Sample records for knife fryburg mondak

  1. A knife-edge array field emission cathode

    SciTech Connect (OSTI)

    Lee, B.

    1994-08-01T23:59:59.000Z

    many cathode applications require a new type of cathode that is able to produce short pulsed electron beams at high emission current. Gated field emitter arrays of micrometer size are recognized as candidates to meet this need and have become the research focus of vacuum microelectronics. Existing fabrication methods produce emitters that are limited either in frequency response or in current emission. One reason is that the structure of these emitters are not sufficiently optimized. In this study, the author investigated the factors that affect the performance of field emitters. An optimum emitter structure, the knife-edge field emitter array, was developed from the analysis. Large field enhancement factor, large effective emission area, and small emitter capacitance are the advantages of the structure. The author next explored various options of fabricating the knife-edge emitter structure. He proposed a unique thin film process procedure and developed the fabrication techniques to build the emitters on (110) silicon wafers. Data from the initial cathode tests showed very low onset voltages and Fowler-Nordheim type emission. Emission simulation based on the fabricated emitter structure indicated that the knife-edge emitter arrays have the potential to produce high performance in modulation frequency and current emission. Several fabrication issues that await further development are discussed and possible solutions are suggested.

  2. ACQUISITION AND RECONSTRUCTION OF BRAIN TISSUE USING KNIFE-EDGE SCANNING MICROSCOPY

    E-Print Network [OSTI]

    Keyser, John

    ACQUISITION AND RECONSTRUCTION OF BRAIN TISSUE USING KNIFE- EDGE SCANNING MICROSCOPY A Thesis Science #12;ACQUISITION AND RECONSTRUCTION OF BRAIN TISSUE USING KNIFE- EDGE SCANNING MICROSCOPY A Thesis) ______________________________ ______________________________ Ergun Akleman Valerie Taylor (Member) (Head of Department) December 2003 Major Subject: Computer Science

  3. Acquisition and reconstruction of brain tissue using knife-edge scanning microscopy

    E-Print Network [OSTI]

    Mayerich, David Matthew

    2004-09-30T23:59:59.000Z

    ACQUISITION AND RECONSTRUCTION OF BRAIN TISSUE USING KNIFE- EDGE SCANNING MICROSCOPY A Thesis by DAVID MATTHEW MAYERICH Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 2003 Major Subject: Computer Science ACQUISITION AND RECONSTRUCTION OF BRAIN TISSUE USING KNIFE- EDGE SCANNING MICROSCOPY A Thesis by DAVID MATTHEW MAYERICH Submitted to Texas...

  4. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    SciTech Connect (OSTI)

    Womac, A.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Sokhansanj, Shahabaddine [ORNL; Narayan, S. [First American Scientific Co.

    2009-04-01T23:59:59.000Z

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.

  5. Measurement of Gamma Knife registered helmet factors using MOSFETs

    SciTech Connect (OSTI)

    Kurjewicz, Laryssa; Berndt, Anita [Department of Physics, University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba R3B 2E9 (Canada); Division of Medical Physics, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, Manitoba R3E 0V9 (Canada); Winnipeg Centre for Gamma Knife Surgery, Health Sciences Centre, Winnipeg Regional Health Authority, Winnipeg MB R3E 0V9 (Canada); Section of Neurosurgery, Department of Surgery, Department of Radiology, University of Manitoba, Winnipeg MB R3E 0V9 (Canada) and Department of Physics and Astronomy, University of Manitoba, Winnipeg MB R3E 0V9 (Canada)

    2007-03-15T23:59:59.000Z

    The relative dose rate for the different Gamma Knife registered helmets (4, 8, 14, and 18 mm) is characterized by their respective helmet factors. Since the plateau of the dose profile for the 4 mm helmet is at most 1 mm wide, detector choices are limited. Traditionally helmet factors have been measured using 1x1x1 mm{sup 3} thermoluminescent dosimeters (TLDs). However, these are time-consuming, cumbersome measurements. This article investigates the use of metal-oxide-semiconductor field effect transistors (MOSFETs) (active area of 0.2x0.2 mm{sup 2}) as a more accurate and convenient dosimeter. Their suitability for these measurements was confirmed by basic characterization measurements. Helmet factors were measured using both MOSFETs and the established TLD approach. A custom MOSFET cassette was designed in analogy to the Elekta TLD cassette (Elekta Instruments AB) for use with the Elekta dosimetry sphere. Although both dosimeters provided values within 3% of the manufacturer's suggestion, MOSFETs provided superior accuracy and precision, in a fraction of the time required for the TLD measurements. Thus, MOSFETs proved to be a reasonable alternative to TLDs for performing helmet factor measurements.

  6. Gamma Knife Radiosurgery for Brain Metastases From Primary Breast Cancer

    SciTech Connect (OSTI)

    Kased, Norbert, E-mail: Norbert.Kased@ucsf.ed [Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); Binder, Devin K. [Department of Neurological Surgery, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); McDermott, Michael W. [Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); Department of Neurological Surgery, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); Nakamura, Jean L.; Huang, Kim [Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); Berger, Mitchel S. [Department of Neurological Surgery, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); Wara, William M.; Sneed, Penny K. [Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA (United States)

    2009-11-15T23:59:59.000Z

    Purpose: The relative roles of stereotactic radiosurgery (SRS) vs. whole brain radiotherapy (WBRT) in the treatment of patients with brain metastases from breast cancer remain undefined. In this study, we reviewed our experience with these patients. Materials and Methods: We retrospectively reviewed all patients treated between 1991 and 2005 with Gamma Knife SRS for brain metastases from breast cancer. The actuarial survival and freedom from progression endpoints were calculated using the Kaplan-Meier method. Results: Between 1991 and 2005, 176 patients underwent SRS for brain metastases from breast cancer. The median survival time was 16.0 months for 95 newly diagnosed patients and 11.7 months for 81 patients with recurrent brain metastases. In the newly diagnosed patients, omission of upfront WBRT did not significantly affect the MST (p = .20), brain freedom from progression (p = .75), or freedom from new brain metastases (p = .83). Longer survival was associated with age <50 years, Karnofsky performance score >=70, primary tumor control, estrogen receptor positivity, and Her2/neu overexpression. No association was found between the number of treated brain metastases and the survival time. Conclusion: We have described prognostic factors for breast cancer patients treated with SRS for newly diagnosed or recurrent brain metastases. Most patient subsets had a median survival time of >=11 months. Unexpectedly, upfront WBRT did not appear to improve brain freedom from progression, and a larger number of brain metastases was not associated with a shorter survival time. Breast cancer might be distinct from other primary sites in terms of prognostic factors and the roles of WBRT and SRS for brain metastases.

  7. Gamma Knife Radiosurgery for the Treatment of Cystic Cerebral Metastases

    SciTech Connect (OSTI)

    Ebinu, Julius O.; Lwu, Shelly; Monsalves, Eric; Arayee, Mandana [Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, Toronto, Ontario (Canada)] [Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, Toronto, Ontario (Canada); Chung, Caroline; Laperriere, Normand J. [Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Ontario (Canada); Kulkarni, Abhaya V.; Goetz, Pablo [Division of Neurosurgery, Department of Surgery, The Hospital for Sick Children, University of Toronto, Toronto, Ontario (Canada)] [Division of Neurosurgery, Department of Surgery, The Hospital for Sick Children, University of Toronto, Toronto, Ontario (Canada); Zadeh, Gelareh, E-mail: gelareh.zadeh@uhn.on.ca [Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, Toronto, Ontario (Canada)] [Division of Neurosurgery, Department of Surgery, Toronto Western Hospital, Toronto, Ontario (Canada)

    2013-03-01T23:59:59.000Z

    Purpose: To assess the role of Gamma Knife radiosurgery (GKRS) in the treatment of nonsurgical cystic brain metastasis, and to determine predictors of response to GKRS. Methods: We reviewed a prospectively maintained database of brain metastases patients treated at our institution between 2006 and 2010. All lesions with a cystic component were identified, and volumetric analysis was done to measure percentage of cystic volume on day of treatment and consecutive follow-up MRI scans. Clinical, radiologic, and dosimetry parameters were reviewed to establish the overall response of cystic metastases to GKRS as well as identify potential predictive factors of response. Results: A total of 111 lesions in 73 patients were analyzed; 57% of lesions received prior whole-brain radiation therapy (WBRT). Lung carcinoma was the primary cancer in 51% of patients, 10% breast, 10% colorectal, 4% melanoma, and 26% other. Fifty-seven percent of the patients were recursive partitioning analysis class 1, the remainder class 2. Mean target volume was 3.3 mL (range, 0.1-23 mL). Median prescription dose was 21 Gy (range, 15-24 Gy). Local control rates were 91%, 63%, and 37% at 6, 12, and 18 months, respectively. Local control was improved in lung primary and worse in patients with prior WBRT (univariate). Only lung primary predicted local control in multivariate analysis, whereas age and tumor volume did not. Lesions with a large cystic component did not show a poorer response compared with those with a small cystic component. Conclusions: This study supports the use of GKRS in the management of nonsurgical cystic metastases, despite a traditionally perceived poorer response. Our local control rates are comparable to a matched cohort of noncystic brain metastases, and therefore the presence of a large cystic component should not deter the use of GKRS. Predictors of response included tumor subtype. Prior WBRT decreased effectiveness of SRS for local control rates.

  8. The Paradox of Prop. 13: The Informed Public's Misunderstanding of California's Third Rail

    E-Print Network [OSTI]

    Nalder, Kimberly

    2010-01-01T23:59:59.000Z

    Mondak, Jeffery, and Mary Anderson. 2003. “A Knowledge Gap9. Mondak, Jeffery, and Mary Anderson. 2004. “The Knowledge

  9. Semi-Automated Reconstruction of Vascular Networks in Knife-Edge Scanning Microscope Mouse Brain Data

    E-Print Network [OSTI]

    Dileepkumar, Ananth

    2014-08-14T23:59:59.000Z

    The KnifeEdge Scanning Microscope (KESM) enables imaging of an entire mouse brain at sub-micrometer resolution. The data from KESM can be used in the reconstruction of neuronal and vascular structures in the mouse brain. Tracing the vascular network...

  10. Knife-Edge Scanning Microscope Mouse Brain Atlas In Vector Graphics For Enhanced Performance

    E-Print Network [OSTI]

    Choi, Jinho

    2013-07-17T23:59:59.000Z

    KNIFE-EDGE SCANNING MICROSCOPE MOUSE BRAIN ATLAS IN VECTOR GRAPHICS FOR ENHANCED PERFORMANCE A Thesis by JINHO CHOI Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree... of MASTER OF SCIENCE Chair of Committee, Yoonsuck Choe Committee Members, John Keyser Louise Abbott Department Head, Duncan M. \\Hank" Walker August 2013 Major Subject: Computer Science Copyright 2013 Jinho Choi ABSTRACT The microstructure...

  11. In situ tomography of femtosecond optical beams with a holographic knife-edge

    E-Print Network [OSTI]

    Strohaber, James; Kaya, G; N, Kay; Hart, Nathan; Kolomenskii, Alexander; Paulus, Gerhard; Schuessler, Hans

    2011-07-18T23:59:59.000Z

    ? that are mechanically difficult or impossible to reproduce. We test our method by holographically knife-edging and tomographically reconstructing both continuous wave and broadband radiation in transverse optical modes. ?2011 Optical Society of America OCIS codes... the sign of the angular dispersion causing the dispersed broadband beam to exhibit a zero amount of spatial dispersion at the position of the second grating [13]. At all other positions within the setup, except at the position of the first grating...

  12. Experience with the CyberKnife for intracranial stereotactic radiosurgery: Analysis of dosimetry indices

    SciTech Connect (OSTI)

    Floriano, Alejandro, E-mail: afloriano@grupoimo.com; Santa-Olalla, Iciar; Sanchez-Reyes, Alberto

    2014-04-01T23:59:59.000Z

    We evaluated coverage, dose homogeneity, dose conformity, and dose gradient in CyberKnife VSI treatment plans. Several dosimetric indices were calculated, and the results were compared with those of previous publications. The effect of target volume on the radiosurgical treatment indices selected was also investigated. The study population comprised the first 40 patients treated at our department from March 2011 to September 2012. Dosimetric indices were calculated and compared with published results for other frame-based and frameless intracranial stereotactic radiotherapy techniques. A comparison of the indices confirmed the ability of the CyberKnife VSI system to provide very high-quality dosing plans. The results were independent of target volume for coverage, homogeneity, and dose conformity. However, a dependence on target volume was observed for the dose-gradient indices analyzed. Based on the indices proposed, CyberKnife provides very good treatment plans and compares favorably with other techniques in most cases. However, greater consensus on the radiosurgery indices calculated would be desirable to facilitate comparison of the various techniques or the same techniques when applied by different users.

  13. Verification of Gamma Knife extend system based fractionated treatment planning using EBT2 film

    SciTech Connect (OSTI)

    Natanasabapathi, Gopishankar; Bisht, Raj Kishor [Gamma Knife Unit, Department of Neurosurgery, Neurosciences Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029 (India)] [Gamma Knife Unit, Department of Neurosurgery, Neurosciences Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029 (India)

    2013-12-15T23:59:59.000Z

    Purpose: This paper presents EBT2 film verification of fractionated treatment planning with the Gamma Knife (GK) extend system, a relocatable frame system for multiple-fraction or serial multiple-session radiosurgery.Methods: A human head shaped phantom simulated the verification process for fractionated Gamma Knife treatment. Phantom preparation for Extend Frame based treatment planning involved creating a dental impression, fitting the phantom to the frame system, and acquiring a stereotactic computed tomography (CT) scan. A CT scan (Siemens, Emotion 6) of the phantom was obtained with following parameters: Tube voltage—110 kV, tube current—280 mA, pixel size—0.5 × 0.5 and 1 mm slice thickness. A treatment plan with two 8 mm collimator shots and three sectors blocking in each shot was made. Dose prescription of 4 Gy at 100% was delivered for the first fraction out of the two fractions planned. Gafchromic EBT2 film (ISP Wayne, NJ) was used as 2D verification dosimeter in this process. Films were cut and placed inside the film insert of the phantom for treatment dose delivery. Meanwhile a set of films from the same batch were exposed from 0 to 12 Gy doses for calibration purposes. An EPSON (Expression 10000 XL) scanner was used for scanning the exposed films in transparency mode. Scanned films were analyzed with inhouse written MATLAB codes.Results: Gamma index analysis of film measurement in comparison with TPS calculated dose resulted in high pass rates >90% for tolerance criteria of 1%/1 mm. The isodose overlay and linear dose profiles of film measured and computed dose distribution on sagittal and coronal plane were in close agreement.Conclusions: Through this study, the authors propose treatment verification QA method for Extend frame based fractionated Gamma Knife radiosurgery using EBT2 film.

  14. Development of a 3-Dimensional Dosimetry System for Leksell Gamma Knife-Perfexion

    E-Print Network [OSTI]

    Yoon, KyoungJun; Lee, DoHeui; Cho, ByungChul; Lee, SangWook; Ahn, SeungDo

    2015-01-01T23:59:59.000Z

    The purpose of our study is to develop a new, 3-dimensional dosimetry system to verify the accuracy of dose deliveries in Leksell Gamma Knife-Perfexion TM (LGKP) (Elekta, Norcross, GA, USA). The instrument consists of a moving head phantom, an embedded thin active layer and a CCD camera system and was designed to be mounted to LGKP. As an active material concentrically located in the hemispheric head phantom, we choose Gafchromic EBT3 films and Gd2O2S;Tb phosphor sheets for dosimetric measurements. Also, to compensate the lack of backscatter, we located a 1 cm thick PMMA plate downstream of the active layer. The PMMA plate was transparent for scintillation lights to reach the CCD with 1200x1200 pixels by a 5.2 um pitch. Using this system, three hundred images by a 0.2 mm slice gap were acquired under each of three collimator setups, i.e. 4 mm, 8 mm, and 16 mm, respectively. The 2D projected images taken by CCD camera were compared with the dose distributions measured by EBT3 films in the same conditions. All ...

  15. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    SciTech Connect (OSTI)

    Kim, Haksoo; Welford, Scott [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)] [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States); Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W., E-mail: jason.sohn@case.edu [Department of Radiation Oncology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 and University Hospitals of Cleveland, 11100 Euclid Avenue, Cleveland, Ohio 44106 (United States); Sloan, Andrew [Department of Neurosurgery, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)] [Department of Neurosurgery, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)

    2014-02-15T23:59:59.000Z

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A passing rate of 99% was measured in areas of above 40% of the prescription dose. The final inverse treatment plan was comprised of 43 beams ranging from 5 to 12.5 mm in diameter (2.5 mm size increments are available up to 15 mm in diameter collimation). Using the Xsight Spine Tracking module, the CyberKnife system could not reliably identify and track the tiny mouse spine; however, the CyberKnife system could identify and track the fiducial markers on the 3D mold.In vivo positional accuracy analysis using the 3D mold generated a mean error of 1.41 mm ± 0.73 mm when fiducial markers were used for position tracking. Analysis of the dissected brain confirmed the ability to target the correct brain volume. Conclusions: With the use of a stereotactic body mold with fiducial markers, microCT imaging, and resolution down-sampling, the CyberKnife system can successfully perform small-animal radiotherapy studies.

  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. Automatic Seedpoint Selection and Tracing of Microstructures in the Knife-Edge Scanning Microscope Mouse Brain Data Set

    E-Print Network [OSTI]

    Kim, Dongkun

    2011-10-21T23:59:59.000Z

    in neuronal structures [4]. Research about the neuronal structure can also help understand how the neuronal structure processes information. In order to investigate neuronal structures, researchers at the Brain Network Lab (BNL) at Texas A&M University... by re- searchers at the Brain Network Laboratory (BNL) at Texas A&M University (TAMU) to scan entire mouse brains at a sub-micrometer resolution (down to 300 nm). This instrument consists of a high-precision stage, a diamond knife and an illuminator...

  18. Application of the gamma evaluation method in Gamma Knife film dosimetry

    SciTech Connect (OSTI)

    Park, Jeong-Hoon; Han, Jung Ho; Kim, Chae-Yong; Oh, Chang Wan; Lee, Do-Heui; Suh, Tae-Suk; Gyu Kim, Dong; Chung, Hyun-Tai [Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam 463-707, Korea and Department of Biomedical Engineering, College of Medicine, Catholic University of Korea Seoul 137-701 (Korea, Republic of); Department of Neurosurgery, Seoul National University Bundang Hospital, Seongnam 463-707, Korea and Department of Neurosurgery, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of); Department of Neurosurgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul 138-736 (Korea, Republic of); Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Department of Neurosurgery, College of Medicine, Seoul National University, Seoul 110-799 (Korea, Republic of)

    2011-10-15T23:59:59.000Z

    Purpose: Gamma Knife (GK) radiosurgery is a minimally invasive surgical technique for the treatment of intracranial lesions. To minimize neurological deficits, submillimeter accuracy is required during treatment delivery. In this paper, the delivery accuracy of GK radiosurgery was assessed with the gamma evaluation method using planning dose distribution and film measurement data. Methods: Single 4, 8, and 16 mm and composite shot plans were developed for evaluation using the GK Perfexion (PFX) treatment planning system (TPS). The planning dose distributions were exported as digital image communications in medicine - radiation therapy (DICOM RT) files using a new function of GK TPS. A maximum dose of 8 Gy was prescribed for four test plans. Irradiation was performed onto a spherical solid water phantom using Gafchromic EBT2 films in the axial and coronal planes. The exposed films were converted to absolute dose based on a 4th-order polynomial calibration curve determined using ten calibration films. The film measurement results and planning dose distributions were registered for further analysis in the same Leksell coordinate using in-house software. The gamma evaluation method was applied to two dose distributions with varying spatial tolerance (0.3-2.0 mm) and dosimetric tolerance (0.3-2.0%), to verify the accuracy of GK radiosurgery. The result of gamma evaluation was assessed using pass rate, dose gamma index histogram (DGH), and dose pass rate histogram (DPH). Results: The 20, 50, and 80% isodose lines found in film measurements were in close agreement with the planning isodose lines, for all dose levels. The comparison of diagonal line profiles across the axial plane yielded similar results. The gamma evaluation method resulted in high pass rates of >95% within the 50% isodose line for 0.5 mm/0.5% tolerance criteria, in both the axial and coronal planes. They satisfied 1.0 mm/1.0% criteria within the 20% isodose line. Our DGH and DPH also showed that low isodose lines exhibited inferior gamma indexes and pass rates compared with higher isodose lines. Conclusions: The gamma evaluation method was applicable to GK radiosurgery. For all test plans, planning dose distribution and film measurement met the tolerance criteria of 0.5 mm/0.5% within the 50% isodose line which are used for marginal dose prescription.

  19. Cell Detection in Knife-Edge Scanning Microscopy Images of Nissl-stained Mouse and Rat Brain Samples Using Random Forests

    E-Print Network [OSTI]

    Lal Das, Shashwat

    2014-11-26T23:59:59.000Z

    Microscopy has developed into a very powerful medium for studying the brain. The Knife-Edge Scanning Microscope (KESM), for example, is capable of imaging whole rat and mouse brains in three dimensions, and produces over 1.5 terabytes of images per...

  20. Long-term stability of the Leksell Gamma Knife{sup ®} Perfexion™ patient positioning system (PPS)

    SciTech Connect (OSTI)

    Novotny, J., E-mail: josef.novotnyml@homolka.cz [Department of Radiation Oncology, Medical Physics Division, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213 (United States); Department of Medical Physics, Na Homolce Hospital, Prague 150 30 (Czech Republic); Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University in Prague, Prague 120 00 (Czech Republic); Department of Dosimetry and Application of Ionizing Radiation, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague 115 19 (Czech Republic); Department of Radiation Oncology, University Hospital Motol, Prague 150 06 (Czech Republic); Bhatnagar, J. P.; Xu, Y.; Huq, M. S. [Department of Radiation Oncology, Medical Physics Division, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213 (United States)] [Department of Radiation Oncology, Medical Physics Division, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213 (United States)

    2014-03-15T23:59:59.000Z

    Purpose: To assess the long-term mechanical stability and accuracy of the patient positioning system (PPS) of the Leksell Gamma Knife{sup ®} Perfexion™ (LGK PFX). Methods: The mechanical stability of the PPS of the LGK PFX was evaluated using measurements obtained between September 2007 and June 2011. Three methods were employed to measure the deviation of the coincidence of the radiological focus point (RFP) and the PPS calibration center point (CCP). In the first method, the onsite diode test tool with single diode detector was used together with the 4 mm collimator on a daily basis. In the second method, a service diode test tool with three diode detectors was used biannually at the time of the routine preventive maintenance. The test performed with the service diode test tool measured the deviations for all three collimators 4, 8, and 16 mm and also for three different positions of the PPS. The third method employed the conventional film pin-prick method. This test was performed annually for the 4 mm collimator at the time of the routine annual QA. To estimate the effect of the patient weight on the performance of the PPS, the focus precision tests were also conducted with varying weights on the PPS using a set of lead bricks. Results: The average deviations measured from the 641 daily focus precision tests were 0.1 ± 0.1, 0.0 ± 0.0, and 0.0 ± 0.0 mm, respectively, for the 4 mm collimator in the X (left/right of the patient), Y (anterior/posterior of the patient), and Z (superior/inferior of the patient) directions. The average of the total radial deviations as measured during ten semiannual measurements with the service diode test tool were 0.070 ± 0.029, 0.060 ± 0.022, and 0.103 ± 0.028 mm, respectively for the central, long, and short diodes for the 4 mm collimator. Similarly, the average total radial deviations measured during the semiannual measurements for the 4, 8, and 16 mm collimators and using the central diode were 0.070 ± 0.029, 0.097 ± 0.025, 0.159 ± 0.028 mm, respectively. The average values of the deviations as obtained from the five annual film pin-prick tests for the 4 mm collimator were 0.10 ± 0.06, 0.06 ± 0.09, and 0.03 ± 0.03 mm for the X, Y, Z stereotactic directions, respectively. Only a minor change was observed in the total radial deviations of the PPS as a function of the simulated patient weight up to 202 kg on the PPS. Conclusions: Excellent long-term mechanical stability and high accuracy was observed for the PPS of the LGK PFX. No PPS recalibration or any adjustment in the PPS was needed during the monitored period of time. Similarly, the weight on the PPS did not cause any significant disturbance in the performance of the PPS for up to 202 kg simulated patient weight.

  1. Direct Plan Comparison of RapidArc and CyberKnife for Spine Stereotactic Body Radiation Therapy

    E-Print Network [OSTI]

    Choi, Young Eun; Song, Si Yeol; Choi, Eun Kyung; Ahn, Seung Do; Cho, Byungchul

    2015-01-01T23:59:59.000Z

    We compared the treatment planning performance of RapidArc (RA) vs. CyberKnife (CK) for spinal stereotactic body radiation therapy (SBRT). Ten patients with spinal lesions who had been treated with CK were re-planned with RA, which consisted of two complete arcs. Computed tomography (CT) and volumetric dose data of CK, generated using the Multiplan (Accuray) treatment planning system (TPS) and the Ray-Trace algorithm, were imported to Varian Eclipse TPS in Dicom format, and the data were compared with the RA plan using analytical anisotropic algorithm (AAA) dose calculation. The optimized dose priorities for both CK and RA plans were similar for all patients. The highest priority was to provide enough dose coverage to the planned target volume (PTV) while limiting the maximum dose to the spinal cord. Plan quality was evaluated with respect to PTV coverage, conformity index (CI), high-dose spillage, intermediate-dose spillage (R50% and D2cm), and maximum dose to the spinal cord, which are criteria recommended ...

  2. Absolute calibration of the Gamma Knife{sup ®} Perfexion™ and delivered dose verification using EPR/alanine dosimetry

    SciTech Connect (OSTI)

    Hornbeck, Amaury, E-mail: amauryhornbeck@gmail.com, E-mail: tristan.garcia@cea.fr; Garcia, Tristan, E-mail: amauryhornbeck@gmail.com, E-mail: tristan.garcia@cea.fr [CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette Cedex (France)] [CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette Cedex (France); Cuttat, Marguerite; Jenny, Catherine [Radiotherapy Department, Medical Physics Unit, University Hospital Pitié-Salpêtrière, 75013 Paris (France)] [Radiotherapy Department, Medical Physics Unit, University Hospital Pitié-Salpêtrière, 75013 Paris (France)

    2014-06-15T23:59:59.000Z

    Purpose: Elekta Leksell Gamma Knife{sup ®} (LGK) is a radiotherapy beam machine whose features are not compliant with the international calibration protocols for radiotherapy. In this scope, the Laboratoire National Henri Becquerel and the Pitié-Salpêtrière Hospital decided to conceive a new LKG dose calibration method and to compare it with the currently used one. Furthermore, the accuracy of the dose delivered by the LGK machine was checked using an “end-to-end” test. This study also aims to compare doses delivered by the two latest software versions of the Gammaplan treatment planning system (TPS). Methods: The dosimetric method chosen is the electron paramagnetic resonance (EPR) of alanine. Dose rate (calibration) verification was done without TPS using a spherical phantom. Absolute calibration was done with factors calculated by Monte Carlo simulation (MCNP-X). For “end-to-end” test, irradiations in an anthropomorphic head phantom, close to real treatment conditions, are done using the TPS in order to verify the delivered dose. Results: The comparison of the currently used calibration method with the new one revealed a deviation of +0.8% between the dose rates measured by ion chamber and EPR/alanine. For simple fields configuration (less than 16 mm diameter), the “end-to-end” tests showed out average deviations of ?1.7% and ?0.9% between the measured dose and the calculated dose by Gammaplan v9 and v10, respectively. Conclusions: This paper shows there is a good agreement between the new calibration method and the currently used one. There is also a good agreement between the calculated and delivered doses especially for Gammaplan v10.

  3. The Importance of the Conformality, Heterogeneity, and Gradient Indices in Evaluating Gamma Knife Radiosurgery Treatment Plans for Intracranial Meningiomas

    SciTech Connect (OSTI)

    Balagamwala, Ehsan H. [Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH (United States)] [Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH (United States); Suh, John H. [Department of Radiation Oncology, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States)] [Department of Radiation Oncology, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Barnett, Gene H. [Department of Neurosurgery, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States)] [Department of Neurosurgery, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States)] [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Neyman, Gennady [Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH (United States)] [Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH (United States); Cai, Rong S. [Children's Medical Center, Dallas, TX (United States)] [Children's Medical Center, Dallas, TX (United States); Vogelbaum, Michael A. [Department of Neurosurgery, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States)] [Department of Neurosurgery, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Novak, Eric [Department of Quantitative Health Sciences Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States)] [Department of Quantitative Health Sciences Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Chao, Samuel T., E-mail: chaos@ccf.org [Department of Radiation Oncology, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States)

    2012-08-01T23:59:59.000Z

    Purpose: To investigate the relationship between the conformality index (CIn), heterogeneity index (HIn), and gradient index (GIn) and the development of toxicity in patients treated with Gamma Knife radiosurgery (GKRS) for intracranial meningiomas. Methods and Materials: Treatment records of patients treated from 1997 to 2009 with at least 6 months of follow-up were reviewed. The following parameters were collected: CIn, HIn, GIn (ratio of the volume receiving half the prescription isodose to the volume receiving the full prescription isodose), brainstem (BS) maximum dose (MD), BS volume receiving {>=}12 Gy (V12), optic apparatus (OA) MD, OA V8 Gy, OA V10, number of isocenters, number of isocenters outside target volume, and the occurrence of six toxicities. Univariate and multivariate logistic regression modeling were used for analysis. Results: This study included 145 patients (148 meningiomas) with a median follow-up time of 27 months (range, 6-113.9 months). The majority of meningiomas were located in the skull base (53%). The median prescription dose was 13 Gy (range, 10-24 Gy) to the 51.50% (range, 50-92%) isodose. A lower HIn was correlated with a higher GIn (p = 0.007). CIn was not associated with any toxicity. Higher HIn was associated with the development of dizziness (odds ratio [OR] 1.9; p = 0.02), whereas a lower GIn was associated with motor deficits (OR 0.38; p = 0.04) and auditory changes (OR 0.59; p = 0.04). The OA MD, V8, and V12 were not associated with visual changes, but visual changes were associated with a higher number of isocenters outside the target volume (OR 1.93; p = 0.07). BS V12 was correlated with the development of auditory changes (OR 1.05; p = 0.05), whereas patients with higher BS MD tended to have increased toxicity. Conclusions: Close attention must be paid to all three indices (CIn, HIn, GIn) when optimal treatment plans are determined. We recommend that the target CIn should be {<=}2.0, the HIn {<=}2.0, and the GIn {>=}3.0 for intracranial meningiomas.

  4. Semiquantitative Analysis Using Thallium-201 SPECT for Differential Diagnosis Between Tumor Recurrence and Radiation Necrosis After Gamma Knife Surgery for Malignant Brain Tumors

    SciTech Connect (OSTI)

    Matsunaga, Shigeo, E-mail: shigeo-m@mui.biglobe.ne.jp [Department of Neurosurgery, Yokohama Rosai Hospital, Yokohama, Kanagawa (Japan)] [Department of Neurosurgery, Yokohama Rosai Hospital, Yokohama, Kanagawa (Japan); Shuto, Takashi; Takase, Hajime; Ohtake, Makoto; Tomura, Nagatsuki; Tanaka, Takahiro; Sonoda, Masaki [Department of Neurosurgery, Yokohama Rosai Hospital, Yokohama, Kanagawa (Japan)] [Department of Neurosurgery, Yokohama Rosai Hospital, Yokohama, Kanagawa (Japan)

    2013-01-01T23:59:59.000Z

    Purpose: Semiquantitative analysis of thallium-201 chloride single photon emission computed tomography ({sup 201}Tl SPECT) was evaluated for the discrimination between recurrent brain tumor and delayed radiation necrosis after gamma knife surgery (GKS) for metastatic brain tumors and high-grade gliomas. Methods and Materials: The medical records were reviewed of 75 patients, including 48 patients with metastatic brain tumor and 27 patients with high-grade glioma who underwent GKS in our institution, and had suspected tumor recurrence or radiation necrosis on follow-up neuroimaging and deteriorating clinical status after GKS. Analysis of {sup 201}Tl SPECT data used the early ratio (ER) and the delayed ratio (DR) calculated as tumor/normal average counts on the early and delayed images, and the retention index (RI) as the ratio of DR to ER. Results: A total of 107 tumors were analyzed with {sup 201}Tl SPECT. Nineteen lesions were removed surgically and histological diagnoses established, and the other lesions were evaluated with follow-up clinical and neuroimaging examinations after GKS. The final diagnosis was considered to be recurrent tumor in 65 lesions and radiation necrosis in 42 lesions. Semiquantitative analysis demonstrated significant differences in DR (P=.002) and RI (P<.0001), but not in ER (P=.372), between the tumor recurrence and radiation necrosis groups, and no significant differences between metastatic brain tumors and high-grade gliomas in all indices (P=.926 for ER, P=.263 for DR, and P=.826 for RI). Receiver operating characteristics analysis indicated that RI was the most informative index with the optimum threshold of 0.775, which provided 82.8% sensitivity, 83.7% specificity, and 82.8% accuracy. Conclusions: Semiquantitative analysis of {sup 201}Tl SPECT provides useful information for the differentiation between tumor recurrence and radiation necrosis in metastatic brain tumors and high-grade gliomas after GKS, and the RI may be the most valuable index for this purpose.

  5. Gamma Knife Stereotactic Radiosurgery as Salvage Therapy After Failure of Whole-Brain Radiotherapy in Patients With Small-Cell Lung Cancer

    SciTech Connect (OSTI)

    Harris, Sunit [Department of Radiation Oncology, Wake Forest University, Winston-Salem, North Carolina (United States); Chan, Michael D., E-mail: mchan@wfubmc.edu [Department of Radiation Oncology, Wake Forest University, Winston-Salem, North Carolina (United States); Lovato, James F. [Division of Public Health Sciences, Wake Forest University, Winston-Salem, North Carolina (United States); Ellis, Thomas L.; Tatter, Stephen B. [Department of Neurosurgery, Wake Forest University, Winston-Salem, North Carolina (United States); Bourland, J. Daniel; Munley, Michael T.; Guzman, Allan F. de; Shaw, Edward G.; Urbanic, James J.; McMullen, Kevin P. [Department of Radiation Oncology, Wake Forest University, Winston-Salem, North Carolina (United States)

    2012-05-01T23:59:59.000Z

    Purpose: Radiosurgery has been successfully used in selected cases to avoid repeat whole-brain irradiation (WBI) in patients with multiple brain metastases of most solid tumor histological findings. Few data are available for the use of radiosurgery for small-cell lung cancer (SCLC). Methods and Materials: Between November 1999 and June 2009, 51 patients with SCLC and previous WBI and new brain metastases were treated with GammaKnife stereotactic radiosurgery (GKSRS). A median dose of 18 Gy (range, 10-24 Gy) was prescribed to the margin of each metastasis. Patients were followed with serial imaging. Patient electronic records were reviewed to determine disease-related factors and clinical outcomes after GKSRS. Local and distant brain failure rates, overall survival, and likelihood of neurologic death were determined based on imaging results. The Kaplan-Meier method was used to determine survival and local and distant brain control. Cox proportional hazard regression was performed to determine strength of association between disease-related factors and survival. Results: Median survival time for the entire cohort was 5.9 months. Local control rates at 1 and 2 years were 57% and 34%, respectively. Distant brain failure rates at 1 and 2 years were 58% and 75%, respectively. Fifty-three percent of patients ultimately died of neurologic death. On multivariate analysis, patients with stable (hazard ratio [HR] = 2.89) or progressive (HR = 6.98) extracranial disease (ECD) had worse overall survival than patients without evidence of ECD (p = 0.00002). Concurrent chemotherapy improved local control (HR = 89; p = 0.006). Conclusions: GKSRS represents a feasible salvage option in patients with SCLC and brain metastases for whom previous WBI has failed. The status of patients' ECD is a dominant factor predictive of overall survival. Local control may be inferior to that seen with other cancer histological results, although the use of concurrent chemotherapy may help to improve this.

  6. Dose Gradient Near Target-Normal Structure Interface for Nonisocentric CyberKnife and Isocentric Intensity-Modulated Body Radiotherapy for Prostate Cancer

    SciTech Connect (OSTI)

    Hossain, Sabbir, E-mail: hossain99@yahoo.co [Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA (United States); Xia Ping; Huang, Kim; Descovich, Martina; Chuang, Cynthia; Gottschalk, Alexander R.; Roach, Mack; Ma Lijun [Department of Radiation Oncology, University of California, San Francisco, School of Medicine, San Francisco, CA (United States)

    2010-09-01T23:59:59.000Z

    Purpose: The treatment planning quality between nonisocentric CyberKnife (CK) and isocentric intensity modulation treatment was studied for hypofractionated prostate body radiotherapy. In particular, the dose gradient across the target and the critical structures such as the rectum and bladder was characterized. Methods and Materials: In the present study, patients treated with CK underwent repeat planning for nine fixed-field intensity-modulated radiotherapy (IMRT) using identical contour sets and dose-volume constraints. To calculate the dose falloff, the clinical target volume contours were expanded 30 mm anteriorly and posteriorly and 50 mm uniformly in other directions for all patients in the CK and IMRT plans. Results: We found that all the plans satisfied the dose-volume constraints, with the CK plans showing significantly better conformity than the IMRT plans at a relative greater dose inhomogeneity. The rectal and bladder volumes receiving a low dose were also lower for CK than for IMRT. The average conformity index, the ratio of the prescription isodose volume and clinical target volume, was 1.18 {+-} 0.08 for the CK plans vs. 1.44 {+-} 0.11 for the IMRT plans. The average homogeneity index, the ratio of the maximal dose and the prescribed dose to the clinical target volume, was 1.45 {+-} 0.12 for the CK plans vs. 1.28 {+-} 0.06 for the IMRT plans. The average percentage of dose falloff was 2.9% {+-} 0.8%/mm for CK and 3.1% {+-} 1.0%/mm for IMRT in the anterior direction, 3.8% {+-} 1.6%/mm for CK and 3.2% {+-} 1.9%/mm for IMRT in the posterior direction, and 3.6% {+-} 0.4% for CK and 3.6% {+-} 0.4% for IMRT in all directions. Conclusion: Nonisocentric CK was as capable of producing equivalent fast dose falloff as high-number fixed-field IMRT delivery.

  7. Predictive Parameters of CyberKnife Fiducial-less (XSight Lung) Applicability for Treatment of Early Non-Small Cell Lung Cancer: A Single-Center Experience

    SciTech Connect (OSTI)

    Bahig, Houda; Campeau, Marie-Pierre; Vu, Toni; Doucet, Robert; Béliveau Nadeau, Dominic [Radiation Oncology Department, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec (Canada); Fortin, Bernard [Radiation Oncology Department, Maisonneuve-Rosemont Hospital, Montréal, Quebec (Canada); Roberge, David; Lambert, Louise; Carrier, Jean-François [Radiation Oncology Department, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec (Canada); Filion, Edith, E-mail: edith.filion.chum@ssss.gouv.qc.ca [Radiation Oncology Department, Centre Hospitalier de l'Université de Montréal, Montréal, Quebec (Canada)

    2013-11-01T23:59:59.000Z

    Purpose: To determine which parameters allow for CyberKnife fiducial-less tumor tracking in stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer. Methods and Materials: A total of 133 lung SBRT patients were preselected for direct soft-tissue tracking based on manufacturer recommendations (peripherally located tumors ?1.5 cm with a dense appearance) and staff experience. Patients underwent a tumor visualization test to verify adequate detection by the tracking system (orthogonal radiographs). An analysis of potential predictors of successful tumor tracking was conducted looking at: tumor stage, size, histology, tumor projection on the vertebral column or mediastinum, distance to the diaphragm, lung-to-soft tissue ratio, and patient body mass index. Results: Tumor visualization was satisfactory for 88 patients (66%) and unsatisfactory for 45 patients (34%). Median time to treatment start was 6 days in the success group (range, 2-18 days) and 15 days (range, 3-63 days) in the failure group. A stage T2 (P=.04), larger tumor size (volume of 15.3 cm{sup 3} vs 6.5 cm{sup 3} in success and failure group, respectively) (P<.0001), and higher tumor density (0.86 g/cm{sup 3} vs 0.79 g/cm{sup 3}) were predictive of adequate detection. There was a 63% decrease in failure risk with every 1-cm increase in maximum tumor dimension (relative risk for failure = 0.37, CI=0.23-0.60, P=.001). A diameter of 3.6 cm predicted a success probability of 80%. Histology, lung-to-soft tissue ratio, distance to diaphragm, patient's body mass index, and tumor projection on vertebral column and mediastinum were not found to be predictive of success. Conclusions: Tumor size, volume, and density were the most predictive factors of a successful XSight Lung tumor tracking. Tumors >3.5 cm have ?80% chance of being adequately visualized and therefore should all be considered for direct tumor tracking.

  8. Iron aluminide knife and method thereof

    DOE Patents [OSTI]

    Sikka, Vinod K. (Oak Ridge, TN)

    1997-01-01T23:59:59.000Z

    Fabricating an article of manufacture having a Fe.sub.3 Al-based alloy cutting edge. The fabrication comprises the steps of casting an Fe.sub.3 Al-based alloy, extruding into rectangular cross section, rolling into a sheet at 800.degree. C. for a period of time followed by rolling at 650.degree. C., cutting the rolled sheet into an article having an edge, and grinding the edge of the article to form a cutting edge.

  9. Iron aluminide knife and method thereof

    DOE Patents [OSTI]

    Sikka, V.K.

    1997-08-05T23:59:59.000Z

    Fabricating an article of manufacture having a Fe{sub 3}Al-based alloy cutting edge is discussed. The fabrication comprises the steps of casting an Fe{sub 3}Al-based alloy, extruding into rectangular cross section, rolling into a sheet at 800 C for a period of time followed by rolling at 650 C, cutting the rolled sheet into an article having an edge, and grinding the edge of the article to form a cutting edge. 1 fig.

  10. From the Editor Knife Features of Key Gamma

    E-Print Network [OSTI]

    West, Stuart

    and the Anxiety State Anxiety Neurosis Interview Drug Addiction and Its Remedies A Wonder Brain Disease Treatment. The Stethoscope has chosen this week's Cover Story on Psychiatric illness to focus on the causes, treatment, care? The Treatment of Psychiatric Illness Psychological Treatment General Measures or Simple Psychotherapy Simple

  11. Dose distribution close to metal implants in Gamma Knife Radiosurgery: A Monte Carlo study

    E-Print Network [OSTI]

    Yu, K.N.

    Detachable Coil GDC system was used to localize and obliterate the aneurysm.5 Soft platinum coils were­8 II. METHODOLOGY The Monte Carlo system employed is the PRESTA Pa- rameter Reduced Electron be predicted correctly by the present treatment planning system, GammaPlan,1 be- cause the calculations

  12. Gamma Knife Radiosurgery for Patients With Nonfunctioning Pituitary Adenomas: Results From a 15-Year Experience

    SciTech Connect (OSTI)

    Pollock, Bruce E. [Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, MN (United States); Department of Radiation Oncology, Mayo Clinic College of Medicine, Rochester, MN (United States)], E-mail: pollock.bruce@mayo.edu; Cochran, Joseph [Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, MN (United States); Natt, Neena [Department of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN (United States); Brown, Paul D. [Department of Radiation Oncology, Mayo Clinic College of Medicine, Rochester, MN (United States); Erickson, Dana [Department of Endocrinology, Diabetes and Metabolism, Mayo Clinic College of Medicine, Rochester, MN (United States); Link, Michael J. [Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, MN (United States); Garces, Yolanda I.; Foote, Robert L.; Stafford, Scott L.; Schomberg, Paula J. [Department of Radiation Oncology, Mayo Clinic College of Medicine, Rochester, MN (United States)

    2008-04-01T23:59:59.000Z

    Purpose: To evaluate the efficacy and complications of stereotactic radiosurgery for patients with nonfunctioning pituitary adenomas (NFA). Methods and Materials: This was a retrospective review of 62 patients with NFA undergoing radiosurgery between 1992 and 2004, of whom 59 (95%) underwent prior tumor resection. The median treatment volume was 4.0 cm{sup 3} (range, 0.8-12.9). The median treatment dose to the tumor margin was 16 Gy (range, 11-20). The median maximum point dose to the optic apparatus was 9.5 Gy (range, 5.0-12.6). The median follow-up period after radiosurgery was 64 months (range, 23-161). Results: Tumor size decreased for 37 patients (60%) and remained unchanged for 23 patients (37%). Two patients (3%) had tumor growth outside the prescribed treatment volume and required additional treatment (fractionated radiation therapy, n = 1; repeat radiosurgery, n 1). Tumor growth control was 95% at 3 and 7 years after radiosurgery. Eleven (27%) of 41 patients with normal (n = 30) or partial (n = 11) anterior pituitary function before radiosurgery developed new deficits at a median of 24 months after radiosurgery. The risk of developing new anterior pituitary deficits at 5 years was 32%. The 5-year risk of developing new anterior pituitary deficits was 18% for patients with a tumor volume of {<=}4.0 cm{sup 3} compared with 58% for patients with a tumor volume >4.0 cm{sup 3} (risk ratio 4.5; 95% confidence interval = 1.3-14.9, p = 0.02). No patient had a decline in visual function. Conclusions: Stereotactic radiosurgery is effective in the management of patients with residual or recurrent NFA, although longer follow-up is needed to evaluate long-term outcomes. The primary complication is hypopituitarism, and the risk of developing new anterior pituitary deficits correlates with the size of the irradiated tumor.

  13. The Materiality and ‘Enchantment’ of the Gebel el-Arak Knife and the Gerzean Flint Blade Production

    E-Print Network [OSTI]

    Kim, Patricia E.

    2012-01-01T23:59:59.000Z

    2009. Figure 4: Map of Egypt. As published in Friedman 1994.in studying Predynastic Egypt since its acquisition. Made ofdiscussions concerning Egypt’s early relationship with the

  14. Stereotactic Radiosurgical Treatment of Brain Metastases to the Choroid Plexus;Renal cell cancer; Recursive partitioning analysis (RPA); Graded prognostic assessment (GPA); Survival and outcomes; Gamma knife

    SciTech Connect (OSTI)

    Siomin, Vitaly [Department of Neurosurgery, Cleveland Clinic, Cleveland, OH (United States); Lin, Jennifer L. [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Marko, Nicholas F., E-mail: markon@ccf.org [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Department of Neurosurgery, Cleveland Clinic, Cleveland, OH (United States); Barnett, Gene H.; Toms, Steven A. [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Department of Neurosurgery, Cleveland Clinic, Cleveland, OH (United States); Chao, Samuel T. [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Department of Radiation Oncology, Neurological and Taussig Cancer Institutes, Cleveland Clinic, Cleveland, OH (United States); Angelov, Lilyana; Vogelbaum, Michael A. [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Department of Neurosurgery, Cleveland Clinic, Cleveland, OH (United States); Navaratne, Kapila [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Suh, John H. [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Department of Radiation Oncology, Neurological and Taussig Cancer Institutes, Cleveland Clinic, Cleveland, OH (United States); Weil, Robert J. [Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH (United States); Department of Neurosurgery, Cleveland Clinic, Cleveland, OH (United States)

    2011-07-15T23:59:59.000Z

    Purpose: Choroid plexus metastases (CPM) are uncommon lesions. Consequently, optimal management of CPM is uncertain. We summarize our experience with stereotactic radiosurgery (SRS) of CPM. Methods and Materials: Sixteen consecutive patients with presumed CPM treated with SRS between 1997 and 2007 were examined. Twelve were men with a median age at diagnosis of CPM of 61.9 {+-} 9.9 years; 14 had metastases from renal cell carcinoma (RCC). All patients had controlled primary disease at the time of treatment for CPM. Four patients with RCC and 1 with non-small-cell lung cancer had undergone whole-brain radiotherapy (WBRT) previously and 2 had received SRS to other brain metastases. The disease-free interval from the primary diagnosis to CPM diagnosis averaged 39.3 {+-} 46.2 months (range, 1.0-156.3). Five patients were asymptomatic; of the remaining 11, none had symptoms related to CPM. All presented with a single CPM. Results: Average maximum diameter of the CPMs was 2.0 {+-} 1.0 cm (range, 0.9-4.1 cm); mean volume was 2.4 {+-} 2.6 cm{sup 3} (range, 0.2-9.3). Median SRS dose was 24 Gy to the 53% isodose line (range, 14-24 Gy). Survival after SRS to the CPM was 25.3 {+-} 23.4 months (range, 3.2-101.6). Patients in Recursive Partitioning Analysis (RPA) class I (n = 10) had improved survival compared to those in class II (n = 6), as did those with better GPA scores. There were no local failures. After SRS, 1 patient underwent WBRT, 3 patients had one, and another had two subsequent SRS treatments to other brain lesions. Of the 14 patients who have died, 11 succumbed to systemic disease progression, 2 to progressive, multifocal central nervous system disease, and 1 to systemic disease with concurrent, stable central nervous system disease. There were no complications related to SRS. Conclusions: Most CPMs are associated with RCC. SRS represents a safe and viable treatment option as primary modality for these metastases, with excellent outcomes.

  15. Carbohydrate Foods n the past, when Momma prepared those

    E-Print Network [OSTI]

    foods containing simple sugars (fruit juices, rich desserts, milk products). Because diabetes cooling rack 1 - Paring knife 1 - Bread knife 1 - Serving plate or basket 1 - Pair tongs or serving

  16. Efficacy of Consumer-Available Antimicrobials for the Disinfection of Pathogen Contaminated Green Bell Pepper and Efficacy of Consumer Cleaning Methods for the Decontamination of Knives

    E-Print Network [OSTI]

    Perez, Keila Lizth

    2011-08-08T23:59:59.000Z

    , 5SW, 10SW, and ST were equally effective for knife decontamination. No significant difference (p<0.05) was found between log CFU/cm2 on knife blade and log CFU/cm2 transferred to surface of cucumber; therefore, viable organisms remaining on the knife...

  17. Reducing the forces required to delimb hardwoods. Forest Service research paper

    SciTech Connect (OSTI)

    Mattson, J.A.; Sturos, J.B.

    1996-01-29T23:59:59.000Z

    Documents the forces required to delimb hardwoods as a function of knife parameters, and identifies opportunities to reduce forces and increase productivity of machines using delimbing knives.

  18. Aridlands Ecology Lab Protocol Modified: 2009.01.19, S.Castle

    E-Print Network [OSTI]

    Barger, Nichole

    : 5cm PVC coring cylinders (PVC diam.= 5.3cm, height=5cm, volume=110.31cm3 ) Putty knife or solid with the edge of the PVC. Pick a new coring location if this occurs. 3. To extract the PCV core gently dig around the PVC and insert putty knife underneath cylinder while attempting to minimize disturbance. 4

  19. Berkeley Lab Accident Statistics Through May 31, 2012

    E-Print Network [OSTI]

    Eisen, Michael

    ­ May 2012 Slip / Trip / Fall · Strained ankle, abrasion ­The Guest Postdoctoral Fellow slipped off / Engineer was cycling downhill through the Blackberry Gate and starting through a construction lane detour, using an X-Acto knife. The knife slipped and jabbed the employee's finger. · Laceration ­The Guest

  20. Payment and Privacy: A Key for the Development of NFC Mobile Jean Claude Paills, Chrystel Gaber, Vincent Alimi, Marc Pasquet

    E-Print Network [OSTI]

    technology in the mobiles phones (NFC). Given the characteristics of the mobile phone market, this trend mobile network technology such as GSM/UMTS). Mobile will become the "Swiss army knife for day to day Mobile Phone a Swiss Knife? Often, contactless technology is considered to be more sensitive to privacy

  1. United states Department of the Interior Fish and Wildlife Service

    E-Print Network [OSTI]

    the knife blade so that it will scrape along the backbone, then, splits the fish along the back without from the washing tank they are allowed t o drain for a short time. They are then rubbed thoroughly

  2. Science & Cooking SPU-27 Fall 2012 Lab 5: Molten chocolate cake & ice cream

    E-Print Network [OSTI]

    Wolfe, Patrick J.

    pot · 1 induction burner · 8 ramekins · 1 medium bowl (wet ingredients) · 1 spoon · 1 knife · 1 whisk · 1 spatula · 1 oven mitt · 1 convection oven-stick baking spray Procedure: 1. Preheat the oven to 350°F (=177 °C

  3. For years I have been driving by a huge bass tree next to the road by the Souhegan River and never noticed it. It's

    E-Print Network [OSTI]

    New Hampshire, University of

    and we dressed for toxic duty. Wearing a protective hood to keep the huge poison ivy leaves from brushing slice open with a knife. Inside are one or two seeds surrounded by some hollow space. The fresh green

  4. Acculturation in the Upper Middle Missouri Valley as Reflected in Modified Bone Assemblages

    E-Print Network [OSTI]

    Weston, Timothy

    1986-05-01T23:59:59.000Z

    Villages National Historic Site (KNRI) located just north of the town of Stanton, North Dakota at the mouth of the Knife River (Fig. 1). The park was created by an act of Congress In 1974 In order to preserve significant archaeological resources... Villages National Historic Site (KNRI) located just north of the town of Stanton, North Dakota at the mouth of the Knife River (Fig. 1). The park was created by an act of Congress In 1974 In order to preserve significant archaeological resources...

  5. Fabrication of a new type of detector for the SSC 

    E-Print Network [OSTI]

    Roller, Kenneth James

    1990-01-01T23:59:59.000Z

    ) plane. . . 9 Anisotropic etching of silicon. 15 17 10 [a] Wafer after development and [b] wafer after buffered hydrofluoric acid etch and before ODE. . 11 SEM view of wafer 5 with array of "mesa" shaped structures. 24 12 SEM view of wafer 5 with a... "mesa, " structure. 25 13 First silicon knife-edge structure 14 Knif'e-edge with longer isotropic etch time 15 Knife-edge formation after SiOs mask removed. 29 16 XVafer 9 after ODE. . 30 17 Wafer 9 after 15 seconds isotropic etch. 1S W'afer 9...

  6. August and September Approximately 29 percent from husks

    E-Print Network [OSTI]

    minutes. Cool promptly in several changes of cold water and drain. Whole-kernel corn: Cut kernels from. Scrape the cobs with the back of the knife to remove the juice and the hearts of the kernels. Pack corn for approximately the same length of time the corn was blanched) and drain well. Tightly ',vrap ears individually

  7. How We Got Started Sheyenne River

    E-Print Network [OSTI]

    for Riparian Ecosystems · Field Tours · Rancher Meetings · Educational Materials #12;Project Collaborators Source Program #12;· The goals of this project is to improve and strengthen the ability of resource Project #12;· 6 New Riparian ESDs · MLRA 54 · Knife River · Spring Creek · MLRA 55B · Baldhill Creek

  8. Ground Turkey Stroganoff Ingredients

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    Ground Turkey Stroganoff Ingredients: 8 ounces egg noodles, uncooked 1 pound ground turkey 1 onion. Meanwhile, brown ground turkey and onions in non stick skillet until meat is no longer pink and onions cup of egg noodles on plate, top with 1/2 cup of turkey mixture. Equipment: Knife Cutting board

  9. The effect of marbling and subcutaneous fat on the microbiological and sensory characteristics of beef strip loin steaks

    E-Print Network [OSTI]

    Correale, Karen Kross

    1986-01-01T23:59:59.000Z

    a flame-sterilized knife. Twenty-seven steaks were wrapped in an oxygen-permeable (PVC) film (Table 1). Steaks stored in PVC film were placed individually in plastic foam trays (12 x 21 an) and overwrapped with a film (Prime Wrap II, the Goodyear...

  10. Fabrication of Surface Plasmon Resonators by Nanoskiving

    E-Print Network [OSTI]

    Prentiss, Mara

    . The diamond knife cuts cleanly through microplates 35 µm in diameter and 100 nm thick without bending); the single-crystalline gold nanowires fabricated here have much lower radiative loss than polycrystalline to act as surface plasmon resonators, a characteristic that polycrystalline metal nanowires do

  11. Method of making an ultracapacitor electrode

    DOE Patents [OSTI]

    Wei, Chang (Niskayuna, NY); Jerabek, Elihu Calvin (Glenmont, NY); DeJager, Katherine Dana (BJ Goes, NL); LeBlanc, Jr., Oliver Harris (Schenectady, NY)

    2001-10-16T23:59:59.000Z

    A paste of organic solvent with dissolved organic salt and active carbon is formed and a uniform film of the paste is applied onto a substrate by casting the paste into a clearance between a knife blade and the substrate. The paste is evaporated to form a paste electrode for an ultracapacitor.

  12. Method Of Making An Ultracapacitor Electrode

    DOE Patents [OSTI]

    Wei, Chang (Niskayuna, NY); Jerabek, Elihu Calvin (Glenmont, NY); DeJager, Katherine Dana (BJ Goes, NL); LeBlanc, Jr., Oliver Harris (Schenectady, NY)

    2003-05-06T23:59:59.000Z

    A paste of organic solvent with dissolved organic salt and active carbon is formed and a uniform film of the paste is applied onto a substrate by casting the paste into a clearance between a knife blade and the substrate. The paste is evaporated to form a paste electrode for an ultracapacitor.

  13. Current could carry disaster to fragile reef By Zac Anderson & Kate Spinner

    E-Print Network [OSTI]

    Belogay, Eugene A.

    . A king mackerel catapults into the air and tarpon dorsal fins knife the water's surface. Ben Harper plays and nurse sharks pass by. "I can't seem to spend enough time out here," Hughes said, legs crossed on the bow

  14. Associate Dean of Libraries for Library Technology and Management Services

    E-Print Network [OSTI]

    Rock, Chris

    Associate Librarian Pam Hight Assistant Librarian Vacant Assistant Librarian Vacant PC/Network Support IV Scott Knife PC/Network Support II Gary Fabila PC/Network Support II vacant Organization Chart Texas Tech University Libraries June 1, 2012 Public Operations Senior Administrator for Animation Lab Ken Chaffin (Area

  15. STAG UK Newsletter Issue 7

    E-Print Network [OSTI]

    1974-01-01T23:59:59.000Z

    HINI CON MINI CON Who put a notice on. Jenny's back which said tina smoking allowedl'i? Who 1"as ehased out of the kitchen with the bread knife? ,lHO put the notiee on the free buffet table;"Chi.cken Sandwiches free to Committee members only...

  16. GeneWays: a system for extracting, analyzing, visualizing, and integrating molecular pathway data

    E-Print Network [OSTI]

    Yu, Hong

    Center for Biotechnology Information, NLM, NIH, Bethesda, MD 20984, USA Received 13 August 2003 Abstract groups have worked on specific problems in this area, such as automated selection of articles pertinent, or even within the same cell but under different environmental conditions, just as a Swiss Army knife

  17. Beekeeping for Beginners

    E-Print Network [OSTI]

    Parks, Harris Bradley

    1919-01-01T23:59:59.000Z

    ..................................... Start in Beekeeping 1.0 . e Hive ............................................... 11 le Super .............................................. 11 her Tools ............................................. 11 .............................................. e... on waxing rack. 6 Embedding.. ............. 14 4. Extracting. I Tlie full super comb. 2 Uncapping knife and . ' bar. 3 Uncapping. 4 The uncapped comb. 5 Extractor. ................................ i 6 The extracted comb. 15 5. Transferring. 1 The gum...

  18. Quality assurance for gamma knives

    SciTech Connect (OSTI)

    Jones, E.D.; Banks, W.W.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

    1995-09-01T23:59:59.000Z

    This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys, interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations.

  19. Alaskan National Park Glaciers: Status and Trends Second Progress Report: March 30, 2012

    E-Print Network [OSTI]

    Loso, Michael G.

    Alaskan National Park Glaciers: Status and Trends Second Progress Report: March 30, 2012 Anthony;_________________________________________________________________________________________ Cover photo: Knife Creek Glacier in June 2011. The tephra-covered ablation zone of the "fourth" glacier is visible in the middle distance, while in the right foreground a moat is visible where the "first" glacier

  20. Lesson Summary In this activity, students build and decorate their own

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Materials Each Student Needs: · 1- 7 inch Oatmeal container · 1- 3 x 5 Index card · 1 Exact-o knife · 1 Construction paper · Masking tape · 1 Incandescent light bulb · Thick black markers · Markers, aluminum foil or atmosphere. #12;Group Size 1 Expendable Cost per Group $4 Engineering Connection Spectrographs are used both

  1. 3D Printing Prof. Hank Dietz & Paul Eberhart

    E-Print Network [OSTI]

    Dietz, Henry G. "Hank"

    3D Printing Prof. Hank Dietz & Paul Eberhart September 28, 2013 University of Kentucky Electrical/Craft: paper moves in Y, knife in X EDM/Laser: X/Y bed, vaporizes material #12;Subtractive 3D CNC: Computer "The whole is greater than the sum of its parts." ­ Aristotle #12;Additive 3D Building Material

  2. JULY 2005 1 An estimate of tidal energy lost to turbulence at the Hawaiian Ridge

    E-Print Network [OSTI]

    Klymak, Jody M.

    of 2) spring-neap variation in dissipation was observed. The observations also suggest a kinematic-integrated dissipation (D), such that D E1±0.5 at sites along the ridge. This kinematic relationship is supported by combining a simple knife-edge model to estimate internal tide generation with wave-wave interaction time

  3. NATURE PHYSICS | VOL 10 | FEBRUARY 2014 | www.nature.com/naturephysics 81 String and sealing wax --although probably

    E-Print Network [OSTI]

    Loss, Daniel

    , the Japanese space agency, JAXA, launched Hayabusa: the spacecraft made its rendezvous with the asteroid knife-edge moments that characterize so many missions in space. After three years of hibernation out, California. Rosetta launched in 2004 and has executed a series of slingshot manoeuvres, plus its period of no-solar

  4. agbioresearch.msu.edu/centers/saginawvalley Picture Tour of Bean Harvest Operations

    E-Print Network [OSTI]

    1 agbioresearch.msu.edu/centers/saginawvalley Picture Tour of Bean Harvest Operations Saginaw Valley Research and Extension Center agbioresearch.msu.edu Images of: Pulling beans · Windrowing · Direct cut · Transport PULLING BEANS Beans are pulled with knife pullers or rod pullers. Beans are generally

  5. Electric plugs--repair or replace The problem

    E-Print Network [OSTI]

    need s New plug­if your old one cannot be used. (Buy one with a UL label) s A screwdriver s A knife How to 1. Cut the cord off at the damaged part (Fig. 1). 2. Slip the plug back on the cord (Fig. 2). 3

  6. WHAT YOU NEED TO MOVE-IN NECESSITIES TO BRING AT CHECK-IN

    E-Print Network [OSTI]

    Maryland, Baltimore County, University of

    Foreman counter-top grills** Rice-cookers ** Coffeepots without auto-shutoff feature Immersion heaters heaters Kerosene heaters Picture hangers/nails/double backed stick ups Air guns, toy guns, BB/pellet guns, paint guns or water pistols #12; Weapons including any knife that is not designed and typically

  7. U.S. Department of the Interior U.S. Geological Survey

    E-Print Network [OSTI]

    Torgersen, Christian

    -based assessment of conventional and continuous oil and gas resources of the Devonian Three Forks Formation fracturing, which stimulates movement of hydrocarbons in tight-oil reservoirs. Approximately 450 million bar Basin Province boundary Bakken TPS Middle Bakken Conventional AU Nesson-Little Knife Continuous Oil AU

  8. Micromachined electrical cauterizer

    DOE Patents [OSTI]

    Lee, A.P.; Krulevitch, P.A.; Northrup, M.A.

    1999-08-31T23:59:59.000Z

    A micromachined electrical cauterizer is disclosed. Microstructures are combined with microelectrodes for highly localized electro cauterization. Using boron etch stops and surface micromachining, microneedles with very smooth surfaces are made. Micromachining also allows for precision placement of electrodes by photolithography with micron sized gaps to allow for concentrated electric fields. A microcauterizer is fabricated by bulk etching silicon to form knife edges, then parallelly placed microelectrodes with gaps as small as 5 {mu}m are patterned and aligned adjacent the knife edges to provide homeostasis while cutting tissue. While most of the microelectrode lines are electrically insulated from the atmosphere by depositing and patterning silicon dioxide on the electric feedthrough portions, a window is opened in the silicon dioxide to expose the parallel microelectrode portion. This helps reduce power loss and assist in focusing the power locally for more efficient and safer procedures. 7 figs.

  9. Micromachined electrical cauterizer

    DOE Patents [OSTI]

    Lee, Abraham P. (Walnut Creek, CA); Krulevitch, Peter A. (Pleasanton, CA); Northrup, M. Allen (Berkeley, CA)

    1999-01-01T23:59:59.000Z

    A micromachined electrical cauterizer. Microstructures are combined with microelectrodes for highly localized electro cauterization. Using boron etch stops and surface micromachining, microneedles with very smooth surfaces are made. Micromachining also allows for precision placement of electrodes by photolithography with micron sized gaps to allow for concentrated electric fields. A microcauterizer is fabricated by bulk etching silicon to form knife edges, then parallelly placed microelectrodes with gaps as small as 5 .mu.m are patterned and aligned adjacent the knife edges to provide homeostasis while cutting tissue. While most of the microelectrode lines are electrically insulated from the atmosphere by depositing and patterning silicon dioxide on the electric feedthrough portions, a window is opened in the silicon dioxide to expose the parallel microelectrode portion. This helps reduce power loss and assist in focusing the power locally for more efficient and safer procedures.

  10. Apparatus and method for measuring critical current properties of a coated conductor

    DOE Patents [OSTI]

    Mueller, Fred M. (Los Alamos, NM); Haenisch, Jens (Dresden, DE)

    2012-07-24T23:59:59.000Z

    The transverse critical-current uniformity in a superconducting tape was determined using a magnetic knife apparatus. A critical current I.sub.c distribution and transverse critical current density J.sub.c distribution in YBCO coated conductors was measured nondestructively with high resolution using a magnetic knife apparatus. The method utilizes the strong depression of J.sub.c in applied magnetic fields. A narrow region of low, including zero, magnetic field in a surrounding higher field is moved transversely across a sample of coated conductor. This reveals the critical current density distribution. A Fourier series inversion process was used to determine the transverse J.sub.c distribution in the sample.

  11. A high precision, compact electromechanical ground rotation sensor

    SciTech Connect (OSTI)

    Dergachev, V., E-mail: volodya@caltech.edu [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); DeSalvo, R. [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States) [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); University of Sannio, C.so Garibaldi 107, Benevento 82100 (Italy); Asadoor, M. [Mayfield Senior School, 500 Bellefontaine Street, Pasadena, California 91105 (United States) [Mayfield Senior School, 500 Bellefontaine Street, Pasadena, California 91105 (United States); Oklahoma State University, 219 Student Union, Stillwater, Oklahoma 74074 (United States); Bhawal, A. [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States) [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States); Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Gong, P. [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China) [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China); School of Industrial and System Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0205 (United States); Kim, C. [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States); Lottarini, A. [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy) [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Department of Computer Science, Columbia University, 1214 Amsterdam Avenue, New York, New York 10027 (United States); Minenkov, Y. [Sezione INFN Tor Vergata, via della Ricerca Scientifica  1, 00133 Roma (Italy)] [Sezione INFN Tor Vergata, via della Ricerca Scientifica  1, 00133 Roma (Italy); Murphy, C. [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia) [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia); University of Melbourne Grattan Street, Parkville VIC 3010 (Australia); O'Toole, A. [University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States) [University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States); Michigan Technological University, 1400 Townsend Dr, Houghton, Michigan 49931 (United States); Peña Arellano, F. E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); and others

    2014-05-15T23:59:59.000Z

    We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of 1 × 10{sup ?11}m/?( Hz ). We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10{sup ?9} rad /?( Hz ) at 10 mHz and 6.4 × 10{sup ?10} rad /?( Hz ) at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.

  12. Direct observation of molecular arrays in the organized smooth endoplasmic reticulum

    E-Print Network [OSTI]

    Korkhov, Vladimir M; Zuber, Benoit

    2009-08-24T23:59:59.000Z

    resembles the ER stress-induced ER expansion in yeast, where sequestration of the ER membranes into autophagosome-like multilamellar tial for survival [19]. This suggestion is corroborated by the observation that OSER structures induced in mamma- lian cells... with 35° dia- mond knife (Diatome) under standard cutting condi- tions, at -140°C. The cryosections were collected on 1000- mesh grids (Agar Scientific, Essex, United Kingdom) coated with carbon and stored in liquid nitrogen or trans- ferred immediately...

  13. Known Index per Known Index per Known Index per Offenses 100,000 Offenses 100,000 Offenses 100,000

    E-Print Network [OSTI]

    Embezzlement 0 0 0 0 0 0 Stolen Prop., Rec., Possess., Buying 0 0 0 0 0 0 Vandalism 0 0 1 26 0 0 Weapons Other dangerous weapon 0 0 0 0 0 0 Strong arm (hands, feet, etc.) 0 1 26 0 0 Assault (total) 2 56 1 26 0 0 Firearm 0 0 0 0 0 0 Knife or cutting instrument 0 0 0 0 0 0 Other dangerous weapon 0 0 0 0 0 0

  14. Known Index per Known Index per Known Index per Offenses 100,000 Offenses 100,000 Offenses 100,000

    E-Print Network [OSTI]

    0 0 0 Stolen Prop., Rec., Possess., Buying 0 0 0 0 0 0 Vandalism 1 49 3 152 0 0 Weapons, Carrying Other dangerous weapon 0 0 0 0 0 0 Strong arm (hands, feet, etc.) 1 49 2 101 0 0 Assault (total) 0 0 0 0 0 0 Firearm 0 0 0 0 0 0 Knife or cutting instrument 0 0 0 0 0 0 Other dangerous weapon 0 0 0 0 0 0

  15. Food equipment manufacturer takes a slice out of its scrap rate

    SciTech Connect (OSTI)

    Bernard, D.; Hannahs, J. [PMI Food Equipment Group, Troy, OH (United States); Carter, M. [MicroWeld Engineering, Worthington, OH (United States)

    1996-09-01T23:59:59.000Z

    The PMI Food Equipment Group began manufacturing circular slicer knives for its commercial Hobart line of slicers in the early 1930s. The company manufacturers the only cast knife in the food industry. The cast knives offer superior edge retention and overall corrosion resistance. The slicer knives are cast in PMI`s foundry. The casting process sometimes produces shrinkage voids or gas bubbles in the knife blank. Surface discontinuities often do not appear until rough cutting or final machining, i.e., after several hours of value-added manufacturing. Knife blanks with these discontinuities were scrapped and sent back to the foundry for remelting. To scrap the knives at that point meant the cost for casting plus the value-added machining added up to a considerable amount. Weld repair allows the recovery of casting and machining expenses equal to a significant percentage of the total manufacturing cost of slicer knives. Repair costs include welding, grinding, shipping, surface finishing and material handling. Other good applications for this GMAW-P process include repair of jet engine components, rotating process industry equipment, and hardfacing of cutting tools and dies. In addition, dissimilar metals and any material that is heat treated to develop its properties such as precision investment castings are excellent applications. The low resultant distortion, elimination of postweld heat treatment and non-line-of-site welding capability solves thin wall, limited access and precision machined component repair challenges.

  16. Design of a flooring removal system for asbestos backed flooring

    E-Print Network [OSTI]

    Puduru, Pathanjali Sai

    1990-01-01T23:59:59.000Z

    Page 1 Properties of flooring, adhesive and subflooring 2 Results for wood subflooring vvhen t, is 100 deg C 3 Results for vood subflooring when t, is 110 deg C 4 Results for v;ood subfloorin ' when t, is 120 deg C 34 LIST OF FIGURES Figure Pa. ge... 1 Cross section of a, typical non-foam flooring 2 Cross section of a typical foam flooring 3 'Top surface heating of the flooring material . 4 Hot knife at adhessve layer . 10 5 Radiation method of heating 6 Conduction method of heating 12 7...

  17. Variable diameter wind turbine rotor blades

    DOE Patents [OSTI]

    Jamieson, Peter McKeich; Hornzee-Jones, Chris; Moroz, Emilian M.; Blakemore, Ralph W.

    2005-12-06T23:59:59.000Z

    A system and method for changing wind turbine rotor diameters to meet changing wind speeds and control system loads is disclosed. The rotor blades on the wind turbine are able to adjust length by extensions nested within or containing the base blade. The blades can have more than one extension in a variety of configurations. A cable winching system, a hydraulic system, a pneumatic system, inflatable or elastic extensions, and a spring-loaded jack knife deployment are some of the methods of adjustment. The extension is also protected from lightning by a grounding system.

  18. The development of a collagen - nylon microcapsule composite biomaterial 

    E-Print Network [OSTI]

    Yeager, Mark Rutledge

    1974-01-01T23:59:59.000Z

    microcupsules were formed by interfacial poly- condensation and only w, n?cr soluble substances could be encap- sulated. The mechanical tests and toxicological studies demon- strated the feasibility of such a material. 1V ACKNOWLEDGENENT The author wishes... the template os r the material and carefully cutting around 31 the edges with an x-acto knife. The specimen thi. ckness was measured with a dial micrometer. The mechanical testing was preformed on an Instron testing machine equipped with a one pound maximum...

  19. Analysis and optimized design of airlocks for fluidized bed gasifier fuel feed systems

    E-Print Network [OSTI]

    Nuboer, Benito Frans

    1991-01-01T23:59:59.000Z

    for feedrate of 1. 1 kg/min 3. 3 Design results of model for feedrate of 1. 6 kg/min 3. 4 Design results of model for feedrate of 2. 0 kg/min 3. 5 Design results of model for feedrate of 50 kg/min . 3. 6 Design results of model for feedrate of 77 kg... system by LePori et al. (1981), with the star feed wheel replaced by a lock hopper with knife gate valves 3. 5 Schematic of biomass feed system by LePori et al. (1981), with the star feed wheel replaced by a rotary airlock valve 3. 6 The relationship...

  20. Ecology, biology, and coexistence of four species of Aradidae from the southeastern United States

    E-Print Network [OSTI]

    Taylor, Steven Joseph

    1987-01-01T23:59:59.000Z

    " is characterized by wood which is starting to rot and can be peeled off with a knife. Fungus growth is clear ly present under the bark and tunnels made by beetles are present. Temperature and moisture in subcortical spaces of trees at this stage is variable...) showed that millipedes found in association with dead logs partition the habitat into microhabitats by their location on, in, or under the log. Four species of bark beetles (Coleoptera: Scolytidae) have been shown to partition trees by colonizing them...

  1. Fabrication of a new type of detector for the SSC

    E-Print Network [OSTI]

    Roller, Kenneth James

    1990-01-01T23:59:59.000Z

    in Figure 4. A combination of photolithography, ODE, and isotropic etching of silicon gives a pattern of knife-edges spaced 25 ym apart. An insulating layer of silicon dioxide (SiOz) is thermally grown on top of the silicon knit'e- edge surface and a 1 pm... and then coated with photoresist. The primer is spin coated directly onto the silicon surface. Priming just prior to resist coating improves photoresist adliesion by producing a. bonding layer for the photoresist and by removing any residual moisture...

  2. Jurassic conchostracans from Patagonia

    E-Print Network [OSTI]

    Tasch, P.; Volkheimer, W.

    1970-09-16T23:59:59.000Z

    . The estheriid localities in this last-named province include: Malacara, La Matilde, Tordillo, Laguna del Molino, and Laguna del Garb6n. Santa Cruz Province is directly south of Chubut Province. It is obvious that estheriid-bearing beds of Jurassic age... phase of valve growth. MAT ERIAL — Four individual pieces of green- to-red well-indurated, thin-bedded shale (readily scratched with a knife) contain on bedding planes, numerous crushed, incomplete and flattened valves. Nature of preservation of valves...

  3. Vegetables: Selection, Care, Cooking.

    E-Print Network [OSTI]

    Reasonover, Frances; Mason, Louise; Tribble, Marie; Cox, Maeona

    1958-01-01T23:59:59.000Z

    . Pour into a well greased casserole. Set in a pan of hot water. Bake at 350" F. about 45 minutes or until firm. Serves six. Spinach, Swiss chard, artichoke hearts or aspara- gus may be substituted for broccoli. CASSEROLE OF BRUSSELS SPROUTS Heat... ring mold. .. -. Bake in pan of hot water at 350" F. 30 minutes, or until knife comes out clean. Unmold on warm plat- ter. Serves six. 2 packages frozen 2 tablespoons tarragon chopped spinach vinegar 1/2 teaspoon salt 2 hard-cooked eggs, 2...

  4. The feasibility and profitability of short season corn and sorghum cropping systems on the Texas High Plains

    E-Print Network [OSTI]

    Vagts, Todd Anthony

    1995-01-01T23:59:59.000Z

    in the U. S. , therefore, irrigation management, particularly with limited irrigation, is very critical (Howell et al. , 1989). Seasonal ET rates for corn range from 30. 8 to 39. 5 inches with corn yields varying from 132 bu/acre to 204 bu/acre (Eck... 80 bu/acre for grain only wheat and 70 bu/acre for graze-grain wheat. All phosphorous was applied in the fall. Fertilizer was applied in fifteen inch bands in the fall with a knife injector and was applied in granular form in the spring...

  5. Preserving Peppers

    E-Print Network [OSTI]

    Van Laanen, Peggy

    2000-06-26T23:59:59.000Z

    with a fork or slash with a knife. Blister and peel peppers using one of the methods described above. Process pickled products in a boiling water canner to ensure that they will not spoil. Follow proper proce- dure for processing (See L-2216, ?Home... horseradish (optional) 2 to 3 cloves garlic, quartered (optional) Wash peppers. Peel tough-skinned varieties such as chiles. Blanch other peppers for 3 minutes in boiling water. Small peppers may be left whole; large ones should be quartered. Flatten whole...

  6. Waterfowl -- Cooking Care.

    E-Print Network [OSTI]

    Coble, Sally S.; Sweeten, Mary K.

    1979-01-01T23:59:59.000Z

    . Repeat the dipping process until the bird is covered with a heavy coating of set wax. Then use a table knife or sturdy spoon to peel off slabs and strips of wax. The remaining feathers and down on the bird will stick in the wax and come off with it... (dressed weight) Garlic, salt and pepper 1 lemon, halved 4 sprigs parsley 6 slices bacon Y2 cup prepared mustard 2 tablespoons soy sauce 1 cup apricot preserves 1 tablespoon lemon juice 1 teaspoon grated orange peel Y. cup melted butter Sprinkle...

  7. Analysis and optimized design of airlocks for fluidized bed gasifier fuel feed systems 

    E-Print Network [OSTI]

    Nuboer, Benito Frans

    1991-01-01T23:59:59.000Z

    for feedrate of 1. 1 kg/min 3. 3 Design results of model for feedrate of 1. 6 kg/min 3. 4 Design results of model for feedrate of 2. 0 kg/min 3. 5 Design results of model for feedrate of 50 kg/min . 3. 6 Design results of model for feedrate of 77 kg... system by LePori et al. (1981), with the star feed wheel replaced by a lock hopper with knife gate valves 3. 5 Schematic of biomass feed system by LePori et al. (1981), with the star feed wheel replaced by a rotary airlock valve 3. 6 The relationship...

  8. Note: Spatial resolution of Fuji BAS-TR and BAS-SR imaging plates

    SciTech Connect (OSTI)

    Fiksel, G.; Marshall, F. J.; Mileham, C.; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Rd., Rochester, New York 14623-1299 (United States)

    2012-08-15T23:59:59.000Z

    The spatial resolution of two types of imaging plates, Fuji BAS-TR and Fuji BAS-SR, has been measured using a knife-edge x-ray source of 8-keV Cu K{sub {alpha}} radiation. The values for the spatial resolution, defined as the distance between 10% and 90% levels of the edge spread function, are 94 {mu}m and 109 {mu}m, respectively. The resolution values are important for quantitative analysis of x-ray and particle imaging and spectroscopic diagnostics.

  9. Experimental determination of radiated internal wave power without pressure field data

    SciTech Connect (OSTI)

    Lee, Frank M.; Morrison, P. J. [Physics Department and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)] [Physics Department and Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712–1192 (United States); Paoletti, M. S.; Swinney, Harry L. [Physics Department, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)] [Physics Department, The University of Texas at Austin, Austin, Texas 78712–1192 (United States)

    2014-04-15T23:59:59.000Z

    We present a method to determine, using only velocity field data, the time-averaged energy flux (J) and total radiated power P for two-dimensional internal gravity waves. Both (J) and P are determined from expressions involving only a scalar function, the stream function ?. We test the method using data from a direct numerical simulation for tidal flow of a stratified fluid past a knife edge. The results for the radiated internal wave power given by the stream function method agree to within 0.5% with results obtained using pressure and velocity data from the numerical simulation. The results for the radiated power computed from the stream function agree well with power computed from the velocity and pressure if the starting point for the stream function computation is on a solid boundary, but if a boundary point is not available, care must be taken to choose an appropriate starting point. We also test the stream function method by applying it to laboratory data for tidal flow past a knife edge, and the results are found to agree with the direct numerical simulation. The supplementary material includes a Matlab code with a graphical user interface that can be used to compute the energy flux and power from two-dimensional velocity field data.

  10. SU-E-J-225: Quantitative Evaluation of Rigid and Non-Rigid Motion of Liver Tumors Using Stereo Imaging During SBRT

    SciTech Connect (OSTI)

    Xu, Q; Hanna, G; Kubicek, G; Asbell, S; Chen, Y; LaCouture, T [MD Anderson Cancer Center at Cooper, Mt Laurel, NJ (United States); Grimm, J [Holy Redeemer, Meadowbrook, PA (United States); Pahlajani, N [First Radiation and Oncology Group, Jacksonville, FL (United States); Fan, J [Virtua Fox Chase Cancer Center, Philadelphia, PA (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To quantitatively evaluate rigid and nonrigid motion of liver tumors based on fiducial tracking in 3D by stereo imaging during CyberKnife SBRT. Methods: Twenty-five liver patients previously treated with three-fractions of SBRT were retrospectively recruited in this study. During treatment, the 3D locations of fiducials were reported by the CyberKnife system after two orthogonal kV X-ray images were taken and further validated by geometry derivations. A total of 5004 pairs of X-ray images acquired during the course of treatment for all the patients, were analyzed. For rigid motion, the rotational angles and translational shifts by aligning 3D fiducial groups in different image pairs after least-square fitting were reported. For nonrigid motion, the relative interfractional tumor shape variations were reported and correlated to the sum of inter-fiducial distances. The individual fiducial displacements were also reported after rigid corrections and without angle corrections. Results: The relative tumor volume variation indicated by the inter-fiducial distances demonstrated an increasing trend in the second (101.6±3.4%) and third fraction (101.2±5.6%) among most patients. The cause could be possibly due to radiation-induced edema. For all the patients, the translational shift was 8.1±5.7 mm, with shifts in LR, AP and SI were 2.1±2.4 mm, 2.8±2.9 mm and 6.7±5.1 mm, respectively. The greatest translation shift occurred in SI, mainly due the breathing motion of diaphragm The rotational angles were 1.1±1.7°, 1.9±2.6° and 1.6±2.2°, in roll, pitch, and yaw, respectively. The 3D fiducial displacement with rigid corrections were 0.2±0.2 mm and increased to 0.6±0.3 mm without rotational corrections. Conclusion: The fiducial locations in 3D can be precisely reconstructed from CyberKnife stereo imaging system during treatment. The fiducials provide close estimation of both rigid and nonrigid motion of .liver tumors. The reported data could be further utilized for tumor margin design and motion management in in conventional linac-based treatments.

  11. Variable Circular Collimator in Robotic Radiosurgery: A Time-Efficient Alternative to a Mini-Multileaf Collimator?

    SciTech Connect (OSTI)

    Water, Steven van de, E-mail: s.vandewater@erasmusmc.nl [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Hoogeman, Mischa S.; Breedveld, Sebastiaan; Nuyttens, Joost J.M.E. [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Schaart, Dennis R. [Department of Radiation Detection and Medical Imaging, Delft University of Technology, Delft (Netherlands); Heijmen, Ben J.M. [Department of Radiation Oncology, Erasmus Medical Center-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2011-11-01T23:59:59.000Z

    Purpose: Compared with many small circular beams used in CyberKnife treatments, beam's eye view-shaped fields are generally more time-efficient for dose delivery. However, beam's eye view-shaping devices, such as a mini-multileaf collimator (mMLC), are not presently available for CyberKnife, although a variable-aperture collimator (Iris, 12 field diameters; 5-60 mm) is available. We investigated whether the Iris can mimic noncoplanar mMLC treatments using a limited set of principal beam orientations (nodes) to produce time-efficient treatment plans. Methods and Materials: The data from 10 lung cancer patients and the beam-orientation optimization algorithm 'Cycle' were used to generate stereotactic treatment plans (3 x 20 Gy) for a CyberKnife virtually equipped with a mMLC. Typically, 10-16 favorable beam orientations were selected from 117 available robot node positions using beam's eye view-shaped fields with uniform fluence. Second, intensity-modulated Iris plans were generated by inverse optimization of nonisocentric circular candidate beams targeted from the same nodes selected in the mMLC plans. The plans were evaluated using the mean lung dose, lung volume receiving {>=}20 Gy, conformality index, number of nodes, beams, and monitor units, and estimated treatment time. Results: The mMLC plans contained an average of 12 nodes and 11,690 monitor units. For a comparable mean lung dose, the Iris plans contained 12 nodes, 64 beams, and 21,990 monitor units. The estimated fraction duration was 12.2 min (range, 10.8-13.5) for the mMLC plans and 18.4 min (range, 12.9-28.5) for the Iris plans. In contrast to the mMLC plans, the treatment time for the Iris plans increased with an increasing target volume. The Iris plans were, on average, 40% longer than the corresponding mMLC plans for small targets (<80 cm{sup 3}) and {<=}121% longer for larger targets. For a comparable conformality index, similar results were obtained. Conclusion: For stereotactic lung irradiation, time-efficient and high-quality plans were obtained for robotic-controlled noncoplanar treatments using a mMLC. Iris is a time-efficient alternative for small targets, with similar or better plan quality.

  12. Glacial ice composition: A potential long-term record of the chemistry of atmospheric deposition, Wind River Range, Wyoming

    SciTech Connect (OSTI)

    Naftz, D.L. (Geological Survey, Cheyenne, WY (United States)); Rice, J.A. (South Dakota State Univ., Brookings (United States)); Ranville, J.R. (Geological Survey, Denver, CO (United States))

    1991-06-01T23:59:59.000Z

    During a reconnaissance study, ice samples were collected from Knife Point glacier to determine if glaciers in the Wind River Range Could provide a long-term record of the chemical composition of wet deposition. Eight annual ice layers comprising the years 1980-1987 were identified. The concentration of calcium, chloride, and sulfate in the annual-weighted wet deposition samples collected at the National Atmospheric deposition Program (NADP) station near Pinedale, Wyoming, showed a significant, positive correlation to the concentration of the same major ions in composite samples from the annual ice layers. results of the study imply that continuous ice cores reaching to the deeper parts of glaciers in the Wind River Range could provide long-term records of the chemical composition of wet deposition.

  13. Trigeminal neuralgia treatment dosimetry of the Cyberknife

    SciTech Connect (OSTI)

    Ho, Anthony [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Lo, Anthony T., E-mail: tonyho22003@yahoo.com [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Dieterich, Sonja; Soltys, Scott G.; Gibbs, Iris C. [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Chang, Steve G.; Adler, John R. [Department of Neurosurgery, Stanford University, Stanford, CA (United States)

    2012-04-01T23:59:59.000Z

    There are 2 Cyberknife units at Stanford University. The robot of 1 Cyberknife is positioned on the patient's right, whereas the second is on the patient's left. The present study examines whether there is any difference in dosimetry when we are treating patients with trigeminal neuralgia when the target is on the right side or the left side of the patient. In addition, we also study whether Monte Carlo dose calculation has any effect on the dosimetry. We concluded that the clinical and dosimetric outcomes of CyberKnife treatment for trigeminal neuralgia are independent of the robot position. Monte Carlo calculation algorithm may be useful in deriving the dose necessary for trigeminal neuralgia treatments.

  14. Microfabricated high-bandpass foucault aperture for electron microscopy

    DOE Patents [OSTI]

    Glaeser, Robert; Cambie, Rossana; Jin, Jian

    2014-08-26T23:59:59.000Z

    A variant of the Foucault (knife-edge) aperture is disclosed that is designed to provide single-sideband (SSB) contrast at low spatial frequencies but retain conventional double-sideband (DSB) contrast at high spatial frequencies in transmission electron microscopy. The aperture includes a plate with an inner open area, a support extending from the plate at an edge of the open area, a half-circle feature mounted on the support and located at the center of the aperture open area. The radius of the half-circle portion of reciprocal space that is blocked by the aperture can be varied to suit the needs of electron microscopy investigation. The aperture is fabricated from conductive material which is preferably non-oxidizing, such as gold, for example.

  15. Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

    SciTech Connect (OSTI)

    Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

    1995-09-01T23:59:59.000Z

    This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC.

  16. Design and initial characterization of a compact, ultra high vacuum compatible, low frequency, tilt accelerometer

    SciTech Connect (OSTI)

    O’Toole, A., E-mail: amandajotoole@gmail.com, E-mail: riccardo.desalvo@gmail.com [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States); Peña Arellano, F. E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Rodionov, A. V.; Kim, C. [California Institute of Technology, Pasadena, California 91125 (United States); Shaner, M.; Asadoor, M. [Mayfield Senior School, 500 Bellefontaine Street Pasadena, California 91105 (United States); Sobacchi, E. [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Dergachev, V.; DeSalvo, R., E-mail: amandajotoole@gmail.com, E-mail: riccardo.desalvo@gmail.com [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); Bhawal, A. [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States); Gong, P. [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China); Lottarini, A. [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Minenkov, Y. [Sezione INFN Tor Vergata, via della Ricerca Scientfica 1, 00133 Roma (Italy); Murphy, C. [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia)

    2014-07-15T23:59:59.000Z

    A compact tilt accelerometer with high sensitivity at low frequency was designed to provide low frequency corrections for the feedback signal of the Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge designed to avoid the mechanical 1/f noise believed to be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition and control limitations are discussed. The instrument's characterization reported here shows that the hinge is compatible with being metal-hysteresis-free, and therefore also free of the 1/f noise generated by the dislocation Self-Organized Criticality in the metal. A tiltmeter of this kind will be effective to separate the ground tilt component from the signal of horizontal low frequency seismometers, and to correct the ill effects of microseismic tilt in advanced seismic attenuation systems.

  17. Phase I, study of a miniature X-ray source for interstitial radiotherapy of brain metastases

    SciTech Connect (OSTI)

    Douglas, R.M.; Beatty, J.; Biggs, P. [Massachusetts General Hospital, Boston, MA (United States)] [and others] [Massachusetts General Hospital, Boston, MA (United States); and others

    1995-12-31T23:59:59.000Z

    Despite a variety of stereotactic techniques used to increase intracranical local control, dose escalation strategies remain controversial, with respect to therapeutric gain, convenience, and cost effectiveness, in the setting of brain metastases. In this report, we summarize our experience with the safety and efficacy of a new miniature X-ray device for interstitial radiosurgical treatment of intracranial metastatic neoplasms. Although the role of surgical resection of solitary metastases is established, aggressive treatment with proton, gamma knife, and linac radiation therapy for these lesions is under investigation. The new miniature X-ray device offers a very localized, convenient, time and cost efficient means of delivering radiotherapy to these lesions, with lower normal tissue exposure than gamma knife or proton beam techniques. Retreatment of previously irradiated areas are also now under investigation as part of a Phase II trial. The photon radiosurgery system is a miniature battery operated 40 kV x-ray device designed by the Photoelectron Corporation for use in the interstitial treatment of small tumors ({ge}3 cm in diameter) in humans. This 10 cm long, low current, high voltage X-ray generator is easily mounted in a stereotactic frame and produces low energy (10-20 KeV) x-rays to be emitted from the 10 cm long, 3.2 mm diameter probe, after stereotactic insertion into the tumor. Two scintillation detectors positioned on the stereotactic frame near the patient`s scalp monitor radiation. The spherical X-ray beam behaves essentially as a point source, with dose rate nominally 150 cGy/min. at a distance of 10mm, for a beam current of 40 {mu}A and a voltage of 40 kv.

  18. Isotropic three-dimensional MRI-Fricke-infused gel dosimetry

    SciTech Connect (OSTI)

    Cho, Nai-Yu; Chu, Woei-Chyn [Institute of Biomedical Engineering, National Yang-Ming University, Taipei 11221, Taiwan (China); Huang, Sung-Cheng [Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, California 90095 (United States); Chung, Wen-Yuh [Neurological Institute, Taipei Veterans General Hospital, Taipei 11217, Taiwan (China); Guo, Wan-Yuo [Department of Radiology, Taipei Veterans General Hospital, Taipei 11217, Taiwan (China)

    2013-05-15T23:59:59.000Z

    Purpose: Fricke-infused gel has been shown to be a simple and attainable method for the conformal measurement of absorbed radiation dose. Nevertheless, its accuracy is seriously hindered by the irreversible ferric ion diffusion during magnetic resonance imaging, particularly when three-dimensional (3D) dose measurement in radiosurgery is considered. In this study, the authors developed a fast three-dimensional spin-echo based Fricke gel dosimetry technique to reduce the adverse effects of ferric ion diffusion and to obtain an accurate isotropic 3D dose measurement. Methods: A skull shaped phantom containing Fricke-infused gel was irradiated using Leksell Gamma Knife. The rapid image-based dosimetry technique was applied with the use of a 3D fast spin-echo magnetic resonance imaging sequence. The authors mathematically derived and experimentally validated the correlations between dose-response characteristics and parameters of the 3D fast spin-echo MR imaging sequence. Absorbed dose profiles were assessed and compared to the calculated profiles given by the Gamma Knife treatment planning system. Coefficient of variance (CV%) and coefficient of determination (R{sup 2}) were used to evaluate the precision of dose-response curve estimation. The agreement between the measured and the planned 3D dose distributions was quantified by gamma-index analysis of two acceptance criteria. Results: Proper magnetic resonance imaging parameters were explored to render an accurate three-dimensional absorbed dose mapping with a 1 mm{sup 3} isotropic image resolution. The efficacy of the dose-response estimation was approved by an R{sup 2} > 0.99 and an average CV% of 1.6%. Average gamma pass-rate between the experimentally measured and GammaPlan calculated dose distributions were 83.8% and 99.7% for 2%/2 and 3%/3 mm criteria, respectively. Conclusions: With the designed MR imaging sequence and parameters, total 3D MR acquisition time was confined to within 20 min postirradiation, during which time ferric ion diffusion effects were negligible, thus enabling an accurate 3D radiation dose measurement.

  19. High resolution transmission electron microscopy of melamine-formaldehyde aerogels and silica aerogels

    SciTech Connect (OSTI)

    Ruben, G.C. (Dartmouth Coll., Hanover, NH (United States). Dept. of Biological Sciences)

    1991-09-01T23:59:59.000Z

    The goal of the high resolution transmission electron microscopy (HRTEM) was to image the structure of two tetramethyl orthosilicate (TMOS) and two melamine-formaldehyde (MF) aerogels at the single polymer chain level{sup 1,2}. With this level of structural resolution we hoped to interrelate each aerogel's structure with its physical properties and its method of synthesis. Conventional single-step base catalysed TMOS aerogels show strings of spheroidal particles linked together with minimal necking. The spheroidal particles range from 86--132 {Angstrom} and average 113{plus minus}10 {Angstrom} in diameter{sup 2}. In contrast the TMOS aerogels reported on here were made by a two step method. After extended silica chains are grown in solution under acidic conditions with a substoichiometric amount of water, the reaction is stopped and the methanol hydrolysed from TMOS is removed. Then base catalysis and additional water are added to cause gel formation is a nonalcoholic solvent. The MF aerogels were prepared for HRTEM by fracturing them on a stereo microscope stage with razor knife so that fractured pieces with smooth flat surfaces could be selected for platinum-carbon replication. The two silica (TMOS) aerogels were both transparent and difficult to see. These aerogels were fractured on a stereo microscope stage with tweezers. 6 refs., 4 figs.

  20. Fail safe controllable output improved version of the Electromechanical battery

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA)

    1999-01-01T23:59:59.000Z

    Mechanical means are provided to control the voltages induced in the windings of a generator/motor. In one embodiment, a lever is used to withdraw or insert the entire stator windings from the cavity where the rotating field exists. In another embodiment, voltage control and/or switching off of the output is achievable with a variable-coupling generator/motor. A stator is made up of two concentric layers of windings, with a larger number of turns on the inner layer of windings than the outer layer of windings. The windings are to be connected in series electrically, that is, their voltages add vectorially. The mechanical arrangement is such that one or both of the windings can be rotated with respect to the other winding about their common central axis. Another improved design for the stator assembly of electromechanical batteries provides knife switch contacts that are in electrical contact with the stator windings. The operation of this embodiment depends on the fact that an abnormally large torque will be exerted on the stator structure during any short-circuit condition.

  1. Comparing halo bias from abundance and clustering

    E-Print Network [OSTI]

    Hoffmann, Kai; Gaztanaga, Enrique

    2015-01-01T23:59:59.000Z

    We model the abundance of haloes in the $\\sim(3 \\ \\text{Gpc}/h)^3$ volume of the MICE Grand Challenge simulation by fitting the universal mass function with an improved Jack-Knife error covariance estimator that matches theory predictions. We present unifying relations between different fitting models and new predictions for linear ($b_1$) and non-linear ($c_2$ and $c_3$) halo clustering bias. Different mass function fits show strong variations in their overall poor performance when including the low mass range ($M_h \\lesssim 3 \\ 10^{12} \\ M_{\\odot}/h$) in the analysis, which indicates noisy friends-of-friends halo detection given the MICE resolution ($m_p \\simeq 3 \\ 10^{10} \\ M_{\\odot}$/h). Together with fits from the literature we find an overall variance in the amplitudes of around $10%$ in the low mass and up to $50%$ in the high mass (galaxy cluster) range ($M_h > 10^{14} \\ M_{\\odot}/h$). These variations propagate into a $10%$ change in $b_1$ predictions and a $50%$ change in $c_2$ or $c_3$. Despite the...

  2. Fail safe controllable output improved version of the electromechanical battery

    DOE Patents [OSTI]

    Post, R.F.

    1999-01-19T23:59:59.000Z

    Mechanical means are provided to control the voltages induced in the windings of a generator/motor. In one embodiment, a lever is used to withdraw or insert the entire stator windings from the cavity where the rotating field exists. In another embodiment, voltage control and/or switching off of the output is achievable with a variable-coupling generator/motor. A stator is made up of two concentric layers of windings, with a larger number of turns on the inner layer of windings than the outer layer of windings. The windings are to be connected in series electrically, that is, their voltages add vectorially. The mechanical arrangement is such that one or both of the windings can be rotated with respect to the other winding about their common central axis. Another improved design for the stator assembly of electromechanical batteries provides knife switch contacts that are in electrical contact with the stator windings. The operation of this embodiment depends on the fact that an abnormally large torque will be exerted on the stator structure during any short-circuit condition. 4 figs.

  3. Selection of Equipment for Farms in the Texas High Plains.

    E-Print Network [OSTI]

    Barrick, W. C.; Osborn, J. E.

    1971-01-01T23:59:59.000Z

    ,986.00 27,161 .OO 23,986.00 26,55tS' i Wage rate of $3.25 per hour Variable costs 7,400.82 7,886.86 6,729.00 7,219.56 6,271.63 7,059.61 6,27 1.63 7,025 '- Annual costs 10,350.77 11,209.35 9,929.29 10,766.80 9,353.83 10,549.80" 9,353.83" 10,43c' l... 54.8 12 54.8 12 j? ' Lister planter row 4 29.8 4 29.8 4 29.8 4 2; r Chisel ft 11 29.5 11 29.5 13 24.9 13 21 ' Shredder row 2 18.7 2 18.7 2 18.7 2 li' Cultivator row 4 40.6 4 40.6 4 40.6 4 Li . Rotary hoe row 4 11.1 4 11.1 4 11.1 4 11 Knife...

  4. X-ray tests of a two-dimensional stigmatic imaging scheme with variable magnifications

    SciTech Connect (OSTI)

    Lu, J., E-mail: jlu@pppl.gov [Key Laboratory of Optoelectronic Technology and System of Ministry of Education, Chongqing University, Chongqing 400030 (China); Bitter, M.; Hill, K. W.; Delgado-Aparicio, L. F.; Efthimion, P. C.; Pablant, N. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Beiersdorfer, P. [Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Caughey, T. A.; Brunner, J. [Inrad Optics, 181 Legrand Avenue, Northvale, New Jersey 07647 (United States)

    2014-11-15T23:59:59.000Z

    A two-dimensional stigmatic x-ray imaging scheme, consisting of two spherically bent crystals, one concave and one convex, was recently proposed [M. Bitter et al., Rev. Sci. Instrum. 83, 10E527 (2012)]. The Bragg angles and the radii of curvature of the two crystals of this imaging scheme are matched to eliminate the astigmatism and to satisfy the Bragg condition across both crystal surfaces for a given x-ray energy. In this paper, we consider more general configurations of this imaging scheme, which allow us to vary the magnification for a given pair of crystals and x-ray energy. The stigmatic imaging scheme has been validated for the first time by imaging x-rays generated by a micro-focus x-ray source with source size of 8.4 ?m validated by knife-edge measurements. Results are presented from imaging the tungsten L?1 emission at 8.3976 keV, using a convex Si-422 crystal and a concave Si-533 crystal with 2d-spacings of 2.21707 Å and 1.65635 Å and radii of curvature of 500 ± 1 mm and 823 ± 1 mm, respectively, showing a spatial resolution of 54.9 ?m. This imaging scheme is expected to be of interest for the two-dimensional imaging of laser produced plasmas.

  5. Radiosurgery for Craniopharyngioma

    SciTech Connect (OSTI)

    Niranjan, Ajay, E-mail: niranjana@upmc.ed [Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Kano, Hideyuki [Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Mathieu, David [Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC (Canada); Kondziolka, Douglas; Flickinger, John C.; Lunsford, L. Dade [Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA (United States); Center for Image-Guided Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2010-09-01T23:59:59.000Z

    Purpose: To analyze the outcomes of gamma knife stereotactic radiosurgery (SRS) for residual or recurrent craniopharyngiomas and evaluate the factors that optimized the tumor control rates. Methods and Materials: A total of 46 patients with craniopharyngiomas underwent 51 SRS procedures at University of Pittsburgh between 1988 and 2007. The median tumor volume was 1.0 cm{sup 3} (range, 0.07-8.0). The median prescription dose delivered to the tumor margin was 13.0 Gy (range, 9-20). The median maximal dose was 26.0 Gy (range, 20-50). The mean follow-up time was 62.2 months (range, 12-232). Results: The overall survival rate after SRS was 97.1% at 5 years. The 3- and 5-year progression-free survival rates (solid tumor control) were both 91.6%. The overall local control rate (for both solid tumor and cyst control) was 91%, 81%, and 68% at 1, 3, and 5 years, respectively. No patients with normal pituitary function developed hypopopituitarism after SRS. Two patients developed homonymous hemianopsia owing to tumor progression after SRS. Among the factors examined, complete radiosurgical coverage was a significant favorable prognostic factor. Conclusion: SRS is a safe and effective minimally invasive option for the management of residual or recurrent craniopharyngiomas. Complete radiosurgical coverage of the tumor was associated with better tumor control.

  6. A comparison of sample preparation methodology in the evaluation of geosynthetic clay liner (GCL) hydraulic conductivity

    SciTech Connect (OSTI)

    Siebken, J.R. [National Seal Co., Galesburg, IL (United States); Lucas, S. [Albarrie Naue Ltd., Barrie, Ontario (Canada)

    1997-11-01T23:59:59.000Z

    The method of preparing a single needle-punched GCL product for evaluation of hydraulic conductivity in a flexible wall permeameter was examined. The test protocol utilized for this evaluation was GRI Test Method GCL-2 Permeability of GCLs. The GCL product consisted of bentonite clay material supported by a woven and a non-woven geotextile on either side. The method preparation focused on the procedure for separating the test specimen from the larger sample and whether these methods produced difficulty in generating reliable test data. The methods examined included cutting with a razor knife, scissors, and a circular die with the perimeter of the test area under wet and dry conditions. In order to generate as much data as possible, tests were kept brief. Flow was monitored only long enough to determine whether or not preferential flow paths appeared to be present. The results appear to indicate that any of the methods involved will work. Difficulties arose not from the development of preferential flow paths around the edges of the specimens, but from the loss of bentonite from the edges during handling.

  7. Long-Term Outcomes From a Prospective Trial of Stereotactic Body Radiotherapy for Low-Risk Prostate Cancer

    SciTech Connect (OSTI)

    King, Christopher R., E-mail: crking@mednet.ucla.edu [Departments of Radiation Oncology and Urology, University of California Los Angeles School of Medicine, Los Angeles, CA (United States); Brooks, James D.; Gill, Harcharan; Presti, Joseph C. [Department of Urology, Stanford University School of Medicine, Stanford, CA (United States)

    2012-02-01T23:59:59.000Z

    Purpose: Hypofractionated radiotherapy has an intrinsically different normal tissue and tumor radiobiology. The results of a prospective trial of stereotactic body radiotherapy (SBRT) for prostate cancer with long-term patient-reported toxicity and tumor control rates are presented. Methods and Materials: From 2003 through 2009, 67 patients with clinically localized low-risk prostate cancer were enrolled. Treatment consisted of 36.25 Gy in 5 fractions using SBRT with the CyberKnife as the delivery technology. No patient received hormone therapy. Patient self-reported bladder and rectal toxicities were graded on the Radiation Therapy Oncology Group scale (RTOG). Results: Median follow-up was 2.7 years. There were no grade 4 toxicities. Radiation Therapy Oncology Group Grade 3, 2, and 1 bladder toxicities were seen in 3% (2 patients), 5% (3 patients), and 23% (13 patients) respectively. Dysuria exacerbated by urologic instrumentation accounted for both patients with Grade 3 toxicity. Urinary incontinence, complete obstruction, or persistent hematuria was not observed. Rectal Grade 3, 2, and 1 toxicities were seen in 0, 2% (1 patient), and 12.5% (7 patients), respectively. Persistent rectal bleeding was not observed. Low-grade toxicities were substantially less frequent with QOD vs. QD dose regimen (p = 0.001 for gastrointestinal and p = 0.007 for genitourinary). There were two prostate-specific antigen (PSA), biopsy-proven failures with negative metastatic workup. Median PSA at follow-up was 0.5 {+-} 0.72 ng/mL. The 4-year Kaplan-Meier PSA relapse-free survival was 94% (95% confidence interval, 85%-102%). Conclusion: Significant late bladder and rectal toxicities from SBRT for prostate cancer are infrequent. PSA relapse-free survival compares favorably with other definitive treatments. The current evidence supports consideration of stereotactic body radiotherapy among the therapeutic options for localized prostate cancer.

  8. Measurements of elastic modulus using laser-induced surface waves

    SciTech Connect (OSTI)

    Chang, D.J.; Amimoto, S.T.; Gross, R.W.F. [Aerospace Corporation, Los Angeles, CA (United States); Glenn, T. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-12-31T23:59:59.000Z

    In general, the mechanical testing methods that are utilized for alloys and polymers, e.g., dogbone, rheovibron, etc., are not applicable to thin film structures. We wish to report noncontacting measurements of the surface acoustic wave (SAW) velocity and the elastic modulus applicable to thin films of moderate thickness. An accompanying paper extends this technique to smaller film dimensions. A 15 ns pulsed YAG laser was used as the energy source to thermoelastically excite surface waves. The propagation of the waves was then observed by a second, independent He-Ne laser at a distance from the excitation spot. using the knife edge/beam deflection technique. A cylindrical lens was used to reduce the energy loading of the YAG laser on the sample to avoid damaging the surface of the specimen. The Rayleigh wave velocity is calculated from measurements of the arrival time of the surface wave as a function of distance from the ND:YAG laser spot. The shear modulus, G, can be determined from the measured speed of the surface waves, V, the specimen density, p, and Poisson`s ratio, v, according to the following relationship: V = R(v){sm_bullet}(G/p){sup {1/2}} where R(v), expressed as (0.862 + 1.14v)/(l + v), is the ratio of the Rayleigh wave velocity to the shear wave velocity and ranges from 0.86 to 0.95 Table below lists the measured surface wave velocities and the calculated shear modulus for our experimental results and the published values. Excellent agreement is observed. The depth of the SAW is approximately equal to the SAW wavelength which is approximately the laser spot size. Typically 30 {mu}m spot sizes can be readily achieved. In conclusion, SAW velocities and the modulus of elasticity of various materials have been measured. We have demonstrated that this non-contacting method can be used to characterize moderately thin films.

  9. Long-term Evaluation of Radiation-Induced Optic Neuropathy After Single-Fraction Stereotactic Radiosurgery

    SciTech Connect (OSTI)

    Leavitt, Jacqueline A., E-mail: leavitt.jacqueline@mayo.edu [Department of Ophthalmology, Mayo Clinic and Foundation, Rochester, Minnesota (United States); Stafford, Scott L. [Department of Radiation Oncology, Mayo Clinic and Foundation, Rochester, Minnesota (United States); Link, Michael J. [Department of Neurosurgery, Mayo Clinic and Foundation, Rochester, Minnesota (United States); Pollock, Bruce E. [Department of Radiation Oncology, Mayo Clinic and Foundation, Rochester, Minnesota (United States); Department of Neurosurgery, Mayo Clinic and Foundation, Rochester, Minnesota (United States)

    2013-11-01T23:59:59.000Z

    Purpose: To determine the long-term risk of radiation-induced optic neuropathy (RION) in patients having single-fraction stereotactic radiosurgery (SRS) for benign skull base tumors. Methods and Materials: Retrospective review of 222 patients having Gamma Knife radiosurgery for benign tumors adjacent to the anterior visual pathway (AVP) between 1991 and 1999. Excluded were patients with prior or concurrent external beam radiation therapy or SRS. One hundred twenty-nine patients (58%) had undergone previous surgery. Tumor types included confirmed World Health Organization grade 1 or presumed cavernous sinus meningioma (n=143), pituitary adenoma (n=72), and craniopharyngioma (n=7). The maximum dose to the AVP was ?8.0 Gy (n=126), 8.1-10.0 Gy (n=39), 10.1-12.0 Gy (n=47), and >12 Gy (n=10). Results: The mean clinical and imaging follow-up periods were 83 and 123 months, respectively. One patient (0.5%) who received a maximum radiation dose of 12.8 Gy to the AVP developed unilateral blindness 18 months after SRS. The chance of RION according to the maximum radiation dose received by the AVP was 0 (95% confidence interval [CI] 0-3.6%), 0 (95% CI 0-10.7%), 0 (95% CI 0-9.0%), and 10% (95% CI 0-43.0%) for patients receiving ?8 Gy, 8.1-10.0 Gy, 10.1-12.0 Gy, and >12 Gy, respectively. The overall risk of RION in patients receiving >8 Gy to the AVP was 1.0% (95% CI 0-6.2%). Conclusions: The risk of RION after single-fraction SRS in patients with benign skull base tumors who have no prior radiation exposure is very low if the maximum dose to the AVP is ?12 Gy. Physicians performing single-fraction SRS should remain cautious when treating lesions adjacent to the AVP, especially when the maximum dose exceeds 10 Gy.

  10. Stereotactic Radiosurgery for Recurrent or Unresectable Pilocytic Astrocytoma

    SciTech Connect (OSTI)

    Hallemeier, Christopher L. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Pollock, Bruce E. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Department of Neurological Surgery, Mayo Clinic, Rochester, MN (United States); Schomberg, Paula J. [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States); Link, Michael J. [Department of Neurological Surgery, Mayo Clinic, Rochester, MN (United States); Brown, Paul D. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Stafford, Scott L., E-mail: Stafford.scott@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, MN (United States)

    2012-05-01T23:59:59.000Z

    Purpose: To report the outcomes in patients with recurrent or unresectable pilocytic astrocytoma (PA) treated with Gamma Knife stereotactic radiosurgery (SRS). Methods and Materials: Retrospective review of 18 patients (20 lesions) with biopsy-confirmed PA having SRS at our institution from 1992 through 2005. Results: The median patient age at SRS was 23 years (range, 4-56). Thirteen patients (72%) had undergone one or more previous surgical resections, and 10 (56%) had previously received external-beam radiation therapy (EBRT). The median SRS treatment volume was 9.1 cm{sup 3} (range, 0.7-26.7). The median tumor margin dose was 15 Gy (range, 12-20). The median follow-up was 8.0 years (range, 0.5-15). Overall survival at 1, 5, and 10 years after SRS was 94%, 71%, and 71%, respectively. Tumor progression (local solid progression, n = 4; local solid progression + distant, n = 1; distant, n = 2; cyst development/progression, n = 4) was noted in 11 patients (61%). Progression-free survival at 1, 5, and 10 years was 65%, 41%, and 17%, respectively. Prior EBRT was associated with inferior overall survival (5-year risk, 100% vs. 50%, p = 0.03) and progression-free survival (5-year risk, 71% vs. 20%, p = 0.008). Nine of 11 patients with tumor-related symptoms improved after SRS. Symptomatic edema after SRS occurred in 8 patients (44%), which resolved with short-term corticosteroid therapy in the majority of those without early disease progression. Conclusions: SRS has low permanent radiation-related morbidity and durable local tumor control, making it a meaningful treatment option for patients with recurrent or unresectable PA in whom surgery and/or EBRT has failed.

  11. Anniversary Paper: The role of medical physicists in developing stereotactic radiosurgery

    SciTech Connect (OSTI)

    Benedict, Stanley H.; Bova, Frank J.; Clark, Brenda; Goetsch, Steven J.; Hinson, William H.; Leavitt, Dennis D.; Schlesinger, David J.; Yenice, Kamil M. [University of Virginia Health Systems, Charlottesville, Virginia 22908-0375 (United States); University of Florida, Gainesville, Florida 32610 (United States); The Ottawa Hospital Cancer Centre, Ottawa, Ontario K1H 8L6 (Canada); San Diego Medical Physics, Inc., La Jolla, California 92037 (United States); Wake Forest University, Winston-Salem, North Carolina 27157 (United States); LDS Hospital, Salt Lake City, Utah 84143 (United States); University of Virginia Health Systems, Charlottesville, Virginia 22908-0375 (United States); University of Chicago, Chicago, Illinois 60637 (United States)

    2008-09-15T23:59:59.000Z

    This article is a tribute to the pioneering medical physicists over the last 50 years who have participated in the research, development, and commercialization of stereotactic radiosurgery (SRS) and stereotactic radiotherapy utilizing a wide range of technology. The authors have described the evolution of SRS through the eyes of physicists from its beginnings with the Gamma Knife in 1951 to proton and charged particle therapy; modification of commercial linacs to accommodate high precision SRS setups; the multitude of accessories that have enabled fine tuning patients for relocalization, immobilization, and repositioning with submillimeter accuracy; and finally the emerging technology of SBRT. A major theme of the article is the expanding role of the medical physicist from that of advisor to the neurosurgeon to the current role as a primary driver of new technology that has already led to an adaptation of cranial SRS to other sites in the body, including, spine, liver, and lung. SRS continues to be at the forefront of the impetus to provide technological precision for radiation therapy and has demonstrated a host of downstream benefits in improving delivery strategies for conventional therapy as well. While this is not intended to be a comprehensive history, and the authors could not delineate every contribution by all of those working in the pursuit of SRS development, including physicians, engineers, radiobiologists, and the rest of the therapy and dosimetry staff in this important and dynamic radiation therapy modality, it is clear that physicists have had a substantial role in the development of SRS and theyincreasingly play a leading role in furthering SRS technology.

  12. 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.

  13. SU-E-J-135: An Investigation of Ultrasound Imaging for 3D Intra-Fraction Prostate Motion Estimation

    SciTech Connect (OSTI)

    O'Shea, T; Harris, E; Bamber, J [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, Greater London (United Kingdom); Evans, P [Centre for Vision, Speech and Signal Processing, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford (United Kingdom)

    2014-06-01T23:59:59.000Z

    Purpose: This study investigates the use of a mechanically swept 3D ultrasound (US) probe to estimate intra-fraction motion of the prostate during radiation therapy using an US phantom and simulated transperineal imaging. Methods: A 3D motion platform was used to translate an US speckle phantom while simulating transperineal US imaging. Motion patterns for five representative types of prostate motion, generated from patient data previously acquired with a Calypso system, were using to move the phantom in 3D. The phantom was also implanted with fiducial markers and subsequently tracked using the CyberKnife kV x-ray system for comparison. A normalised cross correlation block matching algorithm was used to track speckle patterns in 3D and 2D US data. Motion estimation results were compared with known phantom translations. Results: Transperineal 3D US could track superior-inferior (axial) and anterior-posterior (lateral) motion to better than 0.8 mm root-mean-square error (RMSE) at a volume rate of 1.7 Hz (comparable with kV x-ray tracking RMSE). Motion estimation accuracy was poorest along the US probe's swept axis (right-left; RL; RMSE < 4.2 mm) but simple regularisation methods could be used to improve RMSE (< 2 mm). 2D US was found to be feasible for slowly varying motion (RMSE < 0.5 mm). 3D US could also allow accurate radiation beam gating with displacement thresholds of 2 mm and 5 mm exhibiting a RMSE of less than 0.5 mm. Conclusion: 2D and 3D US speckle tracking is feasible for prostate motion estimation during radiation delivery. Since RL prostate motion is small in magnitude and frequency, 2D or a hybrid (2D/3D) US imaging approach which also accounts for potential prostate rotations could be used. Regularisation methods could be used to ensure the accuracy of tracking data, making US a feasible approach for gating or tracking in standard or hypo-fractionated prostate treatments.

  14. SU-E-T-19: A New End-To-End Test Method for ExacTrac for Radiation and Plan Isocenter Congruence

    SciTech Connect (OSTI)

    Lee, S; Nguyen, N; Liu, F; Huang, Y [Rhode Island Hospital / Warren Alpert Medical, Providence, RI (United States); Sio, T [Mayo Clinic, Rochester, MN (United States); Jung, J [East Carolina University, Greenville, North Carolina (United States); Pyakuryal, A [UniversityIllinois at Chicago, Chicago, IL (United States); Jang, S [Princeton Radiation Oncology Ctr., Jamesburg, NJ (United States)

    2014-06-01T23:59:59.000Z

    Purpose: To combine and integrate quality assurance (QA) of target localization and radiation isocenter End to End (E2E) test of BrainLAB ExacTrac system, a new QA approach was devised using anthropomorphic head and neck phantom. This test insures the target localization as well as radiation isocenter congruence which is one step ahead the current ExacTrac QA procedures. Methods: The head and neck phantom typically used for CyberKnife E2E test was irradiated to the sphere target that was visible in CT-sim images. The CT-sim was performed using 1 mm thickness slice with helical scanning technique. The size of the sphere was 3-cm diameter and contoured as a target volume using iPlan V.4.5.2. A conformal arc plan was generated using MLC-based with 7 fields, and five of them were include couch rotations. The prescription dose was 5 Gy and 95% coverage to the target volume. For the irradiation, two Gafchromic films were perpendicularly inserted into the cube that hold sphere inside. The linac used for the irradiation was TrueBeam STx equipped with HD120 MLC. In order to use ExacTrac, infra-red head–array was used to correlate orthogonal X-ray images. Results: Using orthogonal X-rays of ExacTrac the phantom was positioned. For each field, phantom was check again with X-rays and re-positioned if necessary. After each setup using ExacTrac, the target was irradiated. The films were analyzed to determine the deviation of the radiation isocenter in all three dimensions: superior-inferior, left-right and anterior-posterior. The total combining error was found to be 0.76 mm ± 0.05 mm which was within sub-millimeter accuracy. Conclusion: Until now, E2E test for ExacTrac was separately implemented to test image localization and radiation isocenter. This new method can be used for periodic QA procedures.

  15. Dedicated Linear Accelerator Radiosurgery for Trigeminal Neuralgia: A Single-Center Experience in 179 Patients With Varied Dose Prescriptions and Treatment Plans

    SciTech Connect (OSTI)

    Smith, Zachary A.; Gorgulho, Alessandra A.; Bezrukiy, Nikita; McArthur, David [Department of Neurosurgery, UCLA Medical Center, Los Angeles, CA (United States); Agazaryan, Nzhde; Selch, Michael T. [Department of Radiation Oncology, UCLA Medical Center, Los Angeles, CA (United States); De Salles, Antonio A.F., E-mail: adesalles@mednet.ucla.edu [Department of Neurosurgery, UCLA Medical Center, Los Angeles, CA (United States); Department of Radiation Oncology, UCLA Medical Center, Los Angeles, CA (United States); West Los Angeles Veteran's Administration Hospital, Los Angeles, CA (United States)

    2011-09-01T23:59:59.000Z

    Purpose: Dedicated linear accelerator radiosurgery (D-LINAC) has become an important treatment for trigeminal neuralgia (TN). Although the use of gamma knife continues to be established, few large series exist using D-LINAC. The authors describe their results, comparing the effects of varied target and dose regimens. Methods and Materials: Between August 1995 and January 2008, 179 patients were treated with D-LINAC radiosurgery. Ten patients (5.58%) had no clinical follow-up. The median age was 74.0 years (range, 32-90 years). A total of 39 patients had secondary or atypical pain, and 130 had idiopathic TN. Initially, 28 patients received doses between 70 and 85 Gy, with the 30% isodose line (IDL) touching the brainstem. Then, using 90 Gy, 82 consecutive patients were treated with a 30% IDL and 59 patients with a 50% IDL tangential to the pons. Results: Of 169 patients, 134 (79.3%) experienced significant relief at a mean of 28.8 months (range, 5-142 months). Average time to relief was 1.92 months (range, immediate to 6 months). A total of 31 patients (19.0%) had recurrent pain at 13.5 months. Of 87 patients with idiopathic TN without prior procedures, 79 (90.8%) had initial relief. Among 28 patients treated with 70 Gy and 30% IDL, 18 patients (64.3%) had significant relief, and 10 (35.7%) had numbness. Of the patients with 90 Gy and 30% IDL at the brainstem, 59 (79.0%) had significant relief and 48.9% had numbness. Among 59 consecutive patients with similar dose but the 50% isodoseline at the brainstem, 49 patients (88.0%) had excellent/good relief. Numbness, averaging 2.49 on a subjective scale of 1 to 5, was experienced by 49.7% of the patients, Conclusions: Increased radiation dose and volume of brainstem irradiation may improve clinical outcomes with the trade-off of trigeminal dysfunction. Further study of the implications of dose and target are needed to optimize outcomes and to minimize complications.

  16. Delayed Complications in Patients Surviving at Least 3 Years After Stereotactic Radiosurgery for Brain Metastases

    SciTech Connect (OSTI)

    Yamamoto, Masaaki, E-mail: BCD06275@nifty.com [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan) [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan); Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo (Japan); Kawabe, Takuya [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan) [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan); Department of Neurosurgery, Kyoto Prefectural University of Medicine Graduate School of Medical Sciences, Kyoto (Japan); Higuchi, Yoshinori [Department of Neurosurgery, Chiba University Graduate School of Medicine, Chiba (Japan)] [Department of Neurosurgery, Chiba University Graduate School of Medicine, Chiba (Japan); Sato, Yasunori [Clinical Research Center, Chiba University Graduate School of Medicine, Chiba (Japan)] [Clinical Research Center, Chiba University Graduate School of Medicine, Chiba (Japan); Nariai, Tadashi [Department of Neurosurgery, Graduate School, Tokyo Medical and Dental University School of Medicine, Tokyo (Japan)] [Department of Neurosurgery, Graduate School, Tokyo Medical and Dental University School of Medicine, Tokyo (Japan); Barfod, Bierta E. [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan)] [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan); Kasuya, Hidetoshi [Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo (Japan)] [Department of Neurosurgery, Tokyo Women's Medical University Medical Center East, Tokyo (Japan); Urakawa, Yoichi [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan)] [Katsuta Hospital Mito GammaHouse, Hitachi-naka (Japan)

    2013-01-01T23:59:59.000Z

    Purpose: Little is known about delayed complications after stereotactic radiosurgery in long-surviving patients with brain metastases. We studied the actual incidence and predictors of delayed complications. Patients and Methods: This was an institutional review board-approved, retrospective cohort study that used our database. Among our consecutive series of 2000 patients with brain metastases who underwent Gamma Knife radiosurgery (GKRS) from 1991-2008, 167 patients (8.4%, 89 women, 78 men, mean age 62 years [range, 19-88 years]) who survived at least 3 years after GKRS were studied. Results: Among the 167 patients, 17 (10.2%, 18 lesions) experienced delayed complications (mass lesions with or without cyst in 8, cyst alone in 8, edema in 2) occurring 24.0-121.0 months (median, 57.5 months) after GKRS. The actuarial incidences of delayed complications estimated by competing risk analysis were 4.2% and 21.2% at the 60th month and 120th month, respectively, after GKRS. Among various pre-GKRS clinical factors, univariate analysis demonstrated tumor volume-related factors: largest tumor volume (hazard ratio [HR], 1.091; 95% confidence interval [CI], 1.018-1.154; P=.0174) and tumor volume {<=}10 cc vs >10 cc (HR, 4.343; 95% CI, 1.444-12.14; P=.0108) to be the only significant predictors of delayed complications. Univariate analysis revealed no correlations between delayed complications and radiosurgical parameters (ie, radiosurgical doses, conformity and gradient indexes, and brain volumes receiving >5 Gy and >12 Gy). After GKRS, an area of prolonged enhancement at the irradiated lesion was shown to be a possible risk factor for the development of delayed complications (HR, 8.751; 95% CI, 1.785-157.9; P=.0037). Neurosurgical interventions were performed in 13 patients (14 lesions) and mass removal for 6 lesions and Ommaya reservoir placement for the other 8. The results were favorable. Conclusions: Long-term follow-up is crucial for patients with brain metastases treated with GKRS because the risk of complications long after treatment is not insignificant. However, even when delayed complications occur, favorable outcomes can be expected with timely neurosurgical intervention.

  17. Implementing Strategies for Drying and Pressing Wood Without Emissions Controls

    SciTech Connect (OSTI)

    Sujit Banerjee; Terrance Conners

    2007-09-07T23:59:59.000Z

    Drying and pressing wood for the manufacture of lumber, particleboard, oriented strand board (OSB), veneer and medium density fiberboard (MDF) release volatile organic compounds (VOCs) into the atmosphere. These emissions require control equipment that are capital-intensive and consume significant quantities of natural gas and electricity. The objective of our work was to understand the mechanisms through which volatile organic compounds are generated and released and to develop simple control strategies. Of the several strategies developed, two have been implemented for OSB manufacture over the course of this study. First, it was found that increasing final wood moisture by about 2-4 percentage points reduced the dryer emissions of hazardous air pollutants by over 70%. As wood dries, the escaping water evaporatively cools the wood. This cooling tapers off wood when the wood is nearly dry and the wood temperature rises. Thermal breakdown of the wood tissue occurs and VOCs are released. Raising the final wood moisture by only a few percentage points minimizes the temperature rise and reduces emissions. Evaporative cooling also impacts has implications for VOC release from wood fines. Flaking wood for OSB manufacture inevitable generates fines. Fines dry out rapidly because of their high surface area and evaporative cooling is lost more rapidly than for flakes. As a result, fines emit a disproportionate quantity of VOCs. Fines can be reduced in two ways: through screening of the green furnish and through reducing their generation during flaking. The second approach is preferable because it also increased wood yield. A procedure to do this by matching the sharpness angle of the flaker knife to the ambient temperature was also developed. Other findings of practical interests are as follows: Dielectric heating of wood under low-headspace conditions removes terpenes and other extractives from softwood; The monoterpene content in trees depend upon temperature and seasonal effects; Method 25A emissions from lumber drying can be modeled from a knowledge of the airflow through the kiln; A heat transfer model shows that VOCs released during hot-pressing mainly originate from the surface of the board; and Boiler ash can be used to adsorb formaldehyde from air streams.

  18. Smoothing of respiratory motion traces for motion-compensated radiotherapy

    SciTech Connect (OSTI)

    Ernst, Floris; Schlaefer, Alexander; Schweikard, Achim [Institute for Robotics and Cognitive Systems, University of Luebeck, Ratzeburger Allee 160, Luebeck SH 23538 (Germany)

    2010-01-15T23:59:59.000Z

    Purpose: The CyberKnife system has been used successfully for several years to radiosurgically treat tumors without the need for stereotactic fixation or sedation of the patient. It has been shown that tumor motion in the lung, liver, and pancreas can be tracked with acceptable accuracy and repeatability. However, highly precise targeting for tumors in the lower abdomen, especially for tumors which exhibit strong motion, remains problematic. Reasons for this are manifold, like the slow tracking system operating at 26.5 Hz, and using the signal from the tracking camera ''as is''. Since the motion recorded with the camera is used to compensate for system latency by prediction and the predicted signal is subsequently used to infer the tumor position from a correlation model based on x-ray imaging of gold fiducials around the tumor, camera noise directly influences the targeting accuracy. The goal of this work is to establish the suitability of a new smoothing method for respiratory motion traces used in motion-compensated radiotherapy. The authors endeavor to show that better prediction--With a lower rms error of the predicted signal--and/or smoother prediction is possible using this method. Methods: The authors evaluated six commercially available tracking systems (NDI Aurora, PolarisClassic, Polaris Vicra, MicronTracker2 H40, FP5000, and accuTrack compact). The authors first tracked markers both stationary and while in motion to establish the systems' noise characteristics. Then the authors applied a smoothing method based on the a trous wavelet decomposition to reduce the devices' noise level. Additionally, the smoothed signal of the moving target and a motion trace from actual human respiratory motion were subjected to prediction using the MULIN and the nLMS{sub 2} algorithms. Results: The authors established that the noise distribution for a static target is Gaussian and that when the probe is moved such as to mimic human respiration, it remains Gaussian with the exception of the FP5000 and the Aurora systems. The authors also showed that the proposed smoothing method can indeed be used to filter noise. The signal's jitter dropped by as much as 95% depending on the tracking system employed. Subsequently, the 3D prediction error (rms) for a prediction horizon of 150 ms on a synthetic signal dropped by up to 37% when using a normalized LMS prediction algorithm (nLMS{sub 2}) and hardly changed when using a MULIN algorithm. When smoothing a real signal obtained in our laboratory, the improvement of prediction was similar: Up to 30% for both the nLMS{sub 2} and the best MULIN algorithm. The authors also found a noticeable increase in smoothness of the predicted signal, the relative jitter dropped by up to 95% on the real signal, and on the simulated signal. Conclusions: In conclusion, the authors can say that preprocessing of marker data is very useful in motion-compensated radiotherapy since the quality of prediction increases. This will result in better performance of the correlation model. As a side effect, since the prediction of a preprocessed signal is also less noisy, the authors expect less robot vibration resulting in better targeting accuracy and less strain on the robot gears.