confidence in the accuracy of 3DVH 3D dose calculations which may replace phantom-based IMRT QA. Methods: The dosimetric results from 15 consecutive patient-specific IMRT QA tests performed by composite field irradiation of ion chamber and EDR2 film in a solid water phantom were compared to the predicted doses for those virtual detectors based on the calculated 3D dose by the 3DVH software using mapcheck 2 measured doses of each beam within each plan. For each of the 15 cases, immediately after performing the ion chamber plus film measurements, the mapcheck 2 was used to measure the dose for each beam of the plan. The dose to the volume of the virtual ion chamber and the dose distribution in the plane of the virtual film calculated by the 3DVH software was extracted. The ratio of the measured to 3DVH or eclipse-predicted ion chamber doses was calculated. The same plane in the phantom measured using film and calculated with eclipse was exported from 3DVH and the 2D gamma metric was used to compare the relationship between the film doses and the eclipse or 3DVH predicted planar doses. Also, the 3D gamma value was calculated in the 3DVH software which compares the eclipse dose to the 3DVH predicted dose distribution. For the 2D and 3D gamma metrics, 2% dose and 2 mm distance to agreement (DTA) were used. In addition, a simple dose difference was performed using either a 2% or 3% dose difference tolerance. Results: The mean ratio {+-} standard deviation of the measured vs 3DVH or vs eclipse-predicted dose to the ion chamber was 1.013 {+-} 0.015 and 1.003 {+-} 0.012, respectively. For 3DVH vs eclipse, the mean percentage of pixels failing the 3D gamma metric was 1.2% {+-} 1.4% while the failure rate for the 2D gamma metric was 1.1% {+-} 0.9%. When either 3DVH or eclipse was compared to EDR2 film, the gamma failure rate was 2.3% {+-} 2.0% and 1.6% {+-} 1.7%, respectively. Mean dose difference failures were 9%-27% {+-} 5%-15% for 2 or 3% dose difference tolerances, depending on the combination of systems tested. No statistically significant differences were found for any of the planar dosimetric comparisons. Conclusions: 3DVH + mapcheck 2 predicts the same absolute dose, the percent of pixels failing the gamma metric, and the percent of pixels failing 2% or 3% dose difference tolerance tests as one would have obtained had one made measurements in solid water phantom using an ion chamber and coronal film instead of a diode array. This is also a necessary although not sufficient condition for validation of the accuracy of 3DVH predictions of the 3D dose using beam-by-beam measurements.

  11. 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

  12. 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.

  13. Impact of dose size in single fraction spatially fractionated (grid) radiotherapy for melanoma

    SciTech Connect (OSTI)

    Zhang, Hualin, E-mail: hualin.zhang@northwestern.edu, E-mail: hualinzhang@yahoo.com [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)] [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611 and Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States); Zhong, Hualiang [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan 48202 (United States)] [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan 48202 (United States); Barth, Rolf F. [Department of Pathology, The Ohio State University, Columbus, Ohio 43210 (United States)] [Department of Pathology, The Ohio State University, Columbus, Ohio 43210 (United States); Cao, Minsong; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)] [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States)

    2014-02-15T23:59:59.000Z

    Purpose: To evaluate the impact of dose size in single fraction, spatially fractionated (grid) radiotherapy for selectively killing infiltrated melanoma cancer cells of different tumor sizes, using different radiobiological models. Methods: A Monte Carlo technique was employed to calculate the 3D dose distribution of a commercially available megavoltage grid collimator in a 6 MV beam. The linear-quadratic (LQ) and modified linear quadratic (MLQ) models were used separately to evaluate the therapeutic outcome of a series of single fraction regimens that employed grid therapy to treat both acute and late responding melanomas of varying sizes. The dose prescription point was at the center of the tumor volume. Dose sizes ranging from 1 to 30 Gy at 100% dose line were modeled. Tumors were either touching the skin surface or having their centers at a depth of 3 cm. The equivalent uniform dose (EUD) to the melanoma cells and the therapeutic ratio (TR) were defined by comparing grid therapy with the traditional open debulking field. The clinical outcomes from recent reports were used to verify the authors’ model. Results: Dose profiles at different depths and 3D dose distributions in a series of 3D melanomas treated with grid therapy were obtained. The EUDs and TRs for all sizes of 3D tumors involved at different doses were derived through the LQ and MLQ models, and a practical equation was derived. The EUD was only one fifth of the prescribed dose. The TR was dependent on the prescribed dose and on the LQ parameters of both the interspersed cancer and normal tissue cells. The results from the LQ model were consistent with those of the MLQ model. At 20 Gy, the EUD and TR by the LQ model were 2.8% higher and 1% lower than by the MLQ, while at 10 Gy, the EUD and TR as defined by the LQ model were only 1.4% higher and 0.8% lower, respectively. The dose volume histograms of grid therapy for a 10 cm tumor showed different dosimetric characteristics from those of conventional radiotherapy. A significant portion of the tumor volume received a very large dose in grid therapy, which ensures significant tumor cell killing in these regions. Conversely, some areas received a relatively small dose, thereby sparing interspersed normal cells and increasing radiation tolerance. The radiobiology modeling results indicated that grid therapy could be useful for treating acutely responding melanomas infiltrating radiosensitive normal tissues. The theoretical model predictions were supported by the clinical outcomes. Conclusions: Grid therapy functions by selectively killing infiltrating tumor cells and concomitantly sparing interspersed normal cells. The TR depends on the radiosensitivity of the cell population, dose, tumor size, and location. Because the volumes of very high dose regions are small, the LQ model can be used safely to predict the clinical outcomes of grid therapy. When treating melanomas with a dose of 15 Gy or higher, single fraction grid therapy is clearly advantageous for sparing interspersed normal cells. The existence of a threshold fraction dose, which was found in the authors’ theoretical simulations, was confirmed by clinical observations.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Limits of Equivalence: Thinking Gay Male Subjectivity Outside Feminist Theory

    E-Print Network [OSTI]

    Galloway, Samuel R.

    2010-01-01T23:59:59.000Z

    Limits of Equivalence: Thinking Gay Male Subjectivityor this limit of equivalence? The problem, of course, ispaper, the limits of equivalence emerge: while all subjects

  2. 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.

  3. About Orientifold Planar Equivalence on the Lattice

    E-Print Network [OSTI]

    Agostino Patella

    2006-10-04T23:59:59.000Z

    The orientifold planar equivalence is the equivalence in the large-N limit of the bosonic sectors of the super Yang-Mills and the QCD with a quark in the antisymmetric representation. I give a sketch of the proof of the orientifold planar equivalence in the strong-coupling and large-mass phase on the lattice. It is still matter of discussion, if its validity extends also in the continuum limit.

  4. Optimization Online - Equivalence of an Approximate Linear ...

    E-Print Network [OSTI]

    Alejandro Toriello

    2013-02-07T23:59:59.000Z

    Feb 7, 2013 ... Equivalence of an Approximate Linear Programming Bound with the Held-Karp Bound for the Traveling Salesman Problem. Alejandro Toriello ...

  5. Optimization Online - On Equivalence of Semidefinite Relaxations ...

    E-Print Network [OSTI]

    Yichuan Ding

    2010-04-28T23:59:59.000Z

    Apr 28, 2010 ... On Equivalence of Semidefinite Relaxations for Quadratic Matrix Programming. Yichuan Ding(y7ding ***at*** stanford.edu) Dongdong ...

  6. Energy Conservation Project Evaluation by Investment Equivalents

    E-Print Network [OSTI]

    Larson, R. J.

    1984-01-01T23:59:59.000Z

    proposals, justify energy conservation projects, and choose between energy sensitive alternatives. Investment Equivalents are calculated and are used to evaluate energy savings proposals in sample problems....

  7. Snow water equivalent estimation using blackbox optimization

    E-Print Network [OSTI]

    Stéphane Alarie

    2011-03-07T23:59:59.000Z

    Mar 7, 2011 ... Abstract: Accurate measurements of snow water equivalent (SWE) is an important factor in managing water resources for hydroelectric power ...

  8. Equivalence of Convex Problem Geometry and Computational ...

    E-Print Network [OSTI]

    2009-01-19T23:59:59.000Z

    Equivalence of Convex Problem Geometry and Computational Complexity in the Separation Oracle Model?. Robert M. Freund†and Jorge Vera‡. January 2009.

  9. Probabilities of Radiation Myelopathy Specific to Stereotactic Body Radiation Therapy to Guide Safe Practice

    SciTech Connect (OSTI)

    Sahgal, Arjun, E-mail: arjun.sahgal@rmp.uhn.on.ca [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, ON (Canada) [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, ON (Canada); Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Weinberg, Vivian [University of California San Francisco Helen Diller Family Comprehensive Cancer Center Biostatistics Core, San Francisco, California (United States)] [University of California San Francisco Helen Diller Family Comprehensive Cancer Center Biostatistics Core, San Francisco, California (United States); Ma, Lijun [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California (United States)] [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California (United States); Chang, Eric [Department of Radiation Oncology, University of Southern California and University of Texas MD Anderson Cancer Center, University of Texas, Houston, Texas (United States)] [Department of Radiation Oncology, University of Southern California and University of Texas MD Anderson Cancer Center, University of Texas, Houston, Texas (United States); Chao, Sam [Department of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States); Muacevic, Alexander [European Cyberknife Center Munich in affiliation with University Hospitals of Munich, Munich (Germany)] [European Cyberknife Center Munich in affiliation with University Hospitals of Munich, Munich (Germany); Gorgulho, Alessandra [Department of Neurosurgery, University of California at Los Angeles, Los Angeles, California (United States)] [Department of Neurosurgery, University of California at Los Angeles, Los Angeles, California (United States); Soltys, Scott [Department of Radiation Oncology, Stanford University, Stanford, California (United States)] [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Gerszten, Peter C. [Departments of Neurological Surgery and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States)] [Departments of Neurological Surgery and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Ryu, Sam [Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan (United States)] [Department of Radiation Oncology, Henry Ford Hospital, Detroit, Michigan (United States); Angelov, Lilyana [Department of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States)] [Department of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States); Gibbs, Iris [Department of Radiation Oncology, Stanford University, Stanford, California (United States)] [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada)] [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON (Canada); Larson, David A. [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California (United States)] [Department of Radiation Oncology, University of California at San Francisco, San Francisco, California (United States)

    2013-02-01T23:59:59.000Z

    Purpose: Dose-volume histogram (DVH) results for 9 cases of post spine stereotactic body radiation therapy (SBRT) radiation myelopathy (RM) are reported and compared with a cohort of 66 spine SBRT patients without RM. Methods and Materials: DVH data were centrally analyzed according to the thecal sac point maximum (Pmax) volume, 0.1- to 1-cc volumes in increments of 0.1 cc, and to the 2 cc volume. 2-Gy biologically equivalent doses (nBED) were calculated using an {alpha}/{beta} = 2 Gy (units = Gy{sub 2/2}). For the 2 cohorts, the nBED means and distributions were compared using the t test and Mann-Whitney test, respectively. Significance (P<.05) was defined as concordance of both tests at each specified volume. A logistic regression model was developed to estimate the probability of RM using the dose distribution for a given volume. Results: Significant differences in both the means and distributions at the Pmax and up to the 0.8-cc volume were observed. Concordant significance was greatest for the Pmax volume. At the Pmax volume the fit of the logistic regression model, summarized by the area under the curve, was 0.87. A risk of RM of 5% or less was observed when limiting the thecal sac Pmax volume doses to 12.4 Gy in a single fraction, 17.0 Gy in 2 fractions, 20.3 Gy in 3 fractions, 23.0 Gy in 4 fractions, and 25.3 Gy in 5 fractions. Conclusion: We report the first logistic regression model yielding estimates for the probability of human RM specific to SBRT.

  10. 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.

  11. 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.

  12. Guessing Attacks and the Computational Soundness of Static Equivalence

    E-Print Network [OSTI]

    Warinschi, Bogdan

    Guessing Attacks and the Computational Soundness of Static Equivalence Martin Abadi1 , Mathieu static equivalence. Static equivalence depends on an underlying equa- tional theory. The choice, fundamental cryp- tographic operations. This equational theory yields a notion of static equivalence

  13. Borel equivalence relations which are highly unfree Greg Hjorth

    E-Print Network [OSTI]

    Hjorth, Greg

    * Borel equivalence relations Abstract There is an ergodic, measure preserving, countable Borel equivalence rel* *ation E equivalence relati* *ons may be reduced to Borel equivalence relations arising from a free group action

  14. 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.

  15. The Equivalence of Linear Programs and Zero-Sum Games

    E-Print Network [OSTI]

    2012-01-15T23:59:59.000Z

    In 1951, Dantzig showed the equivalence of linear programming problems and ... This note concerns the equivalence between linear programming (LP) ...

  16. Remarks on statistical errors in equivalent widths

    E-Print Network [OSTI]

    Klaus Vollmann; Thomas Eversberg

    2006-07-03T23:59:59.000Z

    Equivalent width measurements for rapid line variability in atomic spectral lines are degraded by increasing error bars with shorter exposure times. We derive an expression for the error of the line equivalent width $\\sigma(W_\\lambda)$ with respect to pure photon noise statistics and provide a correction value for previous calculations.

  17. 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.

  18. THEOREM 1.1.1 The distinct equivalence classes of an equivalence ...

    E-Print Network [OSTI]

    Preliminary Notions Ch.1. THEOREM 1.1.1 The distinct equivalence classes of an equivalence relation on A provide us with a decomposition of A as a union of ...

  19. Equivalence in Ventilation and Indoor Air Quality

    SciTech Connect (OSTI)

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01T23:59:59.000Z

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  20. 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.

  1. Equivalence Relations in Set Theory, Computation Theory and Complexity Theory

    E-Print Network [OSTI]

    Equivalence Relations in Set Theory, Computation Theory and Complexity Theory Denable Equivalence-preserving transformations Unitary equivalence of unitary operators Conformal equivalence of Riemann surfaces These are analytic (1 1 with parameters) equivalence relations on Polish spaces (think of the reals) #12;Equivalence

  2. Radiation Exposure Information Reporting System (REIRS) Update, 2012

    SciTech Connect (OSTI)

    none,

    2013-01-01T23:59:59.000Z

    A series of graphs gives data through the year 2012 for annual collective doses, collective dose per reactor, number of individuals with measurable doses both in total and per reactor, number of reactors, electricity generated, measurable doses per individual and per megawatt-year, and collective outage hours. Reactors considered include BWR, PWR, and LWR. Also, the total effective dose equivalent for the period 2010-2012 is tabulated for each nuclear power plant considered, and the change over 2009-2011.

  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. 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.

  5. 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.

  6. Intensity-modulated radiation therapy (IMRT) dosimetry of the head and neck: A comparison of treatment plans using linear accelerator-based IMRT and helical tomotherapy

    SciTech Connect (OSTI)

    Sheng Ke [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)]. E-mail: ks2mc@virginia.edu; Molloy, Janelle A. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Read, Paul W. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

    2006-07-01T23:59:59.000Z

    Purpose: To date, most intensity-modulated radiation therapy (IMRT) delivery has occurred using linear accelerators (linacs), although helical tomotherapy has become commercially available. To quantify the dosimetric difference, we compared linac-based and helical tomotherapy-based treatment plans for IMRT of the oropharynx. Methods and Materials: We compared the dosimetry findings of 10 patients who had oropharyngeal carcinoma. Five patients each had cancers in the base of the tongue and tonsil. Each plan was independently optimized using either the CORVUS planning system (Nomos Corporation, Sewickly, PA), commissioned for a Varian 2300 CD linear accelerator (Varian Medical Systems, Palo Alto, CA) with 1-cm multileaf collimator leaves, or helical tomotherapy. The resulting treatment plans were evaluated by comparing the dose-volume histograms, equivalent uniform dose (EUD), dose uniformity, and normal tissue complication probabilities. Results: Helical tomotherapy plans showed improvement of critical structure avoidance and target dose uniformity for all patients. The average equivalent uniform dose reduction for organs at risk (OARs) surrounding the base of tongue and the tonsil were 17.4% and 27.14% respectively. An 80% reduction in normal tissue complication probabilities for the parotid glands was observed in the tomotherapy plans relative to the linac-based plans. The standard deviation of the planning target volume dose was reduced by 71%. In our clinic, we use the combined dose-volume histograms for each class of plans as a reference goal for helical tomotherapy treatment planning optimization. Conclusions: Helical tomotherapy provides improved dose homogeneity and normal structure dose compared with linac-based IMRT in the treatment of oropharyngeal carcinoma resulting in a reduced risk for complications from focal hotspots within the planning target volume and for the adjacent parotid glands.

  7. Bisimulations Meet PCTL Equivalences for Probabilistic Automata

    E-Print Network [OSTI]

    Song, Lei; Godskesen, Jens Chr

    2011-01-01T23:59:59.000Z

    Probabilistic automata (PA) have been successfully applied in the formal verification of concurrent and stochastic systems. Efficient model checking algorithms have been studied, where the most often used logics for expressing properties are based on PCTL and its extension PCTL*. Various behavioral equivalences are proposed for PAs, as a powerful tool for abstraction and compositional minimization for PAs. Unfortunately, the behavioral equivalences are well-known to be strictly stronger than the logical equivalences induced by PCTL or PCTL*. This paper introduces novel notions of strong bisimulation relations, which characterizes PCTL and PCTL* exactly. We also extend weak bisimulations characterizing PCTL and PCTL* without next operator, respectively. Thus, our paper bridges the gap between logical and behavioral equivalences in this setting.

  8. Equivalence semantics for concurrency: comparison and application 

    E-Print Network [OSTI]

    Galpin, Vashti C

    are described by structured operational semantics, and expressed as labelled transition systems. I first consider a hierarchy of bisimulations for extensions to CCS, using both existing and new results to describe the relationships between their equivalences...

  9. The image quality of ion computed tomography at clinical imaging dose levels

    SciTech Connect (OSTI)

    Hansen, David C., E-mail: dch@oncology.au.dk [Department of Experimental Clinical Oncology, Aarhus University Hospital, 8000 Aarhus (Denmark); Bassler, Niels [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus (Denmark); Sørensen, Thomas Sangild [Department of Computer Science, Aarhus University, 8000 Aarhus, Denmark and Department of Clinical Medicine, Aarhus University, 8000 Aarhus (Denmark); Seco, Joao [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School,Boston, Massachusetts 02114 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: Accurately predicting the range of radiotherapy ions in vivo is important for the precise delivery of dose in particle therapy. Range uncertainty is currently the single largest contribution to the dose margins used in planning and leads to a higher dose to normal tissue. The use of ion CT has been proposed as a method to improve the range uncertainty and thereby reduce dose to normal tissue of the patient. A wide variety of ions have been proposed and studied for this purpose, but no studies evaluate the image quality obtained with different ions in a consistent manner. However, imaging doses ion CT is a concern which may limit the obtainable image quality. In addition, the imaging doses reported have not been directly comparable with x-ray CT doses due to the different biological impacts of ion radiation. The purpose of this work is to develop a robust methodology for comparing the image quality of ion CT with respect to particle therapy, taking into account different reconstruction methods and ion species. Methods: A comparison of different ions and energies was made. Ion CT projections were simulated for five different scenarios: Protons at 230 and 330 MeV, helium ions at 230 MeV/u, and carbon ions at 430 MeV/u. Maps of the water equivalent stopping power were reconstructed using a weighted least squares method. The dose was evaluated via a quality factor weighted CT dose index called the CT dose equivalent index (CTDEI). Spatial resolution was measured by the modulation transfer function. This was done by a noise-robust fit to the edge spread function. Second, the image quality as a function of the number of scanning angles was evaluated for protons at 230 MeV. In the resolution study, the CTDEI was fixed to 10 mSv, similar to a typical x-ray CT scan. Finally, scans at a range of CTDEI’s were done, to evaluate dose influence on reconstruction error. Results: All ions yielded accurate stopping power estimates, none of which were statistically different from the ground truth image. Resolution (as defined by the modulation transfer function = 10% point) was the best for the helium ions (18.21 line pairs/cm) and worst for the lower energy protons (9.37 line pairs/cm). The weighted quality factor for the different ions ranged from 1.23 for helium to 2.35 for carbon ions. For the angle study, a sharp increase in absolute error was observed below 45 distinct angles, giving the impression of a threshold, rather than smooth, limit to the number of angles. Conclusions: The method presented for comparing various ion CT modalities is feasible for practical use. While all studied ions would improve upon x-ray CT for particle range estimation, helium appears to give the best results and deserves further study for imaging.

  10. 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.

  11. 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

  12. Testing Equivalence Probabilistically Adnan Darwiche and Jinbo Huang

    E-Print Network [OSTI]

    Huang, Jinbo

    Testing Equivalence Probabilistically Adnan Darwiche and Jinbo Huang Computer Science Department the equivalence of two Ordered Binary Decision Diagrams (OBDDs) can be decided in polynomial time, the equivalence the interest in testing their equivalence. We show that the probabilistic equivalence test for FBDDs holds

  13. Equivalence Structures and Isomorphisms in the Difference Hierarchy

    E-Print Network [OSTI]

    Cenzer, Douglas

    Equivalence Structures and Isomorphisms in the Difference Hierarchy D. Cenzer, G. LaForte and J- ence hierarchy, and of equivalence structures in particular. A equivalence structure A = (A, E) has universe A = and an equivalence relation E. The equivalence class [a] of a A is {b A : a

  14. 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...

  15. 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.

  16. 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.

  17. XRD, lead equivalent and UV-VIS properties study of Ce and Pr lead silicate glasses

    SciTech Connect (OSTI)

    Alias, Nor Hayati, E-mail: norhayati@nuclearmalaysia.gov.my; Abdullah, Wan Shafie Wan, E-mail: norhayati@nuclearmalaysia.gov.my; Isa, Norriza Mohd, E-mail: norhayati@nuclearmalaysia.gov.my; Isa, Muhammad Jamal Md, E-mail: norhayati@nuclearmalaysia.gov.my; Zali, Nurazila Mat; Abdullah, Nuhaslinda Ee [Malaysian Nuclear Agency, 43000, Bangi, Kajang, Selangor (Malaysia); Muhammad, Azali [Malaysian Society for Non-Destructive Testing (Malaysia)

    2014-02-12T23:59:59.000Z

    In this work, Cerium (Ce) and Praseodymium (Pr) containing lead silicate glasses were produced with 2 different molar ratios low (0.2 wt%) and high (0.4wt%). These types of glasses can satisfy the characteristics required for radiation shielding glasses and minimize the lead composition in glass. The radiation shielding properties of the synthesized glasses is explained in the form of lead equivalent study. The XRD diffraction and UV-VIS analysis were performed to observe the structural changes of the synthesis glasses at 1.5 Gy gamma radiation exposures.

  18. S-EQUIVALENCE OF KNOTS Abstract. S-equivalence of classical knots is investigated, as well as its rela-

    E-Print Network [OSTI]

    Kearton, Cherry

    S-EQUIVALENCE OF KNOTS C. KEARTON Abstract. S-equivalence of classical knots is investigated. Finally, we show that every knot is S-equivalent to a prime knot. 1. Introduction An oriented knot k matrices of the same knot are S-equivalent: the definition of S-equivalence is given in, for example, [14

  19. 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

  20. On the Equivalence of Constrained and Compound Optimal Designs

    E-Print Network [OSTI]

    R. Dennis Cook; Weng-Kee Wong

    2011-01-01T23:59:59.000Z

    O n the Equivalence o f C o n s t r a i n e d and C o m p owww.jstor.org On the Equivalence of Constrained and Compoundstandard methodology. Equivalence theorems for specific

  1. SOME APPLICATIONS OF SUPERRIGIDITY TO BOREL EQUIVALENCE RELATIONS

    E-Print Network [OSTI]

    Thomas, Simon

    SOME APPLICATIONS OF SUPERRIGIDITY TO BOREL EQUIVALENCE RELATIONS SIMON THOMAS Abstract.There exists a countable Borel equivalence relation E countable Borel equivalence re* *la- tions. (For example, see [2], [11], [12].) In particular, Adams [1

  2. On the equivalence of nonadiabatic fluids

    E-Print Network [OSTI]

    W. Barreto

    2010-11-17T23:59:59.000Z

    Here we show how an anisotropic fluid in the diffusion limit can be equivalent to an isotropic fluid in the streaming out limit, in spherical symmetry. For a particular equation of state this equivalence is total, from one fluid we can obtain the other and vice versa. A numerical master model is presented, based on a generic equation of state, in which only quantitative differences are displayed between both nonadiabatic fluids. From a deeper view, other difference between fluids is shown as an asymmetry that can be overcome if we consider the appropriate initial-boundary conditions. Equivalence in this context can be considered as a first order method of approximation to study dissipative fluids.

  3. 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.

  4. On Equivalence of Semidefinite Relaxations for Quadratic Matrix ...

    E-Print Network [OSTI]

    2010-04-28T23:59:59.000Z

    Apr 28, 2010 ... 2.2 Equivalence of Vector and Matrix Lifting for QMP1 .... A Schur complement argument now implies the equivalence of this relaxation to the ...

  5. 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.

  6. Cancer risk estimates from radiation therapy for heterotopic ossification prophylaxis after total hip arthroplasty

    SciTech Connect (OSTI)

    Mazonakis, Michalis; Berris, Theoharris; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, 71003 Iraklion, Crete (Greece)] [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, 71003 Iraklion, Crete (Greece); Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)] [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

    2013-10-15T23:59:59.000Z

    Purpose: Heterotopic ossification (HO) is a frequent complication following total hip arthroplasty. This study was conducted to calculate the radiation dose to organs-at-risk and estimate the probability of cancer induction from radiotherapy for HO prophylaxis.Methods: Hip irradiation for HO with a 6 MV photon beam was simulated with the aid of a Monte Carlo model. A realistic humanoid phantom representing an average adult patient was implemented in Monte Carlo environment for dosimetric calculations. The average out-of-field radiation dose to stomach, liver, lung, prostate, bladder, thyroid, breast, uterus, and ovary was calculated. The organ-equivalent-dose to colon, that was partly included within the treatment field, was also determined. Organ dose calculations were carried out using three different field sizes. The dependence of organ doses upon the block insertion into primary beam for shielding colon and prosthesis was investigated. The lifetime attributable risk for cancer development was estimated using organ, age, and gender-specific risk coefficients.Results: For a typical target dose of 7 Gy, organ doses varied from 1.0 to 741.1 mGy by the field dimensions and organ location relative to the field edge. Blocked field irradiations resulted in a dose range of 1.4–146.3 mGy. The most probable detriment from open field treatment of male patients was colon cancer with a high risk of 564.3 × 10{sup ?5} to 837.4 × 10{sup ?5} depending upon the organ dose magnitude and the patient's age. The corresponding colon cancer risk for female patients was (372.2–541.0) × 10{sup ?5}. The probability of bladder cancer development was more than 113.7 × 10{sup ?5} and 110.3 × 10{sup ?5} for males and females, respectively. The cancer risk range to other individual organs was reduced to (0.003–68.5) × 10{sup ?5}.Conclusions: The risk for cancer induction from radiation therapy for HO prophylaxis after total hip arthroplasty varies considerably by the treatment parameters, organ site in respect to treatment volume and patient's gender and age. The presented risk estimates may be useful in the follow-up studies of irradiated patients.

  7. 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.

  8. 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.

  9. An Introduction to Decidability of DPDA Equivalence

    E-Print Network [OSTI]

    Stirling, Colin

    University of Edinburgh email: cps@dcs.ed.ac.uk 1 Introduction The DPDA equivalence problem was posed in 1966 produced a different proof of decidability that is essentially a simplification of S´enizergues's proof [14, the tableau proof system uses conditional proof rules that involve distances between premises. Essentially

  10. An Introduction to Decidability of DPDA Equivalence

    E-Print Network [OSTI]

    Stirling, Colin

    University of Edinburgh email: cps@dcs.ed.ac.uk 1 Introduction The DPDA equivalence problem was posed in 1966 produced a di#erent proof of decidability that is essentially a simplification of Sâ??enizergues's proof [14, the tableau proof system uses conditional proof rules that involve distances between premises. Essentially

  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. Alpha/Beta Ratio for Normal Lung Tissue as Estimated From Lung Cancer Patients Treated With Stereotactic Body and Conventionally Fractionated Radiation Therapy

    SciTech Connect (OSTI)

    Scheenstra, Alize E.H.; Rossi, Maddalena M.G.; Belderbos, José S.A.; Damen, Eugène M.F.; Lebesque, Joos V.; Sonke, Jan-Jakob, E-mail: j.sonke@nki.nl

    2014-01-01T23:59:59.000Z

    Purpose: To estimate the ?/? ratio for which the dose-dependent lung perfusion reductions for stereotactic body radiation therapy (SBRT) and conventionally fractionated radiation therapy (CFRT) are biologically equivalent. Methods and Materials: The relations between local dose and perfusion reduction 4 months after treatment in lung cancer patients treated with SBRT and CFRT were scaled according to the linear-quadratic model using ?/? ratios from 0 Gy to ? Gy. To test for which ?/? ratio both treatments have equal biological effect, a 5-parameter logistic model was optimized for both dose–effect relationships simultaneously. Beside the ?/? ratio, the other 4 parameters were d{sub 50}, the steepness parameter k, and 2 parameters (M{sub SBRT} and M{sub CFRT}) representing the maximal perfusion reduction at high doses for SBRT and CFRT, respectively. Results: The optimal fitted model resulted in an ?/? ratio of 1.3 Gy (0.5-2.1 Gy), M{sub SBRT} = 42.6% (40.4%-44.9%), M{sub CFRT} = 66.9% (61.6%-72.1%), d{sub 50} = 35.4 Gy (31.5-9.2 Gy), and k = 2.0 (1.7-2.3). Conclusions: An equal reduction of lung perfusion in lung cancer was observed in SBRT and CFRT if local doses were converted by the linear-quadratic model with an ?/? ratio equal to 1.3 Gy (0.5-2.1 Gy)

  13. 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

  14. Anticipated Radiological Dose to Worker for Plutonium Stabilization and Handling at PFP Project W-460

    SciTech Connect (OSTI)

    WEISS, E.V.

    2000-03-06T23:59:59.000Z

    This report provides estimates of the expected whole body and extremity radiological dose, expressed as dose equivalent (DE), to workers conducting planned plutonium (Pu) stabilization processes at the Hanford Site Plutonium Finishing Plant (PFP). The report is based on a time and motion dose study commissioned for Project W-460, Plutonium Stabilization and Handling, to provide personnel exposure estimates for construction work in the PFP storage vault area plus operation of stabilization and packaging equipment at PFP.

  15. Anticipated Radiological Dose to Worker for Plutonium Stabilization and Handling at PFP - Project W-460

    E-Print Network [OSTI]

    Weiss, E V

    2000-01-01T23:59:59.000Z

    This report provides estimates of the expected whole body and extremity radiological dose, expressed as dose equivalent (DE), to workers conducting planned plutonium (Pu) stabilization processes at the Hanford Site Plutonium Finishing Plant (PFP). The report is based on a time and motion dose study commissioned for Project W-460, Plutonium Stabilization and Handling, to provide personnel exposure estimates for construction work in the PFP storage vault area plus operation of stabilization and packaging equipment at PFP.

  16. An Equivalence Between Sparse Approximation and Support Vector Machines 1

    E-Print Network [OSTI]

    Poggio, Tomaso

    An Equivalence Between Sparse Approximation and Support Vector Machines 1 Federico Girosi Center is equivalent to SVM in the following sense: if applied to the same data set the two techniques give the same; Chen, Donoho and Saunders, 1995), are actually equivalent, in the case of noiseless data. By equivalent

  17. Guessing Attacks and the Computational Soundness of Static Equivalence

    E-Print Network [OSTI]

    Abadi, Martín

    Guessing Attacks and the Computational Soundness of Static Equivalence Mart´in Abadi1 , Mathieu static equivalence. Static equivalence depends on an underlying equa- tional theory. The choice, fundamental cryp- tographic operations. This equational theory yields a notion of static equivalence

  18. A Stronger Notion of Equivalence for Logic Programs

    E-Print Network [OSTI]

    New South Wales, University of

    A Stronger Notion of Equivalence for Logic Programs Ka-Shu Wong University of New South Wales Sydney 2052, Australia #12;Abstract Several different notions of equivalence have been proposed for logic programs with answer set semantics, most notably strong equivalence. However, strong equivalence

  19. EQUIVALENCE RELATIONS FOR TWO VARIABLE REAL ANALYTIC FUNCTION GERMS

    E-Print Network [OSTI]

    EQUIVALENCE RELATIONS FOR TWO VARIABLE REAL ANALYTIC FUNCTION GERMS SATOSHI KOIKE & ADAM PARUSI´NSKI Abstract. For two variable real analytic function germs we compare the blow- analytic equivalence in the sense of Kuo to the other natural equivalence relations. Our main theorem states that C1 equivalent

  20. THIN EQUIVALENCE RELATIONS AND INNER MODELS PHILIPP SCHLICHT

    E-Print Network [OSTI]

    Schlicht, Philipp

    THIN EQUIVALENCE RELATIONS AND INNER MODELS PHILIPP SCHLICHT Abstract. We describe the inner models with representatives in all equiv- alence classes of thin equivalence relations in a given projective pointclass does not add equivalence classes to thin projective equivalence relations. For example, we show

  1. CCZ and EA Equivalence between Mappings over Finite Abelian Groups

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    CCZ and EA Equivalence between Mappings over Finite Abelian Groups Alexander Pott1 and Yue Zhou1, 410073 Changsha, P.R.China alexander.pott@ovgu.de,yue.zhou@st.ovgu.de Abstract. CCZ- and EA-equivalence abelian groups G and H. We obtain an extension theorem for CCZ- equivalent but not EA-equivalent mappings

  2. COUNTABLE ABELIAN GROUP ACTIONS AND HYPERFINITE EQUIVALENCE RELATIONS

    E-Print Network [OSTI]

    Gao, Su

    COUNTABLE ABELIAN GROUP ACTIONS AND HYPERFINITE EQUIVALENCE RELATIONS SU GAO AND STEVE JACKSON Abstract. An equivalence relation E on a standard Borel space is hyperfinite if E is the increasing union of countably many Borel equivalence relations En where all En-equivalence classs are finite. In this article we

  3. Equivalency-processing parallel photonic integrated circuit EP3

    E-Print Network [OSTI]

    Louri, Ahmed

    Equivalency-processing parallel photonic integrated circuit EP3 IC : equivalence search module present an optoelectronic module called the equivalency-processing parallel photonic integrated circuit EP3 IC that is created specifically to implement high-speed parallel equivalence searches i

  4. 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

  5. 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

  6. Strong Equivalence of Qualitative Optimization Problems

    E-Print Network [OSTI]

    Faber, Wolfgang; Woltran, Stefan

    2011-01-01T23:59:59.000Z

    We introduce the framework of qualitative optimization problems (or, simply, optimization problems) to represent preference theories. The formalism uses separate modules to describe the space of outcomes to be compared (the generator) and the preferences on outcomes (the selector). We consider two types of optimization problems. They differ in the way the generator, which we model by a propositional theory, is interpreted: by the standard propositional logic semantics, and by the equilibrium-model (answer-set) semantics. Under the latter interpretation of generators, optimization problems directly generalize answer-set optimization programs proposed previously. We study strong equivalence of optimization problems, which guarantees their interchangeability within any larger context. We characterize several versions of strong equivalence obtained by restricting the class of optimization problems that can be used as extensions and establish the complexity of associated reasoning tasks. Understanding strong equiv...

  7. Orientifold Planar Equivalence: The Quenched Meson Spectrum

    E-Print Network [OSTI]

    Biagio Lucini; Gregory Moraitis; Agostino Patella; Antonio Rago

    2010-10-28T23:59:59.000Z

    A numerical study of Orientifold Planar Equivalence is performed in SU(N) Yang-Mills theories for N=2,3,4,6. Quenched meson masses are extracted in the antisymmetric, symmetric and adjoint representations for the pseudoscalar and vector channels. An extrapolation of the vector mass as a function of the pseudoscalar mass to the large-N limit shows that the numerical results agree within errors for the three theories, as predicted by Orientifold Planar Equivalence. As a byproduct of the extrapolation, the size of the corrections up to O(1/N^3) are evaluated. A crucial prerequisite for the extrapolation is the determination of an analytical relationship between the corrections in the symmetric and in the antisymmetric representations, order by order in a 1/N expansion.

  8. Equivalence principle in scalar-tensor gravity

    E-Print Network [OSTI]

    Dirk Puetzfeld; Yuri N. Obukhov

    2015-05-06T23:59:59.000Z

    We present a direct confirmation of the validity of the equivalence principle for unstructured test bodies in scalar tensor gravity. Our analysis is complementary to previous approaches and valid for a large class of scalar-tensor theories of gravitation. A covariant approach is used to derive the equations of motion in a systematic way and allows for the experimental test of scalar-tensor theories by means of extended test bodies.

  9. Quantal Definition of the Weak Equivalence Principle

    E-Print Network [OSTI]

    Abel Camacho; Arturo Camacho-Guardian

    2008-11-03T23:59:59.000Z

    The present work analyzes the meaning of the Weak Equivalence Principle in the context of quantum mechanics. A quantal definition for this principle is introduced. This definition does not require the concept of trajectory and relies upon the phase shift induced by a gravitational field in the context of a quantum interference experiment of two coherent beams of particles. In other words, it resorts to wave properties of the system and not to classical concepts as the idea of trajectory.

  10. Einstein's Apple: His First Principle of Equivalence

    E-Print Network [OSTI]

    Engelbert L. Schucking; Eugene J. Surowitz

    2012-08-09T23:59:59.000Z

    After a historical discussion of Einstein's 1907 principle of equivalence, a homogeneous gravitational field in Minkowski spacetime is constructed. It is pointed out that the reference frames in gravitational theory can be understood as spaces with a flat connection and torsion defined through teleparallelism. This kind of torsion was introduced by Einstein in 1928. The concept of torsion is discussed through simple examples and some historical observations.

  11. Equivalent Circuit Modeling of Hysteresis Motors

    SciTech Connect (OSTI)

    Nitao, J J; Scharlemann, E T; Kirkendall, B A

    2009-08-31T23:59:59.000Z

    We performed a literature review and found that many equivalent circuit models of hysteresis motors in use today are incorrect. The model by Miyairi and Kataoka (1965) is the correct one. We extended the model by transforming it to quadrature coordinates, amenable to circuit or digital simulation. 'Hunting' is an oscillatory phenomenon often observed in hysteresis motors. While several works have attempted to model the phenomenon with some partial success, we present a new complete model that predicts hunting from first principles.

  12. Orientifold Planar Equivalence: The Chiral Condensate

    E-Print Network [OSTI]

    Adi Armoni; Biagio Lucini; Agostino Patella; Claudio Pica

    2008-09-29T23:59:59.000Z

    The recently introduced orientifold planar equivalence is a promising tool for solving non-perturbative problems in QCD. One of the predictions of orientifold planar equivalence is that the chiral condensates of a theory with $N_f$ flavours of Dirac fermions in the symmetric (or antisymmetric) representation and $N_f$ flavours of Majorana fermions in the adjoint representation have the same large $N$ value for any value of the mass of the (degenerate) fermions. Assuming the invariance of the theory under charge conjugation, we prove this statement on the lattice for staggered quenched condensates in SU($N$) Yang-Mills in the large $N$ limit. Then, we compute numerically those quenched condensates for $N$ up to 8. After separating the even from the odd corrections in $1/N$, we are able to show that our data support the equivalence; however, unlike other quenched observables, subleading terms in $1/N$ are needed for describing the data for the symmetric and antisymmetric representation at $N$=3. Possible lessons for the unquenched case are discussed.

  13. 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.

  14. 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, ...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Occupational Radiation Exposure at Commercial Nuclear Power Reactors and Other Facilities 2010, Prepared for the Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, May 2012

    SciTech Connect (OSTI)

    D. E. Lewis D. A. Hagemeyer Y. U. McCormick

    2012-07-07T23:59:59.000Z

    This report summarizes the occupational exposure data that are maintained in the U.S. Nuclear Regulatory Commission’s (NRC) Radiation Exposure Information and Reporting System (REIRS). The bulk of the information contained in the report was compiled from the 2010 annual reports submitted by five of the seven categories of NRC licensees subject to the reporting requirements of 10 CFR 20.2206. Because there are no geologic repositories for high-level waste currently licensed and no NRC-licensed low-level waste disposal facilities currently in operation, only five categories will be considered in this report. The annual reports submitted by these licensees consist of radiation exposure records for each monitored individual. These records are analyzed for trends and presented in this report in terms of collective dose and the distribution of dose among the monitored individuals. Annual reports for 2010 were received from a total of 190 NRC licensees. The summation of reports submitted by the 190 licensees indicated that 192,424 individuals were monitored, 81,961 of whom received a measurable dose. When adjusted for transient workers who worked at more than one licensee during the year, there were actually 142,471 monitored individuals and 62,782 who received a measurable dose. The collective dose incurred by these individuals was 10,617 person-rem, which represents a 12% decrease from the 2009 value. This decrease was primarily due to the decrease in collective dose at commercial nuclear power reactors, as well as a decrease in the collective dose for most of the other categories of NRC licensees. The number of individuals receiving a measurable dose also decreased, resulting in an average measurable dose of 0.13 rem for 2010. The average measurable dose is defined as the total effective dose equivalent (TEDE) divided by the number of individuals receiving a measurable dose. In calendar year 2010, the average annual collective dose per reactor for light water reactor (LWR) licensees was 83 person-rem. This represents a 14% decrease from the value reported for 2009 (96 person-rem). The decrease in collective dose for commercial nuclear power reactors was due to an 11% decrease in total outage hours in 2010. During outages, activities involving increased radiation exposure such as refueling and maintenance are performed while the reactor is not in operation. The average annual collective dose per reactor for boiling water reactors (BWRs) was 137 personrem for 35 BWRs, and 55 person-rem for 69 pressurized water reactors (PWRs). Analyses of transient individual data indicate that 29,333 individuals completed work assignments at two or more licensees during the monitoring year. The dose distributions are adjusted each year to account for the duplicate reporting of transient individuals by multiple licensees. The adjustment to account for transient individuals has been specifically noted in footnotes in the figures and tables for commercial nuclear power reactors. In 2010, the average measurable dose per individual for all licensees calculated from reported data was 0.13 rem. Although the average measurable dose per individual from data submitted by licensees was 0.13 rem, a corrected dose distribution resulted in an average measurable dose per individual of 0.17 rem.

  2. Gravitational leptogenesis, C, CP and strong equivalence

    E-Print Network [OSTI]

    J. I. McDonald; Graham M. Shore

    2014-11-13T23:59:59.000Z

    The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit couplings of spacetime curvature to appropriate lepton (or baryon) currents. In this paper, the idea that these strong equivalence principle violating interactions could be generated automatically through quantum loop effects in curved spacetime is explored, focusing on the realisation of the discrete symmetries C, CP and CPT which must be broken to induce matter-antimatter asymmetry. The related issue of quantum corrections to the dispersion relation for neutrino propagation in curved spacetime is considered within a fully covariant framework.

  3. Equivalence Principle and the Baryon Acoustic Peak

    E-Print Network [OSTI]

    Baldauf, Tobias; Simonovi?, Marko; Zaldarriaga, Matias

    2015-01-01T23:59:59.000Z

    We study the dominant effect of a long wavelength density perturbation $\\delta(\\lambda_L)$ on short distance physics. In the non-relativistic limit, the result is a uniform acceleration, fixed by the equivalence principle, and typically has no effect on statistical averages due to translational invariance. This same reasoning has been formalized to obtain a "consistency condition" on the cosmological correlation functions. In the presence of a feature, such as the acoustic peak at $l_{\\rm BAO}$, this naive expectation breaks down for $\\lambda_Lpower spectrum. Finally, the success of BAO reconstruction schemes is argue...

  4. Unit Conversion Factors Quantity Equivalent Values

    E-Print Network [OSTI]

    Ashurst, W. Robert

    Unit Conversion Factors Quantity Equivalent Values Mass 1 kg = 1000 g = 0.001 metric ton = 2.921 inHg at 0 C Energy 1 J = 1 N·m = 107 ergs = 107 dyne·cm = 2.778×10-7 kW·h 1 J = 0.23901 cal = 0·R 10.73 psia·ft3 lbmol·R 62.36 liter·torr mol·K 0.7302 ft3·atm lbmol·R Temperature Conversions: T

  5. The Equivalence Principle in a Quantum World

    E-Print Network [OSTI]

    Bjerrum-Bohr, N E J; El-Menoufi, Basem Kamal; Holstein, Barry R; Planté, Ludovic; Vanhove, Pierre

    2015-01-01T23:59:59.000Z

    We show how modern methods can be applied to quantum gravity at low energy. We test how quantum corrections challenge the classical framework behind the Equivalence Principle, for instance through introduction of non-locality from quantum physics, embodied in the Uncertainty Principle. When the energy is small we now have the tools to address this conflict explicitly. Despite the violation of some classical concepts, the EP continues to provide the core of the quantum gravity framework through the symmetry - general coordinate invariance - that is used to organize the effective field theory.

  6. The Equivalence Principle in a Quantum World

    E-Print Network [OSTI]

    N. E. J. Bjerrum-Bohr; John F. Donoghue; Basem Kamal El-Menoufi; Barry R. Holstein; Ludovic Planté; Pierre Vanhove

    2015-05-19T23:59:59.000Z

    We show how modern methods can be applied to quantum gravity at low energy. We test how quantum corrections challenge the classical framework behind the Equivalence Principle, for instance through introduction of non-locality from quantum physics, embodied in the Uncertainty Principle. When the energy is small we now have the tools to address this conflict explicitly. Despite the violation of some classical concepts, the EP continues to provide the core of the quantum gravity framework through the symmetry - general coordinate invariance - that is used to organize the effective field theory.

  7. AKS systems and Lepage equivalent problems

    E-Print Network [OSTI]

    Santiago Capriotti

    2011-01-06T23:59:59.000Z

    The integrable systems known as "AKS systems" admit a natural formulation in terms of a Hamiltonian picture. The Lagrangian side of these systems are far less known; a version in these terms can be found in a work of Feher et al. The purpose of these notes in to provide a novel description of AKS systems in terms of a variational problem different from the usual in mechanics. Additionally, and using techniques borrowed from an article of M. Gotay, it was possible to build the Hamiltonian side of this variational problem, allowing us to establish the equivalence with the usual approach to these integrable systems.

  8. 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.

  9. 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.

  10. Proton Radiotherapy for Pediatric Bladder/Prostate Rhabdomyosarcoma: Clinical Outcomes and Dosimetry Compared to Intensity-Modulated Radiation Therapy

    SciTech Connect (OSTI)

    Cotter, Shane E. [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Herrup, David A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Friedmann, Alison [Department of Pediatric Hematology-Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Macdonald, Shannon M. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Pieretti, Raphael V. [Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts (United States); Robinson, Gregoire; Adams, Judith; Tarbell, Nancy J. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Yock, Torunn I., E-mail: tyock@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2011-12-01T23:59:59.000Z

    Purpose: In this study, we report the clinical outcomes of 7 children with bladder/prostate rhabdomyosarcoma (RMS) treated with proton radiation and compare proton treatment plans with matched intensity-modulated radiation therapy (IMRT) plans, with an emphasis on dose savings to reproductive and skeletal structures. Methods and Materials: Follow-up consisted of scheduled clinic appointments at our institution or direct communication with the treating physicians for referred patients. Each proton radiotherapy plan used for treatment was directly compared to an IMRT plan generated for the study. Clinical target volumes and normal tissue volumes were held constant to facilitate dosimetric comparisons. Each plan was optimized for target coverage and normal tissue sparing. Results: Seven male patients were treated with proton radiotherapy for bladder/prostate RMS at the Massachusetts General Hospital between 2002 and 2008. Median age at treatment was 30 months (11-70 months). Median follow-up was 27 months (10-90 months). Four patients underwent a gross total resection prior to radiation, and all patients received concurrent chemotherapy. Radiation doses ranged from 36 cobalt Gray equivalent (CGE) to 50.4 CGE. Five of 7 patients were without evidence of disease and with intact bladders at study completion. Target volume dosimetry was equivalent between the two modalities for all 7 patients. Proton radiotherapy led to a significant decrease in mean organ dose to the bladder (25.1 CGE vs. 33.2 Gy; p = 0.03), testes (0.0 CGE vs. 0.6 Gy; p = 0.016), femoral heads (1.6 CGE vs. 10.6 Gy; p = 0.016), growth plates (21.7 CGE vs. 32.4 Gy; p = 0.016), and pelvic bones (8.8 CGE vs. 13.5 Gy; p = 0.016) compared to IMRT. Conclusions: This study provides evidence of significant dose savings to normal structures with proton radiotherapy compared to IMRT and is well tolerated in this patient population. The long-term impact of these reduced doses can be tested in future studies incorporating extended follow-up, objective outcome measures, and quality-of-life analyses.

  11. 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.

  12. 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+}.

  13. 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...

  14. 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,...

  15. Breakdown of the Equivalence between Energy Content and Weight in a Weak Gravitational Field for a Quantum Body

    E-Print Network [OSTI]

    Andrei Lebed

    2012-05-14T23:59:59.000Z

    It is shown that weight operator of a composite quantum body in a weak external gravitational field in the post-Newtonian approximation of the General Relativity does not commute with its energy operator, taken in the absence of the field. Nevertheless, the weak equivalence between the expectations values of weight and energy is shown to survive at a macroscopic level for stationary quantum states for the simplest composite quantum body - a hydrogen atom. Breakdown of the weak equivalence between weight and energy at a microscopic level for stationary quantum states can be experimentally detected by studying unusual electromagnetic radiation, emitted by the atoms, supported and moved in the Earth gravitational field with constant velocity, using spacecraft or satellite. For superpositions of stationary quantum states, a breakdown of the above mentioned equivalence at a macroscopic level leads to time dependent oscillations of the expectation values of weight, where the equivalence restores after averaging over time procedure.

  16. 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.

  17. Asymptotic Equivalence and Adaptive Estimation for Robust Nonparametric Regression

    E-Print Network [OSTI]

    Zhou, Harrison Huibin

    Asymptotic Equivalence and Adaptive Estimation for Robust Nonparametric Regression T. Tony Cai1 and Harrison H. Zhou2 University of Pennsylvania and Yale University Abstract Asymptotic equivalence theory. In this paper we develop asymptotic equivalence results for robust nonparametric regression with unbounded loss

  18. Borel equivalence relations and everywhere faithful actions of free products

    E-Print Network [OSTI]

    Miller, Benjamin

    Borel equivalence relations and everywhere faithful actions of free products Benjamin D. Miller July 13, 2006 Abstract We study the circumstances under which an aperiodic countable Borel equivalence equivalence class. An action of a group G on a set X is faithful if g G x X (g · x = x). The orbits of a G

  19. Weak Order Equivalence for Logic Programs with Preferences

    E-Print Network [OSTI]

    Schaub, Torsten

    Weak Order Equivalence for Logic Programs with Preferences Kathrin Konczak Institut f¨ur Informatik, notions of equivalence for Answer Set Programming have been stud- ied intensively and were shown to be beneficial for modular programming and automated optimization. In [9], the novel notion of strong equivalence

  20. Checking NFA equivalence with bisimulations up to congruence

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Checking NFA equivalence with bisimulations up to congruence Filippo Bonchi CNRS, ENS Lyon--We introduce bisimulation up to congruence as a technique for proving language equivalence of non algorithm. I. INTRODUCTION Checking language equivalence of finite automata is a clas- sical problem

  1. Isomorphism of subshifts is a universal countable Borel equivalence relation

    E-Print Network [OSTI]

    Clemens, John D.

    Isomorphism of subshifts is a universal countable Borel equivalence relation John D. Clemens July 17, 2007 Abstract We use the theory of Borel equivalence relations to analyze the equiva- lence relation of isomorphism among one-dimensional subshifts. We show that this equivalence relation

  2. Checking NFA equivalence with bisimulations up to congruence

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Checking NFA equivalence with bisimulations up to congruence Filippo Bonchi Damien Pous CNRS, ENS introduce bisimulation up to congruence as a technique for proving language equivalence of non Language Equivalence, Automata, Bisimulation, Coin- duction, Up-to techniques, Congruence, Antichains. 1

  3. Reducing Equational Theories for the Decision of Static Equivalence #

    E-Print Network [OSTI]

    Treinen, Ralf - Laboratoire Preuves, Programmes et Systèmes, Université Paris 7

    Reducing Equational Theories for the Decision of Static Equivalence # Steve Kremer 1 , Antoine, CNRS, France Abstract. Static equivalence is a well established notion of indistin­ guishability of sequences of terms which is useful in the symbolic analysis of cryptographic protocols. Static equivalence

  4. A Language-Independent Proof System for Mutual Program Equivalence

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A Language-Independent Proof System for Mutual Program Equivalence S¸tefan Ciob^aca1 , Dorel Lucanu, France 3 University of Illinois at Urbana-Champaign, USA Abstract. Two programs are mutually equivalent if they both diverge or they end up in similar states. Mutual equivalence is an adequate no- tion

  5. Regular Equivalence and Dynamic Logic Maarten Marx and Michael Masuch

    E-Print Network [OSTI]

    Amsterdam, University of

    Regular Equivalence and Dynamic Logic Maarten Marx #3; and Michael Masuch Institure for Logic equivalence relation on a social network. That is, a formal language of position terms is de#12;ned with the property that on #12;nite networks, two actors are regularly equivalent if and only if they cannot

  6. ccsd00003913, ZETA FUNCTIONS AND BLOW-NASH EQUIVALENCE

    E-Print Network [OSTI]

    ccsd­00003913, version 1 ­ 17 Jan 2005 ZETA FUNCTIONS AND BLOW-NASH EQUIVALENCE GOULWEN FICHOU Abstract. We propose a re#12;nement of the notion of blow-Nash equivalence between Nash function germs, which has been introduced in [2] as an analog in the Nash setting of the blow-analytic equivalence de#12

  7. ASYMPTOTIC EQUIVALENCE FOR INHOMOGENEOUS JUMP DIFFUSION PROCESSES AND WHITE NOISE.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ASYMPTOTIC EQUIVALENCE FOR INHOMOGENEOUS JUMP DIFFUSION PROCESSES AND WHITE NOISE. ESTER MARIUCCI Laboratoire Jean Kuntzmann, Grenoble. Abstract. We prove the global asymptotic equivalence between the experi. These asymptotic equivalences are established by constructing explicit Markov kernels that can be used to reproduce

  8. On the Equivalence of Distributed Systems with Queries and Communication$

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    On the Equivalence of Distributed Systems with Queries and Communication$ Serge Abiteboula , Balder a common goal, such as eval- uating some query. We study the equivalence of such systems. We model for performing tasks such as sending, receiving and querying data. As our model is quite general, the equivalence

  9. Mining Complex Boolean Expressions for Sequential Equivalence Checking

    E-Print Network [OSTI]

    Ramakrishnan, Naren

    Mining Complex Boolean Expressions for Sequential Equivalence Checking Neha Goel, Michael S. Hsiao-flops in a sequential circuit for sequential equivalence checking. In contrast to traditional learning methods, our be arbitrary boolean expressions and can thus prune a large don't care space during equivalence checking

  10. Stutter Equivalence for In nite State Systems Zhendong Su

    E-Print Network [OSTI]

    Su, Zhendong

    Stutter Equivalence for In#12;nite State Systems Zhendong Su EECS Department, University of California, Berkeley zhendong@cs.berkeley.edu Abstract. In this paper, we study the state equivalences closure of bisimilarity is a full abstract semantics for STL AU . Next, we suggest a new state equivalence

  11. Equivalence Relations Definition of a relation on a set

    E-Print Network [OSTI]

    Singman, David

    Equivalence Relations Definition of a relation on a set Let A be any set. Any subset have 1R1, 2R3, 3R1, 2 R2, 3 R2, etc. #12;A special kind of relation- an Equivalence relation There is a type of relation, it's known as an equivalence relation, which is particularly useful. Definition

  12. On the Equivalence of Distributed Systems with Queries and Communication

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    On the Equivalence of Distributed Systems with Queries and Communication Serge Abiteboul INRIA, such as evaluate some query. We study the equivalence of such systems. We model a dis- tributed system such as sending, receiving and querying data. As our model is quite general, the equivalence problem turns out

  13. On the Complexity of the Equivalence Problem for Probabilistic Automata

    E-Print Network [OSTI]

    Ouaknine, Joël

    On the Complexity of the Equivalence Problem for Probabilistic Automata Stefan Kiefer1 , Andrzej S equivalence of probabilistic automata is a key prob- lem for establishing various behavioural and anonymity properties of probabilistic systems. In recent experiments a randomised equivalence test based on polynomial

  14. Complexity of Equivalence Problems for Concurrent Systems of Finite Agents

    E-Print Network [OSTI]

    Rabinovich, Alexander

    Complexity of Equivalence Problems for Concurrent Systems of Finite Agents Alexander Rabinovich@math.tau.ac.il 1 #12; Running head: Equivalence of Concurrent Systems Mailing address: Alexander Rabinovich that one wants to check whether p ¸ q for one of the commonly used equivalence ¸. We show that this ques

  15. The equivalence principle in classical mechanics and quantum mechanics

    E-Print Network [OSTI]

    Philip D. Mannheim

    2000-04-03T23:59:59.000Z

    We discuss our understanding of the equivalence principle in both classical mechanics and quantum mechanics. We show that not only does the equivalence principle hold for the trajectories of quantum particles in a background gravitational field, but also that it is only because of this that the equivalence principle is even to be expected to hold for classical particles at all.

  16. 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.

  17. 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.

  18. 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)

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy

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

    Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; Nelson, Johanna; Shapiro, David; Stewart, Andrew; Turner, Joshua; Jacobsen, Chris

    2009-01-01T23:59:59.000Z

    Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite numerical aperture and efficiency of the optics. In simulations with objects representing isolated cells such as yeast, we find that XDM has the potential for delivering equivalent resolution imagesmore »using fewer photons. This can be an important advantage for studying radiation-sensitive biological and soft matter specimens.« less

  7. Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy

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

    Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; Nelson, Johanna; Shapiro, David; Stewart, Andrew; Turner, Joshua; Jacobsen, Chris

    2009-01-01T23:59:59.000Z

    Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite numerical aperture and efficiency of the optics. In simulations with objects representing isolated cells such as yeast, we find that XDM has the potential for delivering equivalent resolution images using fewer photons. This can be an important advantage for studying radiation-sensitive biological and soft matter specimens.

  8. 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

  9. Spectral equivalences from Bethe Ansatz equations

    E-Print Network [OSTI]

    Dorey, P; Tateo, R; Dorey, Patrick; Dunning, Clare; Tateo, Roberto

    2001-01-01T23:59:59.000Z

    The one-dimensional Schr\\"odinger equation for the potential $x^6+\\alpha x^2 +l(l+1)/x^2$ has many interesting properties. For certain values of the parameters l and alpha the equation is in turn supersymmetric (Witten), quasi-exactly solvable (Turbiner), and it also appears in Lipatov's approach to high energy QCD. In this paper we signal some further curious features of these theories, namely novel spectral equivalences with particular second- and third-order differential equations. These relationships are obtained via a recently-observed connection between the theories of ordinary differential equations and integrable models. Generalised supersymmetry transformations acting at the quasi-exactly solvable points are also pointed out, and an efficient numerical procedure for the study of these and related problems is described. Finally we generalise slightly and then prove a conjecture due to Bessis, Zinn-Justin, Bender and Boettcher, concerning the reality of the spectra of certain PT-symmetric quantum-mecha...

  10. Breakdown of the equivalence between gravitational mass and energy for a composite quantum body

    E-Print Network [OSTI]

    Andrei G. Lebed

    2014-04-14T23:59:59.000Z

    The simplest quantum composite body, a hydrogen atom, is considered in the presence of a weak external gravitational field. We define an operator for the passive gravitational mass of the atom in the post-Newtonian approximation of the general relativity and show that it does not commute with its energy operator. Nevertheless, the equivalence between the expectation values of the mass and energy is shown to survive at a macroscopic level for stationary quantum states. Breakdown of the equivalence between passive gravitational mass and energy at a microscopic level for stationary quantum states can be experimentally detected by studying unusual electromagnetic radiation, emitted by the atoms, supported by and moving in the Earth's gravitational field with constant velocity, using spacecraft or satellite

  11. The Equivalent Thermal Resistance of Tile Roofs with and without Batten Systems

    SciTech Connect (OSTI)

    Miller, William A [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    Clay and concrete tile roofs were installed on a fully instrumented attic test facility operating in East Tennessee s climate. Roof, attic and deck temperatures and heat flows were recorded for each of the tile roofs and also on an adjacent attic cavity covered with a conventionally pigmented and direct-nailed asphalt shingle roof. The data were used to benchmark a computer tool for simulation of roofs and attics and the tool used to develop an approach for computing an equivalent seasonal R-value for sub-tile venting. The approach computed equal heat fluxes through the ceilings of roofs having different combinations of surface radiation properties and or building constructions. A direct nailed shingle roof served as a control for estimating the equivalent thermal resistance of the air space. Simulations were benchmarked to data in the ASHRAE Fundamentals for the thermal resistance of inclined and closed air spaces.

  12. 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 Reconstruction (HEDR) Project is to estimate radiation doses from Hanford Site operations since 1944 to populations and individuals. The primary objectives of work to be performed in FY 1992 is to determine the appropriate scope (space, time, and radionuclides, pathways and individuals/population groups) and accuracy (level of uncertainty in dose estimates) for the project. Another objective is to use a refined computer model to estimate Native American tribal doses and individual doses for the Hanford Thyroid Disease Study (HTDS). Project scope and accuracy requirements defined in FY 1992 can translated into model and data requirements that must be satisfied during FY 1993.

  13. FY 1992 revised task plans for the Hanford Environmental Dose Reconstruction Project. Revision 1

    SciTech Connect (OSTI)

    Shipler, D.B.

    1992-04-01T23:59:59.000Z

    The purpose of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate radiation doses from Hanford Site operations since 1944 to populations and individuals. The primary objectives of work to be performed in FY 1992 is to determine the appropriate scope (space, time, and radionuclides, pathways and individuals/population groups) and accuracy (level of uncertainty in dose estimates) for the project. Another objective is to use a refined computer model to estimate Native American tribal doses and individual doses for the Hanford Thyroid Disease Study (HTDS). Project scope and accuracy requirements defined in FY 1992 can translated into model and data requirements that must be satisfied during FY 1993.

  14. Method for radiation detection and measurement

    DOE Patents [OSTI]

    Miller, S.D.

    1993-12-21T23:59:59.000Z

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength. 9 figures.

  15. COLUMBIA UNIVERSITY PREGNANCY POLICY FOR RADIATION WORKERS

    E-Print Network [OSTI]

    Jia, Songtao

    COLUMBIA UNIVERSITY PREGNANCY POLICY FOR RADIATION WORKERS POLICY: Under applicable regulations and Federal statutes (2), it is the policy of the Columbia University to limit the radiation dose (3). Further, it is the policy of the Columbia University to provide counseling and education

  16. Method for radiation detection and measurement

    DOE Patents [OSTI]

    Miller, Steven D. (Richland, WA)

    1993-01-01T23:59:59.000Z

    Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength.

  17. Determination of photon conversion factors relating exposure and dose for several extremity phantom designs

    SciTech Connect (OSTI)

    Roberson, P.L.; Eichner, F.N.; Reece, W.D. (Pacific Northwest Lab., Richland, WA (USA))

    1989-11-01T23:59:59.000Z

    Dosimetric measurements were performed to determine the exposure-to-dose conversion factors (Cx) for simple extremity phantoms suitable for extremity dosimeter performance testing. The phantoms studied represented the forearm or lower leg and the finger. Measurements were performed for solid plastic phantoms and for phantoms containing simulated bone material to determine the effect of backscattered radiations from the simulated bone to the phantom surface. Photon beam energies used for the measurements ranged from 16 keV to 1.25 MeV (average). The Cx factors for the finger phantoms did not vary significantly with phantom composition. The Cx factors in the arm/leg phantoms with the bone simulant material differed significantly from those for the solid plastic phantom over the energy range of 40-100 keV. This effect was attributed to the preferential absorption of the lower energy backscattered photons by the higher atomic number material that was contained in the bone-simulant insert. The position of the bone-simulating material below the surface of the phantom was more important than its size or level of bone equivalency. For calibrations and dosimeter testing, Al was found adequate as a bone-simulating material.

  18. Residual radioactive contamination from decommissioning: Technical basis for translating contamination levels to annual dose

    SciTech Connect (OSTI)

    Kennedy, W.E. Jr.; Peloquin, R.A. (Pacific Northwest Lab., Richland, WA (USA))

    1990-01-01T23:59:59.000Z

    This document describes the generic modeling of the total effective dose equivalent (TEDE) to an individual in a population from a unit concentration of residual radioactive contamination. Radioactive contamination inside buildings and soil contamination are considered. Unit concentration TEDE factors by radionuclide, exposure pathway, and exposure scenario are calculated. Reference radiation exposure scenarios are used to derive unit concentration TEDE factors for about 200 individual radionuclides and parent-daughter mixtures. For buildings, these unit concentration factors list the annual TEDE for volume and surface contamination situations. For soil, annual TEDE factors are presented for unit concentrations of radionuclides in soil during residential use of contaminated land and the TEDE per unit total inventory for potential use of drinking water from a ground-water source. Because of the generic treatment of potentially complex ground-water systems, the annual TEDE factors for drinking water for a given inventory may only indicate when additional site data or modeling sophistication are warranted. Descriptions are provided of the models, exposure pathways, exposure scenarios, parameter values, and assumptions used. An analysis of the potential annual TEDE resulting from reference mixtures of residual radionuclides is provided to demonstrate application of the TEDE factors. 62 refs., 5 figs., 66 tabs.

  19. Orbit Equivalence and Von Neumann Rigidity for Actions of Wreath Product Groups

    E-Print Network [OSTI]

    Sizemore, James Owen

    2012-01-01T23:59:59.000Z

    B. Weiss. “An amenable equivalence relation is gen- eratedFur99] Alex Furman. “Orbit equivalence rigidity. ” Ann. ofand Yehuda Shalom. “Orbit equivalence rigidity and bounded

  20. [Semantic equivalence of the Brazilian Portuguese version of the "Body Change Inventory"].

    E-Print Network [OSTI]

    Conti, MA; Ferreira, ME; Amaral, AC; Hearst, N; Cordás, TA; Scagliusi, FB

    2012-01-01T23:59:59.000Z

    Inventory” Semantic Equivalence of the Brazilian Portugueseuation for semantic equivalence of the BCI in the Portuguese3) evaluation of semantic equivalence; and (4) assessment of

  1. Applying modality and equivalence concepts to pattern finding in social process-produced data

    E-Print Network [OSTI]

    Hanneman, Robert A.; Shelton, Christian R.

    2011-01-01T23:59:59.000Z

    on generalized concepts of equivalence. J Math Sociol 19(1):53 Everett MG (1994) Regular equivalence: general theory. JHC (1971) Structural equivalence of individuals in social

  2. A reassessment of equivalence in yield from marine reserves and traditional fisheries management

    E-Print Network [OSTI]

    White, Crow; Kendall, Bruce E.

    2007-01-01T23:59:59.000Z

    and Botsford, L. W. 1999. Equivalence in yield from marineJune 2007 A reassessment of equivalence in yield from marineidentical model generates equivalence in yield between the

  3. Critical dose and toxicity index of organs at risk in radiotherapy: Analyzing the calculated effects of modified dose fractionation in non–small cell lung cancer

    SciTech Connect (OSTI)

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Benassi, Marcello [Service of Medical Physics, Scientific Institute of Tumours of Romagna I.R.S.T., Meldola (Italy); Caivano, Rocchina [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Fiorentino, Alba [U.O. of Radiotherapy, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Nappi, Antonio [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Salvatore, Marco [U.O. of Nuclear Medicine, I.R.C.C.S. SDN Foundation, Naples (Italy); Storto, Giovanni [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy)

    2014-04-01T23:59:59.000Z

    To increase the efficacy of radiotherapy for non–small cell lung cancer (NSCLC), many schemes of dose fractionation were assessed by a new “toxicity index” (I), which allows one to choose the fractionation schedules that produce less toxic treatments. Thirty-two patients affected by non resectable NSCLC were treated by standard 3-dimensional conformal radiotherapy (3DCRT) with a strategy of limited treated volume. Computed tomography datasets were employed to re plan by simultaneous integrated boost intensity-modulated radiotherapy (IMRT). The dose distributions from plans were used to test various schemes of dose fractionation, in 3DCRT as well as in IMRT, by transforming the dose-volume histogram (DVH) into a biological equivalent DVH (BDVH) and by varying the overall treatment time. The BDVHs were obtained through the toxicity index, which was defined for each of the organs at risk (OAR) by a linear quadratic model keeping an equivalent radiobiological effect on the target volume. The less toxic fractionation consisted in a severe/moderate hyper fractionation for the volume including the primary tumor and lymph nodes, followed by a hypofractionation for the reduced volume of the primary tumor. The 3DCRT and IMRT resulted, respectively, in 4.7% and 4.3% of dose sparing for the spinal cord, without significant changes for the combined-lungs toxicity (p < 0.001). Schedules with reduced overall treatment time (accelerated fractionations) led to a 12.5% dose sparing for the spinal cord (7.5% in IMRT), 8.3% dose sparing for V{sub 20} in the combined lungs (5.5% in IMRT), and also significant dose sparing for all the other OARs (p < 0.001). The toxicity index allows to choose fractionation schedules with reduced toxicity for all the OARs and equivalent radiobiological effect for the tumor in 3DCRT, as well as in IMRT, treatments of NSCLC.

  4. 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.

  5. Phase 1 of the Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    Not Available

    1990-07-20T23:59:59.000Z

    For more than 40 years, the US government made plutonium for nuclear weapons at the Hanford Site in southeastern Washington State. Radioactive materials were released to both the air and water from Hanford. People could have been exposed to these materials, called radionuclides. The Hanford Environmental Dose Reconstruction (HEDR) Project is a multi-year scientific study to estimate the radiation doses the public may have received as a results of these releases. The study began in 1988. During the first phase, scientists began to develop and test methods for reconstructing the radiation doses. To do this, scientists found or reconstructed information about the amount and type of radionuclides that were released from Hadford facilities, where they traveled in environment, and how they reached people. Information about the people who could have been exposed was also found or reconstructed. Scientists then developed a computer model that can estimate doses from radiation exposure received many years ago. All the information that had been gathered was fed into the computer model. Then scientists did a test run'' to see whether the model was working properly. As part of its test run,'' scientists asked the computer model to generate two types of preliminary results: amounts of radionuclides in the environment (air, soil, pasture grass, food, and milk) and preliminary doses people could have received from all the routes of radiation exposure, called exposure pathways. Preliminary dose estimates were made for categories of people who shared certain characteristics and for the Phase 1 population as a whole. 26 refs., 48 figs.

  6. acids biologically equivalent: Topics by E-print Network

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

    on Complexity of Computer Computations, IBM Thomas J. Watson Research Center, Yorktown Heights, New York, on March 22, 1972. The equivalence problem is to determine the ......

  7. Optimization Online - On the equivalence of the method of conjugate ...

    E-Print Network [OSTI]

    Anders Forsgren

    2015-03-09T23:59:59.000Z

    Mar 9, 2015 ... Abstract: In this paper we state necessary and sufficient conditions for equivalence of the method of conjugate gradients and quasi-Newton ...

  8. Equivalent circuit modeling of hybrid electric vehicle drive train

    E-Print Network [OSTI]

    Routex, Jean-Yves

    2001-01-01T23:59:59.000Z

    . . . . Figure 3. 4. 6: The motor shaft at no load. Figure 3. 4. 7: Bond graph for the motor shaft. . . Figure 3. 4. 8: Equivalent circuit of the motor shaft. Figure 3. 5. 1: Concrete example: the elevator Figure 3. 5. 2: Electro-mechanical model... model of the elevator. Figure 3. 5. 8: Final equivalent circuit of the elevator. Figure 4. 1. 1: Mechanical model of a shaft. Figure 4. 1. 2: Equivalent circuit of the shaft. Figure 4. 1. 3: Mechanical model of a gearbox. Figure 4. 1. 4: Equivalent...

  9. Stability of the Gauge Equivalent Classes in Inverse Stationary ...

    E-Print Network [OSTI]

    2011-06-28T23:59:59.000Z

    mines the gauge equivalent class of the attenuation and scattering coefficients. ...... [18] M. Mokhtar-Kharroubi, Mathematical Topics in Neutron Transport Theory

  10. Derivation of Equivalent Continuous Dilution for Cyclic, Unsteady Driving Forces

    E-Print Network [OSTI]

    Mortensen, Dorthe K.

    2011-01-01T23:59:59.000Z

    problem of determining equivalency for different approaches to ventilationproblem at hand. Although we are often more accustomed to dealing with ventilation

  11. Evaluation of offsite dose assessment methodologies used in the nuclear industry

    E-Print Network [OSTI]

    Berry, Robert Orwell

    1992-01-01T23:59:59.000Z

    power plant, special studies have been done to estimate the doses due to releases from these facilities. To establish a consistent methodology to be used in the determination of the radiation doses from nuclear power plants the U. S. Nuclear..., Part 20, "Standards for Protection Against Radiation" (10CFR20). Specific design objectives for light-water-cooled nuclear power reactors on exposure levels in unrestricted areas outside these facilities are presented in 10CFR50. Some of the newly...

  12. Real time sensor for therapeutic radiation delivery

    DOE Patents [OSTI]

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

    1998-01-01T23:59:59.000Z

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body.

  13. Real time sensor for therapeutic radiation delivery

    DOE Patents [OSTI]

    Bliss, M.; Craig, R.A.; Reeder, P.L.

    1998-01-06T23:59:59.000Z

    The invention is a real time sensor for therapeutic radiation. A probe is placed in or near the patient that senses in real time the dose at the location of the probe. The strength of the dose is determined by either an insertion or an exit probe. The location is determined by a series of vertical and horizontal sensing elements that gives the operator a real time read out dose location relative to placement of the patient. The increased accuracy prevents serious tissue damage to the patient by preventing overdose or delivery of a dose to a wrong location within the body. 14 figs.

  14. Custom Device for Low-Dose Gamma Irradiation of Biological Samples

    E-Print Network [OSTI]

    Bi, Ruoming

    2012-02-14T23:59:59.000Z

    , the structural material is efficient to absorb most of the cosmic-ray energy and reduce the interior dose rate to below 1.2 mGy per day. However, the biological effects of prolonged exposure to low-dose radiation are not well understood. The purpose...

  15. A revised dosimetric model for calculation of electron dose in the small intestine

    E-Print Network [OSTI]

    Bhuiyan, Md. Nasir Uddin

    2000-01-01T23:59:59.000Z

    1. Summary of descriptive parameters characterizing the adult human SI. . . . . . 59 Table 2. Elemental composition of soft tissue 66 Table 3. Ratio (v) of electron absorbed dose at mean depth of stem cells (sensitive cells) to absorbed dose... LIST OF ACRONYMS GI ICRP DLI Absorbed Fraction Gastrointestinal International Commission on Radiological Protection Dist' Large Intestine Medical Internal Radiation Dose SEE SI ST PLI Specific Absorbed Fraction Specific Effective Energy...

  16. Ground-water contribution to dose from past Hanford Operations. Hanford Environmental Dose Reconstruction Project

    SciTech Connect (OSTI)

    Freshley, M.D.; Thorne, P.D.

    1992-08-01T23:59:59.000Z

    The Hanford Environmental Dose Reconstruction (HEDR) 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 migrating 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 next to the Columbia River downstream of Hanford that draw some or all of their water from the river (riparian wells); and (4) through atmospheric deposition resulting in contamination of a small watershed that, in turn, results in contamination of a shallow well or spring by transport in the ground water. These four pathways make up the ``ground-water pathway,`` which is the subject of this study. Assessment of the ground-water pathway was performed by (1) reviewing the existing extensive literature on ground water and ground-water monitoring at Hanford and (2) performing calculations to estimate radionuclide concentrations where no monitoring data were collected. Radiation doses that would result from exposure to these radionuclides were calculated.

  17. Joule Equivalent of Electrical Energy by Dr. James E. Parks

    E-Print Network [OSTI]

    Tennessee, University of

    Joule Equivalent of Electrical Energy by Dr. James E. Parks Department of Physics and Astronomy 401 The objectives of this experiment are: (1) to understand the equivalence of electrical energy and heat energy, (2) to learn techniques of calorimetry, (3) to learn how to measure electrical energy, and (4) to measure

  18. Standardized radiological dose evaluations

    SciTech Connect (OSTI)

    Peterson, V.L.; Stahlnecker, E.

    1996-05-01T23:59:59.000Z

    Following the end of the Cold War, the mission of Rocky Flats Environmental Technology Site changed from production of nuclear weapons to cleanup. Authorization baseis documents for the facilities, primarily the Final Safety Analysis Reports, are being replaced with new ones in which accident scenarios are sorted into coarse bins of consequence and frequency, similar to the approach of DOE-STD-3011-94. Because this binning does not require high precision, a standardized approach for radiological dose evaluations is taken for all the facilities at the site. This is done through a standard calculation ``template`` for use by all safety analysts preparing the new documents. This report describes this template and its use.

  19. Danger radiations

    ScienceCinema (OSTI)

    None

    2011-04-25T23:59:59.000Z

    Le conférencier Mons.Hofert parle des dangers et risques des radiations, le contrôle des zones et les précautions à prendre ( p.ex. film badge), comment mesurer les radiations etc.

  20. Radiation hardness of the storage phosphor europium doped potassium chloride for radiation therapy dosimetry

    SciTech Connect (OSTI)

    Driewer, Joseph P.; Chen, Haijian; Osvet, Andres; Low, Daniel A.; Li, H. Harold [Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 and Nuclear Science and Engineering Institute, University of Missouri, E4431 Lafferre Hall, Columbia, Missouri 65211 (United States); Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States); Department of Materials Science and Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Martensstrasse 7, Erlangen 91058 (Germany); Department of Radiation Oncology, Washington University School of Medicine, 4921 Parkview Place, Campus Box 8224, St. Louis, Missouri 63110 (United States)

    2011-08-15T23:59:59.000Z

    Purpose: An important property of a reusable dosimeter is its radiation hardness, that is, its ability to retain its dosimetric merits after irradiation. The radiation hardness of europium doped potassium chloride (KCl:Eu{sup 2+}), a storage phosphor material recently proposed for radiation therapy dosimetry, is examined in this study. Methods: Pellet-style KCl:Eu{sup 2+} dosimeters, 6 mm in diameter, and 1 mm thick, were fabricated in-house for this study. The pellets were exposed by a 6 MV photon beam or in a high dose rate {sup 137}Cs irradiator. Macroscopic properties, such as radiation sensitivity, dose response linearity, and signal stability, were studied with a laboratory photostimulated luminescence (PSL) readout system. Since phosphor performance is related to the state of the storage centers and the activator, Eu{sup 2+}, in the host lattice, spectroscopic and temporal measurements were carried out in order to explore radiation-induced changes at the microscopic level. Results: KCl:Eu{sup 2+} dosimeters retained approximately 90% of their initial signal strength after a 5000 Gy dose history. Dose response was initially supralinear over the dose range of 100-700 cGy but became linear after 60 Gy. Linearity did not change significantly in the 0-5000 Gy dose history spanned in this study. Annealing high dose history chips resulted in a return of supralinearity and a recovery of sensitivity. There were no significant changes in the PSL stimulation spectra, PSL emission spectra, photoluminescence spectra, or luminescence lifetime, indicating that the PSL signal process remains intact after irradiation but at a reduced efficiency due to reparable radiation-induced perturbations in the crystal lattice. Conclusions: Systematic studies of KCl:Eu{sup 2+} material are important for understanding how the material can be optimized for radiation therapy dosimetry purposes. The data presented here indicate that KCl:Eu{sup 2+} exhibits strong radiation hardness and lends support for further investigations of this novel material.

  1. Elliptic flow due to radiation in heavy-ion collisions

    E-Print Network [OSTI]

    Biró, T S; Schram, Zs

    2015-01-01T23:59:59.000Z

    In this paper we demonstrate that radiation patterns could cause flow-like behaviour without any reference to hydrodynamic description. For that purpose we use a statistical ensemble of radiating dipoles, motivated by the investigation of the equivalent photon yield produced by decelerating charges. For the elliptic asymmetry factor we find a reasonable agreement with experimental data.

  2. Elliptic flow due to radiation in heavy-ion collisions

    E-Print Network [OSTI]

    T. S. Biró; M. Horváth; Zs. Schram

    2015-03-23T23:59:59.000Z

    In this paper we demonstrate that radiation patterns could cause flow-like behaviour without any reference to hydrodynamic description. For that purpose we use a statistical ensemble of radiating dipoles, motivated by the investigation of the equivalent photon yield produced by decelerating charges. For the elliptic asymmetry factor we find a reasonable agreement with experimental data.

  3. *can substitute CSE 131 or equivalent and ESE 101 or equivalent Updated June 2013 Mechanical Engineering Sample Curriculum

    E-Print Network [OSTI]

    Subramanian, Venkat

    *can substitute CSE 131 or equivalent and ESE 101 or equivalent Updated June 2013 Mechanical of Thermal Systems MEMS 412 3 Modeling Simulation and Control MEMS 4301 3 Structural Dynamics and Vibration MEMS 431 4 Intro to Circuits ESE 230 4 Engineering Ethics and Sustainability ENGR 4501 1 Engineering

  4. Establishment and validation of a method for multi-dose irradiation of cells in 96-well microplates

    SciTech Connect (OSTI)

    Abatzoglou, Ioannis; Zois, Christos E.; Pouliliou, Stamatia [Department of Radiotherapy/Oncology, Radiobiology and Radiopathology Unit, Democritus University of Thrace, Alexandroupolis (Greece)] [Department of Radiotherapy/Oncology, Radiobiology and Radiopathology Unit, Democritus University of Thrace, Alexandroupolis (Greece); Koukourakis, Michael I., E-mail: targ@her.forthnet.gr [Department of Radiotherapy/Oncology, Radiobiology and Radiopathology Unit, Democritus University of Thrace, Alexandroupolis (Greece)

    2013-02-15T23:59:59.000Z

    Highlights: ? We established a method for multi-dose irradiation of cell cultures within a 96-well plate. ? Equations to adjust to preferable dose levels are produced and provided. ? Up to eight different dose levels can be tested in one microplate. ? This method results in fast and reliable estimation of radiation dose–response curves. -- Abstract: Microplates are useful tools in chemistry, biotechnology and molecular biology. In radiobiology research, these can be also applied to assess the effect of a certain radiation dose delivered to the whole microplate, to test radio-sensitivity, radio-sensitization or radio-protection. Whether different radiation doses can be accurately applied to a single 96-well plate to further facilitate and accelerated research by one hand and spare funds on the other, is a question dealt in the current paper. Following repeated ion-chamber, TLD and radiotherapy planning dosimetry we established a method for multi-dose irradiation of cell cultures within a 96-well plate, which allows an accurate delivery of desired doses in sequential columns of the microplate. Up to eight different dose levels can be tested in one microplate. This method results in fast and reliable estimation of radiation dose–response curves.

  5. Health Impacts from Acute Radiation Exposure

    SciTech Connect (OSTI)

    Strom, Daniel J.

    2003-09-30T23:59:59.000Z

    Absorbed doses above1-2 Gy (100-200 rads) received over a period of a day or less lead to one or another of the acute radiation syndromes. These are the hematopoietic syndrome, the gastrointestinal (GI) syndrome, the cerebrovascular (CV) syndrome, the pulmonary syndrome, or the cutaneous syndrome. The dose that will kill about 50% of the exposed people within 60 days with minimal medical care, LD50-60, is around 4.5 Gy (450 rads) of low-LET radiation measured free in air. The GI syndrome may not be fatal with supportive medical care and growth factors below about 10 Gy (1000 rads), but above this is likely to be fatal. Pulmonary and cutaneous syndromes may or may not be fatal, depending on many factors. The CV syndrome is invariably fatal. Lower acute doses, or protracted doses delivered over days or weeks, may lead to many other health outcomes than death. These include loss of pregnancy, cataract, impaired fertility or temporary or permanent sterility, hair loss, skin ulceration, local tissue necrosis, developmental abnormalities including mental and growth retardation in persons irradiated as children or fetuses, radiation dermatitis, and other symptoms listed in Table 2 on page 12. Children of parents irradiated prior to conception may experience heritable ill-health, that is, genetic changes from their parents. These effects are less strongly expressed than previously thought. Populations irradiated to high doses at high dose rates have increased risk of cancer incidence and mortality, taken as about 10-20% incidence and perhaps 5-10% mortality per sievert of effective dose of any radiation or per gray of whole-body absorbed dose low-LET radiation. Cancer risks for non-uniform irradiation will be less.

  6. ORISE: Dose modeling and assessments

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

    or state regulatory compliance requirements are being met during the decontamination and decommissioning of nuclear facilities. Dose modeling is an important step in the...

  7. Measurement of natural radioactivity and assessment of radiation hazard indices in soil samples at Pengerang, Kota Tinggi, Johor

    SciTech Connect (OSTI)

    Hassan, Nur Nazihah; Khoo, Kok Siong [School of Applied Physics, Faculty of Science and Technology, University Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2014-02-12T23:59:59.000Z

    Pengerang area consists of a mix of private plantation, individual residential lots and state land, which is leased for agriculture related activities. The analysis was conducted to determine the specific activity of the initial value and the radiation hazard indices in the surrounding area in Pengerang. This area will be developed into a major downstream for oil and gas. The aims of this preliminary study were 1) to determine the specific activities of {sup 238}U, {sup 232}Th, {sup 226}Ra and {sup 40}K of soil samples at six selected areas by Gamma-ray spectrometry and 2) to calculate the radiation hazard indices. The specific activities (Bq/kg) of the samples ranged from 7.08±5.01 to 36.29±25.72 Bq/kg, 5.62±3.98 to 34.53±24.07 Bq/kg, 4.75±3.42 to 24.76±17.66 Bq/kg and 10.58±7.51 to 101.25±72.00 Bq/kg for {sup 238}U, {sup 232}Th, {sup 226}Ra and {sup 40}K, respectively. These values were well within the range that reported by UNSCEAR. The study also examined the radiation hazard indices, the mean values obtained were 48.49±28.06 Bq/kg for Radium Equivalent Activity (Raeq), 0.34 Bq/kg for Representative Level Index (I{sub ?}), 21.83 nGy/h for Absorbed dose rates (D), 0.27 mSv/y for Annual Effective Dose Rates (Deff), 0.13 and 0.18 for External Hazards Index (H{sub ex}) and Internal Hazard Index (H{sub in}), respectively. These calculated hazard indices were used to estimate the potential radiological health risk in soil and the dose rates associated with it were well below their permissible limit. The overall findings show that no radiological threat to the health of the population in the study area.

  8. Does administering iodine in radiological procedures increase patient doses?

    SciTech Connect (OSTI)

    He, Wenjun; Yao, Hai, E-mail: haiyao@clemson.edu [Clemson-MUSC Bioengineering Program, Department of Bioengineering, Clemson University, Charleston, South Carolina 29425 (United States); Huda, Walter; Mah, Eugene [Department of Radiology and Radiological Science, Medical University of South Carolina (MUSC), Charleston, South Carolina 29425 (United States)

    2014-11-01T23:59:59.000Z

    Purpose: The authors investigated the changes in the pattern of energy deposition in tissue equivalent phantoms following the introduction of iodinated contrast media. Methods: The phantom consisted of a small “contrast sphere,” filled with water or iodinated contrast, located at the center of a 28 cm diameter water sphere. Monte Carlo simulations were performed using MCNP5 codes, validated by simulating irradiations with analytical solutions. Monoenergetic x-rays ranging from 35 to 150 keV were used to simulate exposures to spheres containing contrast agent with iodine concentrations ranging from 1 to 100 mg/ml. Relative values of energy imparted to the contrast sphere, as well as to the whole phantom, were calculated. Changes in patterns of energy deposition around the contrast sphere were also investigated. Results: Small contrast spheres can increase local absorbed dose by a factor of 13, but the corresponding increase in total energy absorbed was negligible (<1%). The highest localized dose increases were found to occur at incident photon energies of about 60 keV. For a concentration of about 10 mg/ml, typical of clinical practice, localized absorbed doses were generally increased by about a factor of two. At this concentration of 10 mg/ml, the maximum increase in total energy deposition in the phantom was only 6%. These simulations demonstrated that increases in contrast sphere doses were offset by corresponding dose reductions at distal and posterior locations. Conclusions: Adding iodine can result in values of localized absorbed dose increasing by more than an order of magnitude, but the total energy deposition is generally very modest (i.e., <10%). Their data show that adding iodine primarily changes the pattern of energy deposition in the irradiated region, rather than increasing patient doses per se.

  9. Parameterization of solar flare dose 

    E-Print Network [OSTI]

    Lamarche, Anne Helene

    1995-01-01T23:59:59.000Z

    A critical aspect of missions to the Moon or Mars is the safety and health of the crew. Radiation in space is a hazard for astronauts, especially high-energy radiation following certain types of solar flares. A solar flare ...

  10. Does the Equivalence between Gravitational Mass and Energy Survive for a Composite Quantum Body?

    E-Print Network [OSTI]

    Andrei G. Lebed

    2014-04-14T23:59:59.000Z

    We define passive and active gravitational mass operators of the simplest composite quantum body - a hydrogen atom. Although they do not commute with its energy operator, the equivalence between the expectation values of passive and active gravitational masses and energy is shown to survive for stationary quantum states. In our calculations of passive gravitational mass operator, we take into account not only kinetic and Coulomb potential energies but also the so-called relativistic corrections to electron motion in a hydrogen atom. Inequivalence between passive and active gravitational masses and energy at a macroscopic level is demonstrated to reveal itself as time dependent oscillations of the expectation values of the gravitational masses for superpositions of stationary quantum states. Breakdown of the equivalence between passive gravitational mass and energy at a microscopic level reveals itself as unusual electromagnetic radiation, emitted by macroscopic ensemble of hydrogen atoms, moved by small spacecraft with constant velocity in the Earth's gravitational field. We suggest the corresponding experiment on the Earth's orbit to detect this radiation, which would be the first direct experiment where quantum effects in general relativity are observed.

  11. 74Exploring Nuclear Decay and Radiation Dose The devastating earthquake

    E-Print Network [OSTI]

    and fall to the ground, contaminating the soil. Cesium-137 has a half-life of 30 years, while Iodine-131 in the vented gases are Cesium-137 and Iodine-131. These will become incorporated into atmospheric dust grains

  12. ambient radiation dose: Topics by E-print Network

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

    Vibration TestForced Vibration Test Seismic-B Building Bogazici University 12;Seismic Retrofitting Before Retrofit After Retrofit Dimension (cm ? cm mode in E-W 3 3.5 4...

  13. Annual report shows potential INL radiation doses well below safe

    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 Office511041cloth DocumentationProductsAlternative FuelsSanta3 Table 3.EnergyAug412Electricity

  14. Observable Equivalence between General Relativity and Shape Dynamics

    E-Print Network [OSTI]

    Tim Koslowski

    2012-03-29T23:59:59.000Z

    In this conceptual paper we construct a local version of Shape Dynamics that is equivalent to General Relativity in the sense that the algebras of Dirac observables weakly coincide. This allows us to identify Shape Dynamics observables with General Relativity observables, whose observables can now be interpreted as particular representative functions of observables of a conformal theory at fixed York time. An application of the observable equivalence of General Relativity and Shape Dynamics is to define the quantization of General Relativity through quantizing Shape Dynamics and using observable equivalence. We investigate this proposal explicitly for gravity in 2+1 dimensions.

  15. Radiation Exposure Information Reporting System (REIRS) Update, 2012, Presented at the 32nd Annual International Dosimetry and Records Symposium, June 2-6, 2013

    SciTech Connect (OSTI)

    none,

    2013-01-01T23:59:59.000Z

    A series of graphs gives data through the year 2012 for annual collective doses, collective dose per reactor, number of individuals with measurable doses both in total and per reactor, number of reactors, electricity generated, measurable doses per individual and per megawatt-year, and collective outage hours. Reactors considered include BWR, PWR, and LWR. Also, the total effective dose equivalent for the period 2010-2012 is tabulated for each nuclear power plant considered, and the change over 2009-2011.

  16. Meeting Report--NASA Radiation Biomarker Workshop

    SciTech Connect (OSTI)

    Straume, Tore; Amundson, Sally A,; Blakely, William F.; Burns, Frederic J.; Chen, Allen; Dainiak, Nicholas; Franklin, Stephen; Leary, Julie A.; Loftus, David J.; Morgan, William F.; Pellmar, Terry C.; Stolc, Viktor; Turteltaub, Kenneth W.; Vaughan, Andrew T.; Vijayakumar, Srinivasan; Wyrobek, Andrew J.

    2008-05-01T23:59:59.000Z

    A summary is provided of presentations and discussions from the NASA Radiation Biomarker Workshop held September 27-28, 2007, at NASA Ames Research Center in Mountain View, California. Invited speakers were distinguished scientists representing key sectors of the radiation research community. Speakers addressed recent developments in the biomarker and biotechnology fields that may provide new opportunities for health-related assessment of radiation-exposed individuals, including for long-duration space travel. Topics discussed include the space radiation environment, biomarkers of radiation sensitivity and individual susceptibility, molecular signatures of low-dose responses, multivariate analysis of gene expression, biomarkers in biodefense, biomarkers in radiation oncology, biomarkers and triage following large-scale radiological incidents, integrated and multiple biomarker approaches, advances in whole-genome tiling arrays, advances in mass-spectrometry proteomics, radiation biodosimetry for estimation of cancer risk in a rat skin model, and confounding factors. Summary conclusions are provided at the end of the report.

  17. RIS-M-2483 A PILOT INVESTIGATION OP NATORAL RADIATION IN DANISH HOUSES

    E-Print Network [OSTI]

    EQUIVALENTS; DOSB RATES; DOSBMBTBRS; BTCHING; EXPERIMEN- TAL DATA; GAMMA RADIATION; HOUSES; NATURALRISø-M-2483 A PILOT INVESTIGATION OP NATORAL RADIATION IN DANISH HOUSES A. Sørensen, L. Bøtter radiation in Denmark. A passive cup dosemeter was designed containing CR39 track detectors and TLD

  18. An evaluation of the TSE MR sequence for time efficient data acquisition in polymer gel dosimetry of applications involving high doses and steep dose gradients

    SciTech Connect (OSTI)

    Baras, P.; Seimenis, I.; Sandilos, P.; Vlahos, L.; Bieganski, T.; Georgiou, E.; Pantelis, E.; Papagiannis, P.; Sakelliou, L. [Philips Hellas Medical Systems, 44 Kifissias Ave., Maroussi 151 25, Athens (Greece); Department of Radiology, Medical School, University of Athens, Areteion Hospital, 76 Vas. Sofias Ave., 115 28 Athens (Greece) and Medical Physics Department, Hygeia Hospital, Kiffisias Avenue, 24 Erythrou Stavrou, Marousi, 151 23, Athens (Greece); Department of Radiology, Mother's Memorial Hospital, Rzgowska 281/289, 93-388, Lodz (Poland); Medical Physics Department, University of Athens, 75 Mikras Asias, 115 27 Athens (Greece); Nuclear and Particle Physics Section, Physics Department, University of Athens, Panepistimioupolis, Ilisia, 157 71 Athens (Greece)

    2005-11-15T23:59:59.000Z

    The use of magnetic resonance imaging as a readout method for polymer gel dosimetry commonly involves long imaging sessions, particularly when high spatial resolution is required in all three dimensions, for the investigation of dose distributions with steep dose gradients and stringent dose delivery specifications. In this work, a volume selective turbo spin echo (TSE) pulse sequence is compared to the established Carr-Purcell-Meiboom-Gill (CPMG) multiecho acquisition with regard to providing accurate dosimetric results in significantly reduced imaging times. Polyethylene glycol diacrylate based (PABIG) gels were irradiated and subsequently scanned to obtain R2 relaxation rate measurements, using a CPMG multiecho sequence and a dual echo TSE utilizing an acceleration (turbo) factor of 64. R2 values, plotted against corresponding Monte Carlo dose calculations, provided calibration data of PABIG gels dose response over a wide dose range. A linear R2 versus dose relationship was demonstrated for both sequences with TSE results presenting reduced dose sensitivity. Although TSE data were found to deviate from linearity at lower doses compared to CPMG data, a relatively wide dynamic dose range of response extending up to approximately 100 Gy was observed for both sequences. The TSE and CPMG sequences were evaluated with a brachytherapy irradiation using a high dose rate {sup 192}Ir source and a gamma knife stereotactic radiosurgery irradiation with a single 4 mm collimator helmet shot. Dosimetric results obtained with the TSE and CPMG are shown to compare equally well with the expected dose distributions for these irradiations. The 60-fold scan time reduction achieved with TSE implies that this sequence could prove to be a useful tool for the introduction of polymer gel dosimetry in clinical radiation therapy applications involving high doses and steep dose gradients.

  19. Violation of the Weak Equivalence Principle in Bekenstein's theory

    E-Print Network [OSTI]

    L. Kraiselburd; H. Vucetich

    2009-02-24T23:59:59.000Z

    Bekenstein has shown that violation of Weak Equivalence Principle is strongly supressed in his model of charge variation. In this paper, it is shown that nuclear magnetic energy is large enough to produce observable effects in Eotvos experiments.

  20. Equivalence of the Husain and the Pleba?ski equations

    E-Print Network [OSTI]

    M. Jakimowicz; J. Tafel

    2006-03-31T23:59:59.000Z

    We show that Husain's reduction of the self-dual Einstein equations is equivalent to the Pleba\\'nski equation. The B\\"acklund transformation between these equations is found. Contact symmetries of the Husain equation are derived.