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Sample records for hijiori hdr test

  1. One month circulation test at the Hijiori HDR test site in 1996

    SciTech Connect

    Sato, Yoshiteru; Matsunaga, Isao; Nagai, Masahiro

    1996-12-31

    As shown in Table 1, four wells have been used for circulation tests at Hijiori. The diameters of all the open-hole sections of the wells are 8-{1/2} inches. SKG-2 is an injection well. An 1800 m deep reservoir was stimulated hydraulically by water injection into the open-hole section of SKG-2 in 1986. HDR-1 is also an injection well. A 2200 m deep reservoir was stimulated by water injection into the open-hole section of HDR-1 in 1992. HDR-2a and HDR-3 are used to produce steam and hot water from both reservoirs. The subsurface system was created In granodiorite basement rock with temperatures of 250 {degrees}C at a depth of 2,500 m and 270{degrees} C at depth of 2,700 m.

  2. Transient analysis of the 1991 Hijiori Shallow Reservoir Circulation Test

    SciTech Connect

    Hyodo, M.; Shinohara, N.; Takasugi, S.; Wright, C.A.; Conant, R..

    1996-01-24

    Like any dynamic system, HDR reservoirs cannot be fully characterized by their steady-state behavior. Circulation tests analysis should be performed on both the steady-state response and the transient response of HDR systems. Transient analysis allows not only estimation of critical reservoir parameters and how these parameters change with operating conditions / history, but transient analysis also aids in evaluating the feasibility of various modes of HDR system operation (base load, load following, etc.). This paper details the transient analysis of NEDO's FY 1991 Shallow Reservoir Circulation Test at the Hijiori HDR site in Japan. Reservoir fluid storage is carefully bounded through the employment of two distinct methods for calculation of the fluid storage from the observed transient response. A brief discussion is also included of the distribution of reservoir fluid storage; the relationship between pressure, reservoir stress, and apparent reservoir capacitance; and appropriate circulation test design to facilitate transient analysis.

  3. Overview of the Hijiori shallow reservoir circulation tests and reservoir fluid storage analysis

    SciTech Connect

    Takahiro Shiga; Masami Hyodo; Shinji Takasugi; Wright, C.A.; Conant, R.A.

    1996-01-24

    Since 1985, NEDO has advanced a]Hot Dry Rock project in Hijiori, Japan. Circulation tests have been performed in FY1991 (in a shallow reservoir), and in FY1995 (in both shallow and deep reservoirs). In 1991 circulation test, the result was that 78% fluid recovery at an injection rate of 60 tons/hour and production temperatures of 150 °C - 190 °C . However no detailed analysis of flow conditions was given. Therefore, a simplified HDR model has been proposed to understand the Hijion HDR reservoir. We have analyzed the 1991 circulation test using the model. This study is very important for analyzing the circulation test in both of shallow and deep reservoir which was conducted in 1995. This paper summarizes the 1991 circulation test at the Hijiori HDR test site, and estimation of the reservoir fluid storage by using "unrecovered" flow from the new conceptual idea of HDR reservoir model.

  4. Interference of production between two wells during a one month circulation test at the Hijiori Hot Dry Rock test site

    SciTech Connect

    Tenma, Norio; yamaguchi, Tsutomu; Matsunaga, Isao; Kuriyagawa, Michio; Sato, Yoshiteru

    1996-01-24

    In 1995, a one-month circulation test (Exp.9501) was carried out with HDR-1 as an injection well and HDR-2 and HDR-3 as production wells at the Hijiori HDR site in Yamagata prefecture, Japan. There are two reservoirs in a high temperature granite at the site. Exp.9501 was the first circulation test to evaluate characteristics of the deeper reservoir at about 2200 m deep and was a preliminary test for the subsequent two-years circulation test. The interference between the two reservoirs was observed because of water level changes in production wells. This observation was simulated by using a wellbore heat transfer ( WBHT) code and concluded that this could occur when downhole pressure changed by heating up of the wellbore. Geochemistry of the produced fluid support this conclusion.

  5. Interference of production between two wells during a one month circulation test at the Hijiori Hot Dry Rock test site

    SciTech Connect

    Tenma, Norio; Yamaguchi, Tsutomu; Matsunaga, Isao

    1996-12-31

    In 1995, a one-month circulation test (Exp.9501) was carried out with HDR-1 as an injection well and HDR-2 and HDR-3 as production wells at the Hijiori HDR site in Yamagata prefecture, Japan. There are two reservoirs in a high temperature granite at the site. Exp.9501 was the first circulation test to evaluate characteristics of the deeper reservoir at about 2200 m deep and was a preliminary test for the subsequent two-years circulation test. The interference between the two reservoirs was observed because of water level changes in production wells. This observation was simulated by using a wellbore heat transfer (WBHT) code and concluded that this could occur when downhole pressure changed by heating up of the wellbore. Geochemistry of the produced fluid support this conclusion.

  6. Development of hot dry rock technology at Hijiori test site: Program for a long-term circulation test

    SciTech Connect

    Tenma, Norio; Iwakiri, Shunichi; Matsunaga, Isao

    1998-10-01

    Since 1985, the New Energy and Industrial Technology Development Organization (NEDO) has continued the development of hot dry rock power generation in Hijiori Hot Dry Rock test site, Yamagata prefecture, Japan, as part of the Sunshine Project and succeeding New Sunshine Project sponsored by the Agency of Industrial Science and Technology (AIST), a branch of the Ministry of International Trade and Industry (MITI). The objective of this project is to identify the feasibility of a Hot Dry Rock power generation system in Japan. Thus, the research and development being undertaken at Hijiori HDR test site is aiming to establish hot rock drilling technology, logging borehole technology for evaluating the state of the rock around the well, hydraulic fracturing technology for creating artificial fractures in rock, fracture mapping technology for surveying the reservoir area, and reservoir evaluation technology for predicting reservoir longevity.

  7. HDR Opportunities and Challenges Beyond the Long-Term Flow Test

    SciTech Connect

    Duchane, David

    1992-03-24

    The long term flow test (LTFT) of the worlds largest, deepest, and hottest hot dry rock (HDR) reservoir currently underway at Fenton Hill, NM, is expected to demonstrate that thermal energy can be mined from hot rock within the earth on a sustainable basis with minimal water consumption. This test will simulate the operations of a commercial facility in some ways, but it will not show that energy from HDR can be produced at a variety of locations with different geological settings. Since the Fenton Hill system was designed as a research facility rather than strictly for production purposes, it will also not demonstrate economic viability, although it may well give indications of system modifications needed for economic HDR operations. A second production site must be constructed, ideally under the direction of the private geothermal community, to begin the process of proving that the vast HDR resources can be accessed on a worldwide scale. This facility should be designed and engineered to produce and market energy at competitive prices. At the same time, a wide variety of techniques to advance the state-of-the-art of HDR technology must be pursued to develop this infant technology rapidly to its maximum potential. A number of design and operational techniques have been conceived which may lead to improved economics in HDR systems. After careful technical and economic scrutiny, those showing merit should be vigorously pursued. Finally, research and development work in areas such as reservoir interrogation, and system modeling must be accelerated to increase the competitiveness and geographical applications of HDR and the geothermal industry in general. This paper addresses the above issues in detail and outlines possible paths to future prosperity for the commercial geothermal industry.

  8. A summary of the Fire Testing Program at the German HDR Test Facility

    SciTech Connect

    Nowlen, S.P.

    1995-11-01

    This report provides an overview of the fire safety experiments performed under the sponsorship of the German government in the containment building of the decommissioned pilot nuclear power plant known as HDR. This structure is a highly complex, multi-compartment, multi-level building which has been used as the test bed for a wide range of nuclear power plant operation safety experiments. These experiments have included numerous fire tests. Test fire fuel sources have included gas burners, wood cribs, oil pools, nozzle release oil fires, and cable in cable trays. A wide range of ventilation conditions including full natural ventilation, full forced ventilation, and combined natural and forced ventilation have been evaluated. During most of the tests, the fire products mixed freely with the full containment volume. Macro-scale building circulation patterns which were very sensitive to such factors as ventilation configuration were observed and characterized. Testing also included the evaluation of selective area pressurization schemes as a means of smoke control for emergency access and evacuation stairwells.

  9. HDR imaging evaluation of a NT-proBNP test with a mobile phone.

    PubMed

    Preechaburana, P; Macken, S; Suska, A; Filippini, D

    2011-01-15

    The determination of NT-proBNP levels is key for the monitoring of patients with diagnosed heart failure and it is a routine measurement typically performed at health care centers, which would benefit from decentralized alternatives. Here we investigate the quantitative evaluation of a well-established NT-proBNP test using a standard mobile phone (Nokia 6720) as measuring platform rather than a dedicated instrument. A Java ME software developed for this application controls the illumination and imaging of the proBNP test under defined time intervals, which enables the composition of multi-exposure sets that are processed as high dynamic range (HDR) images for contrast enhancement. The results show that HDR processing significantly increases the sensitivity and resolution of the technique achieving a performance within the diagnostics range. These results demonstrate the feasibility to exploit a ubiquitous device to decentralize the evaluation of a routine test and identify key processing alternatives to bring the performance of such systems within the diagnostics range.

  10. High level seismic/vibrational tests at the HDR: An overview

    SciTech Connect

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Schrammel, D.; Malcher, L.; Steinhilber, H.; Costello, J.F.

    1991-12-31

    As part of the Phase II testing at the HDR Test Facility in Kahl/Main, FRG, two series of high-level seismic/vibrational experiments were performed. In the first of these (SHAG) a coast-down shaker, mounted on the reactor operating floor and capable of generating 1000 tonnes of force, was used to investigate full-scale structural response, soil-structure interaction (SSI), and piping/equipment response at load levels equivalent to those of a design basis earthquake. The HDR soil/structure system was tested to incipient failure exhibiting highly nonlinear response. In the load transmission from structure to piping/equipment significant response amplifications and shifts to higher frequencies occurred. The performance of various pipe support configurations was evaluated. This latter effort was continued in the second series of tests (SHAM), in which an in-plant piping system was investigated at simulated seismic loads (generated by two servo-hydraulic actuators each capable of generating 40 tonnes of force), that exceeded design levels manifold and resulted in considerable pipe plastification and failure of some supports (snubbers). The evaluation of six different support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is essential to limiting pipe stresses. Pipe strains at loads exceeding the design level eightfold were still tolerable, indicating that pipe failure even under extreme seismic loads is unlikely inspite of multiple support failures. Conservatively, an excess capacity (margin) of at least four was estimated for the piping system, and the pipe damping was found to be 4%. Comparisons of linear and nonlinear computational results with measurements showed that analytical predictions have wide scatter and do not necessarily yield conservative responses, underpredicting, in particular, peak support forces.

  11. High level seismic/vibrational tests at the HDR: An overview

    SciTech Connect

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J. ); Schrammel, D.; Malcher, L. ); Steinhilber, H. ); Costello, J.F. . Office of Nuclear Regulatory Research)

    1991-01-01

    As part of the Phase II testing at the HDR Test Facility in Kahl/Main, FRG, two series of high-level seismic/vibrational experiments were performed. In the first of these (SHAG) a coast-down shaker, mounted on the reactor operating floor and capable of generating 1000 tonnes of force, was used to investigate full-scale structural response, soil-structure interaction (SSI), and piping/equipment response at load levels equivalent to those of a design basis earthquake. The HDR soil/structure system was tested to incipient failure exhibiting highly nonlinear response. In the load transmission from structure to piping/equipment significant response amplifications and shifts to higher frequencies occurred. The performance of various pipe support configurations was evaluated. This latter effort was continued in the second series of tests (SHAM), in which an in-plant piping system was investigated at simulated seismic loads (generated by two servo-hydraulic actuators each capable of generating 40 tonnes of force), that exceeded design levels manifold and resulted in considerable pipe plastification and failure of some supports (snubbers). The evaluation of six different support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is essential to limiting pipe stresses. Pipe strains at loads exceeding the design level eightfold were still tolerable, indicating that pipe failure even under extreme seismic loads is unlikely inspite of multiple support failures. Conservatively, an excess capacity (margin) of at least four was estimated for the piping system, and the pipe damping was found to be 4%. Comparisons of linear and nonlinear computational results with measurements showed that analytical predictions have wide scatter and do not necessarily yield conservative responses, underpredicting, in particular, peak support forces.

  12. Image and video compression for HDR content

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Reinhard, Erik; Agrafiotis, Dimitris; Bull, David R.

    2012-10-01

    High Dynamic Range (HDR) technology can offer high levels of immersion with a dynamic range meeting and exceeding that of the Human Visual System (HVS). A primary drawback with HDR images and video is that memory and bandwidth requirements are significantly higher than for conventional images and video. Many bits can be wasted coding redundant imperceptible information. The challenge is therefore to develop means for efficiently compressing HDR imagery to a manageable bit rate without compromising perceptual quality. In this paper, we build on previous work of ours and propose a compression method for both HDR images and video, based on an HVS optimised wavelet subband weighting method. The method has been fully integrated into a JPEG 2000 codec for HDR image compression and implemented as a pre-processing step for HDR video coding (an H.264 codec is used as the host codec for video compression). Experimental results indicate that the proposed method outperforms previous approaches and operates in accordance with characteristics of the HVS, tested objectively using a HDR Visible Difference Predictor (VDP). Aiming to further improve the compression performance of our method, we additionally present the results of a psychophysical experiment, carried out with the aid of a high dynamic range display, to determine the difference in the noise visibility threshold between HDR and Standard Dynamic Range (SDR) luminance edge masking. Our findings show that noise has increased visibility on the bright side of a luminance edge. Masking is more consistent on the darker side of the edge.

  13. ICFT: An initial closed-loop flow test of the Fenton Hill Phase II HDR reservoir

    SciTech Connect

    Dash, Z.V.; Aguilar, R.G.; Dennis, B.R.; Dreesen, D.S.; Fehler, M.C.; Hendron, R.H.; House, L.S.; Ito, H.; Kelkar, S.M.; Malzahn, M.V.

    1989-02-01

    A 30-day closed-loop circulation test of the Phase II Hot Dry Rock reservoir at Fenton Hill, New Mexico, was conducted to determine the thermal, hydraulic, chemical, and seismic characteristics of the reservoir in preparation for a long-term energy-extraction test. The Phase II heat-extraction loop was successfully tested with the injection of 37,000 m/sup 3/ of cold water and production of 23,300 m/sup 3/ of hot water. Up to 10 MW/sub t/ was extracted when the production flow rate reached 0.0139 m/sup 3//s at 192/degree/C. By the end of the test, the water-loss rate had decreased to 26% and a significant portion of the injected water was recovered; 66% during the test and an additional 20% during subsequent venting. Analysis of thermal, hydraulic, geochemical, tracer, and seismic data suggests the fractured volume of the reservoir was growing throughout the test. 19 refs., 64 figs., 19 tabs.

  14. Tone compatibility between HDR displays

    NASA Astrophysics Data System (ADS)

    Bist, Cambodge; Cozot, Rémi; Madec, Gérard; Ducloux, Xavier

    2016-09-01

    High Dynamic Range (HDR) is the latest trend in television technology and we expect an in ux of HDR capable consumer TVs in the market. Initial HDR consumer displays will operate on a peak brightness of about 500-1000 nits while in the coming years display peak brightness is expected to go beyond 1000 nits. However, professionally graded HDR content can range from 1000 to 4000 nits. As with Standard Dynamic Range (SDR) content, we can expect HDR content to be available in variety of lighting styles such as low key, medium key and high key video. This raises concerns over tone-compatibility between HDR displays especially when adapting to various lighting styles. It is expected that dynamic range adaptation between HDR displays uses similar techniques as found with tone mapping and tone expansion operators. In this paper, we survey simple tone mapping methods of 4000 nits color-graded HDR content for 1000 nits HDR displays. We also investigate tone expansion strategies when HDR content graded in 1000 nits is displayed on 4000 nits HDR monitors. We conclude that the best tone reproduction technique between HDR displays strongly depends on the lighting style of the content.

  15. Automatic face recognition in HDR imaging

    NASA Astrophysics Data System (ADS)

    Pereira, Manuela; Moreno, Juan-Carlos; Proença, Hugo; Pinheiro, António M. G.

    2014-05-01

    The gaining popularity of the new High Dynamic Range (HDR) imaging systems is raising new privacy issues caused by the methods used for visualization. HDR images require tone mapping methods for an appropriate visualization on conventional and non-expensive LDR displays. These visualization methods might result in completely different visualization raising several issues on privacy intrusion. In fact, some visualization methods result in a perceptual recognition of the individuals, while others do not even show any identity. Although perceptual recognition might be possible, a natural question that can rise is how computer based recognition will perform using tone mapping generated images? In this paper, a study where automatic face recognition using sparse representation is tested with images that result from common tone mapping operators applied to HDR images. Its ability for the face identity recognition is described. Furthermore, typical LDR images are used for the face recognition training.

  16. Next stages in HDR technology development

    SciTech Connect

    Duchane, D.V.

    1993-03-01

    Twenty years of research and development have brought HDR heat mining technology from the purely conceptual stage to the establishment of an engineering-scale heat mine at Fenton Hill, NM. In April 1992, a long-term flow test (LTFT) of the HDR reservoir at Fenton Hill was begun. The test was carried out under steady-state conditions on a continuous basis for four months, but a major equipment failure in late July forced a temporary suspension of operations. Even this short test provided valuable information and extremely encouraging results as summarized below: There was no indication of thermal drawdown of the reservoir. There was evidence of increasing access to hot rock with time. Water consumption was in the rangki of 10--12%. Measured pumping costs were $0.003 per kilowatt of energy produced. Temperature logs conducted in the reservoir production zone during and after the flow test confirmed the fact that there was no decline in the average temperature of the fluid being produced from the reservoir. In fact, tracer testing showed that the fluid was taking more indirect pathways and thus contacting a greater amount of hot rock as the test progressed. Water usage quickly dropped to a level of 10--15 gallons per minute, an amount equivalent to about 10--12% of the injected fluid volume. At a conversion rate of 10--15%, these would translate to effective ``fuel costs`` of 2--3{cents} per kilowatt hour of electricity production potential. The completion of the LTFT will set the stage for commercialization of HDR but will not bring HDR technology to maturity. Relatively samples extensions of the current technology may bring significant improvements in efficiency, and these should be rapidly investigated. In the longer run, advanced operational concepts could further improve the efficiency of HDR energy extraction and may even offer the possibility of cogeneration schemes which solve both energy and water problems throughout the world.

  17. Virtual HDR{sup SM} CyberKnife Treatment for Localized Prostatic Carcinoma: Dosimetry Comparison With HDR Brachytherapy and Preliminary Clinical Observations

    SciTech Connect

    Fuller, Donald B. Naitoh, John; Lee, Charles; Hardy, Steven C.; Jin, Haoran

    2008-04-01

    Background: We tested our ability to approximate the dose (38 Gy), fractionation (four fractions), and distribution of high-dose-rate (HDR) brachytherapy for prostate cancer with CyberKnife (CK) stereotactic body radiotherapy (SBRT) plans. We also report early clinical observations of CK SBRT treatment. Methods and Materials: Ten patients were treated with CK. For each CK SBRT plan, an HDR plan was designed using common contour sets and simulated HDR catheters. Planning target volume coverage, intraprostatic dose escalation, and urethra, rectum, and bladder exposure were compared. Results: Planning target volume coverage by the prescription dose was similar for CK SBRT and HDR plans, whereas percent of volume of interest receiving 125% of prescribed radiation dose (V125) and V150 values were higher for HDR, reflecting higher doses near HDR source dwell positions. Urethra dose comparisons were lower for CK SBRT in 9 of 10 cases, suggesting that CK SBRT may more effectively limit urethra dose. Bladder maximum point doses were higher with HDR, but bladder dose falloff beyond the maximum dose region was more rapid with HDR. Maximum rectal wall doses were similar, but CK SBRT created sharper rectal dose falloff beyond the maximum dose region. Second CK SBRT plans, constructed by equating urethra radiation dose received by point of maximum exposure of volume of interest to the HDR plan, significantly increased V125 and V150. Clinically, 4-month post-CK SBRT median prostate-specific antigen levels decreased 86% from baseline. Acute toxicity was primarily urologic and returned to baseline by 2 months. Acute rectal morbidity was minimal and transient. Conclusions: It is possible to construct CK SBRT plans that closely recapitulate HDR dosimetry and deliver the plans noninvasively.

  18. User's manual for HDR3 computer code

    SciTech Connect

    Arundale, C.J.

    1982-10-01

    A description of the HDR3 computer code and instructions for its use are provided. HDR3 calculates space heating costs for a hot dry rock (HDR) geothermal space heating system. The code also compares these costs to those of a specific oil heating system in use at the National Aeronautics and Space Administration Flight Center at Wallops Island, Virginia. HDR3 allows many HDR system parameters to be varied so that the user may examine various reservoir management schemes and may optimize reservoir design to suit a particular set of geophysical and economic parameters.

  19. Live HDR video streaming on commodity hardware

    NASA Astrophysics Data System (ADS)

    McNamee, Joshua; Hatchett, Jonathan; Debattista, Kurt; Chalmers, Alan

    2015-09-01

    High Dynamic Range (HDR) video provides a step change in viewing experience, for example the ability to clearly see the soccer ball when it is kicked from the shadow of the stadium into sunshine. To achieve the full potential of HDR video, so-called true HDR, it is crucial that all the dynamic range that was captured is delivered to the display device and tone mapping is confined only to the display. Furthermore, to ensure widespread uptake of HDR imaging, it should be low cost and available on commodity hardware. This paper describes an end-to-end HDR pipeline for capturing, encoding and streaming high-definition HDR video in real-time using off-the-shelf components. All the lighting that is captured by HDR-enabled consumer cameras is delivered via the pipeline to any display, including HDR displays and even mobile devices with minimum latency. The system thus provides an integrated HDR video pipeline that includes everything from capture to post-production, archival and storage, compression, transmission, and display.

  20. Analysis of visual quality improvements provided by known tools for HDR content

    NASA Astrophysics Data System (ADS)

    Kim, Jaehwan; Alshina, Elena; Lee, JongSeok; Park, Youngo; Choi, Kwang Pyo

    2016-09-01

    In this paper, the visual quality of different solutions for high dynamic range (HDR) compression using MPEG test contents is analyzed. We also simulate the method for an efficient HDR compression which is based on statistical property of the signal. The method is compliant with HEVC specification and also easily compatible with other alternative methods which might require HEVC specification changes. It was subjectively tested on commercial TVs and compared with alternative solutions for HDR coding. Subjective visual quality tests were performed using SUHD TVs model which is SAMSUNG JS9500 with maximum luminance up to 1000nit in test. The solution that is based on statistical property shows not only improvement of objective performance but improvement of visual quality compared to other HDR solutions, while it is compatible with HEVC specification.

  1. Harmony search optimization for HDR prostate brachytherapy

    NASA Astrophysics Data System (ADS)

    Panchal, Aditya

    In high dose-rate (HDR) prostate brachytherapy, multiple catheters are inserted interstitially into the target volume. The process of treating the prostate involves calculating and determining the best dose distribution to the target and organs-at-risk by means of optimizing the time that the radioactive source dwells at specified positions within the catheters. It is the goal of this work to investigate the use of a new optimization algorithm, known as Harmony Search, in order to optimize dwell times for HDR prostate brachytherapy. The new algorithm was tested on 9 different patients and also compared with the genetic algorithm. Simulations were performed to determine the optimal value of the Harmony Search parameters. Finally, multithreading of the simulation was examined to determine potential benefits. First, a simulation environment was created using the Python programming language and the wxPython graphical interface toolkit, which was necessary to run repeated optimizations. DICOM RT data from Varian BrachyVision was parsed and used to obtain patient anatomy and HDR catheter information. Once the structures were indexed, the volume of each structure was determined and compared to the original volume calculated in BrachyVision for validation. Dose was calculated using the AAPM TG-43 point source model of the GammaMed 192Ir HDR source and was validated against Varian BrachyVision. A DVH-based objective function was created and used for the optimization simulation. Harmony Search and the genetic algorithm were implemented as optimization algorithms for the simulation and were compared against each other. The optimal values for Harmony Search parameters (Harmony Memory Size [HMS], Harmony Memory Considering Rate [HMCR], and Pitch Adjusting Rate [PAR]) were also determined. Lastly, the simulation was modified to use multiple threads of execution in order to achieve faster computational times. Experimental results show that the volume calculation that was

  2. Seismic investigations of the HDR Safety Program. Summary report

    SciTech Connect

    Malcher, L.; Schrammel, D.; Steinhilber, H.; Kot, C.A.

    1994-08-01

    The primary objective of the seismic investigations, performed at the HDR facility in Kahl/Main, FRG was to validate calculational methods for the seismic evaluation of nuclear-reactor systems, using experimental data from an actual nuclear plant. Using eccentric mass shaker excitation the HDR soil/structure system was tested to incipient failure, exhibiting highly nonlinear response and demonstrating that structures not seismically designed can sustain loads equivalent to a design basin earthquake (DBE). Load transmission from the structure to piping/equipment indicated significant response amplifications and shifts to higher frequencies, while the response of tanks/vessels depended mainly on their support conditions. The evaluation of various piping support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is important to limiting pipe greens. Piping at loads exceeding the DBE eightfold still had significant margins and failure is improbable inspite of multiple support failures. The mean value for pipe damping, even under extreme loads, was found to be about 4%. Comparison of linear and nonlinear computational results with piping response measurements showed that predictions have a wide scatter and do not necessarily yield conservative responses underpredicting, in particular, peak support forces. For the soil/structure system the quality of the predictions did not depend so much on the complexity of the modeling, but rather on whether the model captured the salient features and nonlinearities of the system.

  3. Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

    SciTech Connect

    Yang, Xiaofeng Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Curran, Walter J.; Liu, Tian; Mao, Hui

    2014-11-01

    Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

  4. The conception and implementation of a local HDR fusion algorithm depending on contrast and luminosity parameters

    NASA Astrophysics Data System (ADS)

    Besrour, Amine; Abdelkefi, Fatma; Siala, Mohamed; Snoussi, Hichem

    2015-09-01

    Nowadays, the high dynamic range (HDR) imaging represents the subject of the most researches. The major problem lies in the implementation of the best algorithm to acquire the best video quality. In fact, the major constraint is to conceive an optimal fusion which must meet the rapid movement of video frames. The implemented merging algorithms were not quick enough to reconstitute the HDR video. In this paper, we detail each of the previous existing works before detailing our algorithm and presenting results from the acquired HDR images, tone mapped with various techniques. Our proposed algorithm guarantees a more enhanced and faster solution compared to the existing ones. In fact, it has the ability to calculate the saturation matrix related to the saturation rate of the neighboring pixels. The computed coefficients are affected respectively to each picture from the tested ones. This analysis provides faster and efficient results in terms of quality and brightness. The originality of our work remains on its processing method including the pixels saturation in the totality of the captured pictures and their combination in order to obtain the best pictures illustrating all the possible details. These parameters are computed for each zone depending on the contrast and the luminosity of the current pixel and its neighboring. The final HDR image's coefficients are calculated dynamically ensuring the best image quality equilibrating the brightness and contrast values and making the perfect final image.

  5. Creating cinematic wide gamut HDR-video for the evaluation of tone mapping operators and HDR-displays

    NASA Astrophysics Data System (ADS)

    Froehlich, Jan; Grandinetti, Stefan; Eberhardt, Bernd; Walter, Simon; Schilling, Andreas; Brendel, Harald

    2014-03-01

    High quality video sequences are required for the evaluation of tone mapping operators and high dynamic range (HDR) displays. We provide scenic and documentary scenes with a dynamic range of up to 18 stops. The scenes are staged using professional film lighting, make-up and set design to enable the evaluation of image and material appearance. To address challenges for HDR-displays and temporal tone mapping operators, the sequences include highlights entering and leaving the image, brightness changing over time, high contrast skin tones, specular highlights and bright, saturated colors. HDR-capture is carried out using two cameras mounted on a mirror-rig. To achieve a cinematic depth of field, digital motion picture cameras with Super-35mm size sensors are used. We provide HDR-video sequences to serve as a common ground for the evaluation of temporal tone mapping operators and HDR-displays. They are available to the scientific community for further research.

  6. Ghost removing for HDR real-time video stream generation

    NASA Astrophysics Data System (ADS)

    Bouderbane, Mustapha; Dubois, Julien; Heyrman, Barthélémy; Lapray, Pierre-Jean; Ginhac, Dominique

    2016-04-01

    High dynamic range (HDR) imaging generation from a set of low dynamic range images taken in different exposure times is a low cost and an easy technique. This technique provides a good result for static scenes. Temporal exposure bracketing cannot be applied directly for dynamic scenes, since camera or object motion in bracketed exposures creates ghosts in the resulting HDR image. In this paper we describe a real-time ghost removing hardware implementation on high dynamic range video ow added for our HDR FPGA based smart camera which is able to provide full resolution (1280 x 1024) HDR video stream at 60 fps. We present experimental results to show the efficiency of our implemented method in ghost removing.

  7. Single-layer HDR video coding with SDR backward compatibility

    NASA Astrophysics Data System (ADS)

    Lasserre, S.; François, E.; Le Léannec, F.; Touzé, D.

    2016-09-01

    The migration from High Definition (HD) TV to Ultra High Definition (UHD) is already underway. In addition to an increase of picture spatial resolution, UHD will bring more color and higher contrast by introducing Wide Color Gamut (WCG) and High Dynamic Range (HDR) video. As both Standard Dynamic Range (SDR) and HDR devices will coexist in the ecosystem, the transition from Standard Dynamic Range (SDR) to HDR will require distribution solutions supporting some level of backward compatibility. This paper presents a new HDR content distribution scheme, named SL-HDR1, using a single layer codec design and providing SDR compatibility. The solution is based on a pre-encoding HDR-to-SDR conversion, generating a backward compatible SDR video, with side dynamic metadata. The resulting SDR video is then compressed, distributed and decoded using standard-compliant decoders (e.g. HEVC Main 10 compliant). The decoded SDR video can be directly rendered on SDR displays without adaptation. Dynamic metadata of limited size are generated by the pre-processing and used to reconstruct the HDR signal from the decoded SDR video, using a post-processing that is the functional inverse of the pre-processing. Both HDR quality and artistic intent are preserved. Pre- and post-processing are applied independently per picture, do not involve any inter-pixel dependency, and are codec agnostic. Compression performance, and SDR quality are shown to be solidly improved compared to the non-backward and backward-compatible approaches, respectively using the Perceptual Quantization (PQ) and Hybrid Log Gamma (HLG) Opto-Electronic Transfer Functions (OETF).

  8. The effect of split pixel HDR image sensor technology on MTF measurements

    NASA Astrophysics Data System (ADS)

    Deegan, Brian M.

    2014-03-01

    Split-pixel HDR sensor technology is particularly advantageous in automotive applications, because the images are captured simultaneously rather than sequentially, thereby reducing motion blur. However, split pixel technology introduces artifacts in MTF measurement. To achieve a HDR image, raw images are captured from both large and small sub-pixels, and combined to make the HDR output. In some cases, a large sub-pixel is used for long exposure captures, and a small sub-pixel for short exposures, to extend the dynamic range. The relative size of the photosensitive area of the pixel (fill factor) plays a very significant role in the output MTF measurement. Given an identical scene, the MTF will be significantly different, depending on whether you use the large or small sub-pixels i.e. a smaller fill factor (e.g. in the short exposure sub-pixel) will result in higher MTF scores, but significantly greater aliasing. Simulations of split-pixel sensors revealed that, when raw images from both sub-pixels are combined, there is a significant difference in rising edge (i.e. black-to-white transition) and falling edge (white-to-black) reproduction. Experimental results showed a difference of ~50% in measured MTF50 between the falling and rising edges of a slanted edge test chart.

  9. HDR video synthesis for vision systems in dynamic scenes

    NASA Astrophysics Data System (ADS)

    Shopovska, Ivana; Jovanov, Ljubomir; Goossens, Bart; Philips, Wilfried

    2016-09-01

    High dynamic range (HDR) image generation from a number of differently exposed low dynamic range (LDR) images has been extensively explored in the past few decades, and as a result of these efforts a large number of HDR synthesis methods have been proposed. Since HDR images are synthesized by combining well-exposed regions of the input images, one of the main challenges is dealing with camera or object motion. In this paper we propose a method for the synthesis of HDR video from a single camera using multiple, differently exposed video frames, with circularly alternating exposure times. One of the potential applications of the system is in driver assistance systems and autonomous vehicles, involving significant camera and object movement, non- uniform and temporally varying illumination, and the requirement of real-time performance. To achieve these goals simultaneously, we propose a HDR synthesis approach based on weighted averaging of aligned radiance maps. The computational complexity of high-quality optical flow methods for motion compensation is still pro- hibitively high for real-time applications. Instead, we rely on more efficient global projective transformations to solve camera movement, while moving objects are detected by thresholding the differences between the trans- formed and brightness adapted images in the set. To attain temporal consistency of the camera motion in the consecutive HDR frames, the parameters of the perspective transformation are stabilized over time by means of computationally efficient temporal filtering. We evaluated our results on several reference HDR videos, on synthetic scenes, and using 14-bit raw images taken with a standard camera.

  10. HDR quality assurance methods for personal digital assistants.

    PubMed

    Astrahan, Melvin A

    2004-01-01

    An important component of every clinical high-dose-rate (HDR) brachytherapy program is quality assurance (QA). One of the QA recommendations of the AAPM TG59 report is an independent verification on the results of treatment planning. It is desirable for the verification procedure to be as quick and easy to perform as possible and yet to have a high probability of detecting significant errors. The objective of this work is to describe the dosimetric methods and software developed to implement a departmental HDR QA program using personal digital assistants (PDAs). Verification of MammoSite treatment plans is presented as a practical example. PDAs that run the PalmOS were selected for their low cost and popularity among health care professionals. General-purpose applications were developed for linear sources, planar, and volume implants, that estimate the total dwell time of an HDR implant. This value can then be compared to the total dwell time calculated by the primary treatment planning system. The software incorporates the Paterson-Parker (PP) radium tables and the Greenfield-Tichman-Norman (GTN) version of the Quimby radium tables, which have been modified to a form more convenient for HDR calculations. A special purpose application based on the AAPM TG43 formalism was developed for the MammoSite breast applicator. For QA calculations perpendicular to the center of a single Iridium-192 (192I) HDR source, as exemplified by MammoSite treatments, linearly interpolating the PP or GTN tables is equivalent to applying the TG43 formalism at distances up to 5 cm from the source axis. The MammoSite-specific software also offers the option to calculate dosimetry based on the balloon volume. The PDA clock/calendar permits the software to automatically account for source decay. The touch-sensitive screen allows the familiar tabular format to be maintained while minimizing the effort required for calculations. The PP and GTN radium implant tables are easily modified to a form

  11. Optimizing parametrial aperture design utilizing HDR brachytherapy isodose distribution

    PubMed Central

    Chapman, Katherine L.; Ohri, Nitin; Showalter, Timothy N.

    2013-01-01

    Treatment of cervical cancer includes combination of external beam radiation therapy (EBRT) and brachytherapy (BRT). Traditionally, coronal images displaying dose distribution from a ring and tandem (R&T) implant aid in construction of parametrial boost fields. This research aimed to evaluate a method of shaping parametrial fields utilizing contours created from the high-dose-rate (HDR) BRT dose distribution. Eleven patients receiving HDR-BRT via R&T were identified. The BRT and EBRT CT scans were sent to FocalSim (v4.62)® and fused based on bony anatomy. The contour of the HDR isodose line was transferred to the EBRT scan. The EBRT scan was sent to CMS-XIO (v4.62)® for planning. This process provides an automated, potentially more accurate method of matching the medial parametrial border to the HDR dose distribution. This allows for a 3D-view of dose from HDR-BRT for clinical decision-making, utilizes a paperless process and saves time over the traditional technique. PMID:23634156

  12. FVP10: enhancements of VPX for SDR/HDR applications

    NASA Astrophysics Data System (ADS)

    Topiwala, Pankaj; Dai, Wei; Krishnan, Madhu

    2016-09-01

    This paper describes a study to investigate possible ways to improve the VPX codecs in the context of both 8-bit SDR video and 10-bit HDR video content, for two types of applications: streaming and high quality (near lossless) coding for content contribution editing. For SDR content, the following tools are investigated: (a) lapped biorthogonal transforms for near lossless applications; and (b) optimized resampling filter pairs for adaptive resolution coding in streaming applications. For HDR content, a data adaptive grading technique in conjunction with the VP9/VP10 encoder is studied. Both the objective metrics (measured using BD rate) and informal subjective visual quality assessments are recorded. It is asserted that useful improvements are possible in each of these categories. In particular, substantial value is offered in the coding of HDR content, and especially in creating a coding scheme offering backwards compatibility with SDR.

  13. Fast HDR image upscaling using locally adapted linear filters

    NASA Astrophysics Data System (ADS)

    Talebi, Hossein; Su, Guan-Ming; Yin, Peng

    2015-02-01

    A new method for upscaling high dynamic range (HDR) images is introduced in this paper. Overshooting artifact is the common problem when using linear filters such as bicubic interpolation. This problem is visually more noticeable while working on HDR images where there exist more transitions from dark to bright. Our proposed method is capable of handling these artifacts by computing a simple gradient map which enables the filter to be locally adapted to the image content. This adaptation consists of first, clustering pixels into regions with similar edge structures and second, learning the shape and length of our symmetric linear filter for each of these pixel groups. This new filter can be implemented in a separable fashion which perfectly fits hardware implementations. Our experimental results show that training our filter with HDR images can effectively reduce the overshooting artifacts and improve upon the visual quality of the existing linear upscaling approaches.

  14. TU-C-201-00: Clinical Implementation of HDR Brachytherapy

    SciTech Connect

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  15. TU-C-201-02: Clinical Implementation of HDR: Afterloader and Applicator Selection

    SciTech Connect

    Esthappan, J.

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  16. Evaluating HDR photos using Web 2.0 technology

    NASA Astrophysics Data System (ADS)

    Qiu, Guoping; Mei, Yujie; Duan, Jiang

    2011-01-01

    High dynamic range (HDR) photography is an emerging technology that has the potential to dramatically enhance the visual quality and realism of digital photos. One of the key technical challenges of HDR photography is displaying HDR photos on conventional devices through tone mapping or dynamic range compression. Although many different tone mapping techniques have been developed in recent years, evaluating tone mapping operators prove to be extremely difficult. Web2.0, social media and crowd-sourcing are emerging Internet technologies which can be harnessed to harvest the brain power of the mass to solve difficult problems in science, engineering and businesses. Paired comparison is used in the scientific study of preferences and attitudes and has been shown to be capable of obtaining an interval-scale ordering of items along a psychometric dimension such as preference or importance. In this paper, we exploit these technologies for evaluating HDR tone mapping algorithms. We have developed a Web2.0 style system that enables Internet users from anywhere to evaluate tone mapped HDR photos at any time. We adopt a simple paired comparison protocol, Internet users are presented a pair of tone mapped images and are simply asked to select the one that they think is better or click a "no difference" button. These user inputs are collected in the web server and analyzed by a rank aggregation algorithm which ranks the tone mapped photos according to the votes they received. We present experimental results which demonstrate that the emerging Internet technologies can be exploited as a new paradigm for evaluating HDR tone mapping algorithms. The advantages of this approach include the potential of collecting large user inputs under a variety of viewing environments rather than limited user participation under controlled laboratory environments thus enabling more robust and reliable quality assessment. We also present data analysis to correlate user generated qualitative

  17. FY 1996 Summary of Hot Dry Rock Geothermal Power Project

    SciTech Connect

    1996-12-31

    The report describes progress and status of the HDR project at Hijiori. The year was notable for a flow enhancement test of a system with two production wells in operation. Other items include a geochemical survey, reinterpretation of acoustic emission data from 1988 through 1995, borehole measurements to find intersections with fractures, a geological survey, preparation for modeling fractures, improvements in crack simulation in a reservoir analysis model, and environmental survey work. (DJE 2005)

  18. Interstitial HDR brachytherapy (HDR-BT) in early stage mobile tongue cancers in young patients – Gliwice experience

    PubMed Central

    Białas, Brygida; Fijałkowski, Marek; Składowski, Krzysztof; Szlag, Marta; Cholewka, Agnieszka

    2010-01-01

    Purpose In early stage mobile tongue cancer radical radiotherapy offers good local control and organ preservation, which is especially important in the group of young patients. In our department, for many years HDR-BT has been performed in mobile tongue cancers as a sole treatment or as a “boost” with EBRT. The aim of the study was to show our experience with HDR-BT in early stage mobile tongue cancers among young patients. Material and methods From 2001 to 2006 in Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Gliwice Branch, five patients under 45 years with mobile tongue cancer were treated with HDR brachytherapy (T1N0M0 – 3/5 and T2N0M0 – 2/5); 4 with HDR brachytherapy “boost” and 1 as a sole treatment. One woman was previously treated with tumour resection, but because of positive surgical margins was referred for radiotherapy. All patients had clinically negative lymph nodes, without dissection. They were treated with interstitial HDR-BT (3-8 catheters). In 4 patients treated with HDR-BT as a “boost”, total doses ranged from 18 to 21 Gy given in 6-7 fractions (twice a day, 3 Gy per fraction). Total doses in EBRT (to local lymph nodes and tumour bed) ranged from 50 to 60 Gy (1.8-2 Gy per fraction 5 days/week). One patient, treated with radical HDR brachytherapy, received 45 Gy in 10 fractions and 50 Gy in EBRT to regional lymph nodes. Results We did not notice local recurrences or distant metastases in our group of patients. Median follow-up was 67 months (range 47-79 months). All patients preserved normal tongue function. A severe late complication occurred in 1 patient – fracture of the mandible. Conclusions In the analysed group of young patients with mobile tongue cancer interstitial HDR brachytherapy in combination with EBRT was an effective and well tolerated treatment modality which allowed preservation of the tongue and its function. PMID:27829846

  19. Vitamin D deficiency in a patient with HDR syndrome.

    PubMed

    Kostoglou-Athanassiou, Ifigenia; Stefanopoulos, Dimitrios; Karfi, Areti; Athanassiou, Panagiotis

    2015-07-08

    The case of a patient with clinical symptoms, laboratory and imaging findings of hypoparathyroidism, sensorineural deafness, renal dysplasia HDR, or Barakat syndrome (hypoparathyroidism, deafness, renal dysplasia), and vitamin D deficiency, is presented. A Caucasian man aged 51 years with a history of chronic hypocalcaemia since childhood, was admitted with hypertonia of the body and extremities, and loss of consciousness. On admission, he was found to have severe hypocalcaemia, hyperphosphataemia, severe hypoparathyroidism, low serum magnesium and mild renal insufficiency. Calcium gluconate was administered intravenously supplemented with magnesium, and the patient recovered consciousness while clinical and laboratory findings improved. Evaluation revealed left renal aplasia and sensorineural deafness affecting both ears. Vitamin D deficiency was also present. He was given calcium and vitamin D supplements orally, and the hypocalcaemia was corrected. This case is described as it is an extremely rare case of HDR syndrome with concurrent vitamin D deficiency.

  20. WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

    SciTech Connect

    Craciunescu, O; Todor, D; Leeuw, A de

    2014-06-15

    In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy.

  1. SU-E-T-124: Dosimetric Comparison of HDR Brachytherapy and Intensity Modulated Proton Therapy

    SciTech Connect

    Wu, J; Wu, H; Das, I

    2014-06-01

    Purpose: Brachytherapy is known to be able to deliver more radiation dose to tumor while minimizing radiation dose to surrounding normal tissues. Proton therapy also provides superior dose distribution due to Bragg peak. Since both HDR and Intensity Modulated Proton Therapy (IMPT) are beneficial for their quick dose drop off, our goal in this study is to compare the pace of dose gradient drop-off between HDR and IMPT plans based on the same CT image data-set. In addition, normal tissues sparing were also compared among HDR, IMPT and SBRT. Methods: Five cervical cancer cases treated with EBRT + HDR boost combination with Tandem and Ovoid applicator were used for comparison purpose. Original HDR plans with prescribed dose of 5.5 Gy x 5 fractions were generated and optimized. The 100% isodose line of HDR plans was converted to a dose volume, and treated as CTV for IMPT and SBRT planning. The same HDR CT scans were also used for IMPT plan and SBRT plan for direct comparison. The philosophy of the IMPT and SBRT planning was to create the same CTV coverage as HDR plans. All three modalities treatment plans were compared to each other with a set of predetermined criteria. Results: With similar target volume coverage in cervix cancer boost treatment, HDR provides a slightly sharper dose drop-off from 100% to 50% isodose line, averagely in all directions compared to IMPT. However, IMPT demonstrated more dose gradient drop-off at the junction of the target and normal tissues by providing more normal tissue sparing and superior capability to reduce integral dose. Conclusion: IMPT is capable of providing comparable dose drop-off as HDR. IMPT can be explored as replacement for HDR brachytherapy in various applications.

  2. TU-C-201-01: Clinical Implementation of HDR: A New User’s Perspective

    SciTech Connect

    Al-Hallaq, H.

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  3. Expert viewing protocol performance study: the case of subjective evaluation of HDR coding

    NASA Astrophysics Data System (ADS)

    Baroncini, Vittorio; Baroncini, Giacomo; Topiwala, Pankaj

    2016-09-01

    This paper tries to examine the results of a subjective evaluation experiment, made by means of the new Expert Viewing Protocol, recently approved by ITU-R Study Group 6 [1]. The EVP subjective test was designed and performed to compare different HDR coding technologies during an MPEG meeting (San Diego, CA, February 2016) [2]. Thanks to the wide and enthusiastic participation of the MPEG experts to the subjective evaluation experiment, it was possible to collect data from a total of sixteen viewers; this allowed to perform a sort of "validation" of the performance of the EVP. The ITU-R Recommendation states that tests with nine viewers is sufficient to get acceptable results from an EVP experiment. In our case, having data from 16 viewers, it was possible to compute the MOS and the Confidence Interval data as if it were a standard subjective assessment experiment (which typically requires more viewers). This allowed a sort of "validation" of the results obtained using results from 9 experts only vs. the results obtained using the data from the 16 viewers. The analysis of the raw data showed a rather good conversion of the EVP results towards the results obtained using the full viewers' data set. The results of the EVP evaluation of MPEG HDR content was described in details in a previous paper [3], to which we defer for details on the EVP protocol procedure and rules. This paper instead tries to answer to a demand for further clarification on the "context" and "limitations of use" of the EVP when performed in alternative to a formal subjective experiment trial.

  4. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    NASA Astrophysics Data System (ADS)

    Borot de Battisti, M.; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm3to 23.3 cm3) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.

  5. WE-E-BRD-01: HDR Brachytherapy I: Overview of Clinical Application and QA

    SciTech Connect

    Libby, B; Showalter, T

    2014-06-15

    With the increased usage of high dose rate (HDR) brachytherapy and the introduction of dedicated image guided brachytherapy suites, it is necessary to review the processes and procedures associated with safely delivering these treatments in the expedited time scales that dedicated treatment suites afford. The speakers will present the clinical aspects of switching from LDR to HDR treatments, including guidelines for patient selection, and the clinical outcomes comparing LDR to HDR. The speakers will also discuss the HDR treatment process itself, because the shortened clinical timeline involved with a streamlined scan/plan/treat workflow can introduce other issues. Safety and QA aspects involved with the streamlined process, including increased personnel required for parallel tasks, and possible interfering tasks causing delays in patient treatments will also be discussed. Learning Objectives: To understand the clinical aspects of HDR Brachytherapy, including common clinical indications, patient selection, and the evolving evidence in support of this therapeutic modality To review the current prominent clinical trials for HDR brachytherapy To interpret the established guidelines for HDR brachytherapy quality assurance for implementation into practical clinical settings. To introduce the basic requirements for image guided brachytherapy.

  6. Microseismicity and Stimulated Hydrogeologic Structures in HDR/HWR Reservoirs

    NASA Astrophysics Data System (ADS)

    Niitsuma, H.

    2006-12-01

    Fluid injection to enhance productivity in oil and geothermal reservoir has been widely conducted since 1980's. The fluid injection is also one of the key technologies to create artificial circulation system in Hot Dry Rock (HDR)/ Hot Wet Rock (HWR) geothermal development. It is advantageous for understanding fluid induced faulting to analyze the subsurface response during the fluid injections, because the injection processes are controlled and hydraulic data are recorded. Some of this information can be obtained from well logs such as flow, temperature, pressure, BHTV, FMI, etc. However, they only provide restricted information near the well. Microseismic monitoring is currently the best available method for obtaining three-dimensional information about reservoirs and fracture systems at locations remote from boreholes. The primary problem of the method is its location accuracy. When located with conventional location algorithms, the events are frequently seen to be distributed as a cloud with little macro- or microstructure. It is difficult to meaningfully correlate such images with logging data of existing wells. Therefore, information on detailed reservoir structure, fracture orientation, and hydraulic behavior cannot be obtained from the application of conventional microseismic location techniques. There have been considerable improvements in microseismic mapping technology in these fifteen years. Various techniques to reduce location error have been developed which include collapsing, doublet/multiplet analysis, double-difference method, and multiplet-clustering analysis. These high resolution mapping techniques demonstrate that the diffuse clouds obtained using conventional techniques are largely artefacts of location error, and reveal macro- and microstructures within the cloud that can be correlated with geological and hydraulic structures identified from well logs. These high-resolution seismic mapping techniques have been applied to the microseismic data

  7. Penile cancer brachytherapy HDR mould technique used at the Holycross Cancer Center

    PubMed Central

    Kubicka-Mendak, Iwona; Łyczek, Jarosław; Pawłowski, Piotr; Stawiarska, Iwona; Miedzinska, Joanna; Banatkiewicz, Paweł; Łaskawska-Wiatr, Aldona; Wittych, Justyna

    2011-01-01

    The aim of this pictorial essay is to present the mould based HDR brachytherapy technique used at the Holycross Cancer Center for penile cancer patients. We use images to describe this method step by step. PMID:23346132

  8. Penile cancer brachytherapy HDR mould technique used at the Holycross Cancer Center.

    PubMed

    Matys, Robert; Kubicka-Mendak, Iwona; Lyczek, Jarosław; Pawłowski, Piotr; Stawiarska, Iwona; Miedzinska, Joanna; Banatkiewicz, Paweł; Laskawska-Wiatr, Aldona; Wittych, Justyna

    2011-12-01

    The aim of this pictorial essay is to present the mould based HDR brachytherapy technique used at the Holycross Cancer Center for penile cancer patients. We use images to describe this method step by step.

  9. SU-E-T-758: To Determine the Source Dwell Positions of HDR Brachytherapy Using 2D 729 Ion Chamber Array

    SciTech Connect

    Kumar, Syam; Sitha

    2015-06-15

    Purpose: Determination of source dwell positions of HDR brachytherapy using 2D 729 ion chamber array Methods: Nucletron microselectron HDR and PTW 2D array were used for the study. Different dwell positions were assigned in the HDR machine. Rigid interstitial needles and vaginal applicator were positioned on the 2D array. The 2D array was exposed for this programmed dwell positions. The positional accuracy of the source was analyzed after the irradiation of the 2D array. This was repeated for different dwell positions. Different test plans were transferred from the Oncentra planning system and irradiated with the same applicator position on the 2D array. The results were analyzed using the in house developed excel program. Results: Assigned dwell positions versus corresponding detector response were analyzed. The results show very good agreement with the film measurements. No significant variation found between the planned and measured dwell positions. Average dose response with 2D array between the planned and nearby dwell positions was found to be 0.0804 Gy for vaginal cylinder applicator and 0.1234 Gy for interstitial rigid needles. Standard deviation between the doses for all the measured dwell positions for interstitial rigid needle for 1 cm spaced positions were found to be 0.33 and 0.37 for 2cm spaced dwell positions. For intracavitory vaginal applicator this was found to be 0.21 for 1 cm spaced dwell positions and 0.06 for 2cm spaced dwell positions. Intracavitory test plans reproduced on the 2D array with the same applicator positions shows the ideal dose distribution with the TPS planned. Conclusion: 2D array is a good tool for determining the dwell position of HDR brachytherapy. With the in-house developed program in excel it is easy and accurate. The traditional way with film analysis can be replaced by this method, as the films will be more costly.

  10. SU-E-T-785: Using Systems Engineering to Design HDR Skin Treatment Operation for Small Lesions to Enhance Patient Safety

    SciTech Connect

    Saw, C; Baikadi, M; Peters, C; Brereton, H

    2015-06-15

    Purpose: Using systems engineering to design HDR skin treatment operation for small lesions using shielded applicators to enhance patient safety. Methods: Systems engineering is an interdisciplinary field that offers formal methodologies to study, design, implement, and manage complex engineering systems as a whole over their life-cycles. The methodologies deal with human work-processes, coordination of different team, optimization, and risk management. The V-model of systems engineering emphasize two streams, the specification and the testing streams. The specification stream consists of user requirements, functional requirements, and design specifications while the testing on installation, operational, and performance specifications. In implementing system engineering to this project, the user and functional requirements are (a) HDR unit parameters be downloaded from the treatment planning system, (b) dwell times and positions be generated by treatment planning system, (c) source decay be computer calculated, (d) a double-check system of treatment parameters to comply with the NRC regulation. These requirements are intended to reduce human intervention to improve patient safety. Results: A formal investigation indicated that the user requirements can be satisfied. The treatment operation consists of using the treatment planning system to generate a pseudo plan that is adjusted for different shielded applicators to compute the dwell times. The dwell positions, channel numbers, and the dwell times are verified by the medical physicist and downloaded into the HDR unit. The decayed source strength is transferred to a spreadsheet that computes the dwell times based on the type of applicators and prescribed dose used. Prior to treatment, the source strength, dwell times, dwell positions, and channel numbers are double-checked by the radiation oncologist. No dosimetric parameters are manually calculated. Conclusion: Systems engineering provides methodologies to

  11. Commissioning and quality assurance procedures for the HDR Valencia skin applicators

    PubMed Central

    Granero, Domingo; Candela-Juan, Cristian; Ballester, Facundo; Ouhib, Zoubir; Vijande, Javier; Richart, Jose

    2016-01-01

    The Valencia applicators (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden) are cup-shaped tungsten applicators with a flattening filter used to collimate the radiation produced by a high-dose-rate (HDR) 192Ir source, and provide a homogeneous absorbed dose at a given depth. This beam quality provides a good option for the treatment of skin lesions at shallow depth (3-4 mm). The user must perform commissioning and periodic testing of these applicators to guarantee the proper and safe delivery of the intended absorbed dose, as recommended in the standards in radiation oncology. In this study, based on AAPM and GEC-ESTRO guidelines for brachytherapy units and our experience, a set of tests for the commissioning and periodic testing of the Valencia applicators is proposed. These include general considerations, verification of the manufacturer documentation and physical integrity, evaluation of the source-to-indexer distance and reproducibility, setting the library plan in the treatment planning system, evaluation of flatness and symmetry, absolute output and percentage depth dose verification, independent calculation of the treatment time, and visual inspection of the applicator before each treatment. For each test, the proposed methodology, equipment, frequency, expected results, and tolerance levels (when applicable) are provided. PMID:27895687

  12. SU-E-T-254: Development of a HDR-BT QA Tool for Verification of Source Position with Oncentra Applicator Modeling

    SciTech Connect

    Kumazaki, Y; Miyaura, K; Hirai, R; Miyazawa, K; Makino, S; Tamaki, T; Shikama, N; Kato, S

    2015-06-15

    Purpose: To develop a High Dose Rate Brachytherapy (HDR-BT) quality assurance (QA) tool for verification of source position with Oncentra applicator modeling, and to report the results of radiation source positions with this tool. Methods: We developed a HDR-BT QA phantom and automated analysis software for verification of source position with Oncentra applicator modeling for the Fletcher applicator used in the MicroSelectron HDR system. This tool is intended for end-to-end tests that mimic the clinical 3D image-guided brachytherapy (3D-IGBT) workflow. The phantom is a 30x30x3 cm cuboid phantom with radiopaque markers, which are inserted into the phantom to evaluate applicator tips and reference source positions; positions are laterally shifted 10 mm from the applicator axis. The markers are lead-based and scatter radiation to expose the films. Gafchromic RTQA2 films are placed on the applicators. The phantom includes spaces to embed the applicators. The source position is determined as the distance between the exposed source position and center position of two pairs of the first radiopaque markers. We generated a 3D-IGBT plan with applicator modeling. The first source position was 6 mm from the applicator tips, and the second source position was 10 mm from the first source position. Results: All source positions were consistent with the exposed positions within 1 mm for all Fletcher applicators using in-house software. Moreover, the distance between source positions was in good agreement with the reference distance. Applicator offset, determined as the distance from the applicator tips at the first source position in the treatment planning system, was accurate. Conclusion: Source position accuracy of applicator modeling used in 3D-IGBT was acceptable. This phantom and software will be useful as a HDR-BT QA tool for verification of source position with Oncentra applicator modeling.

  13. Tracer measurements during long-term circulation of the Rosemanowes HDR geothermal system

    SciTech Connect

    Kwakwa, K.A.

    1988-01-01

    Circulation experiments have been in operation for over two years in the artificially stimulated hot dry rock (HDR) doublet of the Camborne School of Mines (CSM) research facility in Cornwall, England. During that period tracer tests have been run at intervals using inert and reactive compounds. Initially, the results of the inert tracer investigations showed that the active volume (indicated by modal and median volumes) of the circulating system was dormant. Then, after a period of sustained oscillation, notable increases in active volume were observed which depended on both the subsequent flow rate changes and circulation time. these dynamic changes had almost reached optimum values when a downhole pump was introduced in the production well. The drawdown in the production well caused a reduction of the modal volume, whilst the median volume remained almost the same. Since then, the active volume has remained unchanged and irresponsive to circulation time and flow rate. The results of the reactive tracer tests confirm increasing chemical reaction with increasing circulation time and correlate qualitatively with the opening of newer and hotter pathways within the reservoir. However, repeated production logs throughout the circulation have identified flow paths that have depleted thermally; a discrepancy that can be explained by the geometry of the system and the preferential downward reservoir growth.

  14. SU-F-BRA-04: Prostate HDR Brachytherapy with Multichannel Robotic System

    SciTech Connect

    Joseph, F Maria; Podder, T; Yu, Y

    2015-06-15

    Purpose: High-dose-rate (HDR) brachytherapy is gradually becoming popular in treating patients with prostate cancers. However, placement of the HDR needles at desired locations into the patient is challenging. Application of robotic system may improve the accuracy of the clinical procedure. This experimental study is to evaluate the feasibility of using a multichannel robotic system for prostate HDR brachytherapy. Methods: In this experimental study, the robotic system employed was a 6-DOF Multichannel Image-guided Robotic Assistant for Brachytherapy (MIRAB), which was designed and fabricated for prostate seed implantation. The MIRAB has the provision of rotating 16 needles while inserting them. Ten prostate HDR brachytherapy needles were simultaneously inserted using MIRAB into a commercially available prostate phantom. After inserting the needles into the prostate phantom at desired locations, 2mm thick CT slices were obtained for dosimetric planning. HDR plan was generated using Oncetra planning system with a total prescription dose of 34Gy in 4 fractions. Plan quality was evaluated considering dose coverage to prostate and planning target volume (PTV), with 3mm margin around prostate, as well as the dose limit to the organs at risk (OARs) following the American Brachytherapy Society (ABS) guidelines. Results: From the CT scan, it is observed that the needles were inserted straight into the desired locations and they were adequately spaced and distributed for a clinically acceptable HDR plan. Coverage to PTV and prostate were about 91% (V100= 91%) and 96% (V100=96%), respectively. Dose to 1cc of urethra, rectum, and bladder were within the ABS specified limits. Conclusion: The MIRAB was able to insert multiple needles simultaneously into the prostate precisely. By controlling the MIRAB to insert all the ten utilized needles into the prostate phantom, we could achieve the robotic HDR brachytherapy successfully. Further study for assessing the system

  15. Comparison of radiation shielding requirements for HDR brachytherapy using 169Yb and 192Ir sources.

    PubMed

    Lymperopoulou, G; Papagiannis, P; Sakelliou, L; Georgiou, E; Hourdakis, C J; Baltas, D

    2006-07-01

    169Yb has received a renewed focus lately as an alternative to 192Ir sources for high dose rate (HDR) brachytherapy. Following the results of a recent work by our group which proved 169Yb to be a good candidate for HDR prostate brachytherapy, this work seeks to quantify the radiation shielding requirements for 169Yb HDR brachytherapy applications in comparison to the corresponding requirements for the current 192Ir HDR brachytherapy standard. Monte Carlo simulation (MC) is used to obtain 169Yb and 192Ir broad beam transmission data through lead and concrete. Results are fitted to an analytical equation which can be used to readily calculate the barrier thickness required to achieve a given dose rate reduction. Shielding requirements for a HDR brachytherapy treatment room facility are presented as a function of distance, occupancy, dose limit, and facility workload, using analytical calculations for both 169Yb and 192Ir HDR sources. The barrier thickness required for 169Yb is lower than that for 192Ir by a factor of 4-5 for lead and 1.5-2 for concrete. Regarding 169Yb HDR brachytherapy applications, the lead shielding requirements do not exceed 15 mm, even in highly conservative case scenarios. This allows for the construction of a lead door in most cases, thus avoiding the construction of a space consuming, specially designed maze. The effects of source structure, attenuation by the patient, and scatter conditions within an actual treatment room on the above-noted findings are also discussed using corresponding MC simulation results.

  16. WE-G-BRC-02: Risk Assessment for HDR Brachytherapy.

    PubMed

    Mayadev, J

    2016-06-01

    Failure Mode and Effects Analysis (FMEA) originated as an industrial engineering technique used for risk management and safety improvement of complex processes. In the context of radiotherapy, the AAPM Task Group 100 advocates FMEA as the framework of choice for establishing clinical quality management protocols. However, there is concern that widespread adoption of FMEA in radiation oncology will be hampered by the perception that implementation of the tool will have a steep learning curve, be extremely time consuming and labor intensive, and require additional resources. To overcome these preconceptions and facilitate the introduction of the tool into clinical practice, the medical physics community must be educated in the use of this tool and the ease in which it can be implemented. Organizations with experience in FMEA should share their knowledge with others in order to increase the implementation, effectiveness and productivity of the tool. This session will include a brief, general introduction to FMEA followed by a focus on practical aspects of implementing FMEA for specific clinical procedures including HDR brachytherapy, physics plan review and radiosurgery. A description of common equipment and devices used in these procedures and how to characterize new devices for safe use in patient treatments will be presented. This will be followed by a discussion of how to customize FMEA techniques and templates to one's own clinic. Finally, cases of common failure modes for specific procedures (described previously) will be shown and recommended intervention methodologies and outcomes reviewed.

  17. High-temperature logging for basic development of HDR reservoirs

    SciTech Connect

    Mathews, M.; Pettitt, R.A.; Miles, D.J.

    1981-01-01

    The second phase of the Hot Dry Rock (HDR) Geothermal Development Program at Fenton Hill, New Mexico, consists of two boreholes, directionally-drilled in a northeast direction, inclined at an angle of 35/sup 0/, with a vertical separation of 365 m (1200 ft). The two boreholes will be connected by 12 to 15 vertical parallel fractures to make a geothermal reservoir calculated to produce 20 MW(e) for 20 years. Accurate temperature measurements, borehole caliper logs, and directional surveys are required for the successful development and operation of this man-made system. Obtaining these data is extremely difficult because of the bottom hole static temperature of 335/sup 0/C (635/sup 0/F) at a depth of 4660 m (15,289 ft), the 35/sup 0/ deviation, the abrasive formation, and the presence of sticky drilling residue products. The efforts during July, August, and September 1980, to obtain these data are presented as a case history. The temperature logs and borehole directional survey produced realistic results; but the borehole caliper measurements were inconsistent and unreliable, due to the developmental stage of the caliper tools.

  18. NPIP: A skew line needle configuration optimization system for HDR brachytherapy

    SciTech Connect

    Siauw, Timmy; Cunha, Adam; Berenson, Dmitry; Atamtuerk, Alper; Hsu, I-Chow; Goldberg, Ken; Pouliot, Jean

    2012-07-15

    or fewer needles than the current HDR brachytherapy workflow. Combined with robot assisted brachytherapy, this system has the potential to reduce side effects associated with treatment. A physical trial should be done to test the implant feasibility of NPIP needle configurations.

  19. Efficacy and toxicity of MDR versus HDR brachytherapy for primary vaginal cancer.

    PubMed

    Rutkowski, T; Białas, B; Rembielak, A; Fijałkowski, M; Nowakowski, K

    2002-01-01

    The retrospective analysis includes a group of 50 patients with primary, invasive vaginal cancer treated with brachytherapy in the period of 1982-1993. Over 80% cases were squamous cell carcinoma. There were 14 patients in stage I according to FIGO classification and 20%, 36%, and 16% of patients in stage II, III and IV, respectively. Twenty one patients (42%) received MDR brachytherapy using Cs137 source, the remaining 29 (58%) were treated with HDR using Co60 or Ir192 sources. Among 50 patients 31 (62%) received also external beam irradiation. An overall 5-year actuarial disease-free survival was 40%, and it was 78.6% (11/14), 40% (4/10), 27.8% (5/18), 0% (0/8) for stage I, II, III and IV, respectively. For MDR or HDR5-year disease-free survival was 38% and 41%, respectively. No influence of dose rate on survival has been found (p=0.7). Local failure occurred in 20 patients (40%). Recurrences appeared in 10 patients (20%). Late complications rate was 0% and 17% for MDR and HDR, respectively. Effectiveness of brachytherapy MDR and HDR was similar, whereas serious late complications developed more often after HDR brachytherapy.

  20. BrachyView, a novel in-body imaging system for HDR prostate brachytherapy: Experimental evaluation

    SciTech Connect

    Safavi-Naeini, M.; Han, Z.; Alnaghy, S.; Cutajar, D.; Petasecca, M.; Lerch, M. L. F.; Rosenfeld, A. B.; Franklin, D. R.; Bucci, J.; Carrara, M.; Zaider, M.

    2015-12-15

    Purpose: This paper presents initial experimental results from a prototype of high dose rate (HDR) BrachyView, a novel in-body source tracking system for HDR brachytherapy based on a multipinhole tungsten collimator and a high resolution pixellated silicon detector array. The probe and its associated position estimation algorithms are validated and a comprehensive evaluation of the accuracy of its position estimation capabilities is presented. Methods: The HDR brachytherapy source is moved through a sequence of positions in a prostate phantom, for various displacements in x, y, and z. For each position, multiple image acquisitions are performed, and source positions are reconstructed. Error estimates in each dimension are calculated at each source position and combined to calculate overall positioning errors. Gafchromic film is used to validate the accuracy of source placement within the phantom. Results: More than 90% of evaluated source positions were estimated with an error of less than one millimeter, with the worst-case error being 1.3 mm. Experimental results were in close agreement with previously published Monte Carlo simulation results. Conclusions: The prototype of HDR BrachyView demonstrates a satisfactory level of accuracy in its source position estimation, and additional improvements are achievable with further refinement of HDR BrachyView’s image processing algorithms.

  1. FV10: an efficient single-layer approach to HDR coding, with backward compatibility options

    NASA Astrophysics Data System (ADS)

    Topiwala, Pankaj; Dai, Wei; Krishnan, Madhu

    2016-09-01

    High Dynamic Range and Wide Color Gamut (HDR/WCG) video is now at the forefront of modern broadcast and other video delivery systems. The efficient transmission and display of such video over diverse networks and systems is an important problem. This paper presents a novel, state of the art approach in HDR/WCG video coding (called FV10) which uses a new, fully automatic video data adaptive regrading process, which converts HDR to Standard Dynamic Range (SDR). Our method differs from one developed recently in standards committees (the Joint Collaborative Team on Video Coding, or JCT-VC, of ITU|ISO/IEC), based on the HEVC Main10 Profile as the core codec, which is an HDR10 compliant system ("anchor"). FV10 also works entirely within the framework of HEVC Main10 Profile, but makes greater use of existing SEI messages. Reconstructed video using our methods show a subjective visual quality superior to the output of an example HDR10 anchor. Moreover, a usable backwards compatible SDR video is obtained as a byproduct in the processing chain, allowing service efficiencies. Representative objective results for the system include: results for RGB-PSNR, DE100, MD100, tOSNR-XYZ were -46.0%, -21.6%, -29.6%, 16.2% respectively.

  2. Trans-Pacific HDR Satellite Communications Experiment Phase-2 Project Plan and Experimental Network

    NASA Technical Reports Server (NTRS)

    Hsu, Eddie; Kadowaki, Naoto; Yoshimura, Naoko; Takahashi, Takashi; Yoshikawa, Makoto; Bergman, Larry; Bhasin, Kul

    2000-01-01

    The trans-Pacific high data rate (TP-HDR) satellite communications experiment was proposed at the Japan-U.S. Cooperation in Space (JUCS) Program Workshop held in Hawaii in 1993 and remote high definition video post-production was demonstrated as the first phase trial. ATM-based 45 Mbps trans-Pacific link was established in the first phase, and the following experiments with 155 Mbps was planned as the phase 2. This paper describes the experimental network configuration and project plan of TP-HDR experiment phase 2. Additional information is provided in the original.

  3. SU-D-19A-07: Dosimetric Comparison of HDR Plesiotherapy and Electron Beam Therapy for Superficial Lesions

    SciTech Connect

    Mitchell, A; Jacob, D; Andreou, K; Raben, A; Chen, H; Koprowski, C; Mourtada, F

    2014-06-01

    Purpose: Large superficial (skin, soft tissue sarcoma) lesions located on curved areas are hard to treat with electrons. The Freiburg Flap (Nucletron, Netherlands) is a flexible mesh style surface which can be easily shaped to fit curved surfaces for reproducible HDR fraction delivery. To understand the fundamental dosimetric differences, a dosimetric comparison was made between HDR plesiotherapy (Freiburg applicator for lesions over 4cm) and external electron beam radiotherapy over cases with varying target curvature (both stylized and clinical cases). Methods: Four stylized cases with variable complexity were created using artificial DICOM axial CT slices and RT structures (a square and three curved structures on a 4.5cm radius cylinder). They were planned using Oncentra v4.3 and exported to Pinnacle v9.6 for electrons planning. The HDR source dwell positions were optimized for the best coverage of the targets using graphical optimization. Electron treatment plans were created in Pinnacle using the same CT and RT structures of three HDR cases with surface lesions previously treated with the Freiburg flap. The En face electron plans used 6-12 MeV electrons and 0.5–1 cm bolus was added to increase surface dose. The electron plans were prescribed to an isodose line to conform to the target. Results: For all lesions, the average target dose coverage was similar (D90ave of 100% for HDR vs 101% for electrons). For lesions with high curvature, the HDR coverage was better (D90 102% vs D90 97% for electron). For all cases, adjacent structures high dose region was lower for HDR than electrons (D1cc 100% for HDR vs D1cc 111% for electrons). Conclusion: HDR plesiotherapy offers excellent target conformity for superficial targets similar to electrons. However, for lesions with complex curved surfaces, HDR has the advantage to achieve better dose distributions using graphical optimization to spare adjacent normal tissue while maximizing target coverage.

  4. A Prospective Cohort Study to Compare Treatment Results Between 2 Fractionation Schedules of High-Dose-Rate Intracavitary Brachytherapy (HDR-ICBT) in Patients With Cervical Cancer

    SciTech Connect

    Huang, Eng-Yen; Sun, Li-Min; Lin, Hao; Lan, Jen-Hong; Chanchien, Chan-Chao; Huang, Yu-Jie; Wang, Chang-Yu; Wang, Chong-Jong

    2013-01-01

    Purpose: To compare the treatment results of 2 fractionation schedules for high-dose-rate intracavitary brachytherapy (HDR-ICBT) in patients with cervical cancer. Methods and Materials: From June 2001 through January 2008, 267 patients with stage IB-IVA cervical cancer were enrolled in the study. All patients underwent 4-field pelvic irradiation and HDR-ICBT. The median central and parametrial doses were 39.6 Gy and 45 Gy, respectively. Patient underwent either 6 Gy Multiplication-Sign 4 (HDR-4) (n=144) or 4.5 Gy Multiplication-Sign 6 (HDR-6) (n=123) to point A of ICBT using {sup 192}Ir isotope twice weekly. The rates of overall survival, locoregional failure, distant metastasis, proctitis, cystitis, and enterocolitis were compared between HDR-4 and HDR-6. Results: There were no significant differences in the demographic data between HDR-4 and HDR-6 except for total treatment time. The 5-year proctitis rates were 23.0% and 21.5% in HDR-4 and HDR-6 (P=.399), respectively. The corresponding rates of grade 2-4 proctitis were 18.7% and 9.6% (P=.060). The corresponding rates of grades 3-4 proctitis were 5.2% and 1.3% (P=.231). Subgroup analysis revealed that HDR-4 significantly increased grade 2-4 proctitis in patients aged {>=}62 years old (P=.012) but not in patients aged <62 years (P=.976). The rates of overall survival, locoregional failure, distant metastasis, cystitis, and enterocolitis were not significantly different between HDR-4 and HDR-6 schedules. Conclusion: The small fraction size of HDR-ICBT is associated with grade 2 proctitis without compromise of prognosis in elderly patients. This schedule is suggested for patients who tolerate an additional 2 applications of HDR-ICBT.

  5. Evaluation of PC-ISO for customized, 3D Printed, gynecologic 192-Ir HDR brachytherapy applicators.

    PubMed

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-08

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. 

  6. Evaluation of PC-ISO for customized, 3D printed, gynecologic 192Ir HDR brachytherapy applicators.

    PubMed

    Cunha, J Adam M; Mellis, Katherine; Sethi, Rajni; Siauw, Timmy; Sudhyadhom, Atchar; Garg, Animesh; Goldberg, Ken; Hsu, I-Chow; Pouliot, Jean

    2015-01-01

    The purpose of this study was to evaluate the radiation attenuation properties of PC-ISO, a commercially available, biocompatible, sterilizable 3D printing material, and its suitability for customized, single-use gynecologic (GYN) brachytherapy applicators that have the potential for accurate guiding of seeds through linear and curved internal channels. A custom radiochromic film dosimetry apparatus was 3D-printed in PC-ISO with a single catheter channel and a slit to hold a film segment. The apparatus was designed specifically to test geometry pertinent for use of this material in a clinical setting. A brachytherapy dose plan was computed to deliver a cylindrical dose distribution to the film. The dose plan used an 192Ir source and was normalized to 1500 cGy at 1 cm from the channel. The material was evaluated by comparing the film exposure to an identical test done in water. The Hounsfield unit (HU) distributions were computed from a CT scan of the apparatus and compared to the HU distribution of water and the HU distribution of a commercial GYN cylinder applicator. The dose depth curve of PC-ISO as measured by the radiochromic film was within 1% of water between 1 cm and 6 cm from the channel. The mean HU was -10 for PC-ISO and -1 for water. As expected, the honeycombed structure of the PC-ISO 3D printing process created a moderate spread of HU values, but the mean was comparable to water. PC-ISO is sufficiently water-equivalent to be compatible with our HDR brachytherapy planning system and clinical workflow and, therefore, it is suitable for creating custom GYN brachytherapy applicators. Our current clinical practice includes the use of custom GYN applicators made of commercially available PC-ISO when doing so can improve the patient's treatment. PACS number: none.

  7. Dosimetric evaluation of PLATO and Oncentra treatment planning systems for High Dose Rate (HDR) brachytherapy gynecological treatments

    NASA Astrophysics Data System (ADS)

    Singh, Hardev; Herman, Tania De La Fuente; Showalter, Barry; Thompson, Spencer J.; Syzek, Elizabeth J.; Herman, Terence; Ahmad, Salahuddin

    2012-10-01

    This study compares the dosimetric differences in HDR brachytherapy treatment plans calculated with Nucletron's PLATO and Oncentra MasterPlan treatment planning systems (TPS). Ten patients (1 T1b, 1 T2a, 6 T2b, 2 T4) having cervical carcinoma, median age of 43.5 years (range, 34-79 years) treated with tandem & ring applicator in our institution were selected retrospectively for this study. For both Plato and Oncentra TPS, the same orthogonal films anterior-posterior (AP) and lateral were used to manually draw the prescription and anatomical points using definitions from the Manchester system and recommendations from the ICRU report 38. Data input for PLATO was done using a digitizer and Epson Expression 10000XL scanner was used for Oncentra where the points were selected on the images in the screen. The prescription doses for these patients were 30 Gy to points right A (RA) and left A (LA) delivered in 5 fractions with Ir-192 HDR source. Two arrangements: one dwell position and two dwell positions on the tandem were used for dose calculation. The doses to the patient points right B (RB) and left B (LB), and to the organs at risk (OAR), bladder and rectum for each patient were calculated. The mean dose and the mean percentage difference in dose calculated by the two treatment planning systems were compared. Paired t-tests were used for statistical analysis. No significant differences in mean RB, LB, bladder and rectum doses were found with p-values > 0.14. The mean percent difference of doses in RB, LB, bladder and rectum are found to be less than 2.2%, 1.8%, 1.3% and 2.2%, respectively. Dose calculations based on the two different treatment planning systems were found to be consistent and the treatment plans can be made with either system in our department without any concern.

  8. Dosimetric evaluation of PLATO and Oncentra treatment planning systems for High Dose Rate (HDR) brachytherapy gynecological treatments

    SciTech Connect

    Singh, Hardev; De La Fuente Herman, Tania; Showalter, Barry; Thompson, Spencer J.; Syzek, Elizabeth J.; Herman, Terence; Ahmad, Salahuddin

    2012-10-23

    This study compares the dosimetric differences in HDR brachytherapy treatment plans calculated with Nucletron's PLATO and Oncentra MasterPlan treatment planning systems (TPS). Ten patients (1 T1b, 1 T2a, 6 T2b, 2 T4) having cervical carcinoma, median age of 43.5 years (range, 34-79 years) treated with tandem and ring applicator in our institution were selected retrospectively for this study. For both Plato and Oncentra TPS, the same orthogonal films anterior-posterior (AP) and lateral were used to manually draw the prescription and anatomical points using definitions from the Manchester system and recommendations from the ICRU report 38. Data input for PLATO was done using a digitizer and Epson Expression 10000XL scanner was used for Oncentra where the points were selected on the images in the screen. The prescription doses for these patients were 30 Gy to points right A (RA) and left A (LA) delivered in 5 fractions with Ir-192 HDR source. Two arrangements: one dwell position and two dwell positions on the tandem were used for dose calculation. The doses to the patient points right B (RB) and left B (LB), and to the organs at risk (OAR), bladder and rectum for each patient were calculated. The mean dose and the mean percentage difference in dose calculated by the two treatment planning systems were compared. Paired t-tests were used for statistical analysis. No significant differences in mean RB, LB, bladder and rectum doses were found with p-values > 0.14. The mean percent difference of doses in RB, LB, bladder and rectum are found to be less than 2.2%, 1.8%, 1.3% and 2.2%, respectively. Dose calculations based on the two different treatment planning systems were found to be consistent and the treatment plans can be made with either system in our department without any concern.

  9. SU-E-T-205: Improving Quality Assurance of HDR Brachytherapy: Verifying Agreement Between Planned and Delivered Dose Distributions Using DICOM RTDose and Advanced Film Dosimetry

    SciTech Connect

    Palmer, A L; Bradley, D A; Nisbet, A

    2014-06-01

    Purpose: HDR brachytherapy is undergoing significant development, and quality assurance (QA) checks must keep pace. Current recommendations do not adequately verify delivered against planned dose distributions: This is particularly relevant for new treatment planning system (TPS) calculation algorithms (non TG-43 based), and an era of significant patient-specific plan optimisation. Full system checks are desirable in modern QA recommendations, complementary to device-centric individual tests. We present a QA system incorporating TPS calculation, dose distribution export, HDR unit performance, and dose distribution measurement. Such an approach, more common in external beam radiotherapy, has not previously been reported in the literature for brachytherapy. Methods: Our QA method was tested at 24 UK brachytherapy centres. As a novel approach, we used the TPS DICOM RTDose file export to compare planned dose distribution with that measured using Gafchromic EBT3 films placed around clinical brachytherapy treatment applicators. Gamma analysis was used to compare the dose distributions. Dose difference and distance to agreement were determined at prescription Point A. Accurate film dosimetry was achieved using a glass compression plate at scanning to ensure physically-flat films, simultaneous scanning of known dose films with measurement films, and triple-channel dosimetric analysis. Results: The mean gamma pass rate of RTDose compared to film-measured dose distributions was 98.1% at 3%(local), 2 mm criteria. The mean dose difference, measured to planned, at Point A was -0.5% for plastic treatment applicators and -2.4% for metal applicators, due to shielding not accounted for in TPS. The mean distance to agreement was 0.6 mm. Conclusion: It is recommended to develop brachytherapy QA to include full-system verification of agreement between planned and delivered dose distributions. This is a novel approach for HDR brachytherapy QA. A methodology using advanced film

  10. A gEUD-based inverse planning technique for HDR prostate brachytherapy: Feasibility study

    SciTech Connect

    Giantsoudi, D.; Baltas, D.; Karabis, A.; Mavroidis, P.; Zamboglou, N.; Tselis, N.; Shi, C.; Papanikolaou, N.

    2013-04-15

    Purpose: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization. Methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators. Results: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D{sub 10} or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume. Conclusions: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.

  11. [Enhancement of artemisinin biosynthesis in transgenic Artemisia annua L. by overexpressed HDR and ADS genes].

    PubMed

    Wang, Ya-Xiong; Long, Shi-Ping; Zeng, Li-Xia; Xiang, Li-En; Lin, Zhi; Chen, Min; Liao, Zhi-Hua

    2014-09-01

    Artemisnin is a novel sesquiterpene lactone with an internal peroxide bridge structure, which is extracted from traditional Chinese herb Artemisia annua L. (Qinghao). Recommended by World Health Organization, artemisinin is the first-line drug in the treatment of encephalic and chloroquine-resistant malaria. In the present study, transgenic A. annua plants were developed by overexpressing the key enzymes involved in the biosynthetic pathway of artemisinin. Based on Agrobacterium-mediated transformation methods, transgenic plants of A. annua with overexpression of both HDR and ADS were obtained through hygromycin screening. The genomic PCR analysis confirmed six transgenic lines in which both HDR and ADS were integrated into genome. The gene expression analysis given by real-time quantitative PCR showed that all the transgenic lines had higher expression levels of HDR and ADS than the non-transgenic control (except ah3 in which the expression level of ADS showed no significant difference compared with control); and the HPLC analysis of artemisinin demonstrated that transgenic A. annua plants produced artemisinin at significantly higher level than non-transgenic plants. Especially, the highest content of artemisinin was found in transgenic line ah70, in which the artemisinin content was 3.48 times compared with that in non-transgenic lines. In summary, overexpression of HDR and ADS facilitated artemisinin biosynthesis and this method could be applied to develop transgenic plants of A. annua with higher yield of artemisinin.

  12. Systematic quantification of HDR and NHEJ reveals effects of locus, nuclease, and cell type on genome-editing.

    PubMed

    Miyaoka, Yuichiro; Berman, Jennifer R; Cooper, Samantha B; Mayerl, Steven J; Chan, Amanda H; Zhang, Bin; Karlin-Neumann, George A; Conklin, Bruce R

    2016-03-31

    Precise genome-editing relies on the repair of sequence-specific nuclease-induced DNA nicking or double-strand breaks (DSBs) by homology-directed repair (HDR). However, nonhomologous end-joining (NHEJ), an error-prone repair, acts concurrently, reducing the rate of high-fidelity edits. The identification of genome-editing conditions that favor HDR over NHEJ has been hindered by the lack of a simple method to measure HDR and NHEJ directly and simultaneously at endogenous loci. To overcome this challenge, we developed a novel, rapid, digital PCR-based assay that can simultaneously detect one HDR or NHEJ event out of 1,000 copies of the genome. Using this assay, we systematically monitored genome-editing outcomes of CRISPR-associated protein 9 (Cas9), Cas9 nickases, catalytically dead Cas9 fused to FokI, and transcription activator-like effector nuclease at three disease-associated endogenous gene loci in HEK293T cells, HeLa cells, and human induced pluripotent stem cells. Although it is widely thought that NHEJ generally occurs more often than HDR, we found that more HDR than NHEJ was induced under multiple conditions. Surprisingly, the HDR/NHEJ ratios were highly dependent on gene locus, nuclease platform, and cell type. The new assay system, and our findings based on it, will enable mechanistic studies of genome-editing and help improve genome-editing technology.

  13. Perioperative high dose rate (HDR) brachytherapy in unresectable locally advanced pancreatic tumors

    PubMed Central

    Waniczek, Dariusz; Piecuch, Jerzy; Mikusek, Wojciech; Arendt, Jerzy; Białas, Brygida

    2011-01-01

    Purpose The aim of the study was to present an original technique of catheter implantation for perioperative HDR-Ir192 brachytherapy in patients after palliative operations of unresectable locally advanced pancreatic tumors and to estimate the influence of perioperative HDR-Ir192 brachytherapy on pain relief in terminal pancreatic cancer patients. Material and methods Eight patients with pancreatic tumors located in the head of pancreas underwent palliative operations with the use of HDR-Ir192 brachytherapy. All patients qualified for surgery reported pain of high intensity and had received narcotic painkillers prior to operation. During the last phase of the surgery, the Nucletron® catheters were implanted in patients to prepare them for later perioperative brachytherapy. Since the 6th day after surgery HDR brachytherapy was performed. Before each brachytherapy fraction the location of implants were checked using fluoroscopy. A fractional dose was 5 Gy and a total dose was 20 Gy in the area of radiation. A comparative study of two groups of patients (with and without brachytherapy) with stage III pancreatic cancer according to the TNM scale was taken in consideration. Results and Conclusions The authors claim that the modification of catheter implantation using specially designed cannula, facilitates the process of inserting the catheter into the tumor, shortens the time needed for the procedure, and reduces the risk of complications. Mean survival time was 5.7 months. In the group of performed brachytherapy, the mean survival time was 6.7 months, while in the group of no brachytherapy performed – 4.4 months. In the group of brachytherapy, only one patient increased the dose of painkillers in the last month of his life. Remaining patients took constant doses of medicines. Perioperative HDR-Ir192 brachytherapy could be considered as a practical application of adjuvant therapy for pain relief in patients with an advanced pancreatic cancer. PMID:27895674

  14. SU-E-T-574: Fessiblity of Using the Calypso System for HDR Interstitial Catheter Reconstruction

    SciTech Connect

    Li, J S; Ma, C

    2014-06-01

    Purpose: It is always a challenge to reconstruct the interstitial catheter for high dose rate (HDR) brachytherapy on patient CT or MR images. This work aims to investigate the feasibility of using the Calypso system (Varian Medical, CA) for HDR catheter reconstruction utilizing its accuracy on tracking the electromagnetic transponder location. Methods: Experiment was done with a phantom that has a HDR interstitial catheter embedded inside. CT scan with a slice thickness of 1.25 mm was taken for this phantom with two Calypso beacon transponders in the catheter. The two transponders were connected with a wire. The Calypso system was used to record the beacon transponders’ location in real time when they were gently pulled out with the wire. The initial locations of the beacon transponders were used for registration with the CT image and the detected transponder locations were used for the catheter path reconstruction. The reconstructed catheter path was validated on the CT image. Results: The HDR interstitial catheter was successfully reconstructed based on the transponders’ coordinates recorded by the Calypso system in real time when the transponders were pulled in the catheter. After registration with the CT image, the shape and location of the reconstructed catheter are evaluated against the CT image and the result shows an accuracy of 2 mm anywhere in the Calypso detectable region which is within a 10 cm X 10 cm X 10 cm cubic box for the current system. Conclusion: It is feasible to use the Calypso system for HDR interstitial catheter reconstruction. The obstacle for its clinical usage is the size of the beacon transponder whose diameter is bigger than most of the interstitial catheters used in clinic. Developing smaller transponders and supporting software and hardware for this application is necessary before it can be adopted for clinical use.

  15. Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

    NASA Astrophysics Data System (ADS)

    Palmer, Antony L.; Lee, Chris; Ratcliffe, Ailsa J.; Bradley, David; Nisbet, Andrew

    2013-10-01

    A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit.

  16. Handheld directional reflectometer: an angular imaging device to measure BRDF and HDR in real time

    NASA Astrophysics Data System (ADS)

    Mattison, Phillip R.; Dombrowski, Mark S.; Lorenz, James M.; Davis, Keith J.; Mann, Harley C.; Johnson, Philip; Foos, Bryan

    1998-10-01

    Many applications require quantitative measurements of surface light scattering, including quality control on production lines, inspection of painted surfaces, inspection of field repairs, etc. Instruments for measuring surface scattering typically fall into two main categories, namely bidirectional reflectometers, which measure the angular distribution of scattering, and hemispherical directional reflectometers, which measure the total scattering into the hemisphere above the surface. Measurement of the bi-directional reflectance distribution function (BRDF) gives the greatest insight into how light is scattered from a surface. Measurements of BRDF, however, are typically very lengthy measurements taken by moving a source and detector to map the scattering. Since BRDF has four angular degrees of freedom, such measurements can require hours to days to complete. Instruments for measuring BRDF are also typically laboratory devices, although a field- portable bi-directional reflectometer does exist. Hemispherical directional reflectance (HDR) is a much easier measurement to make, although care must be taken to use the proper methodology when measuring at wavelengths beyond 10 micrometer, since integrating spheres (typically used to make such measurements) are very energy inefficient and lose their integrating properties at very long wavelengths. A few field- portable hemispherical directional reflectometers do exist, but typically measure HDR only at near-normal angles. Boeing Defense and Space Group and Surface Optics Corporation, under a contract from the Air Force Research Laboratory, have developed a new hand-held instrument capable of measuring both BRDF and HDR using a unique, patented angular imaging technique. A combination of an hemi-ellipsoidal mirror and an additional lens translate the angular scatter from a surface into a two-dimensional spatial distribution, which is recorded by an imaging array. This configuration fully maps the scattering from a half

  17. A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images

    NASA Astrophysics Data System (ADS)

    Zhen, Xin; Chen, Haibin; Yan, Hao; Zhou, Linghong; Mell, Loren K.; Yashar, Catheryn M.; Jiang, Steve; Jia, Xun; Gu, Xuejun; Cervino, Laura

    2015-04-01

    Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based ‘thin-plate-spline robust point matching’ algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses.

  18. A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images.

    PubMed

    Zhen, Xin; Chen, Haibin; Yan, Hao; Zhou, Linghong; Mell, Loren K; Yashar, Catheryn M; Jiang, Steve; Jia, Xun; Gu, Xuejun; Cervino, Laura

    2015-04-07

    Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based 'thin-plate-spline robust point matching' algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses.

  19. HDR Pathological Image Enhancement Based on Improved Bias Field Correction and Guided Image Filter

    PubMed Central

    Zhu, Ganzheng; Li, Siqi; Gong, Shang; Yang, Benqiang; Zhang, Libo

    2016-01-01

    Pathological image enhancement is a significant topic in the field of pathological image processing. This paper proposes a high dynamic range (HDR) pathological image enhancement method based on improved bias field correction and guided image filter (GIF). Firstly, a preprocessing including stain normalization and wavelet denoising is performed for Haematoxylin and Eosin (H and E) stained pathological image. Then, an improved bias field correction model is developed to enhance the influence of light for high-frequency part in image and correct the intensity inhomogeneity and detail discontinuity of image. Next, HDR pathological image is generated based on least square method using low dynamic range (LDR) image, H and E channel images. Finally, the fine enhanced image is acquired after the detail enhancement process. Experiments with 140 pathological images demonstrate the performance advantages of our proposed method as compared with related work. PMID:28116303

  20. Dosimetric study of surface applicators of HDR brachytherapy GammaMed Plus equipment

    SciTech Connect

    Reyes-Rivera, E. E-mail: modesto@fisica.ugto.mx Sosa, M. E-mail: modesto@fisica.ugto.mx Reyes, U. E-mail: modesto@fisica.ugto.mx Jesús Bernal-Alvarado, José de E-mail: theo@fisica.ugto.mx Córdova, T. E-mail: theo@fisica.ugto.mx Gil-Villegas, A. E-mail: theo@fisica.ugto.mx; Monzón, E.

    2014-11-07

    The cone type surface applicators used in HDR brachytherapy for treatment of small skin lesions are an alternative to be used with both electron beams and orthovoltage X-ray equipment. For a good treatment planning is necessary to know the dose distribution of these applicators, which can be obtained by experimental measurement and Monte Carlo simulation as well. In this study the dose distribution of surface applicators of 3 and 3.5 cm diameter, respectively of HDR brachytherapy GammaMed Plus equipment has been estimated using the Monte Carlo method, MCNP code. The applicators simulated were placed on the surface of a water phantom of 20 × 20 × 20 cm and the dose was calculated at depths from 0 to 3 cm with increments of 0.25 mm. The dose profiles obtained at depth show the expected gradients for surface therapy.

  1. Air kerma standard for calibration of well-type chambers in Brazil using {sup 192}Ir HDR sources and its traceability

    SciTech Connect

    Di Prinzio, Renato; Almeida, Carlos Eduardo de

    2009-03-15

    In Brazil there are over 100 high dose rate (HDR) brachytherapy facilities using well-type chambers for the determination of the air kerma rate of {sup 192}Ir sources. This paper presents the methodology developed and extensively tested by the Laboratorio de Ciencias Radiologicas (LCR) and presently in use to calibrate those types of chambers. The system was initially used to calibrate six well-type chambers of brachytherapy services, and the maximum deviation of only 1.0% was observed between the calibration coefficients obtained and the ones in the calibration certificate provided by the UWADCL. In addition to its traceability to the Brazilian National Standards, the whole system was taken to University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) for a direct comparison and the same formalism to calculate the air kerma was used. The comparison results between the two laboratories show an agreement of 0.9% for the calibration coefficients. Three Brazilian well-type chambers were calibrated at the UWADCL, and by LCR, in Brazil, using the developed system and a clinical HDR machine. The results of the calibration of three well chambers have shown an agreement better than 1.0%. Uncertainty analyses involving the measurements made both at the UWADCL and LCR laboratories are discussed.

  2. Trans-Pacific HDR Satellite Communications Experiment Phase-2: Experimental Network and Demonstration Plan

    NASA Technical Reports Server (NTRS)

    Kadowaki, Naoto; Yoshimura, Naoko; Takahashi, Takashi; Yoshikawa, Makoto; Hsu, Eddie; Bergman, Larry; Bhasin, Kul; Gary, Pat

    1998-01-01

    The trans-Pacific high data rate (TP-HDR) satellite communications experiment was proposed at the Japan-U.S. Cooperation in Space (JUCS) Program Workshop held in Hawaii in 1993 and remote high definition video post-production was demonstrated as the first phase trial. Following the first phase, the second phase experiment is currently prepared. This paper describes the experimental network configuration, application demonstration, and performance evaluation plan of the second phase experiment.

  3. HDR (Hot Dry Rock) technology transfer activities in the Clear Lake Area, California

    SciTech Connect

    Burns, K.; Potter, R.

    1990-01-01

    A large Hot Dry Rock resource has been recognized in northern California. It underlies the region extending NE of The Geysers to N of the City of Clearlake. The long-range productive potential is thousands of megawatts. The geothermal resource is heterogeneous. There are two mechanisms of heat flow occurring together. One is fluid transport, up natural zones of permeability, to outflows as surface springs. The other is conductive heat flow through impermeable rock. The temperature isotherms are thought to be nearly level surfaces, for example, the 300{degree}C isotherm is at about 8000 ft depth, with spikes'' or ridges'' occurring around narrow zones of fluid flow. While there is accessible heat at shallow depth in the naturally permeable rocks, the really substantial resource is in the impermeable rock. This is the HDR resource. The potential reservoir rocks are Franciscan greywackes and greenstones. Recorded drilling problems appear to be mainly due to intersection with serpentinites or to the effects of stimulation, so are potentially avoidable. Greywacke is favoured as a reservoir rock, and is expected to fail by brittle fracture. The water shortages in Northern California appear to be surmountable. Leakoff rates are expected to be low. Sewerage water may be available for fill and makeup. There is a possibility of combining HDR heat power production with sewerage disposal. To establish the first HDR producer in Northern California offers challenges in technology transfer. Two significant challenges will be creation of dispersed permeability in a greywacke reservoir, and pressure management in the vicinity of naturally permeable zones. A successful demonstration of HDR production technology will improve the long-term prospects for the geothermal power industry in California. 29 refs., 20 figs., 4 tabs.

  4. SU-E-J-270: Study of PET Response to HDR Brachytherapy of Rectal Cancer

    SciTech Connect

    Hobbs, R; Le, Y; Armour, E; Efron, J; Azad, N; Wahl, R; Gearhart, S; Herman, J

    2014-06-01

    Purpose: Dose-response studies in radiation therapy are typically using single response values for tumors across ensembles of tumors. Using the high dose rate (HDR) treatment plan dose grid and pre- and post-therapy FDG-PET images, we look for correlations between voxelized dose and FDG uptake response in individual tumors. Methods: Fifteen patients were treated for localized rectal cancer using 192Ir HDR brachytherapy in conjunction with surgery. FDG-PET images were acquired before HDR therapy and 6–8 weeks after treatment (prior to surgery). Treatment planning was done on a commercial workstation and the dose grid was calculated. The two PETs and the treatment dose grid were registered to each other using non-rigid registration. The difference in PET SUV values before and after HDR was plotted versus absorbed radiation dose for each voxel. The voxels were then separated into bins for every 400 cGy of absorbed dose and the bin average values plotted similarly. Results: Individual voxel doses did not correlate with PET response; however, when group into tumor subregions corresponding to dose bins, eighty percent of the patients showed a significant positive correlation (R2 > 0) between PET uptake difference in the targeted region and the absorbed dose. Conclusion: By considering larger ensembles of voxels, such as organ average absorbed dose or the dose bins considered here, valuable information may be obtained. The dose-response correlations as measured by FDG-PET difference potentially underlines the importance of FDG-PET as a measure of response, as well as the value of voxelized information.

  5. IPIP: A new approach to inverse planning for HDR brachytherapy by directly optimizing dosimetric indices

    SciTech Connect

    Siauw, Timmy; Cunha, Adam; Atamtuerk, Alper; Hsu, I-Chow; Pouliot, Jean; Goldberg, Ken

    2011-07-15

    Purpose: Many planning methods for high dose rate (HDR) brachytherapy require an iterative approach. A set of computational parameters are hypothesized that will give a dose plan that meets dosimetric criteria. A dose plan is computed using these parameters, and if any dosimetric criteria are not met, the process is iterated until a suitable dose plan is found. In this way, the dose distribution is controlled by abstract parameters. The purpose of this study is to develop a new approach for HDR brachytherapy by directly optimizing the dose distribution based on dosimetric criteria. Methods: The authors developed inverse planning by integer program (IPIP), an optimization model for computing HDR brachytherapy dose plans and a fast heuristic for it. They used their heuristic to compute dose plans for 20 anonymized prostate cancer image data sets from patients previously treated at their clinic database. Dosimetry was evaluated and compared to dosimetric criteria. Results: Dose plans computed from IPIP satisfied all given dosimetric criteria for the target and healthy tissue after a single iteration. The average target coverage was 95%. The average computation time for IPIP was 30.1 s on an Intel(R) Core{sup TM}2 Duo CPU 1.67 GHz processor with 3 Gib RAM. Conclusions: IPIP is an HDR brachytherapy planning system that directly incorporates dosimetric criteria. The authors have demonstrated that IPIP has clinically acceptable performance for the prostate cases and dosimetric criteria used in this study, in both dosimetry and runtime. Further study is required to determine if IPIP performs well for a more general group of patients and dosimetric criteria, including other cancer sites such as GYN.

  6. The Ansel Adams zone system: HDR capture and range compression by chemical processing

    NASA Astrophysics Data System (ADS)

    McCann, John J.

    2010-02-01

    We tend to think of digital imaging and the tools of PhotoshopTM as a new phenomenon in imaging. We are also familiar with multiple-exposure HDR techniques intended to capture a wider range of scene information, than conventional film photography. We know about tone-scale adjustments to make better pictures. We tend to think of everyday, consumer, silver-halide photography as a fixed window of scene capture with a limited, standard range of response. This description of photography is certainly true, between 1950 and 2000, for instant films and negatives processed at the drugstore. These systems had fixed dynamic range and fixed tone-scale response to light. All pixels in the film have the same response to light, so the same light exposure from different pixels was rendered as the same film density. Ansel Adams, along with Fred Archer, formulated the Zone System, staring in 1940. It was earlier than the trillions of consumer photos in the second half of the 20th century, yet it was much more sophisticated than today's digital techniques. This talk will describe the chemical mechanisms of the zone system in the parlance of digital image processing. It will describe the Zone System's chemical techniques for image synthesis. It also discusses dodging and burning techniques to fit the HDR scene into the LDR print. Although current HDR imaging shares some of the Zone System's achievements, it usually does not achieve all of them.

  7. Impact of using linear optimization models in dose planning for HDR brachytherapy

    SciTech Connect

    Holm, Aasa; Larsson, Torbjoern; Carlsson Tedgren, Aasa

    2012-02-15

    Purpose: Dose plans generated with optimization models hitherto used in high-dose-rate (HDR) brachytherapy have shown a tendency to yield longer dwell times than manually optimized plans. Concern has been raised for the corresponding undesired hot spots, and various methods to mitigate these have been developed. The hypotheses upon this work is based are (a) that one cause for the long dwell times is the use of objective functions comprising simple linear penalties and (b) that alternative penalties, as these are piecewise linear, would lead to reduced length of individual dwell times. Methods: The characteristics of the linear penalties and the piecewise linear penalties are analyzed mathematically. Experimental comparisons between the two types of penalties are carried out retrospectively for a set of prostate cancer patients. Results: When the two types of penalties are compared, significant changes can be seen in the dwell times, while most dose-volume parameters do not differ significantly. On average, total dwell times were reduced by 4.2%, with a reduction of maximum dwell times by 25%, when the alternative penalties were used. Conclusions: The use of linear penalties in optimization models for HDR brachytherapy is one cause for the undesired long dwell times that arise in mathematically optimized plans. By introducing alternative penalties, a significant reduction in dwell times can be achieved for HDR brachytherapy dose plans. Although various measures for mitigating the long dwell times are already available, the observation that linear penalties contribute to their appearance is of fundamental interest.

  8. Near constant-time optimal piecewise LDR to HDR inverse tone mapping

    NASA Astrophysics Data System (ADS)

    Chen, Qian; Su, Guan-Ming; Yin, Peng

    2015-02-01

    In a backward compatible HDR image/video compression, it is a general approach to reconstruct HDR from compressed LDR as a prediction to original HDR, which is referred to as inverse tone mapping. Experimental results show that 2- piecewise 2nd order polynomial has the best mapping accuracy than 1 piece high order or 2-piecewise linear, but it is also the most time-consuming method because to find the optimal pivot point to split LDR range to 2 pieces requires exhaustive search. In this paper, we propose a fast algorithm that completes optimal 2-piecewise 2nd order polynomial inverse tone mapping in near constant time without quality degradation. We observe that in least square solution, each entry in the intermediate matrix can be written as the sum of some basic terms, which can be pre-calculated into look-up tables. Since solving the matrix becomes looking up values in tables, computation time barely differs regardless of the number of points searched. Hence, we can carry out the most thorough pivot point search to find the optimal pivot that minimizes MSE in near constant time. Experiment shows that our proposed method achieves the same PSNR performance while saving 60 times computation time compared to the traditional exhaustive search in 2-piecewise 2nd order polynomial inverse tone mapping with continuous constraint.

  9. Developing A Directional High-Dose Rate (d-HDR) Brachytherapy Source

    NASA Astrophysics Data System (ADS)

    Heredia, Athena Yvonne

    Conventional sources used in brachytherapy provide nearly isotropic or radially symmetric dose distributions. Optimizations of dose distributions have been limited to varied dwell times at specified locations within a given treatment volume, or manipulations in source position for seed implantation techniques. In years past, intensity modulated brachytherapy (IMBT) has been used to reduce the amount of radiation to surrounding sensitive structures in select intracavitary cases by adding space or partial shields. Previous work done by Lin et al., at the University of Wisconsin-Madison, has shown potential improvements in conformality for brachytherapy treatments using a directionally shielded low dose rate (LDR) source for treatments in breast and prostate. Directional brachytherapy sources irradiate approximately half of the radial angles around the source, and adequately shield a quarter of the radial angles on the opposite side, with sharp gradient zones between the treated half and shielded quarter. With internally shielded sources, the radiation can be preferentially emitted in such a way as to reduce toxicities in surrounding critical organs. The objective of this work is to present findings obtained in the development of a new directional high dose rate (d-HDR) source. To this goal, 103Pd (Z = 46) is reintroduced as a potential radionuclide for use in HDR brachytherapy. 103Pd has a low average photon energy (21 keV) and relatively short half -life (17 days), which is why it has historically been used in low dose rate applications and implantation techniques. Pd-103 has a carrier-free specific activity of 75000 Ci/g. Using cyclotron produced 103Pd, near carrier-free specific activities can be achieved, providing suitability for high dose rate applications. The evolution of the d-HDR source using Monte Carlo simulations is presented, along with dosimetric parameters used to fully characterize the source. In addition, a discussion on how to obtain elemental

  10. High dynamic range adaptive real-time smart camera: an overview of the HDR-ARTiST project

    NASA Astrophysics Data System (ADS)

    Lapray, Pierre-Jean; Heyrman, Barthélémy; Ginhac, Dominique

    2015-04-01

    Standard cameras capture only a fraction of the information that is visible to the human visual system. This is specifically true for natural scenes including areas of low and high illumination due to transitions between sunlit and shaded areas. When capturing such a scene, many cameras are unable to store the full Dynamic Range (DR) resulting in low quality video where details are concealed in shadows or washed out by sunlight. The imaging technique that can overcome this problem is called HDR (High Dynamic Range) imaging. This paper describes a complete smart camera built around a standard off-the-shelf LDR (Low Dynamic Range) sensor and a Virtex-6 FPGA board. This smart camera called HDR-ARtiSt (High Dynamic Range Adaptive Real-time Smart camera) is able to produce a real-time HDR live video color stream by recording and combining multiple acquisitions of the same scene while varying the exposure time. This technique appears as one of the most appropriate and cheapest solution to enhance the dynamic range of real-life environments. HDR-ARtiSt embeds real-time multiple captures, HDR processing, data display and transfer of a HDR color video for a full sensor resolution (1280 1024 pixels) at 60 frames per second. The main contributions of this work are: (1) Multiple Exposure Control (MEC) dedicated to the smart image capture with alternating three exposure times that are dynamically evaluated from frame to frame, (2) Multi-streaming Memory Management Unit (MMMU) dedicated to the memory read/write operations of the three parallel video streams, corresponding to the different exposure times, (3) HRD creating by combining the video streams using a specific hardware version of the Devebecs technique, and (4) Global Tone Mapping (GTM) of the HDR scene for display on a standard LCD monitor.

  11. SU-E-T-242: Design of a Novel Afterloader Clearance QA Device for Biliary HDR Therapy

    SciTech Connect

    Mullins, JP; Deufel, CL

    2015-06-15

    Purpose: Bile duct cancer affects 2–3 thousand people annually in the United States. Radiation therapy has been shown to double median survival, with combined external beam and intraluminal high dose-rate (HDR) brachytherapy being most effective. Endoscopic retrograde cholangiopancreatography (ERCP) biliary HDR, a less-invasive alternative to trans-hepatic brachytherapy, is delivered through a catheter that travels a tortuous path from nose to bile duct, requiring wire drive force and dexterity beyond typical afterloader performance specifications. Thus, specific afterloader quality assurance(QA) is recommended for this procedure. Our aim was to create a device and process for Varisource afterloader clearance QA with objectives that it be quantitative and can monitor afterloader performance over time, compare performance between two distinct afterloaders and potentially Result in a predictive nomogram for patient-specific clearance. Methods: Based on retrospective reconstruction of 20 ERCP patient anatomies, we designed a phantom to test afterloader ability to drive the source wire along an intended treatment path. The ability of the afterloader to fully extend the intended treatment path is a function of number and diameters of turns. We have determined experimentally that relative position of the turns does not impact performance. Results: Both patient and QA paths involve three common turns/loops: a large turn representing the stomach(10.8cm±2.0cm), an elliptical loop representing the duodenum(7.3cm±1.5cmx4.8cm±0.7cm), and a final turn at the end of the bile duct that may be tight for some patient-specific anatomies and absent in others(3.7cm±0.7cm, where present). Our phantom design uses anatomical average turn diameters for the stomach and duodenum then terminates in a turn of quantitatively selectable diameter. The smallest final turn diameter that an afterloader can pass is recorded as the QA parameter. Conclusion: With this device and QA process, we

  12. Overexpression and Suppression of Artemisia annua 4-Hydroxy-3-Methylbut-2-enyl Diphosphate Reductase 1 Gene (AaHDR1) Differentially Regulate Artemisinin and Terpenoid Biosynthesis

    PubMed Central

    Ma, Dongming; Li, Gui; Zhu, Yue; Xie, De-Yu

    2017-01-01

    4-Hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR) catalyzes the last step of the 2-C-methyl-D-erythritol 4- phosphate (MEP) pathway to synthesize isopentenyl pyrophosphate (IPP) and dimethylallyl diphosphate (DMAPP). To date, little is known regarding effects of an increase or a decrease of a HDR expression on terpenoid and other metabolite profiles in plants. In our study, an Artemisia annua HDR cDNA (namely AaHDR1) was cloned from leaves. Expression profiling showed that it was highly expressed in leaves, roots, stems, and flowers with different levels. Green florescence protein fusion and confocal microscope analyses showed that AaHDR1 was localized in chloroplasts. The overexpression of AaHDR1 increased contents of artemisinin, arteannuin B and other sesquiterpenes, and multiple monoterpenes. By contrast, the suppression of AaHDR1 by anti-sense led to opposite results. In addition, an untargeted metabolic profiling showed that the overexpression and suppression altered non-polar metabolite profiles. In conclusion, the overexpression and suppression of AaHDR1 protein level in plastids differentially affect artemisinin and other terpenoid biosynthesis, and alter non-polar metabolite profiles of A. annua. Particularly, its overexpression leading to the increase of artemisinin production is informative to future metabolic engineering of this antimalarial medicine. PMID:28197158

  13. SU-E-T-169: Characterization of Pacemaker/ICD Dose in SAVI HDR Brachytherapy

    SciTech Connect

    Kalavagunta, C; Lasio, G; Yi, B; Zhou, J; Lin, M

    2015-06-15

    Purpose: It is important to estimate dose to pacemaker (PM)/Implantable Cardioverter Defibrillator (ICD) before undertaking Accelerated Partial Breast Treatment using High Dose Rate (HDR) brachytherapy. Kim et al. have reported HDR PM/ICD dose using a single-source balloon applicator. To the authors knowledge, there have so far not been any published PM/ICD dosimetry literature for the Strut Adjusted Volume Implant (SAVI, Cianna Medical, Aliso Viejo, CA). This study aims to fill this gap by generating a dose look up table (LUT) to predict maximum dose to the PM/ICD in SAVI HDR brachytherapy. Methods: CT scans for 3D dosimetric planning were acquired for four SAVI applicators (6−1-mini, 6−1, 8−1 and 10−1) expanded to their maximum diameter in air. The CT datasets were imported into the Elekta Oncentra TPS for planning and each applicator was digitized in a multiplanar reconstruction window. A dose of 340 cGy was prescribed to the surface of a 1 cm expansion of the SAVI applicator cavity. Cartesian coordinates of the digitized applicator were determined in the treatment leading to the generation of a dose distribution and corresponding distance-dose prediction look up table (LUT) for distances from 2 to 15 cm (6-mini) and 2 to 20 cm (10–1).The deviation between the LUT doses and the dose to the cardiac device in a clinical case was evaluated. Results: Distance-dose look up table were compared to clinical SAVI plan and the discrepancy between the max dose predicted by the LUT and the clinical plan was found to be in the range (−0.44%, 0.74%) of the prescription dose. Conclusion: The distance-dose look up tables for SAVI applicators can be used to estimate the maximum dose to the ICD/PM, with a potential usefulness for quick assessment of dose to the cardiac device prior to applicator placement.

  14. SU-E-T-149: Brachytherapy Patient Specific Quality Assurance for a HDR Vaginal Cylinder Case

    SciTech Connect

    Barbiere, J; Napoli, J; Ndlovu, A

    2015-06-15

    Purpose: Commonly Ir-192 HDR treatment planning system commissioning is only based on a single absolute measurement of source activity supplemented by tabulated parameters for multiple factors without independent verification that the planned distribution corresponds to the actual delivered dose. The purpose on this work is to present a methodology using Gafchromic film with a statistically valid calibration curve that can be used to validate clinical HDR vaginal cylinder cases by comparing the calculated plan dose distribution in a plane with the corresponding measured planar dose. Methods: A vaginal cylinder plan was created with Oncentra treatment planning system. The 3D dose matrix was exported to a Varian Eclipse work station for convenient extraction of a 2D coronal dose plane corresponding to the film position. The plan was delivered with a sheet of Gafchromic EBT3 film positioned 1mm from the catheter using an Ir-192 Nucletron HDR source. The film was then digitized with an Epson 10000 XL color scanner. Film analysis is performed with MatLab imaging toolbox. A density to dose calibration curve was created using TG43 formalism for a single dwell position exposure at over 100 points for statistical accuracy. The plan and measured film dose planes were registered using a known dwell position relative to four film marks. The plan delivered 500 cGy to points 2 cm from the sources. Results: The distance to agreement of the 500 cGy isodose between the plan and film measurement laterally was 0.5 mm but can be as much as 1.5 mm superior and inferior. The difference between the computed plan dose and film measurement was calculated per pixel. The greatest errors up to 50 cGy are near the apex. Conclusion: The methodology presented will be useful to implement more comprehensive quality assurance to verify patient-specific dose distributions.

  15. Economic Predictions for Heat Mining: A Review and Analysis of Hot Dry Rock (HDR) Geothermal Energy Technology

    SciTech Connect

    Tester, Jefferson W.; Herzog, Howard J.

    1990-07-01

    The main objectives of this study were first, to review and analyze several economic assessments of Hot Dry Rock (HDR) geothermal energy systems, and second, to reformulate an economic model for HDR with revised cost components. The economic models reviewed include the following studies sponsored by Electric Power Research Institute (EPRI)-Cummings and Morris (1979), Los Alamos National Laboratory (LANL)-Murphy, et al. (1982), United Kingdom (UK)-Shock (1986), Japan-Hori, et al. (1986), Meridian-Entingh (1987) and Bechtel (1988). A general evaluation of the technical feasibility of HDR technology components was also conducted in view of their importance in establishing drilling and reservoir performance parameters required for any economic assessment. In this review, only economic projections for base load electricity produced from HDR systems were considered. Bases of 1989 collars ($) were selected to normalize costs. Following the evaluation of drilling and reservoir performance, power plant choices and cost estimates are discussed in section 6 of the report. In Section 7, the six economics studies cited above are reviewed and compared in terms of their key resource, reservoir and plant performance, and cost assumptions. Based on these comparisons, the report estimates parameters for three composite cases. Important parameters include: (1) resource quality-average geothermal gradient (C/km) and well depth, (2) reservoir performance-effective productivity, flow impedance, and lifetime (thermal drawdown rate), (3) cost components-drilling, reservoir formation, and power plant costs and (4) economic factors-discount and interest rates, taxes, etc. In Section 8, composite case conditions were used to reassess economic projections for HDR-produced electricity. In Section 9, a generalized economic model for HDR-produced electricity is presented to show the effects of resource grade, reservoir performance parameters, and other important factors on projected costs. A

  16. MO-C-17A-11: A Segmentation and Point Matching Enhanced Deformable Image Registration Method for Dose Accumulation Between HDR CT Images

    SciTech Connect

    Zhen, X; Chen, H; Zhou, L; Yan, H; Jiang, S; Jia, X; Gu, X; Mell, L; Yashar, C; Cervino, L

    2014-06-15

    Purpose: To propose and validate a novel and accurate deformable image registration (DIR) scheme to facilitate dose accumulation among treatment fractions of high-dose-rate (HDR) gynecological brachytherapy. Method: We have developed a method to adapt DIR algorithms to gynecologic anatomies with HDR applicators by incorporating a segmentation step and a point-matching step into an existing DIR framework. In the segmentation step, random walks algorithm is used to accurately segment and remove the applicator region (AR) in the HDR CT image. A semi-automatic seed point generation approach is developed to obtain the incremented foreground and background point sets to feed the random walks algorithm. In the subsequent point-matching step, a feature-based thin-plate spline-robust point matching (TPS-RPM) algorithm is employed for AR surface point matching. With the resulting mapping, a DVF characteristic of the deformation between the two AR surfaces is generated by B-spline approximation, which serves as the initial DVF for the following Demons DIR between the two AR-free HDR CT images. Finally, the calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. Results: The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative results as well as the visual inspection of the DIR indicate that our proposed method can suppress the interference of the applicator with the DIR algorithm, and accurately register HDR CT images as well as deform and add interfractional HDR doses. Conclusions: We have developed a novel and robust DIR scheme that can perform registration between HDR gynecological CT images and yield accurate registration results. This new DIR scheme has potential for accurate interfractional HDR dose accumulation. This work is supported in part by the National Natural ScienceFoundation of China (no 30970866 and no

  17. WE-A-17A-10: Fast, Automatic and Accurate Catheter Reconstruction in HDR Brachytherapy Using An Electromagnetic 3D Tracking System

    SciTech Connect

    Poulin, E; Racine, E; Beaulieu, L; Binnekamp, D

    2014-06-15

    Purpose: In high dose rate brachytherapy (HDR-B), actual catheter reconstruction protocols are slow and errors prompt. The purpose of this study was to evaluate the accuracy and robustness of an electromagnetic (EM) tracking system for improved catheter reconstruction in HDR-B protocols. Methods: For this proof-of-principle, a total of 10 catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a Philips-design 18G biopsy needle (used as an EM stylet) and the second generation Aurora Planar Field Generator from Northern Digital Inc. The Aurora EM system exploits alternating current technology and generates 3D points at 40 Hz. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical CT system with a resolution of 0.089 mm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, 5 catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 seconds or less. This would imply that for a typical clinical implant of 17 catheters, the total reconstruction time would be less than 3 minutes. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.92 ± 0.37 mm and 1.74 ± 1.39 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be significantly more accurate (unpaired t-test, p < 0.05). A mean difference of less than 0.5 mm was found between successive EM reconstructions. Conclusion: The EM reconstruction was found to be faster, more accurate and more robust than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators. We would like to disclose that the equipments, used in this study, is coming from a collaboration with Philips Medical.

  18. HDR Brachytherapy Dose Distribution is Influenced by the Metal Material of the Applicator.

    PubMed

    Wu, Chin-Hui; Liao, Yi-Jen; Shiau, An-Cheng; Lin, Hsin-Yu; Hsueh Liu, Yen-Wan; Hsu, Shih-Ming

    2015-12-11

    Applicators containing metal have been widely used in recent years when applying brachytherapy to patients with cervical cancer. However, the high dose rate (HDR) treatment-planning system (TPS) that is currently used in brachytherapy still assumes that the treatment environment constitutes a homogeneous water medium and does not include a dose correction for the metal material of the applicator. The primary purpose of this study was to evaluate the HDR (192)Ir dose distribution in cervical cancer patients when performing brachytherapy using a metal-containing applicator. Thermoluminescent dosimeter (TLD) measurements and Monte Carlo N-Particle eXtended (MCNPX) code were used to explore the doses to the rectum and bladder when using a Henschke applicator containing metal during brachytherapy. When the applicator was assumed to be present, the absolute dose difference between the TLD measurement and MCNPX simulation values was within approximately 5%. A comparison of the MCNPX simulation and TPS calculation values revealed that the TPS overestimated the International Commission of Radiation Units and Measurement (ICRU) rectum and bladder reference doses by 57.78% and 49.59%, respectively. We therefore suggest that the TPS should be modified to account for the shielding effects of the applicator to ensure the accuracy of the delivered doses.

  19. HDR Brachytherapy Dose Distribution is Influenced by the Metal Material of the Applicator

    PubMed Central

    Wu, Chin-Hui; Liao, Yi-Jen; Shiau, An-Cheng; Lin, Hsin-Yu; Hsueh Liu, Yen-Wan; Hsu, Shih-Ming

    2015-01-01

    Applicators containing metal have been widely used in recent years when applying brachytherapy to patients with cervical cancer. However, the high dose rate (HDR) treatment-planning system (TPS) that is currently used in brachytherapy still assumes that the treatment environment constitutes a homogeneous water medium and does not include a dose correction for the metal material of the applicator. The primary purpose of this study was to evaluate the HDR 192Ir dose distribution in cervical cancer patients when performing brachytherapy using a metal-containing applicator. Thermoluminescent dosimeter (TLD) measurements and Monte Carlo N-Particle eXtended (MCNPX) code were used to explore the doses to the rectum and bladder when using a Henschke applicator containing metal during brachytherapy. When the applicator was assumed to be present, the absolute dose difference between the TLD measurement and MCNPX simulation values was within approximately 5%. A comparison of the MCNPX simulation and TPS calculation values revealed that the TPS overestimated the International Commission of Radiation Units and Measurement (ICRU) rectum and bladder reference doses by 57.78% and 49.59%, respectively. We therefore suggest that the TPS should be modified to account for the shielding effects of the applicator to ensure the accuracy of the delivered doses. PMID:26658746

  20. Image guided Brachytherapy: The paradigm of Gynecologic and Partial Breast HDR Brachytherapy

    NASA Astrophysics Data System (ADS)

    Diamantopoulos, S.; Kantemiris, I.; Konidari, A.; Zaverdinos, P.

    2015-09-01

    High dose rate (HDR) brachytherapy uses high strength radioactive sources and temporary interstitial implants to conform the dose to target and minimize the treatment time. The advances of imaging technology enable accurate reconstruction of the implant and exact delineation of high-risk CTV and the surrounding critical structures. Furthermore, with sophisticated treatment planning systems, applicator devices and stepping source afterloaders, brachytherapy evolved to a more precise, safe and individualized treatment. At the Radiation Oncology Department of Metropolitan Hospital Athens, MRI guided HDR gynecologic (GYN) brachytherapy and accelerated partial breast irradiation (APBI) with brachytherapy are performed routinely. Contouring and treatment planning are based on the recommendations of the GEC - ESTRO Working group. The task of this presentation is to reveal the advantages of 3D image guided brachytherapy over 2D brachytherapy. Thus, two patients treated at our department (one GYN and one APBI) will be presented. The advantage of having adequate dose coverage of the high risk CTV and simultaneous low doses to the OARs when using 3D image- based brachytherapy will be presented. The treatment techniques, equipment issues, as well as implantation, imaging and treatment planning procedures will be described. Quality assurance checks will be treated separately.

  1. Oxidative stress markers in prostate cancer patients after HDR brachytherapy combined with external beam radiation.

    PubMed

    Woźniak, Alina; Masiak, Rafał; Szpinda, Michał; Mila-Kierzenkowska, Celestyna; Woźniak, Bartosz; Makarewicz, Roman; Szpinda, Anna

    2012-01-01

    Assessment of oxidative stress markers was perfomed in prostate cancer (PCa) patients subjected to high-dose brachytherapy (HDR) with external beam radiotherapy (EBRT). Sixty men with PCa were subjected to combined two-fraction treatment with HDR (tot. 20 Gy) and EBRT (46 Gy). Blood samples were taken before treatment, immediately afterwards, after 1.5-3 months, and approx. 2 years. Control group consisted of 30 healthy men. Erythrocyte glutathione peroxidase activity in the patients was lower than in healthy subjects by 34% (P < 0.001), 50% (P < 0.001), 30% (P < 0.05), and 61% (P < 0.001), respectively, at all periods. No significant differences were found by comparing superoxide dismutase and catalase activity in PCa patients with that of the controls. After 2 years of the end of treatment, the activity of studied enzymes demonstrated a decreasing tendency versus before therapy. Blood plasma thiobarbituric acid reactive substances (TBARS) concentration was higher than in the controls at all periods, while erythrocyte TBARS decreased after 2 years to control levels. The results confirm that in the course of PCa, imbalance of oxidant-antioxidant processes occurs. The therapy did not alter the levels of oxidative stress markers, which may prove its applicability. Two years is too short a period to restore the oxidant-antioxidant balance.

  2. A study on the dose distributions in various materials from an Ir-192 HDR brachytherapy source.

    PubMed

    Hsu, Shih-Ming; Wu, Chin-Hui; Lee, Jeng-Hung; Hsieh, Ya-Ju; Yu, Chun-Yen; Liao, Yi-Jen; Kuo, Li-Cheng; Liang, Ji-An; Huang, David Y C

    2012-01-01

    Dose distributions of (192)Ir HDR brachytherapy in phantoms simulating water, bone, lung tissue, water-lung and bone-lung interfaces using the Monte Carlo codes EGS4, FLUKA and MCNP4C are reported. Experiments were designed to gather point dose measurements to verify the Monte Carlo results using Gafchromic film, radiophotoluminescent glass dosimeter, solid water, bone, and lung phantom. The results for radial dose functions and anisotropy functions in solid water phantom were consistent with previously reported data (Williamson and Li). The radial dose functions in bone were affected more by depth than those in water. Dose differences between homogeneous solid water phantoms and solid water-lung interfaces ranged from 0.6% to 14.4%. The range between homogeneous bone phantoms and bone-lung interfaces was 4.1% to 15.7%. These results support the understanding in dose distribution differences in water, bone, lung, and their interfaces. Our conclusion is that clinical parameters did not provide dose calculation accuracy for different materials, thus suggesting that dose calculation of HDR treatment planning systems should take into account material density to improve overall treatment quality.

  3. Variability of Marker-Based Rectal Dose Evaluation in HDR Cervical Brachytherapy

    SciTech Connect

    Wang Zhou; Jaggernauth, Wainwright; Malhotra, Harish K.; Podgorsak, Matthew B.

    2010-01-01

    In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

  4. A study of optimization techniques in HDR brachytherapy for the prostate

    NASA Astrophysics Data System (ADS)

    Pokharel, Ghana Shyam

    Several studies carried out thus far are in favor of dose escalation to the prostate gland to have better local control of the disease. But optimal way of delivery of higher doses of radiation therapy to the prostate without hurting neighboring critical structures is still debatable. In this study, we proposed that real time high dose rate (HDR) brachytherapy with highly efficient and effective optimization could be an alternative means of precise delivery of such higher doses. This approach of delivery eliminates the critical issues such as treatment setup uncertainties and target localization as in external beam radiation therapy. Likewise, dosimetry in HDR brachytherapy is not influenced by organ edema and potential source migration as in permanent interstitial implants. Moreover, the recent report of radiobiological parameters further strengthen the argument of using hypofractionated HDR brachytherapy for the management of prostate cancer. Firstly, we studied the essential features and requirements of real time HDR brachytherapy treatment planning system. Automating catheter reconstruction with fast editing tools, fast yet accurate dose engine, robust and fast optimization and evaluation engine are some of the essential requirements for such procedures. Moreover, in most of the cases we performed, treatment plan optimization took significant amount of time of overall procedure. So, making treatment plan optimization automatic or semi-automatic with sufficient speed and accuracy was the goal of the remaining part of the project. Secondly, we studied the role of optimization function and constraints in overall quality of optimized plan. We have studied the gradient based deterministic algorithm with dose volume histogram (DVH) and more conventional variance based objective functions for optimization. In this optimization strategy, the relative weight of particular objective in aggregate objective function signifies its importance with respect to other objectives

  5. Balloon-based adjuvant radiotherapy in breast cancer: comparison between 99mTc and HDR 192Ir*

    PubMed Central

    de Campos, Tarcísio Passos Ribeiro; de Lima, Carla Flavia; Cuperschmid, Ethel Mizrahy

    2016-01-01

    Objective To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with 99mTc and balloon brachytherapy with high-dose-rate (HDR) 192Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and Methods Simulations of implants with 99mTc-filled and HDR 192Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results The 99mTc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h-1.mCi-1 and 0.190 cGyh-1.mCi-1 at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh-1.mCi-1, respectively, for the HDR 192Ir balloon. An exposure time of 24 hours was required for the 99mTc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR 192Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion Temporary 99mTc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR 192Ir balloon implantation, which is the current standard in clinical practice. PMID:27141131

  6. A Structural-Thermal Model of the Karkonosze Pluton (Sudetes Mountains, SW Poland) for Hot Dry Rock (HDR) Geothermal Use

    NASA Astrophysics Data System (ADS)

    Bujakowski, Wiesław; Barbacki, Antoni; Miecznik, Maciej; Pająk, Leszek; Skrzypczak, Robert

    2016-12-01

    The main objective of this study was to develop a spatial temperature distribution of the Karkonosze Pluton to indicate optimum locations for HDR systems at drillable depth. HDR geothermal technology makes it possible to extract heat from the Earth in areas where no hydro-geothermal resources are present. To produce electricity in a binary cycle, system temperatures of > 100°C are usually required. In this paper, the authors have analysed the potential opportunities for applying HDR technology in the area of the Karkonosze Pluton, which is regarded as an optimum location for the application of the HDR concept (due to the potential for stimulation offered by the mechanical properties of the granites, radiogenic heat production, modern tectonic activity, and the thickness of the pluton). The model used in the analysis, which takes into account a hypothetical assessment of the manner and paths of fluid migration within the pluton, provides an insight into the spatial distribution of subsurface temperatures. It thus allows the location of relatively shallow high-temperature zones, which are optimal for the efficient application of HDR technology, to be identified. With respect to this technology, the Szklarska Poręba area and the NE part of the pluton seem to be better targets than the Cieplice central area, where the model indicated much lower temperatures (e.g. at a depth of 5,000 m, estimated temperatures in the vicinity of Szklarska Poręba were about 185°C and in the vicinity of Cieplice they were about 140°C).

  7. Determination of transit dose profile for a {sup 192}Ir HDR source

    SciTech Connect

    Fonseca, G. P.; Antunes, P. C. G.; Yoriyaz, H.

    2013-05-15

    Purpose: Several studies have reported methodologies to calculate and correct the transit dose component of the moving radiation source for high dose rate (HDR) brachytherapy planning systems. However, most of these works employ the average source speed, which varies significantly with the measurement technique used, and does not represent a realistic speed profile, therefore, providing an inaccurate dose determination. In this work, the authors quantified the transit dose component of a HDR unit based on the measurement of the instantaneous source speed to produce more accurate dose values. Methods: The Nucletron microSelectron-HDR Ir-192 source was characterized considering the Task Group 43 (TG-43U1) specifications. The transit dose component was considered through the calculation of the dose distribution using a Monte Carlo particle transport code, MCNP5, for each source position and correcting it by the source speed. The instantaneous source speed measurements were performed in a previous work using two optical fibers connected to a photomultiplier and an oscilloscope. Calculated doses were validated by comparing relative dose profiles with those obtained experimentally using radiochromic films. Results: TG-43U1 source parameters were calculated to validate the Monte Carlo simulations. These agreed with the literature, with differences below 1% for the majority of the points. Calculated dose profiles without transit dose were also validated by comparison with ONCENTRA{sup Registered-Sign} Brachy v. 3.3 dose values, yielding differences within 1.5%. Dose profiles obtained with MCNP5 corrected using the instantaneous source speed profile showed differences near dwell positions of up to 800% in comparison to values corrected using the average source speed, but they are in good agreement with the experimental data, showing a maximum discrepancy of approximately 3% of the maximum dose. Near a dwell position the transit dose is about 22% of the dwell dose delivered

  8. Source position verification and dosimetry in HDR brachytherapy using an EPID

    SciTech Connect

    Smith, R. L.; Taylor, M. L.; McDermott, L. N.; Franich, R. D.; Haworth, A.; Millar, J. L.

    2013-11-15

    Purpose: Accurate treatment delivery in high dose rate (HDR) brachytherapy requires correct source dwell positions and dwell times to be administered relative to each other and to the surrounding anatomy. Treatment delivery inaccuracies predominantly occur for two reasons: (i) anatomical movement or (ii) as a result of human errors that are usually related to incorrect implementation of the planned treatment. Electronic portal imaging devices (EPIDs) were originally developed for patient position verification in external beam radiotherapy and their application has been extended to provide dosimetric information. The authors have characterized the response of an EPID for use with an {sup 192}Ir brachytherapy source to demonstrate its use as a verification device, providing both source position and dosimetric information.Methods: Characterization of the EPID response using an {sup 192}Ir brachytherapy source included investigations of reproducibility, linearity with dose rate, photon energy dependence, and charge build-up effects associated with exposure time and image acquisition time. Source position resolution in three dimensions was determined. To illustrate treatment verification, a simple treatment plan was delivered to a phantom and the measured EPID dose distribution compared with the planned dose.Results: The mean absolute source position error in the plane parallel to the EPID, for dwells measured at 50, 100, and 150 mm source to detector distances (SDD), was determined to be 0.26 mm. The resolution of the z coordinate (perpendicular distance from detector plane) is SDD dependent with 95% confidence intervals of ±0.1, ±0.5, and ±2.0 mm at SDDs of 50, 100, and 150 mm, respectively. The response of the EPID is highly linear to dose rate. The EPID exhibits an over-response to low energy incident photons and this nonlinearity is incorporated into the dose calibration procedure. A distance (spectral) dependent dose rate calibration procedure has been

  9. Calculated organ doses using Monte Carlo simulations in a reference male phantom undergoing HDR brachytherapy applied to localized prostate carcinoma

    SciTech Connect

    Candela-Juan, Cristian; Perez-Calatayud, Jose; Ballester, Facundo; Rivard, Mark J.

    2013-03-15

    Purpose: The aim of this study was to obtain equivalent doses in radiosensitive organs (aside from the bladder and rectum) when applying high-dose-rate (HDR) brachytherapy to a localized prostate carcinoma using {sup 60}Co or {sup 192}Ir sources. These data are compared with results in a water phantom and with expected values in an infinite water medium. A comparison with reported values from proton therapy and intensity-modulated radiation therapy (IMRT) is also provided. Methods: Monte Carlo simulations in Geant4 were performed using a voxelized phantom described in International Commission on Radiological Protection (ICRP) Publication 110, which reproduces masses and shapes from an adult reference man defined in ICRP Publication 89. Point sources of {sup 60}Co or {sup 192}Ir with photon energy spectra corresponding to those exiting their capsules were placed in the center of the prostate, and equivalent doses per clinical absorbed dose in this target organ were obtained in several radiosensitive organs. Values were corrected to account for clinical circumstances with the source located at various positions with differing dwell times throughout the prostate. This was repeated for a homogeneous water phantom. Results: For the nearest organs considered (bladder, rectum, testes, small intestine, and colon), equivalent doses given by {sup 60}Co source were smaller (8%-19%) than from {sup 192}Ir. However, as the distance increases, the more penetrating gamma rays produced by {sup 60}Co deliver higher organ equivalent doses. The overall result is that effective dose per clinical absorbed dose from a {sup 60}Co source (11.1 mSv/Gy) is lower than from a {sup 192}Ir source (13.2 mSv/Gy). On the other hand, equivalent doses were the same in the tissue and the homogeneous water phantom for those soft tissues closer to the prostate than about 30 cm. As the distance increased, the differences of photoelectric effect in water and soft tissue, and appearance of other materials

  10. A BrachyPhantom for verification of dose calculation of HDR brachytherapy planning system

    SciTech Connect

    Austerlitz, C.; Campos, C. A. T.

    2013-11-15

    Purpose: To develop a calibration phantom for {sup 192}Ir high dose rate (HDR) brachytherapy units that renders possible the direct measurement of absorbed dose to water and verification of treatment planning system.Methods: A phantom, herein designated BrachyPhantom, consists of a Solid Water™ 8-cm high cylinder with a diameter of 14 cm cavity in its axis that allows the positioning of an A1SL ionization chamber with its reference measuring point at the midheight of the cylinder's axis. Inside the BrachyPhantom, at a 3-cm radial distance from the chamber's reference measuring point, there is a circular channel connected to a cylindrical-guide cavity that allows the insertion of a 6-French flexible plastic catheter from the BrachyPhantom surface. The PENELOPE Monte Carlo code was used to calculate a factor, P{sub sw}{sup lw}, to correct the reading of the ionization chamber to a full scatter condition in liquid water. The verification of dose calculation of a HDR brachytherapy treatment planning system was performed by inserting a catheter with a dummy source in the phantom channel and scanning it with a CT. The CT scan was then transferred to the HDR computer program in which a multiple treatment plan was programmed to deliver a total dose of 150 cGy to the ionization chamber. The instrument reading was then converted to absorbed dose to water using the N{sub gas} formalism and the P{sub sw}{sup lw} factor. Likewise, the absorbed dose to water was calculated using the source strength, S{sub k}, values provided by 15 institutions visited in this work.Results: A value of 1.020 (0.09%, k= 2) was found for P{sub sw}{sup lw}. The expanded uncertainty in the absorbed dose assessed with the BrachyPhantom was found to be 2.12% (k= 1). To an associated S{sub k} of 27.8 cGy m{sup 2} h{sup −1}, the total irradiation time to deliver 150 cGy to the ionization chamber point of reference was 161.0 s. The deviation between the absorbed doses to water assessed with the Brachy

  11. The contribution from transit dose for (192)Ir HDR brachytherapy treatments.

    PubMed

    Fonseca, G P; Landry, G; Reniers, B; Hoffmann, A; Rubo, R A; Antunes, P C G; Yoriyaz, H; Verhaegen, F

    2014-04-07

    Brachytherapy treatment planning systems that use model-based dose calculation algorithms employ a more accurate approach that replaces the TG43-U1 water dose formalism and adopt the TG-186 recommendations regarding composition and geometry of patients and other relevant effects. However, no recommendations were provided on the transit dose due to the source traveling inside the patient. This study describes a methodology to calculate the transit dose using information from the treatment planning system (TPS) and considering the source's instantaneous and average speed for two prostate and two gynecological cases. The trajectory of the (192)Ir HDR source was defined by importing applicator contour points and dwell positions from the TPS. The transit dose distribution was calculated using the maximum speed, the average speed and uniform accelerations obtained from the literature to obtain an approximate continuous source distribution simulated with a Monte Carlo code. The transit component can be negligible or significant depending on the speed profile adopted, which is not clearly reported in the literature. The significance of the transit dose can also be due to the treatment modality; in our study interstitial treatments exhibited the largest effects. Considering the worst case scenario the transit dose can reach 3% of the prescribed dose in a gynecological case with four catheters and up to 11.1% when comparing the average prostate dose for a case with 16 catheters. The transit dose component increases by increasing the number of catheters used for HDR brachytherapy, reducing the total dwell time per catheter or increasing the number of dwell positions with low dwell times. This contribution may become significant (>5%) if it is not corrected appropriately. The transit dose cannot be completely compensated using simple dwell time corrections since it may have a non-uniform distribution. An accurate measurement of the source acceleration and maximum speed should

  12. Dosimetric comparison between the microSelectron HDR 192Ir v2 source and the BEBIG 60Co source for HDR brachytherapy using the EGSnrc Monte Carlo transport code

    PubMed Central

    Islam, M. Anwarul; Akramuzzaman, M. M.; Zakaria, G. A.

    2012-01-01

    Manufacturing of miniaturized high activity 192Ir sources have been made a market preference in modern brachytherapy. The smaller dimensions of the sources are flexible for smaller diameter of the applicators and it is also suitable for interstitial implants. Presently, miniaturized 60Co HDR sources have been made available with identical dimensions to those of 192Ir sources. 60Co sources have an advantage of longer half life while comparing with 192Ir source. High dose rate brachytherapy sources with longer half life are logically pragmatic solution for developing country in economic point of view. This study is aimed to compare the TG-43U1 dosimetric parameters for new BEBIG 60Co HDR and new microSelectron 192Ir HDR sources. Dosimetric parameters are calculated using EGSnrc-based Monte Carlo simulation code accordance with the AAPM TG-43 formalism for microSlectron HDR 192Ir v2 and new BEBIG 60Co HDR sources. Air-kerma strength per unit source activity, calculated in dry air are 9.698×10-8 ± 0.55% U Bq-1 and 3.039×10-7 ± 0.41% U Bq-1 for the above mentioned two sources, respectively. The calculated dose rate constants per unit air-kerma strength in water medium are 1.116±0.12% cGy h-1U-1 and 1.097±0.12% cGy h-1U-1, respectively, for the two sources. The values of radial dose function for distances up to 1 cm and more than 22 cm for BEBIG 60Co HDR source are higher than that of other source. The anisotropic values are sharply increased to the longitudinal sides of the BEBIG 60Co source and the rise is comparatively sharper than that of the other source. Tissue dependence of the absorbed dose has been investigated with vacuum phantom for breast, compact bone, blood, lung, thyroid, soft tissue, testis, and muscle. No significant variation is noted at 5 cm of radial distance in this regard while comparing the two sources except for lung tissues. The true dose rates are calculated with considering photon as well as electron transport using appropriate cut

  13. Cloning, molecular characterization and functional analysis of 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase (HDR) gene for diterpenoid tanshinone biosynthesis in Salvia miltiorrhiza Bge. f. alba.

    PubMed

    Hao, Gangping; Shi, Renjiu; Tao, Ru; Fang, Qian; Jiang, Xingyu; Ji, Haiwei; Feng, Lei; Huang, Luqi

    2013-09-01

    The enzyme 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase (HDR) is a terminal-acting enzyme in the plastid MEP pathway, which produce isoprenoid precursors. The full-length cDNA of HDR, designated SmHDR1 (Genbank Accession No. JX516088), was isolated for the first time from Salvia miltiorrhiza Bge. f. alba. SmHDR1 contains a 1389-bp open reading frame encoding 463 amino acids. The deduced SmHDR1 protein, which shows high identity to HDRs of other plant species, is predicted to possess a chloroplast transit peptide at the N-terminus and four conserved cysteine residues. Transcription pattern analysis revealed that SmHDR1 has high levels of transcription in leaves and low levels of transcription in roots and stems. The expression of SmHDR1 was induced by 0.1 mM methyl-jasmonate (MeJA) and salicylic acid (SA), but not by 0.1 mM abscisic acid (ABA), in the hairy roots of S. miltiorrhiza Bge. f. alba. Complementation of SmHDR1 in the Escherichia coli HDR mutant MG1655 ara < > ispH demonstrated the function of this enzyme. A functional color assay in E. coli showed that SmHDR1 accelerates the biosynthesis of β-carotene, indicating that SmHDR1 encodes a functional protein. Overexpression of SmHDR1 enhanced the production of tanshinones in cultured hairy roots of S. miltiorrhiza Bge. f. alba. These results indicate that SmHDR1 is a novel and important enzyme involved in the biosynthesis of diterpenoid tanshinones in S. miltiorrhiza Bge. f. alba.

  14. HDR and LDR Brachytherapy in the Treatment of Lip Cancer: the Experience of the Catalan Institute of Oncology

    PubMed Central

    Mena, Estefanía Palacios; Fabregas, Joan Pera; Miguelez, Cristina Gutiérrez; Guedea, Ferran

    2010-01-01

    Purpose Lip cancer can be treated by surgery, external radiotherapy, and/or brachytherapy (BT). In recent years, BT has become increasingly favored for this type of cancer. The aim of the present study was to analyze local control and survival of patients treated at our institution between July 1989 and June 2008. Material and methods We performed a retrospective study of 121 patients (109 males and 12 females) who underwent lip cancer brachytherapy from July 1989 to June 2008. Median age was 67 years and median follow-up was 31.8 months (range 20-188 months). Out of 121 patients, 100 (82.6%) were treated with low dose rate (LDR) BT while the remaining 21 patients (17.4%) received high dose rate (HDR) BT. Results The most common cell type was squamous cell carcinoma (115 cases; 95%) and most tumors were located on the lower lip (107 patients; 88.4%). Most cases were either stage T1 (62 patients; 51.2%), or T2 (44 cases; 36.4%). After 15 years of follow-up, overall survival was 89.5%, cause-specific survival 97.8%, and disease-free survival 86.6%. Local, regional, and distant control at 15 years were 90%, 92%, and 98.8%, respectively. Grade 3 mucosal toxicity was observed in 23% of patients treated with LDR compared to 33% of HDR patients, and grade 4 mucosal toxicity in 9% versus 0% in the HDR group. Conclusions Our findings confirm that brachytherapy is an effective treatment for lip cancer. The results from our series are in line with those published elsewhere. Based on our limited data, HDR appears to be equally as good as LDR, although this needs to be confirmed by further studies. PMID:28031737

  15. Evaluation of scatter contribution and distance error by iterative methods for strength determination of HDR 192Ir brachytherapy source.

    PubMed

    Kumar, Sudhir; Srinivasan, Panchapakesan; Sharma, Sunil D; Subbaiah, Kamatam V; Mayya, Yelia S

    2010-01-01

    High-dose rate (HDR) 192Ir brachytherapy sources are commonly used for management of malignancies by brachytherapy applications. Measurement of source strength at the hospital is an important dosimetry requirement. The use of 0.6-cm(3) cylindrical ionization chamber is one of the methods of measuring the source strength at the hospitals because this chamber is readily available for beam calibration and dosimetry. While using the cylindrical chamber for this purpose, it is also required to determine the positioning error of the ionization chamber, with respect to the source, commonly called a distance error (c). The contribution of scatter radiation (M(s)) from floor, walls, ceiling, and other materials available in the treatment room also need to be determined accurately so that appropriate correction can be applied while calculating the source strength from the meter reading. Iterative methods of Newton-Raphson and least-squares were used in this work to determine scatter contribution in the experimentally observed meter reading (pC/s) of a cylindrical ionization chamber. Monte Carlo simulation was also used to cross verify the results of the least-squares method. The experimentally observed, least-squares calculated and Monte Carlo estimated values of meter readings from HDR 192Ir brachytherapy source were in good agreement. Considering procedural simplicity, the method of least-squares is recommended for use at the hospitals to estimate values of f (constant of proportionality), c, and M(s) required to determine the strength of HDR 192Ir brachytherapy sources.

  16. A Feasibility Study of Fricke Dosimetry as an Absorbed Dose to Water Standard for 192Ir HDR Sources

    PubMed Central

    deAlmeida, Carlos Eduardo; Ochoa, Ricardo; de Lima, Marilene Coelho; David, Mariano Gazineu; Pires, Evandro Jesus; Peixoto, José Guilherme; Salata, Camila; Bernal, Mario Antônio

    2014-01-01

    High dose rate brachytherapy (HDR) using 192Ir sources is well accepted as an important treatment option and thus requires an accurate dosimetry standard. However, a dosimetry standard for the direct measurement of the absolute dose to water for this particular source type is currently not available. An improved standard for the absorbed dose to water based on Fricke dosimetry of HDR 192Ir brachytherapy sources is presented in this study. The main goal of this paper is to demonstrate the potential usefulness of the Fricke dosimetry technique for the standardization of the quantity absorbed dose to water for 192Ir sources. A molded, double-walled, spherical vessel for water containing the Fricke solution was constructed based on the Fricke system. The authors measured the absorbed dose to water and compared it with the doses calculated using the AAPM TG-43 report. The overall combined uncertainty associated with the measurements using Fricke dosimetry was 1.4% for k = 1, which is better than the uncertainties reported in previous studies. These results are promising; hence, the use of Fricke dosimetry to measure the absorbed dose to water as a standard for HDR 192Ir may be possible in the future. PMID:25521914

  17. HDR brachytherapy of prostate cancer – two years experience in Greater Poland Cancer Centre

    PubMed Central

    Skowronek, Janusz; Chicheł, Adam

    2009-01-01

    Purpose The aim of this work was to analyze the results and complications of three treatment schemes of patients with initially localized prostate cancer after two years of observation time. Material and methods Sixty-three patients were enrolled into the study and divided into groups according to radiation schemes (I group – EBRT 50 Gy/BRT 15 Gy, II – EBRT 46 Gy/BRT 2 × 10 Gy, III group – BRT 3 × 15 Gy). Group I, II and III consisted of 46 (73%), 14 (22.2%), 3 (4.8%) patients, respectively. The low-, intermediate- and high risk groups consisted of 23 (36.5%), 18 (28.5%) and 22 (35%) men, respectively. Results and tolerance of the treatment and acute complications in analyzed groups were discussed. Results Median observation time was 24 months. Complete remission was observed in 43 patients (68.3%) out of the whole group. Locoregional and distal metastases progression were noted in 4 patients (6.4%). Partial remission was observed in low-, intermediate- and high risk group: 7.9%, 9.5% and 9.5% of all men. Nadir of PSA results were estimated as mean value of 0.094 ng/ml, average 0.0-0.63. The mean value for the complete group decreased from 0.98 ng/ml (range 0.0-9.7) in the third months to 0.32 ng/ml after one year (0.0-3.34) of the end of treatment time. Urologic and gastrointenstinal side effects were noted in different rates according to 1 month observation (dysuria – 22.2%, urinary incontinence – 7.9%, frequency – 58.7%, weak stream – 68.3%, rectal bleeding – 15.9%). Conclusions 1. HDR brachytherapy of prostate cancer can be used as a boost after or before the external beam radiation therapy in different treatment schemes. 2. In selected groups under investigation trials, sole HDR-BRT is a suitable method of treatment. 3. To confirm superiority of analyzed modality treatment a prospective investigation with larger groups of patients would be required. PMID:27807455

  18. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    SciTech Connect

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc; Binnekamp, Dirk

    2015-03-15

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora{sup ®} Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators.

  19. Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-Year Disease-Free Survival and Toxicity Observations

    PubMed Central

    Fuller, Donald Blake; Naitoh, John; Mardirossian, George

    2014-01-01

    Purpose: Prostate stereotactic body radiotherapy (SBRT) may substantially recapitulate the dose distribution of high-dose-rate (HDR) brachytherapy, representing an externally delivered “Virtual HDR” treatment method. Herein, we present 5-year outcomes from a cohort of consecutively treated virtual HDR SBRT prostate cancer patients. Methods: Seventy-nine patients were treated from 2006 to 2009, 40 low-risk, and 39 intermediate-risk, under IRB-approved clinical trial, to 38 Gy in four fractions. The planning target volume (PTV) included prostate plus a 2-mm volume expansion in all directions, with selective use of a 5-mm prostate-to-PTV expansion and proximal seminal vesicle coverage in intermediate-risk patients, to better cover potential extraprostatic disease; rectal PTV margin reduced to zero in all cases. The prescription dose covered >95% of the PTV (V100 ≥95%), with a minimum 150% PTV dose escalation to create “HDR-like” PTV dose distribution. Results: Median pre-SBRT PSA level of 5.6 ng/mL decreased to 0.05 ng/mL 5 years out and 0.02 ng/mL 6 years out. At least one PSA bounce was seen in 55 patients (70%) but only 3 of them subsequently relapsed, biochemical-relapse-free survival was 100 and 92% for low-risk and intermediate-risk patients, respectively, by ASTRO definition (98 and 92% by Phoenix definition). Local relapse did not occur, distant metastasis-free survival was 100 and 95% by risk-group, and disease-specific survival was 100%. Acute and late grade 2 GU toxicity incidence was 10 and 9%, respectively; with 6% late grade 3 GU toxicity. Acute urinary retention did not occur. Acute and late grade 2 GI toxicity was 0 and 1%, respectively, with no grade 3 or higher toxicity. Of patient’s potent pre-SBRT, 65% remained so at 5 years. Conclusion: Virtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported

  20. TU-AB-201-05: Automatic Adaptive Per-Operative Re-Planning for HDR Prostate Brachytherapy - a Simulation Study On Errors in Needle Positioning

    SciTech Connect

    Borot de Battisti, M; Maenhout, M; Lagendijk, J J W; Van Vulpen, M; Moerland, M A; Senneville, B Denis de

    2015-06-15

    Purpose: To develop adaptive planning with feedback for MRI-guided focal HDR prostate brachytherapy with a single divergent needle robotic implant device. After each needle insertion, the dwell positions for that needle are calculated and the positioning of remaining needles and dosimetry are both updated based on MR imaging. Methods: Errors in needle positioning may occur due to inaccurate needle insertion (caused by e.g. the needle’s bending) and unpredictable changes in patient anatomy. Consequently, the dose plan quality might dramatically decrease compared to the preplan. In this study, a procedure was developed to re-optimize, after each needle insertion, the remaining needle angulations, source positions and dwell times in order to obtain an optimal coverage (D95% PTV>19 Gy) without exceeding the constraints of the organs at risk (OAR) (D10% urethra<21 Gy, D1cc bladder<12 Gy and D1cc rectum<12 Gy). Complete HDR procedures with 6 needle insertions were simulated for a patient MR-image set with PTV, prostate, urethra, bladder and rectum delineated. Random angulation errors, modeled by a Gaussian distribution (standard deviation of 3 mm at the needle’s tip), were generated for each needle insertion. We compared the final dose parameters for the situations (I) without re-optimization and (II) with the automatic feedback. Results: The computation time of replanning was below 100 seconds on a current desk computer. For the patient tested, a clinically acceptable dose plan was achieved while applying the automatic feedback (median(range) in Gy, D95% PTV: 19.9(19.3–20.3), D10% urethra: 13.4(11.9–18.0), D1cc rectum: 11.0(10.7–11.6), D1cc bladder: 4.9(3.6–6.8)). This was not the case without re-optimization (median(range) in Gy, D95% PTV: 19.4(14.9–21.3), D10% urethra: 12.6(11.0–15.7), D1cc rectum: 10.9(8.9–14.1), D1cc bladder: 4.8(4.4–5.2)). Conclusion: An automatic guidance strategy for HDR prostate brachytherapy was developed to compensate

  1. The Application of Elliptic Cylindrical Phantom in Brachytherapy Dosimetric Study of HDR 192Ir Source

    NASA Astrophysics Data System (ADS)

    Ahn, Woo Sang; Park, Sung Ho; Jung, Sang Hoon; Choi, Wonsik; Do Ahn, Seung; Shin, Seong Soo

    2014-06-01

    The purpose of this study is to determine the radial dose function of HDR 192Ir source based on Monte Carlo simulation using elliptic cylindrical phantom, similar to realistic shape of pelvis, in brachytherapy dosimetric study. The elliptic phantom size and shape was determined by analysis of dimensions of pelvis on CT images of 20 patients treated with brachytherapy for cervical cancer. The radial dose function obtained using the elliptic cylindrical water phantom was compared with radial dose functions for different spherical phantom sizes, including the Williamsion's data loaded into conventional planning system. The differences in the radial dose function for the different spherical water phantoms increase with radial distance, r, and the largest differences in the radial dose function appear for the smallest phantom size. The radial dose function of the elliptic cylindrical phantom significantly decreased with radial distance in the vertical direction due to different scatter condition in comparison with the Williamson's data. Considering doses to ICRU rectum and bladder points, doses to reference points can be underestimated up to 1-2% at the distance from 3 to 6 cm. The radial dose function in this study could be used as realistic data for calculating the brachytherapy dosimetry for cervical cancer.

  2. Optimization of HDR brachytherapy dose distributions using linear programming with penalty costs

    SciTech Connect

    Alterovitz, Ron; Lessard, Etienne; Pouliot, Jean; Hsu, I-Chow Joe; O'Brien, James F.; Goldberg, Ken

    2006-11-15

    Prostate cancer is increasingly treated with high-dose-rate (HDR) brachytherapy, a type of radiotherapy in which a radioactive source is guided through catheters temporarily implanted in the prostate. Clinicians must set dwell times for the source inside the catheters so the resulting dose distribution minimizes deviation from dose prescriptions that conform to patient-specific anatomy. The primary contribution of this paper is to take the well-established dwell times optimization problem defined by Inverse Planning by Simulated Annealing (IPSA) developed at UCSF and exactly formulate it as a linear programming (LP) problem. Because LP problems can be solved exactly and deterministically, this formulation provides strong performance guarantees: one can rapidly find the dwell times solution that globally minimizes IPSA's objective function for any patient case and clinical criteria parameters. For a sample of 20 prostates with volume ranging from 23 to 103 cc, the new LP method optimized dwell times in less than 15 s per case on a standard PC. The dwell times solutions currently being obtained clinically using simulated annealing (SA), a probabilistic method, were quantitatively compared to the mathematically optimal solutions obtained using the LP method. The LP method resulted in significantly improved objective function values compared to SA (P=1.54x10{sup -7}), but none of the dosimetric indices indicated a statistically significant difference (P<0.01). The results indicate that solutions generated by the current version of IPSA are clinically equivalent to the mathematically optimal solutions.

  3. A novel optical calorimetry dosimetry approach applied to an HDR Brachytherapy source

    NASA Astrophysics Data System (ADS)

    Cavan, A.; Meyer, J.

    2013-06-01

    The technique of Digital Holographic Interferometry (DHI) is applied to the measurement of radiation absorbed dose distribution in water. An optical interferometer has been developed that captures the small variations in the refractive index of water due to the radiation induced temperature increase ΔT. The absorbed dose D is then determined with high temporal and spatial resolution using the calorimetric relation D=cΔT (where c is the specific heat capacity of water). The method is capable of time resolving 3D spatial calorimetry. As a proof-of-principle of the approach, a prototype DHI dosimeter was applied to the measurement of absorbed dose from a High Dose Rate (HDR) Brachytherapy source. Initial results are in agreement with modelled doses from the Brachyvision treatment planning system, demonstrating the viability of the system for high dose rate applications. Future work will focus on applying corrections for heat diffusion and geometric effects. The method has potential to contribute to the dosimetry of diverse high dose rate applications which require high spatial resolution such as microbeam radiotherapy (MRT) or small field proton beam dosimetry but may potentially also be useful for interface dosimetry.

  4. HDR {sup 192}Ir source speed measurements using a high speed video camera

    SciTech Connect

    Fonseca, Gabriel P.; Rubo, Rodrigo A.; Sales, Camila P. de; Verhaegen, Frank

    2015-01-15

    Purpose: The dose delivered with a HDR {sup 192}Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a {sup 192}Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases.

  5. SU-E-T-560: Commissioning An HDR Freiburg Flap Applicator for Skin Lesion Treatment

    SciTech Connect

    Dou, K; Li, B; Lerma, F; Aroumougame, V; Sarfaraz, M; Laser, B; Jacobs, M

    2014-06-01

    Purpose: Flexible Freiburg flap used with high dose rate afterloaders is easy to cut into any size for any body site and to dwell with a precise source position, conforms to curved skin surface and then to the planned target. However, unlike intracavity or interstitial situations, incomplete scatter environment due to flap applicators exposed to air might lead to dose difference between the delivered and planned. This research is focused on the dose deviation of incomplete scatter versus full scatter. Methods: A 12x12 cm of Freiburg flap applicator was used for the validation. A Nucletron Oncentra Brachy Ver. 4.3 treatment planning system (TPS) was used for treatment planning. However, no heterogeneity correction incorporated into the brachytherap TPS needs to be considered. A Philips Brilliance CT Big Bore was employed for CT scan. Radiation was delivered using a Nucletron HDR remote afterloader system. A 10cm bolus was used to cover the flap for obtaining a full scatter. An OSL, ion chamber, and Gafchromic EBT2 film were used for commissioning the flap applicator. Results: The applicator calibration at 5mm depth was performed using an OSL dosimeter. Applicator source dwelling positions with 1D and 2D array exposed to and recorded by Gafchromic EBT2 film showed an agreement within 1mm. 1D array of Freiburg flap exhibited 4.2% cooler in dose with incomplete scatter than full scatter. 2D array showed 7.1% lower in dose for incomplete scatter than full scatter. The deviation was found more than 10% beyond 8cm in depth. Conclusion: Significant dose deviation caused by the incomplete scatter environment was found to be 7.1% at 1cm depth. This deviation was increased with increasing depth. The inaccuracy resulted from the incomplete scatter can be fixed by either placing a bolus on the top of the flap or making the plan at least 7% hotter.

  6. SU-E-T-783: Using Matrixx to Determine Transit Dose Contribution Over Clinically Useful Limits of HDR Source Activity

    SciTech Connect

    Bhagwat, M; O’Farrell, D; Wagar, M; Buzurovic, I; Friesen, S; Damato, A; Devlin, P; Cormack, R

    2015-06-15

    Purpose: Most HDR brachytherapy treatment planning systems (TPS) use TG-43 formalism to calculate dose without including transit dose corrections. Historically, measurement of this contribution has required sophisticated apparatus unavailable in most hospitals. We use Matrixx to investigate several scenarios where transit dose contribution may effect a clinical treatment. Methods: Treatment plans were generated using Oncentra Brachy TPS (Version 4.3.0.410, Nucletron ) on a CT scan of a 24-catheter Freiburg applicator (Nucletron ) laid flat on the MatriXX (IBA) detector. This detector is an array of 1020 parallel plate ion chambers. All 24 catheters were digitized and dwells within a central square region of 5×5cm of the applicator were activated. Each of the active catheters had 6 dwells in increments of 1.0cm. The plans were normalized to 10mm. This places the 100% isodose line at the correct effective point of measurement, which lies half-way between the parallel plates of the ion chambers. It is also within the clinically relevant treatment depth for superficial applications. A total of 6 plans were delivered for 3 prescription doses, 1Gy, 2Gy and 4Gy using source activities of 2.9Ci and 11.2Ci. The MatriXX array was operated to capture dosimetric snaps every 500ms and yielded an integral dose at the end of treatment. Results: A comparison of integral dose from 2 different source activities shows that the transit dose contribution is larger when the source activity is higher. It is also observed that the relative transit dose contribution decreases as prescription dose increases. This is quantified by the Gamma analysis. Conclusion: We have demonstrated that the Matrixx detector can be used to evaluate the contribution for a HDR source during transit from the HDR afterloader to a dwell location, and between adjacent dwell locations.

  7. SU-E-T-517: Analytic Formalism to Compute in Real Time Dose Distributions Delivered by HDR Units

    SciTech Connect

    Pokhrel, S; Loyalka, S; Palaniswaamy, G; Rangaraj, D; Izaguirre, E

    2014-06-01

    Purpose: Develop an analytical algorithm to compute the dose delivered by Ir-192 dwell positions with high accuracy using the 3-dimensional (3D) dose distribution of an HDR source. Using our analytical function, the dose delivered by an HDR unit as treatment progresses can be determined using the actual delivered temporal and positional data of each individual dwell. Consequently, true delivered dose can be computed when each catheter becomes active. We hypothesize that the knowledge of such analytical formulation will allow developing HDR systems with a real time treatment evaluation tool to avoid mistreatments. Methods: In our analytic formulation, the dose is computed by using the full anisotropic function data of the TG 43 formalism with 3D ellipsoidal function. The discrepancy between the planned dose and the delivered dose is computed using an analytic perturbation method over the initial dose distribution. This methodology speeds up the computation because only changes in dose discrepancies originated by spatial and temporal deviations are computed. A dose difference map at the point of interest is obtained from these functions and this difference can be shown during treatment in real time to examine the treatment accuracy. Results: We determine the analytical solution and a perturbation function for the 3 translational 3 rotational, and 1D temporal errors in source distributions. The analytic formulation is a sequence of simple equations that can be processed in any modern computer in few seconds. Because computations are based in an analytical solution, small deviations of the dose when sub-millimeter positional changes occur can be detected. Conclusions: We formulated an analytical method to compute 4D dose distributions and dose differences based on an analytical solution and perturbations to the original dose. This method is highly accurate and can be.

  8. An Eight-Year Experience of HDR Brachytherapy Boost for Localized Prostate Cancer: Biopsy and PSA Outcome

    SciTech Connect

    Bachand, Francois; Martin, Andre-Guy; Beaulieu, Luc; Harel, Francois M.Sc.; Vigneault, Eric

    2009-03-01

    Purpose: To evaluate the biochemical recurrence-free survival (bRFS), the 2-year biopsy outcome and the prostate-specific antigen (PSA) bounce in patients with localized prostate cancer treated with an inversely planned high-dose-rate (HDR) brachytherapy boost. Materials and methods: Data were collected from 153 patients treated between 1999 and 2006 with external beam pelvic radiation followed by an HDR Ir-192 prostate boost. These patients were given a boost of 18 to 20 Gy using inverse-planning with simulated annealing (IPSA).We reviewed and analyzed all prostate-specific antigen levels and control biopsies. Results: The median follow-up was 44 months (18-95 months). When categorized by risk of progression, 74.5% of patients presented an intermediate risk and 14.4% a high one. Prostate biopsies at 2 years posttreatment were negative in 86 of 94 patients (91.5%), whereas two biopsies were inconclusive. Biochemical control at 60 months was at 96% according to the American Society for Therapeutic Radiology and Oncology and the Phoenix consensus definitions. A PSA bounce (PSA values of 2 ng/mL or more above nadir) was observed in 15 patients of 123 (9.8%). The median time to bounce was 15.2 months (interquartile range, 11.0-17.7) and the median bounce duration 18.7 months (interquartile range, 12.1-29). The estimate of overall survival at 60 months was 97.1% (95% CI, 91.6-103%). Conclusions: Considering that inverse planned HDR brachytherapy prostate boosts led to an excellent biochemical response, with a 2-year negative biopsy rate, we recommend a conservative approach in face of a PSA bounce even though it was observed in 10% of patients.

  9. MO-FG-210-02: Implementation of Image-Guided Prostate HDR Brachytherapy Using MR-Ultrasound Fusion

    SciTech Connect

    Libby, B.

    2015-06-15

    Ultrasound (US) is one of the most widely used imaging modalities in medical practice. Since US imaging offers real-time imaging capability, it has becomes an excellent option to provide image guidance for brachytherapy (IGBT). (1) The physics and the fundamental principles of US imaging are presented, and the typical steps required to commission an US system for IGBT is provided for illustration. (2) Application of US for prostate HDR brachytherapy, including partial prostate treatments using MR-ultrasound co-registration to enable a focused treatment on the disease within the prostate is also presented. Prostate HDR with US image guidance planning can benefit from real time visualization of the needles, and fusion of the ultrasound images with T2 weighted MR allows the focusing of the treatment to the specific areas of disease within the prostate, so that the entire gland need not be treated. Finally, (3) ultrasound guidance for an eye plaque program is presented. US can be a key component of placement and QA for episcleral plaque brachytherapy for ocular cancer, and the UCLA eye plaque program with US for image guidance is presented to demonstrate the utility of US verification of plaque placement in improving the methods and QA in episcleral plaque brachytherapy. Learning Objectives: To understand the physics of an US system and the necessary aspects of commissioning US for image guided brachytherapy (IGBT). To understand real time planning of prostate HDR using ultrasound, and its application in partial prostate treatments using MR-ultrasound fusion to focus treatment on disease within the prostate. To understand the methods and QA in applying US for localizing the target and the implant during a episcleral plaque brachytherapy procedures.

  10. SU-E-T-380: Evaluation of BEBIG HDR 60Co System for AccuBoost Therapy

    SciTech Connect

    Zehtabian, M; Sina, S; Rivard, M; Meigooni, A Soleimani

    2015-06-15

    Purpose: In this project, the possibility of utilizing the BEBIG 60Co HDR system for AccuBoostTM treatment has been evaluated. Methods: Dose distributions in various breast sizes have been calculated for both Co-60 and Ir-192 sources using the MCNP5 code. These calculations were performed in breast tissues with thicknesses of 4cm, 6cm, and 8cm. The initial calculations were performed with the same applicator dimensions as the existing applicators used with the HDR Ir-192 system. The activity of the Co-60 source was selected such that the dose at the breast center was the same as the values from 192Ir. Then, the applicator thicknesses were increased to twice of those used with HDR Ir-192 system, for reducing skin and chest doses by Co-60 system. Dose to breast skin and chest wall were compared for both applicators types, with and without inclusion of a focusing cone at the applicator center. Results: The results showed that loading HDR Co-60 source inside the thin applicators impose higher doses to breast skin and chest wall compared to the 192Ir source. The area of the chest wall covered by 10Gy when treated by Co-60 with the thin and thick applicators, or treated by Ir-192 with thin applicator are 79cm2, 39cm2, and 3.8cm2, respectively. These values are reduced to 34cm2, 0cm2, and 0cm2 by using the focusing cone. It is worth noting that the breast skin areas covered by the 60Gy isodose line are 9.9cm2 and 7.8cm2 for Co-60 with the thin and thick applicators, respectively, while it is 20cm2 for Ir-192 when no focusing cone is present. These values are 0cm2, 0cm2, and 11cm2 in the presence of the focusing cone. Conclusion: The results indicate that using Co-60 with the thicker applicators is beneficial because of the higher half-life of Co-60, and the reduced maximum skin dose when compared with Ir-192.

  11. Results of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) in treatment of obstructive endobronchial non-small cell lung cancer

    NASA Astrophysics Data System (ADS)

    Weinberg, Benjamin D.; Allison, Ron R.; Sibata, Claudio; Parent, Teresa; Downie, Gordon

    2009-06-01

    We reviewed the outcome of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) for patients with symptomatic obstruction from endobronchial non-small cell lung cancer. Methods: Nine patients who received combined PDT and HDR for endobronchial cancers were identified and their charts reviewed. The patients were eight males and one female aged 52-73 at diagnosis, initially presenting with various stages of disease: stage IA (N=1), stage IIA (N=1), stage III (N=6), and stage IV (N=1). Intervention was with HDR (500 cGy to 5 mm once weekly for 3 weeks) and PDT (2 mg/kg Photofrin, followed by 200 J/cm2 illumination 48 hours post infusion). Treatment group 1 (TG-1, N=7) received HDR first; Treatment group 2 (TG-2, N=2) received PDT first. Patients were followed by regular bronchoscopies. Results: Treatments were well tolerated, all patients completed therapy, and none were lost to follow-up. In TG-1, local tumor control was achieved in six of seven patients for: 3 months (until death), 15 months, 2+ years (until death), 2+ years (ongoing), and 5+ years (ongoing, N=2). In TG-2, local control was achieved in only one patient, for 84 days. Morbidities included: stenosis and/or other reversible benign local tissue reactions (N=8); photosensitivity reaction (N=2), and self-limited pleural effusion (N=2). Conclusions: Combined HDR/PDT treatment for endobronchial tumors is well tolerated and can achieve prolonged local control with acceptable morbidity when PDT follows HDR and when the spacing between treatments is one month or less. This treatment regimen should be studied in a larger patient population.

  12. Validation of a novel robot-assisted 3DUS system for real-time planning and guidance of breast interstitial HDR brachytherapy

    SciTech Connect

    Poulin, Eric; Beaulieu, Luc; Gardi, Lori; Barker, Kevin; Montreuil, Jacques; Fenster, Aaron

    2015-12-15

    Purpose: In current clinical practice, there is no integrated 3D ultrasound (3DUS) guidance system clinically available for breast brachytherapy. In this study, the authors present a novel robot-assisted 3DUS system for real-time planning and guidance of breast interstitial high dose rate (HDR) brachytherapy treatment. Methods: For this work, a new computer controlled robotic 3DUS system was built to perform a hybrid motion scan, which is a combination of a 6 cm linear translation with a 30° rotation at both ends. The new 3DUS scanner was designed to fit on a modified Kuske assembly, keeping the current template grid configuration but modifying the frame to allow the mounting of the 3DUS system at several positions. A finer grid was also tested. A user interface was developed to perform image reconstruction, semiautomatic segmentation of the surgical bed as well as catheter reconstruction and tracking. A 3D string phantom was used to validate the geometric accuracy of the reconstruction. The volumetric accuracy of the system was validated with phantoms using magnetic resonance imaging (MRI) and computed tomography (CT) images. In order to accurately determine whether 3DUS can effectively replace CT for treatment planning, the authors have compared the 3DUS catheter reconstruction to the one obtained from CT images. In addition, in agarose-based phantoms, an end-to-end procedure was performed by executing six independent complete procedures with both 14 and 16 catheters, and for both standard and finer Kuske grids. Finally, in phantoms, five end-to-end procedures were performed with the final CT planning for the validation of 3DUS preplanning. Results: The 3DUS acquisition time is approximately 10 s. A paired Student t-test showed that there was no statistical significant difference between known and measured values of string separations in each direction. Both MRI and CT volume measurements were not statistically different from 3DUS volume (Student t-test: p > 0

  13. Dosimetric impact of applicator displacement during high dose rate (HDR) Cobalt-60 brachytherapy for cervical cancer: A planning study

    NASA Astrophysics Data System (ADS)

    Yong, J. S.; Ung, N. M.; Jamalludin, Z.; Malik, R. A.; Wong, J. H. D.; Liew, Y. M.; Ng, K. H.

    2016-02-01

    We investigated the dosimetric impact of applicator displacement on dose specification during high dose rate (HDR) Cobalt-60 (Co-60) brachytherapy for cervical cancer through a planning study. Eighteen randomly selected HDR full insertion plans were restrospectively studied. The tandem and ovoids were virtually shifted translationally and rotationally in the x-, y- and z-axis directions on the treatment planning system. Doses to reference points and volumes of interest in the plans with shifted applicators were compared with the original plans. The impact of dose displacement on 2D (point-based) and 3D (volume-based) treatment planning techniques was also assessed. A ±2 mm translational y-axis applicator shift and ±4° rotational x-axis applicator shift resulted in dosimetric changes of more than 5% to organs at risk (OAR) reference points. Changes to the maximum doses to 2 cc of the organ (D2cc) in 3D planning were statistically significant and higher than the reference points in 2D planning for both the rectum and bladder (p<0.05). Rectal D2cc was observed to be the most sensitive to applicator displacement among all dose metrics. Applicator displacement that is greater than ±2 mm translational y-axis and ±4° rotational x-axis resulted in significant dose changes to the OAR. Thus, steps must be taken to minimize the possibility of applicator displacement during brachytherapy.

  14. A linear programming model for optimizing HDR brachytherapy dose distributions with respect to mean dose in the DVH-tail

    SciTech Connect

    Holm, Åsa; Larsson, Torbjörn; Tedgren, Åsa Carlsson

    2013-08-15

    Purpose: Recent research has shown that the optimization model hitherto used in high-dose-rate (HDR) brachytherapy corresponds weakly to the dosimetric indices used to evaluate the quality of a dose distribution. Although alternative models that explicitly include such dosimetric indices have been presented, the inclusion of the dosimetric indices explicitly yields intractable models. The purpose of this paper is to develop a model for optimizing dosimetric indices that is easier to solve than those proposed earlier.Methods: In this paper, the authors present an alternative approach for optimizing dose distributions for HDR brachytherapy where dosimetric indices are taken into account through surrogates based on the conditional value-at-risk concept. This yields a linear optimization model that is easy to solve, and has the advantage that the constraints are easy to interpret and modify to obtain satisfactory dose distributions.Results: The authors show by experimental comparisons, carried out retrospectively for a set of prostate cancer patients, that their proposed model corresponds well with constraining dosimetric indices. All modifications of the parameters in the authors' model yield the expected result. The dose distributions generated are also comparable to those generated by the standard model with respect to the dosimetric indices that are used for evaluating quality.Conclusions: The authors' new model is a viable surrogate to optimizing dosimetric indices and quickly and easily yields high quality dose distributions.

  15. SU-E-T-362: Automatic Catheter Reconstruction of Flap Applicators in HDR Surface Brachytherapy

    SciTech Connect

    Buzurovic, I; Devlin, P; Hansen, J; O'Farrell, D; Bhagwat, M; Friesen, S; Damato, A; Lewis, J; Cormack, R

    2014-06-01

    Purpose: Catheter reconstruction is crucial for the accurate delivery of radiation dose in HDR brachytherapy. The process becomes complicated and time-consuming for large superficial clinical targets with a complex topology. A novel method for the automatic catheter reconstruction of flap applicators is proposed in this study. Methods: We have developed a program package capable of image manipulation, using C++class libraries of The-Visualization-Toolkit(VTK) software system. The workflow for automatic catheter reconstruction is: a)an anchor point is placed in 3D or in the axial view of the first slice at the tip of the first, last and middle points for the curved surface; b)similar points are placed on the last slice of the image set; c)the surface detection algorithm automatically registers the points to the images and applies the surface reconstruction filter; d)then a structured grid surface is generated through the center of the treatment catheters placed at a distance of 5mm from the patient's skin. As a result, a mesh-style plane is generated with the reconstructed catheters placed 10mm apart. To demonstrate automatic catheter reconstruction, we used CT images of patients diagnosed with cutaneous T-cell-lymphoma and imaged with Freiburg-Flap-Applicators (Nucletron™-Elekta, Netherlands). The coordinates for each catheter were generated and compared to the control points selected during the manual reconstruction for 16catheters and 368control point Results: The variation of the catheter tip positions between the automatically and manually reconstructed catheters was 0.17mm(SD=0.23mm). The position difference between the manually selected catheter control points and the corresponding points obtained automatically was 0.17mm in the x-direction (SD=0.23mm), 0.13mm in the y-direction (SD=0.22mm), and 0.14mm in the z-direction (SD=0.24mm). Conclusion: This study shows the feasibility of the automatic catheter reconstruction of flap applicators with a high level

  16. SU-C-16A-03: Direction Modulated Brachytherapy for HDR Treatment of Cervical Cancer

    SciTech Connect

    Han, D; Webster, M; Scanderbeg, D; Yashar, C; Choi, D; Song, B; Song, W; Devic, S; Ravi, A

    2014-06-15

    Purpose: To investigate a new Directional Modulated Brachytherapy (DMBT) intra-uterine tandem using various 192-Ir after-loaders. Methods: Dose distributions from the 192-Ir sources were modulated using a 6.3mm diameter tungsten shield (18.0g/cm3). The source moved along 6 longitudinal grooves, each 1.3mm in diameter, evenly spaced along periphery of the shield, The tungsten rod was enclosqed by 0.5mm thick Delrin (1.41g/cc). Monte Carlo N particle (MCNPX) was used to calculate dose distributions. 51million particles were calculated on 504 cores of a supercomputer. Fifteen different patients originally treated with a traditional tandem-and-ovoid applicator, with 5 fractions each, (15 patients X 5 fxs = 75 plans) were re-planned with the DMBT applicator combined with traditional ovoids, on an in-house developed HDR brachytherapy planning platform, which used intensity modulated planning capabilities using a constrained gradient optimization algorithm. For all plans the prescription dose was 6 Gy and they were normalized to match the clinical treated V100. Results: Generally, the DMBT plan quality was a remarkable improvement from conventional T and O plans because of the anisotropic dose distribution of DMBT. The largest difference was to the bladder which had a 0.59±0.87 Gy (8.5±28.7%) reduction in dose. This was because of the the horseshoe shape (U-shape) of the bladder. The dose reduction to rectum and sigmoid were 0.48±0.55 Gy (21.1±27.2%) and 0.10±0.38 Gy (40.6±214.9%), respectively. The D90 to the HRCTV was 6.55±0.96 Gy (conventional T and O) and 6.59±1.06 Gy (DMBT). Conclusion: For image guided adaptive brachytherapy, greater flexibility of radiation intensity is essential and DMBT can be the solution.

  17. Physics-aspects of dose accuracy in high dose rate (HDR) brachytherapy: source dosimetry, treatment planning, equipment performance and in vivo verification techniques.

    PubMed

    Palmer, Antony; Bradley, David; Nisbet, Andrew

    2012-06-01

    This study provides a review of recent publications on the physics-aspects of dosimetric accuracy in high dose rate (HDR) brachytherapy. The discussion of accuracy is primarily concerned with uncertainties, but methods to improve dose conformation to the prescribed intended dose distribution are also noted. The main aim of the paper is to review current practical techniques and methods employed for HDR brachytherapy dosimetry. This includes work on the determination of dose rate fields around brachytherapy sources, the capability of treatment planning systems, the performance of treatment units and methods to verify dose delivery. This work highlights the determinants of accuracy in HDR dosimetry and treatment delivery and presents a selection of papers, focusing on articles from the last five years, to reflect active areas of research and development. Apart from Monte Carlo modelling of source dosimetry, there is no clear consensus on the optimum techniques to be used to assure dosimetric accuracy through all the processes involved in HDR brachytherapy treatment. With the exception of the ESTRO mailed dosimetry service, there is little dosimetric audit activity reported in the literature, when compared with external beam radiotherapy verification.

  18. Comparison of methods for the measurement of radiation dose distributions in high dose rate (HDR) brachytherapy: Ge-doped optical fiber, EBT3 Gafchromic film, and PRESAGE{sup Registered-Sign} radiochromic plastic

    SciTech Connect

    Palmer, A. L.; Di Pietro, P.; Alobaidli, S.; Issa, F.; Doran, S.; Bradley, D.; Nisbet, A.

    2013-06-15

    Purpose: Dose distribution measurement in clinical high dose rate (HDR) brachytherapy is challenging, because of the high dose gradients, large dose variations, and small scale, but it is essential to verify accurate treatment planning and treatment equipment performance. The authors compare and evaluate three dosimetry systems for potential use in brachytherapy dose distribution measurement: Ge-doped optical fibers, EBT3 Gafchromic film with multichannel analysis, and the radiochromic material PRESAGE{sup Registered-Sign} with optical-CT readout. Methods: Ge-doped SiO{sub 2} fibers with 6 {mu}m active core and 5.0 mm length were sensitivity-batched and their thermoluminescent properties used via conventional heating and annealing cycles. EBT3 Gafchromic film of 30 {mu}m active thickness was calibrated in three color channels using a nominal 6 MV linear accelerator. A 48-bit transmission scanner and advanced multichannel analysis method were utilized to derive dose measurements. Samples of the solid radiochromic polymer PRESAGE{sup Registered-Sign }, 60 mm diameter and 100 mm height, were analyzed with a parallel beam optical CT scanner. Each dosimetry system was used to measure the dose as a function of radial distance from a Co-60 HDR source, with results compared to Monte Carlo TG-43 model data. Each system was then used to measure the dose distribution along one or more lines through typical clinical dose distributions for cervix brachytherapy, with results compared to treatment planning system (TPS) calculations. Purpose-designed test objects constructed of Solid Water and held within a full-scatter water tank were utilized. Results: All three dosimetry systems reproduced the general shape of the isolated source radial dose function and the TPS dose distribution. However, the dynamic range of EBT3 exceeded those of doped optical fibers and PRESAGE{sup Registered-Sign }, and the latter two suffered from unacceptable noise and artifact. For the experimental

  19. SU-E-T-459: Impact of Source Position and Traveling Time On HDR Skin Surface Applicator Dosimetry

    SciTech Connect

    Jeong, J; Barker, C; Zaider, M; Cohen, G

    2015-06-15

    Purpose: Observed dosimetric discrepancy between measured and treatment planning system (TPS) predicted values, during applicator commissioning, were traced to source position uncertainty in the applicator. We quantify the dosimetric impact of this geometric uncertainty, and of the source traveling time inside the applicator, and propose corrections for clinical use. Methods: We measured the dose profiles from the Varian Leipzig-style (horizontal) HDR skin applicator, using EBT3 film, photon diode, and optically stimulated luminescence dosimeter (OSLD) and three different GammaMed HDR afterloders. The dose profiles and depth dose of each aperture were measured at several depths (up to about 10 mm, depending on the dosimeter). The measured dose profiles were compared with Acuros calculated profiles in BrachyVision TPS. For the impact of the source position, EBT3 film measurements were performed with applicator, facing-down and facing-up orientations. The dose with and without source traveling was measured with diode detector using HDR timer and electrometer timer, respectively. Results: Depth doses measured using the three dosimeters were in good agreement, but were consistently higher than the Acuros dose calculations. Measurements with the applicator facing-up were significantly lower than those in the facing-down position with maximum difference of about 18% at the surface, due to source sag inside the applicator. Based on the inverse-square law, the effective source sag was evaluated to be about 0.5 mm from the planned position. The additional dose from the source traveling was about 2.8% for 30 seconds with 10 Ci source, decreasing with increased dwelling time and decreased source activity. Conclusion: Due to the short source-to-surface distance of the applicator, the small source sag inside the applicator has significant dosimetric impact, which should be considered before the clinical use of the applicator. Investigation of the effect for other applicators

  20. Absolute depth-dose-rate measurements for an 192Ir HDR brachytherapy source in water using MOSFET detectors.

    PubMed

    Zilio, Valéry Olivier; Joneja, Om Parkash; Popowski, Youri; Rosenfeld, Anatoly; Chawla, Rakesh

    2006-06-01

    Reported MOSFET measurements concern mostly external radiotherapy and in vivo dosimetry. In this paper, we apply the technique for absolute dosimetry in the context of HDR brachytherapy using an 192Ir source. Measured radial dose rate distributions in water for different planes perpendicular to the source axis are presented and special attention is paid to the calibration of the R and K type detectors, and to the determination of appropriate correction factors for the sensitivity variation with the increase of the threshold voltage and the energy dependence. The experimental results are compared with Monte Carlo simulated dose rate distributions. The experimental results show a good agreement with the Monte Carlo simulations: the discrepancy between experimental and Monte Carlo results being within 5% for 82% of the points and within 10% for 95% of the points. Moreover, all points except two are found to lie within the experimental uncertainties, confirming thereby the quality of the results obtained.

  1. Endocavity Ultrasound Hyperthermia for Locally Advanced Cervical Cancer: Patient-specific Modeling, Experimental Verification, and Combination with HDR Brachytherapy

    SciTech Connect

    Wootton, Jeffery; Diederich, Chris; Chen Xin; Prakash, Punit; Juang, Titania

    2010-03-09

    The feasibility of targeted hyperthermia delivery by an intrauterine ultrasound applicator to patient-specific treatment volumes in conjunction with HDR brachytherapy was investigated using theory and experiment. 30 HDR brachytherapy treatment plans were inspected to define hyperthermia treatment volumes (HTVs) based on tumor and radiation target volumes. Several typical cases were imported into a patient-specific treatment planning platform that optimized acoustic output power from an endocavity multisectored tubular array to conform temperature and thermal dose to HTVs. Perfusion was within a clinical range of 0.5-3 kg m{sup -3} s{sup -1}. Applicators were constructed with 1-3 elements at 6.5-8 MHz with 90 deg. -360 deg. sectoring and 25-35 mm heating length housed in a water-cooled PET catheter. Acoustic output was compared to heating in ex vivo tissue assessed with implanted thermometry. Radiation attenuation through the device was measured in an ionization chamber. The HTV extends 2-4 cm in diameter and 2-4 cm in length. The bladder and rectum can be within 10-12 mm. HTV targets can be covered with temperature clouds >41 deg. and thermal dose t{sup 43}>5 min with 45 deg. C maximum temperature and rectal temperature <41.5 deg. C. Sectored applicators preferentially direct energy laterally into the parametrium to limit heating of rectum and bladder. Interstitial brachytherapy catheters within the HTV could be used for thermal feedback during HT treatment. Temperature distributions in phantom show preferential heating within sectors and align well with acoustic output. Heating control along the device length and in angle is evident. A 4-6% reduction in radiation transmission through the transducers was observed, which could likely be compensated for in planning. Patient-specific modeling and experimental heating demonstrated 3-D conformal heating capabilities of endocavity ultrasound applicators.

  2. TU-AB-201-04: Optimizing the Number of Catheter Implants and Their Tracks for Prostate HDR Brachytherapy

    SciTech Connect

    Riofrio, D; Luan, S; Zhou, J; Ma, L

    2015-06-15

    Purpose: In prostate HDR brachytherapy, interstitial implants are placed manually on the fly. The aim for this research is to develop a computer algorithm to find optimal and reliable implant trajectories using minimal number of implants. Methods: Our new algorithm mainly uses these key ideas: (1) positive charged static particles are uniformly placed on the surface of prostate and critical structures such as urethra, bladder, and rectum. (2) Positive charged kinetic particles are placed at a cross-section of the prostate with an initial velocity parallel to the principal implant direction. (3) The kinetic particles move through the prostate, interacting with each other, spreading out, while staying away from the prostate surface and critical structures. The initial velocity ensures that the trajectories observe the curvature constraints of typical implant procedures. (4) The finial trajectories of kinetic particles are smoothed using a third-degree polynomial regression, which become the implant trajectories. (5) The dwelling times and final dose distribution are calculated using least-distance programming. Results: (1) We experimented with previously treated cases. Our plan achieves all prescription goals while reducing the number of implants by 41%! Our plan also has less uniform target dose, which implies a higher dose is delivered to the prostate. (2) We expect future implant procedures will be performed under the guidance of such pre-calculated trajectories. To assess the applicability, we randomly perturb the tracks to mimic the manual implant errors. Our studies showed the impact of these perturbations are negligible, which is compensated by the least distance programming. Conclusions: We developed a new inverse planning system for prostate HDR therapy that can find optimal implant trajectories while minimizing the number of implants. For future work, we plan to integrate our new inverse planning system with an existing needle tracking system.

  3. SU-E-T-507: Interfractional Variation of Fiducial Marker Position During HDR Brachytherapy with Cervical Interstitial Needle Template

    SciTech Connect

    Shen, S; Kim, R; Benhabib, S; Araujo, J; Burnett, L; Duan, J; Popple, R; Wu, X; Cardan, R; Brezovich, I

    2014-06-01

    Purpose: HDR brachytherapy using interstitial needle template for cervical cancer is commonly delivered in 4-5 fractions. Routine verification of needle positions before each fraction is often based on radiographic imaging of implanted fiducial markers. The current study evaluated interfractional displacement of implanted fiducial markers using CT images. Methods: 9 sequential patients with cervical interstitial needle implants were evaluated. The superior and inferior borders of the target volumes were defined by fiducial markers in planning CT. The implant position was verified with kV orthogonal images before each fraction. A second CT was acquired prior 3rd fraction (one or 2 days post planning CT). Distances from inferior and superior fiducial markers to pubic symphysis plane (perpendicular to vaginal obtulator)were measured. Distance from needle tip of a reference needle (next to the inferior marker) to the pubic symphysis plane was also determined. The difference in fiducial marker distance or needle tip distance between planning CT and CT prior 3rd fraction were measured to assess markers migration and needle displacement. Results: The mean inferior marker displacement was 4.5 mm and ranged 0.9 to 11.3 mm. The mean superior marker displacement was 2.7 mm and ranged 0 to 10.4 mm. There was a good association between inferior and superior marker displacement (r=0.95). Mean averaged inferior and superior marker displacement was 3.3 mm and ranged from 0.1 to 10.9 mm, with a standard deviation of 3.2 mm. The mean needle displacement was 5.6 mm and ranged 0.2 to 15.6 mm. Needle displacements were reduced (p<0.05) after adjusting according to needle-to-fiducials distance. Conclusion: There were small fiducial marker displacements between HDR fractions. Our study suggests a target margin of 9.7 mm to cover interfractional marker displacements (in 95% cases) for pretreatment verification based on radiographic imaging.

  4. In vivo dosimetry in the urethra using alanine/ESR during (192)Ir HDR brachytherapy of prostate cancer--a phantom study.

    PubMed

    Anton, Mathias; Wagner, Daniela; Selbach, Hans-Joachim; Hackel, Thomas; Hermann, Robert Michael; Hess, Clemens Friedrich; Vorwerk, Hilke

    2009-05-07

    A phantom study for dosimetry in the urethra using alanine/ESR during (192)Ir HDR brachytherapy of prostate cancer is presented. The measurement method of the secondary standard of the Physikalisch-Technische Bundesanstalt had to be slightly modified in order to be able to measure inside a Foley catheter. The absorbed dose to water response of the alanine dosimetry system to (192)Ir was determined with a reproducibility of 1.8% relative to (60)Co. The resulting uncertainty for measurements inside the urethra was estimated to be 3.6%, excluding the uncertainty of the dose rate constant Lambda. The applied dose calculated by a treatment planning system is compared to the measured dose for a small series of (192)Ir HDR irradiations in a gel phantom. The differences between the measured and applied dose are well within the limits of uncertainty. Therefore, the method is considered to be suitable for measurements in vivo.

  5. In vivo dosimetry in the urethra using alanine/ESR during 192Ir HDR brachytherapy of prostate cancer—a phantom study

    NASA Astrophysics Data System (ADS)

    Anton, Mathias; Wagner, Daniela; Selbach, Hans-Joachim; Hackel, Thomas; Hermann, Robert Michael; Hess, Clemens Friedrich; Vorwerk, Hilke

    2009-05-01

    A phantom study for dosimetry in the urethra using alanine/ESR during 192Ir HDR brachytherapy of prostate cancer is presented. The measurement method of the secondary standard of the Physikalisch-Technische Bundesanstalt had to be slightly modified in order to be able to measure inside a Foley catheter. The absorbed dose to water response of the alanine dosimetry system to 192Ir was determined with a reproducibility of 1.8% relative to 60Co. The resulting uncertainty for measurements inside the urethra was estimated to be 3.6%, excluding the uncertainty of the dose rate constant Λ. The applied dose calculated by a treatment planning system is compared to the measured dose for a small series of 192Ir HDR irradiations in a gel phantom. The differences between the measured and applied dose are well within the limits of uncertainty. Therefore, the method is considered to be suitable for measurements in vivo.

  6. Targeting Homology-Directed Recombinational Repair (HDR) of Chromosomal Breaks to Sensitize Prostate Cancer Cells to Poly (ADP-Ribose) Polymerase (PARP) Inhibition

    DTIC Science & Technology

    2013-08-01

    Treatment % G FP p os iti ve Figure 7. Leptomycin B abolishes the HR deficit induced by HR. additionally, it may enhance HR. 4 Task 2. To transiently...Stanley, J , and Yang, ES*. PARP-1: Friend or foe of DNA damage and repair in tumorigenesis? Cancers 2013. 5(3), 943-958. *Corresponding author 7...University School of Medicine, Nashville, TN ABR Holman Research Scholar Nucletron Prostate HDR Training Course 2009 Chief Resident 2009-2010 2005

  7. SU-E-T-634: Analysis of Volume Based GYN HDR Brachytherapy Plans for Dose Calculation to Organs At Risk(OAR)

    SciTech Connect

    Nair, M; Li, C; White, M; Davis, J

    2014-06-15

    Purpose: We have analyzed the dose volume histogram of 140 CT based HDR brachytherapy plans and evaluated the dose received to OAR ; rectum, bladder and sigmoid colon based on recommendations from ICRU and Image guided brachytherapy working group for cervical cancer . Methods: Our treatment protocol consist of XRT to whole pelvis with 45 Gy at 1.8Gy/fraction followed by 30 Gy at 6 Gy per fraction by HDR brachytherapy in 2 weeks . The CT compatible tandem and ovoid applicators were used and stabilized with radio opaque packing material. The patient was stabilized using special re-locatable implant table and stirrups for reproducibility of the geometry during treatment. The CT scan images were taken at 3mm slice thickness and exported to the treatment planning computer. The OAR structures, bladder, rectum and sigmoid colon were outlined on the images along with the applicators. The prescription dose was targeted to A left and A right as defined in Manchester system and optimized on geometry . The dosimetry was compared on all plans using the parameter Ci.sec.cGy-1 . Using the Dose Volume Histogram (DVH) obtained from the plans the doses to rectum, sigmoid colon and bladder for ICRU defined points and 2cc volume were analyzed and reported. The following criteria were used for limiting the tolerance dose by volume (D2cc) were calculated. The rectum and sigmoid colon doses were limited to <75Gy. The bladder dose was limited to < 90Gy from both XRT and HDR brachytherapy. Results: The average total (XRT+HDRBT) BED values to prescription volume was 120 Gy. Dose 2cc to rectum was 70Gy +/− 17Gy, dose to 2cc bladder was 82+/−32 Gy. The average Ci.sec.cGy-1 calculated for the HDR plans was 6.99 +/− 0.5 Conclusion: The image based treatment planning enabled to evaluati volume based dose to critical structures for clinical interpretation.

  8. A Pilot Study of Catheter-Based Ultrasound Hyperthermia with HDR Brachytherapy for Treatment of Locally Advanced Cancer of the Prostate and Cervix

    NASA Astrophysics Data System (ADS)

    Diederich, Chris J.; Wootton, Jeff; Prakash, Punit; Salgaonkar, Vasant; Juang, Titania; Scott, Serena; Chen, Xin; Cunha, Adam; Pouliot, Jean; Hsu, I. C.

    2011-09-01

    Interstitial and endocavity ultrasound devices have been developed specifically for applying hyperthermia within temporary HDR brachytherapy implants during radiation therapy. Catheter-based ultrasound applicators are capable of 3D spatial control of heating in both angle and length of the devices, with enhanced radial penetration of heating compared to other hyperthermia technologies. A pilot study of the combination of catheter based ultrasound with HDR brachytherapy for locally advanced prostate and cervical cancer has been initiated, and preliminary results of the performance and heating distributions are reported herein. The treatment delivery platform consists of a 32 channel RF amplifier and a 48 channel thermocouple monitoring system. Controlling software can monitor and regulate frequency and power to each transducer section as required during the procedure. Interstitial applicators consist of multiple transducer sections of 2-4 cm length×180 deg and 3-4 cm×360 deg. heating patterns to be inserted in specific placed 13g implant catheters. The endocavity device, designed to be inserted within a 6 mm OD plastic tandem catheter within the cervix, consists of 2-3 transducers x dual 180 or 360 deg sectors. 3D temperature based treatment planning and optimization is dovetailed to the HDR optimization based planning to best configure and position the applicators within the catheters, and to determine optimal base power levels to each transducer section. To date we have treated eight cervix implants and four prostate implants. 100% of treatments achieved a goal of >60 min duration, with therapeutic temperatures achieved in all cases. Thermal dosimetry within the hyperthermia target volume (HTV) and clinical target volume (CTV) are reported. Catheter-based ultrasound hyperthermia with HDR appears feasible with therapeutic temperature coverage of the target volume within the prostate or cervix while sparing surrounding more sensitive regions.

  9. SU-E-T-580: On the Significance of Model Based Dosimetry for Breast and Head and Neck 192Ir HDR Brachytherapy

    SciTech Connect

    Peppa, V; Pappas, E; Pantelis, E; Papagiannis, P; Major, T; Polgar, C

    2015-06-15

    Purpose: To assess the dosimetric and radiobiological differences between TG43-based and model-based dosimetry in the treatment planning of {sup 192}Ir HDR brachytherapy for breast and head and neck cancer. Methods: Two cohorts of 57 Accelerated Partial Breast Irradiation (APBI) and 22 head and neck (H&N) patients with oral cavity carcinoma were studied. Dosimetry for the treatment plans was performed using the TG43 algorithm of the Oncentra Brachy v4.4 treatment planning system (TPS). Corresponding Monte Carlo (MC) simulations were performed using MCNP6 with input files automatically prepared by the BrachyGuide software tool from DICOM RT plan data. TG43 and MC data were compared in terms of % dose differences, Dose Volume Histograms (DVHs) and related indices of clinical interest for the Planning Target Volume (PTV) and the Organs-At-Risk (OARs). A radiobiological analysis was also performed using the Equivalent Uniform Dose (EUD), mean survival fraction (S) and Tumor Control Probability (TCP) for the PTV, and the Normal Tissue Control Probability (N TCP) and the generalized EUD (gEUD) for the OARs. Significance testing of the observed differences performed using the Wilcoxon paired sample test. Results: Differences between TG43 and MC DVH indices, associated with the increased corresponding local % dose differences observed, were statistically significant. This is mainly attributed to their consistency however, since TG43 agrees closely with MC for the majority of DVH and radiobiological parameters in both patient cohorts. Differences varied considerably among patients only for the ipsilateral lung and ribs in the APBI cohort, with a strong correlation to target location. Conclusion: While the consistency and magnitude of differences in the majority of clinically relevant DVH indices imply that no change is needed in the treatment planning practice, individualized dosimetry improves accuracy and addresses instances of inter-patient variability observed. Research

  10. Endocervical ultrasound applicator for integrated hyperthermia and HDR brachytherapy in the treatment of locally advanced cervical carcinoma

    PubMed Central

    Wootton, Jeffery H.; Hsu, I-Chow Joe; Diederich, Chris J.

    2011-01-01

    Purpose: The clinical success of hyperthermia adjunct to radiotherapy depends on adequate temperature elevation in the tumor with minimal temperature rise in organs at risk. Existing technologies for thermal treatment of the cervix have limited spatial control or rapid energy falloff. The objective of this work is to develop an endocervical applicator using a linear array of multisectored tubular ultrasound transducers to provide 3-D conformal, locally targeted hyperthermia concomitant to radiotherapy in the uterine cervix. The catheter-based device is integrated within a HDR brachytherapy applicator to facilitate sequential and potentially simultaneous heat and radiation delivery. Methods: Treatment planning images from 35 patients who underwent HDR brachytherapy for locally advanced cervical cancer were inspected to assess the dimensions of radiation clinical target volumes (CTVs) and gross tumor volumes (GTVs) surrounding the cervix and the proximity of organs at risk. Biothermal simulation was used to identify applicator and catheter material parameters to adequately heat the cervix with minimal thermal dose accumulation in nontargeted structures. A family of ultrasound applicators was fabricated with two to three tubular transducers operating at 6.6–7.4 MHz that are unsectored (360°), bisectored (2×180°), or trisectored (3×120°) for control of energy deposition in angle and along the device length in order to satisfy anatomical constraints. The device is housed in a 6 mm diameter PET catheter with cooling water flow for endocervical implantation. Devices were characterized by measuring acoustic efficiencies, rotational acoustic intensity distributions, and rotational temperature distributions in phantom. Results: The CTV in HDR brachytherapy plans extends 20.5±5.0 mm from the endocervical tandem with the rectum and bladder typically <8 mm from the target boundary. The GTV extends 19.4±7.3 mm from the tandem. Simulations indicate that for 60 min

  11. Endocervical ultrasound applicator for integrated hyperthermia and HDR brachytherapy in the treatment of locally advanced cervical carcinoma

    SciTech Connect

    Wootton, Jeffery H.; Hsu, I-Chow Joe; Diederich, Chris J.

    2011-02-15

    Purpose: The clinical success of hyperthermia adjunct to radiotherapy depends on adequate temperature elevation in the tumor with minimal temperature rise in organs at risk. Existing technologies for thermal treatment of the cervix have limited spatial control or rapid energy falloff. The objective of this work is to develop an endocervical applicator using a linear array of multisectored tubular ultrasound transducers to provide 3-D conformal, locally targeted hyperthermia concomitant to radiotherapy in the uterine cervix. The catheter-based device is integrated within a HDR brachytherapy applicator to facilitate sequential and potentially simultaneous heat and radiation delivery. Methods: Treatment planning images from 35 patients who underwent HDR brachytherapy for locally advanced cervical cancer were inspected to assess the dimensions of radiation clinical target volumes (CTVs) and gross tumor volumes (GTVs) surrounding the cervix and the proximity of organs at risk. Biothermal simulation was used to identify applicator and catheter material parameters to adequately heat the cervix with minimal thermal dose accumulation in nontargeted structures. A family of ultrasound applicators was fabricated with two to three tubular transducers operating at 6.6-7.4 MHz that are unsectored (360 deg.), bisectored (2x180 deg.), or trisectored (3x120 deg.) for control of energy deposition in angle and along the device length in order to satisfy anatomical constraints. The device is housed in a 6 mm diameter PET catheter with cooling water flow for endocervical implantation. Devices were characterized by measuring acoustic efficiencies, rotational acoustic intensity distributions, and rotational temperature distributions in phantom. Results: The CTV in HDR brachytherapy plans extends 20.5{+-}5.0 mm from the endocervical tandem with the rectum and bladder typically <8 mm from the target boundary. The GTV extends 19.4{+-}7.3 mm from the tandem. Simulations indicate that for 60

  12. Evaluation of wall correction factor of INER's air-kerma primary standard chamber and dose variation by source displacement for HDR ¹⁹²Ir brachytherapy.

    PubMed

    Lee, J H; Wang, J N; Huang, T T; Su, S H; Chang, B J; Su, C H; Hsu, S M

    2013-01-01

    The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR) ¹⁹²Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan). The Monte Carlo method established in this paper was also employed to respectively simulate wall correction factors of the ¹⁹²Ir air-kerma standard chambers used at the National Institute of Standards and Technology (NIST, USA) and the National Physical Laboratory (NPL, UK) for comparisons and verification. The chamber wall correction calculation results will be incorporated into INER's HDR ¹⁹²Ir primary standard in the future. For the brachytherapy treatment in the esophagus or in the bronchi, the position of the isotope may have displacement in the cavity. Thus the delivered dose would differ from the prescribed dose in the treatment plan. We also tried assessing dose distribution due to the position displacement of HDR ¹⁹²Ir brachytherapy source in a phantom with a central cavity by the Monte Carlo method. The calculated results could offer a clinical reference for the brachytherapy within the human organs with cavity.

  13. Technical Note: Removing the stem effect when performing Ir-192 HDR brachytherapy in vivo dosimetry using plastic scintillation detectors: A relevant and necessary step

    SciTech Connect

    Therriault-Proulx, Francois; Beddar, Sam; Briere, Tina M.; Archambault, Louis; Beaulieu, Luc

    2011-04-15

    Purpose: The purpose of this study was to investigate whether or not a stem effect removal technique is necessary when performing Ir-192 HDR brachytherapy in vivo dosimetry using a scintillation detector. Methods: A red-green-blue photodiode connected to a multichannel electrometer was used to detect the light emitted from a plastic scintillation detector (PSD) during irradiation with an Ir-192 HDR brachytherapy source. Accuracy in dose measurement was compared with and without the use of stem effect removal techniques. Monochromatic and polychromatic filtration techniques were studied. An in-house template was built for accurate positioning of catheters in which the source and the PSD were inserted. Dose distribution was measured up to 5 cm from source to detector in the radial and longitudinal directions. Results: The authors found the stem effect to be particularly important when the source was close to the optical fiber guide and far from the scintillation component of the detector. It can account for up to (72{+-}3)% of the signal under clinically relevant conditions. The polychromatic filtration outperformed the monochromatic filtration as well as the absence of filtration in regard to dose measurement accuracy. Conclusions: It is necessary to implement a stem effect removal technique when building a PSD for in vivo dosimetry during Ir-192 HDR brachytherapy. The PSD that the authors have developed for this study would be suitable for such an application.

  14. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    SciTech Connect

    Kertzscher, Gustavo Andersen, Claus E.; Tanderup, Kari

    2014-05-15

    Purpose: This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction of the dosimeter position. Instead, the treatment is judged based on dose rate comparisons between measurements and calculations of the most viable dosimeter position provided by the AEDA in a data driven approach. As a result, the AEDA compensates for false error cases related to systematic effects of the dosimeter position reconstruction. Given its nearly exclusive dependence on stable dosimeter positioning, the AEDA allows for a substantially simplified and time efficient real-time in vivo BT dosimetry implementation. Methods: In the event of a measured potential treatment error, the AEDA proposes the most viable dosimeter position out of alternatives to the original reconstruction by means of a data driven matching procedure between dose rate distributions. If measured dose rates do not differ significantly from the most viable alternative, the initial error indication may be attributed to a mispositioned or misreconstructed dosimeter (false error). However, if the error declaration persists, no viable dosimeter position can be found to explain the error, hence the discrepancy is more likely to originate from a misplaced or misreconstructed source applicator or from erroneously connected source guide tubes (true error). Results: The AEDA applied on twoin vivo dosimetry implementations for pulsed dose rate BT demonstrated that the AEDA correctly described effects responsible for initial error indications. The AEDA was able to correctly identify the major part of all permutations of simulated guide tube swap errors and simulated shifts of individual needles from the original reconstruction. Unidentified errors corresponded to scenarios where the dosimeter position was

  15. Implant strategies for endocervical and interstitial ultrasound hyperthermia adjunct to HDR brachytherapy for the treatment of cervical cancer

    NASA Astrophysics Data System (ADS)

    Wootton, Jeffery H.; Prakash, Punit; Hsu, I.-Chow Joe; Diederich, Chris J.

    2011-07-01

    Catheter-based ultrasound devices provide a method to deliver 3D conformable heating integrated with HDR brachytherapy delivery. Theoretical characterization of heating patterns was performed to identify implant strategies for these devices which can best be used to apply hyperthermia to cervical cancer. A constrained optimization-based hyperthermia treatment planning platform was used for the analysis. The proportion of tissue >=41 °C in a hyperthermia treatment volume was maximized with constraints Tmax <= 47 °C, Trectum <= 41.5 °C, and Tbladder <= 42.5 °C. Hyperthermia treatment was modeled for generalized implant configurations and complex configurations from a database of patients (n = 14) treated with HDR brachytherapy. Various combinations of endocervical (360° or 2 × 180° output; 6 mm OD) and interstitial (180°, 270°, or 360° output; 2.4 mm OD) applicators within catheter locations from brachytherapy implants were modeled, with perfusion constant (1 or 3 kg m-3 s-1) or varying with location or temperature. Device positioning, sectoring, active length and aiming were empirically optimized to maximize thermal coverage. Conformable heating of appreciable volumes (>200 cm3) is possible using multiple sectored interstitial and endocervical ultrasound devices. The endocervical device can heat >41 °C to 4.6 cm diameter compared to 3.6 cm for the interstitial. Sectored applicators afford tight control of heating that is robust to perfusion changes in most regularly spaced configurations. T90 in example patient cases was 40.5-42.7 °C (1.9-39.6 EM43 °C) at 1 kg m-3 s-1 with 10/14 patients >=41 °C. Guidelines are presented for positioning of implant catheters during the initial surgery, selection of ultrasound applicator configurations, and tailored power schemes for achieving T90 >= 41 °C in clinically practical implant configurations. Catheter-based ultrasound devices, when adhering to the guidelines, show potential to generate conformal therapeutic

  16. Dose Reduction Study in Vaginal Balloon Packing Filled With Contrast for HDR Brachytherapy Treatment;HDR; Uterine cervix cancer; Vaginal balloon packing; Contrast; Monte Carlo

    SciTech Connect

    Saini, Amarjit S.; Zhang, Geoffrey G.; Finkelstein, Steven E.; Biagioli, Matthew C.

    2011-07-15

    Purpose: Vaginal balloon packing is a means to displace organs at risk during high dose rate brachytherapy of the uterine cervix. We tested the hypothesis that contrast-filled vaginal balloon packing reduces radiation dose to organs at risk, such as the bladder and rectum, in comparison to water- or air-filled balloons. Methods and Materials: In a phantom study, semispherical vaginal packing balloons were filled with air, saline solution, and contrast agents. A high dose rate iridium-192 source was placed on the anterior surface of the balloon, and the diode detector was placed on the posterior surface. Dose ratios were taken with each material in the balloon. Monte Carlo (MC) simulations, by use of the MC computer program DOSXYZnrc, were performed to study dose reduction vs. balloon size and contrast material, including commercially available iodine- and gadolinium-based contrast agents. Results: Measured dose ratios on the phantom with the balloon radius of 3.4 cm were 0.922 {+-} 0.002 for contrast/saline solution and 0.808 {+-} 0.001 for contrast/air. The corresponding ratios by MC simulations were 0.895 {+-} 0.010 and 0.781 {+-} 0.010. The iodine concentration in the contrast was 23.3% by weight. The dose reduction of contrast-filled balloon ranges from 6% to 15% compared with water-filled balloon and 11% to 26% compared with air-filled balloon, with a balloon size range between 1.4 and 3.8 cm, and iodine concentration in contrast of 24.9%. The dose reduction was proportional to the contrast agent concentration. The gadolinium-based contrast agents showed less dose reduction because of much lower concentrations in their solutions. Conclusions: The dose to the posterior wall of the bladder and the anterior wall of the rectum can be reduced if the vaginal balloon is filled with contrast agent in comparison to vaginal balloons filled with saline solution or air.

  17. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

    PubMed Central

    Casey, Kevin E.; Alvarez, Paola; Kry, Stephen F.; Howell, Rebecca M.; Lawyer, Ann; Followill, David

    2013-01-01

    Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom. Methods: The authors designed and built an 8 × 8 × 10 cm3 prototype phantom that had two slots capable of holding Al2O3:C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all 192Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian 192Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits. Results: The linearity correction factor was kL = (−9.43 × 10−5 × dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using 60Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian 192Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a formal RPC

  18. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

    SciTech Connect

    Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David; Alvarez, Paola; Lawyer, Ann

    2013-11-15

    Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm{sup 3} prototype phantom that had two slots capable of holding Al{sub 2}O{sub 3}:C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all {sup 192}Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian {sup 192}Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k{sub L}= (−9.43 × 10{sup −5}× dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using {sup 60}Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian {sup 192}Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance

  19. TU-F-BRF-02: MR-US Prostate Registration Using Patient-Specific Tissue Elasticity Property Prior for MR-Targeted, TRUS-Guided HDR Brachytherapy

    SciTech Connect

    Yang, X; Rossi, P; Ogunleye, T; Jani, A; Curran, W; Liu, T

    2014-06-15

    Purpose: High-dose-rate (HDR) brachytherapy has become a popular treatment modality for prostate cancer. Conventional transrectal ultrasound (TRUS)-guided prostate HDR brachytherapy could benefit significantly from MR-targeted, TRUS-guided procedure where the tumor locations, acquired from the multiparametric MRI, are incorporated into the treatment planning. In order to enable this integration, we have developed a MR-TRUS registration with a patient-specific biomechanical elasticity prior. Methods: The proposed method used a biomechanical elasticity prior to guide the prostate volumetric B-spline deformation in the MRI and TRUS registration. The patient-specific biomechanical elasticity prior was generated using ultrasound elastography, where two 3D TRUS prostate images were acquired under different probe-induced pressures during the HDR procedure, which takes 2-4 minutes. These two 3D TRUS images were used to calculate the local displacement (elasticity map) of two prostate volumes. The B-spline transformation was calculated by minimizing the Euclidean distance between the normalized attribute vectors of the prostate surface landmarks on the MR and TRUS. This technique was evaluated through two studies: a prostate-phantom study and a pilot study with 5 patients undergoing prostate HDR treatment. The accuracy of our approach was assessed through the locations of several landmarks in the post-registration and TRUS images; our registration results were compared with the surface-based method. Results: For the phantom study, the mean landmark displacement of the proposed method was 1.29±0.11 mm. For the 5 patients, the mean landmark displacement of the surface-based method was 3.25±0.51 mm; our method, 1.71±0.25 mm. Therefore, our proposed method of prostate registration outperformed the surfaced-based registration significantly. Conclusion: We have developed a novel MR-TRUS prostate registration approach based on patient-specific biomechanical elasticity prior

  20. Acute genitourinary toxicity after high dose rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Second analysis to determine the correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity

    SciTech Connect

    Akimoto, Tetsuo . E-mail: takimoto@showa.gunma-u.ac.jp; Katoh, Hiroyuki; Noda, Shin-ei; Ito, Kazuto; Yamamoto, Takumi; Kashiwagi, Bunzo; Nakano, Takashi

    2005-10-01

    Purpose: We have been treating localized prostate cancer with high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiation therapy (EBRT) at our institution. We recently reported the existence of a correlation between the severity of acute genitourinary (GU) toxicity and the urethral radiation dose in HDR brachytherapy by using different fractionation schema. The purpose of this study was to evaluate the role of the urethral dose in the development of acute GU toxicity more closely than in previous studies. For this purpose, we conducted an analysis of patients who had undergone HDR brachytherapy with a fixed fractionation schema combined with hypofractionated EBRT. Methods and Materials: Among the patients with localized prostate cancer who were treated by 192-iridium HDR brachytherapy combined with hypofractionated EBRT at Gunma University Hospital between August 2000 and November 2004, we analyzed 67 patients who were treated by HDR brachytherapy with the fractionation schema of 9 Gy x two times combined with hypofractionated EBRT. Hypofractionated EBRT was administered at a fraction dose of 3 Gy three times weekly, and a total dose of 51 Gy was delivered to the prostate gland and seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography-guided HDR brachytherapy. The planning target volume was defined as the prostate gland with a 5-mm margin all around, and the planning was conducted based on computed tomography images. The tumor stage was T1c in 13 patients, T2 in 31 patients, and T3 in 23 patients. The Gleason score was 2-6 in 12 patients, 7 in 34 patients, and 8-10 in 21 patients. Androgen ablation was performed in all the patients. The median follow-up duration was 11 months (range 3-24 months). The toxicities were graded based on the Radiation Therapy Oncology Group and the European Organization

  1. SU-E-T-310: Dosimetric Comparison of Tandem and Ovoid (TO) Vs. Tandem and Ring (TR) Applicators in High-Dose Rate (HDR) Brachytherapy (BT) for the Treatment of Locally-Advanced Cervical-Cancer

    SciTech Connect

    Kuo, L; Viswanathan, A; Damato, A

    2015-06-15

    Purpose: To investigate the dosimetric differences associated with the use of TO or TR applicators for cervical-cancer HDR BT. Methods: The records of all cervical-cancer patients treated with image-guided HDR BT in 2013 were reviewed. Image-based planning based on isodose line and DVH metrics inspections was performed following the GEC-ESTRO recommendations. CTV volume, CTV D90, and rectum, bladder and sigmoid D2cc were collected as % of the prescription dose (80Gy EQD2). Patients receiving both TO and TR were identified and plans were compared (paired analysis). A Student T-test was used to evaluate statistical significance (p ≤ 0.05). Results: Twenty-eight patients were identified (20 TR only, 4 TO only, 4 TO and TR), associated with 116 plans (109 TR, 7 TO). Overall metrics: CTV volume, 26.5±10.4 cm3 (TR) and 39.1±14.0 cm3 (TO, p < 0.01); CTV D90, 126±28% (TR) and 110±15% (TO, p = 0.15); rectum D2cc, 56±11% (TR) and 58±19% (TO, p = 0.91); bladder D2cc, 74±20% (TR) and 88±19% (TO, p = 0.09); sigmoid D2cc, 52±17% (TR) and 49±20% (TO, p = 0.63). The paired analysis results were: CTV volume, 37.3±11.9 cm3 (TR) and 51.0±23.1 cm3 (TO, p = 0.23); CTV D90, 111±12% (TR) and 101±17% (TO, p = 0.50); rectum D2cc, 56±12% (TR) and 53±16% (TO, p = 0.71); bladder D2cc, 73±14% (TR) and 90±20% (TO, p = 0.22); sigmoid D2cc, 59±10% (TR) and 59±22% (TO, p = 0.98). Conclusion: TR and TO were both used with good dosimetric results. TO were used for patients with larger CTV volumes than TR, although paired analysis suggest that tissue distortion and contouring bias may partially explain this Result. CTV D90 on average > 80 Gy EQD2 were achieved in both groups despite the different CTV volume. Higher bladder D2cc for TO than TR was observed.

  2. Pre-test estimates of temperature decline for the LANL Fenton Hill Long-Term Flow Test

    SciTech Connect

    Robinson, B.A.; Kruger, P.

    1992-06-01

    Pre-test predications for the Long-Term Flow Test (LTFT) of the experimental Hot Dry Rock (HDR) reservoir at Fenton Hill were made using two models. Both models are dependent on estimates of the ``effective`` reservoir volume accessed by the fluid and the mean fracture spacing (MFS) of major joints for fluid flow. The effective reservoir volume was estimated using a variety of techniques, and the range of values for the MFS was set through experience in modeling the thermal cooldown of other experimental HDR reservoirs. The two pre-test predictions for cooldown to 210{degrees}C (a value taken to compare the models) from initial temperature of 240{degrees}C are 6.1 and 10.7 years. Assuming that a minimum of 10{degrees}C is required to provide an unequivocal indication of thermal cooldown, both models predict that the reservoir will not exhibit observable cooldown for at least two years.

  3. The FlxABCD-HdrABC proteins correspond to a novel NADH dehydrogenase/heterodisulfide reductase widespread in anaerobic bacteria and involved in ethanol metabolism in Desulfovibrio vulgaris Hildenborough.

    PubMed

    Ramos, Ana Raquel; Grein, Fabian; Oliveira, Gonçalo P; Venceslau, Sofia S; Keller, Kimberly L; Wall, Judy D; Pereira, Inês A C

    2015-07-01

    Flavin-based electron bifurcation (FBEB) is an important mechanism for the energy metabolism of anaerobes. A new family of NADH dehydrogenases, the flavin oxidoreductase (FlxABCD, previously called FloxABCD), was proposed to perform FBEB in sulphate-reducing organisms coupled with heterodisulfide reductase (HdrABC). We found that the hdrABC-flxABCD gene cluster is widespread among anaerobic bacteria, pointing to a general and important role in their bioenergetics. In this work, we studied FlxABCD of Desulfovibrio vulgaris Hildenborough. The hdr-flx genes are part of the same transcriptional unit and are increased in transcription during growth in ethanol-sulfate, and to a less extent during pyruvate fermentation. Two mutant strains were generated: one where expression of the hdr-flx genes was interrupted and another lacking the flxA gene. Both strains were unable to grow with ethanol-sulfate, whereas growth was restored in a flxA-complemented strain. The mutant strains also produced very reduced amounts of ethanol compared with the wild type during pyruvate fermentation. Our results show that in D. vulgaris, the FlxABCD-HdrABC proteins are essential for NADH oxidation during growth on ethanol, probably involving a FBEB mechanism that leads to reduction of ferredoxin and the small protein DsrC, while in fermentation they operate in reverse, reducing NAD(+) for ethanol production.

  4. Development of a water calorimetry-based standard for absorbed dose to water in HDR {sup 192}Ir brachytherapy

    SciTech Connect

    Sarfehnia, Arman; Seuntjens, Jan

    2010-04-15

    Purpose: The aim of this article is to develop and evaluate a primary standard for HDR {sup 192}Ir brachytherapy based on 4 deg. C stagnant water calorimetry. Methods: The absolute absorbed dose to water was directly measured for several different Nucletron microSelectron {sup 192}Ir sources of air kerma strength ranging between 21 000 and 38 000 U and for source-to-detector separations ranging between 25 and 70 mm. The COMSOL MULTIPHYSICS software was used to accurately calculate the heat transport in a detailed model geometry. Through a coupling of the ''conduction and convection'' module with the ''Navier-Stokes incompressible fluid'' module in the software, both the conductive and convective effects were modeled. Results: A detailed uncertainty analysis resulted in an overall uncertainty in the absorbed dose of 1.90%(1{sigma}). However, this includes a 1.5% uncertainty associated with a nonlinear predrift correction which can be substantially reduced if sufficient time is provided for the system to come to a new equilibrium in between successive calorimetric runs, an opportunity not available to the authors in their clinical setting due to time constraints on the machine. An average normalized dose rate of 361{+-}7 {mu}Gy/(h U) at a source-to-detector separation of 55 mm was measured for the microSelectron {sup 192}Ir source based on water calorimetry. The measured absorbed dose per air kerma strength agreed to better than 0.8%(1{sigma}) with independent ionization chamber and EBT-1 Gafchromic film reference dosimetry as well as with the currently accepted AAPM TG-43 protocol measurements. Conclusions: This work paves the way toward a primary absorbed dose to water standard in {sup 192}Ir brachytherapy.

  5. The effect of patient inhomogeneities in oesophageal 192Ir HDR brachytherapy: a Monte Carlo and analytical dosimetry study.

    PubMed

    Anagnostopoulos, G; Baltas, D; Pantelis, E; Papagiannis, P; Sakelliou, L

    2004-06-21

    The effect of patient inhomogeneities surrounding the oesophagus on the dosimetry planning of an upper thoracic oesophageal 192Ir HDR brachytherapy treatment is studied. The MCNPX Monte Carlo code is used for dosimetry in a patient-equivalent phantom geometry and results are compared in terms of isodose contours as well as dose volume histograms with corresponding calculations by a contemporary treatment planning system software featuring a full TG-43 dose calculation algorithm (PLATO BPS version 14.2.4). It is found that the presence of patient inhomogeneities does not alter the delivery of the planned dose distribution to the planning treatment volume. Regarding the organs at risk, the common practice of current treatment planning systems (TPSs) to consider the patient geometry as a homogeneous water medium leads to a dose overestimation of up to 13% to the spinal cord and an underestimation of up to 15% to the sternum bone. These findings which correspond to the dose region of about 5-10% of the prescribed dose could only be of significance when brachytherapy is used as a boost to external beam therapy. Additionally, an analytical dosimetry model, which is efficient in calculating dose in mathematical phantoms containing inhomogeneity shells of materials of radiobiological interest, is utilized for dosimetry in the patient-equivalent inhomogeneous phantom geometry. Analytical calculations in this work are in good agreement with corresponding Monte Carlo results within the bone inhomogeneities of spinal cord and sternum bone but, like treatment planning system calculations, the model fails to predict the dose distribution in the proximal lung surface as well as within the lungs just as the TPS does, due to its inherent limitation in treating lateral scatter and backscatter radiation.

  6. Comparison between beta radiation dose distribution due to LDR and HDR ocular brachytherapy applicators using GATE Monte Carlo platform.

    PubMed

    Mostafa, Laoues; Rachid, Khelifi; Ahmed, Sidi Moussa

    2016-08-01

    Eye applicators with 90Sr/90Y and 106Ru/106Rh beta-ray sources are generally used in brachytherapy for the treatment of eye diseases as uveal melanoma. Whenever, radiation is used in treatment, dosimetry is essential. However, knowledge of the exact dose distribution is a critical decision-making to the outcome of the treatment. The Monte Carlo technique provides a powerful tool for calculation of the dose and dose distributions which helps to predict and determine the doses from different shapes of various types of eye applicators more accurately. The aim of this work consisted in using the Monte Carlo GATE platform to calculate the 3D dose distribution on a mathematical model of the human eye according to international recommendations. Mathematical models were developed for four ophthalmic applicators, two HDR 90Sr applicators SIA.20 and SIA.6, and two LDR 106Ru applicators, a concave CCB model and a flat CCB model. In present work, considering a heterogeneous eye phantom and the chosen tumor, obtained results with the use of GATE for mean doses distributions in a phantom and according to international recommendations show a discrepancy with respect to those specified by the manufacturers. The QC of dosimetric parameters shows that contrarily to the other applicators, the SIA.20 applicator is consistent with recommendations. The GATE platform show that the SIA.20 applicator present better results, namely the dose delivered to critical structures were lower compared to those obtained for the other applicators, and the SIA.6 applicator, simulated with MCNPX generates higher lens doses than those generated by GATE.

  7. Evaluation of linear array MOSFET detectors for in vivo dosimetry to measure rectal dose in HDR brachytherapy.

    PubMed

    Haughey, Aisling; Coalter, George; Mugabe, Koki

    2011-09-01

    The study aimed to assess the suitability of linear array metal oxide semiconductor field effect transistor detectors (MOSFETs) as in vivo dosimeters to measure rectal dose in high dose rate brachytherapy treatments. The MOSFET arrays were calibrated with an Ir192 source and phantom measurements were performed to check agreement with the treatment planning system. The angular dependence, linearity and constancy of the detectors were evaluated. For in vivo measurements two sites were investigated, transperineal needle implants for prostate cancer and Fletcher suites for cervical cancer. The MOSFETs were inserted into the patients' rectum in theatre inside a modified flatus tube. The patients were then CT scanned for treatment planning. Measured rectal doses during treatment were compared with point dose measurements predicted by the TPS. The MOSFETs were found to require individual calibration factors. The calibration was found to drift by approximately 1% ±0.8 per 500 mV accumulated and varies with distance from source due to energy dependence. In vivo results for prostate patients found only 33% of measured doses agreed with the TPS within ±10%. For cervix cases 42% of measured doses agreed with the TPS within ±10%, however of those not agreeing variations of up to 70% were observed. One of the most limiting factors in this study was found to be the inability to prevent the MOSFET moving internally between the time of CT and treatment. Due to the many uncertainties associated with MOSFETs including calibration drift, angular dependence and the inability to know their exact position at the time of treatment, we consider them to be unsuitable for in vivo dosimetry in rectum for HDR brachytherapy.

  8. Direct measurement of absorbed dose to water in HDR {sup 192}Ir brachytherapy: Water calorimetry, ionization chamber, Gafchromic film, and TG-43

    SciTech Connect

    Sarfehnia, Arman; Kawrakow, Iwan; Seuntjens, Jan

    2010-04-15

    Purpose: Gafchromic film and ionometric calibration procedures for HDR {sup 192}Ir brachytherapy sources in terms of dose rate to water are presented and the experimental results are compared to the TG-43 protocol as well as with the absolute dose measurement results from a water calorimetry-based primary standard. Methods: EBT-1 Gafchromic films, an A1SL Exradin miniature Shonka thimble type chamber, and an SI HDR 1000 Plus well-type chamber (Standard Imaging, Inc., Middleton, WI) with an ADCL traceable S{sub k} calibration coefficient (following the AAPM TG-43 protocol) were used. The Farmer chamber and Gafchromic film measurements were performed directly in water. All results were compared to direct and absolute absorbed dose to water measurements from a 4 deg. C stagnant water calorimeter. Results: Based on water calorimetry, the authors measured the dose rate to water to be 361{+-}7 {mu}Gy/(h U) at a 55 mm source-to-detector separation. The dose rate normalized to air-kerma strength for all the techniques agree with the water calorimetry results to within 0.83%. The overall 1-sigma uncertainty on water calorimetry, ionization chamber, Gafchromic film, and TG-43 dose rate measurement amounts to 1.90%, 1.44%, 1.78%, and 2.50%, respectively. Conclusions: This work allows us to build a more realistic uncertainty estimate for absorbed dose to water determination using the TG-43 protocol. Furthermore, it provides the framework necessary for a shift from indirect HDR {sup 192}Ir brachytherapy dosimetry to a more accurate, direct, and absolute measurement of absorbed dose to water.

  9. SU-C-BRD-02: A Team Focused Clinical Implementation and Failure Mode and Effects Analysis of HDR Skin Brachytherapy Using Valencia and Leipzig Surface Applicators

    SciTech Connect

    Sayler, E; Harrison, A; Eldredge-Hindy, H; Dinome, J; Munro, S; Anne, R; Comber, E; Lockamy, V

    2014-06-15

    Purpose: and Leipzig applicators (VLAs) are single-channel brachytherapy surface applicators used to treat skin lesions up to 2cm diameter. Source dwell times can be calculated and entered manually after clinical set-up or ultrasound. This procedure differs dramatically from CT-based planning; the novelty and unfamiliarity could lead to severe errors. To build layers of safety and ensure quality, a multidisciplinary team created a protocol and applied Failure Modes and Effects Analysis (FMEA) to the clinical procedure for HDR VLA skin treatments. Methods: team including physicists, physicians, nurses, therapists, residents, and administration developed a clinical procedure for VLA treatment. The procedure was evaluated using FMEA. Failure modes were identified and scored by severity, occurrence, and detection. The clinical procedure was revised to address high-scoring process nodes. Results: Several key components were added to the clinical procedure to minimize risk probability numbers (RPN): -Treatments are reviewed at weekly QA rounds, where physicians discuss diagnosis, prescription, applicator selection, and set-up. Peer review reduces the likelihood of an inappropriate treatment regime. -A template for HDR skin treatments was established in the clinical EMR system to standardize treatment instructions. This reduces the chances of miscommunication between the physician and planning physicist, and increases the detectability of an error during the physics second check. -A screen check was implemented during the second check to increase detectability of an error. -To reduce error probability, the treatment plan worksheet was designed to display plan parameters in a format visually similar to the treatment console display. This facilitates data entry and verification. -VLAs are color-coded and labeled to match the EMR prescriptions, which simplifies in-room selection and verification. Conclusion: Multidisciplinary planning and FMEA increased delectability and

  10. SU-E-T-413: Examining Acquisition Rate for Using MatriXX Ion Chamber Array to Measure HDR Brachytherapy Treatments

    SciTech Connect

    Wagar, M; Bhagwat, M; O’Farrell, D; Friesen, S; Buzurovic, I; Damato, A; Devlin, P; Cormack, R

    2015-06-15

    Purpose: There are unique obstacles to implementing the MatriXX ionchamber array as a QA tool in Brachytherapy given that the device is designed for use in the MV energy range. One of the challenges we investigate is the affect of acquisition rates on dose measurement accuracy for HDR treatment plans. Methods: A treatment plan was optimized in Oncentra Brachy TPS to deliver a planar dose to a 5×5cm region at 10mm depth. The applicator was affixed to the surface of the MatriXX array. The plan was delivered multiple times using a Nucleatron HDR afterloader with a 2.9Ci Ir192 source. For each measurement the sampling rate of the MatriXX movie mode was varied (30ms and 500ms). This experiment was repeated with identical parameters, following a source exchange, with an 11.2Ci Ir192 source. Finally, a single snap measurement was acquired. Analysis was preformed to evaluate the fidelity of the dose delivery for each iteration of the experiment. Evaluation was based on the comparison between the measured and TPS predicted dose. Results: Higher sample rates induce a greater discrepancy between the predicted and measured dose. Delivering the plan using a lower activity source also produced greater discrepancy in the measurement due to the increased delivery time. Analyzing the single snap measurement showed little difference from the 500ms integral dose measurement. Conclusion: The advantage of using movie mode for HDR treatment delivery QA is the ability for real time source tracking in addition to dose measurement. Our analysis indicates that 500ms is an optimal frame rate.

  11. A dosimetric comparison of 169Yb and 192Ir for HDR brachytherapy of the breast, accounting for the effect of finite patient dimensions and tissue inhomogeneities.

    PubMed

    Lymperopoulou, G; Papagiannis, P; Angelopoulos, A; Karaiskos, P; Georgiou, E; Baltas, D

    2006-12-01

    Monte Carlo simulation dosimetry is used to compare 169Yb to 192Ir for breast high dose rate (HDR) brachytherapy applications using multiple catheter implants. Results for bare point sources show that while 169Yb delivers a greater dose rate per unit air kerma strength at the radial distance range of interest to brachytherapy in homogeneous water phantoms, it suffers a greater dose rate deficit in missing scatter conditions relative to 192Ir. As a result of these two opposing factors, in the scatter conditions defined by the presence of the lung and the finite patient dimensions in breast brachytherapy the dose distributions calculated in a patient equivalent mathematical phantom by Monte Carlo simulations for the same implant of either 169Yb or 1921r commercially available sources are found comparable. Dose volume histogram results support that 169Yb could be at least as effective as 192Ir delivering the same dose to the lung and slightly reduced dose to the breast skin. The current treatment planning systems' approach of employing dosimetry data precalculated in a homogeneous water phantom of given shape and dimensions, however, is shown to notably overestimate the delivered dose distribution for 169Yb. Especially at the skin and the lung, the treatment planning system dose overestimation is on the order of 15%-30%. These findings do not undermine the potential of 169Yb HDR sources for breast brachytherapy relative to the most commonly used 192Ir HDR sources. They imply, however, that there could be a need for the amendment of dose calculation algorithms employed in clinical treatment planning of particular brachytherapy applications, especially for intermediate photon energy sources such as 169Yb.

  12. The IPEM code of practice for determination of the reference air kerma rate for HDR (192)Ir brachytherapy sources based on the NPL air kerma standard.

    PubMed

    Bidmead, A M; Sander, T; Locks, S M; Lee, C D; Aird, E G A; Nutbrown, R F; Flynn, A

    2010-06-07

    This paper contains the recommendations of the high dose rate (HDR) brachytherapy working party of the UK Institute of Physics and Engineering in Medicine (IPEM). The recommendations consist of a Code of Practice (COP) for the UK for measuring the reference air kerma rate (RAKR) of HDR (192)Ir brachytherapy sources. In 2004, the National Physical Laboratory (NPL) commissioned a primary standard for the realization of RAKR of HDR (192)Ir brachytherapy sources. This has meant that it is now possible to calibrate ionization chambers directly traceable to an air kerma standard using an (192)Ir source (Sander and Nutbrown 2006 NPL Report DQL-RD 004 (Teddington: NPL) http://publications.npl.co.uk). In order to use the source specification in terms of either RAKR, Κ(R) (ICRU 1985 ICRU Report No 38 (Washington, DC: ICRU); ICRU 1997 ICRU Report No 58 (Bethesda, MD: ICRU)), or air kerma strength, S(K) (Nath et al 1995 Med. Phys. 22 209-34), it has been necessary to develop algorithms that can calculate the dose at any point around brachytherapy sources within the patient tissues. The AAPM TG-43 protocol (Nath et al 1995 Med. Phys. 22 209-34) and the 2004 update TG-43U1 (Rivard et al 2004 Med. Phys. 31 633-74) have been developed more fully than any other protocol and are widely used in commercial treatment planning systems. Since the TG-43 formalism uses the quantity air kerma strength, whereas this COP uses RAKR, a unit conversion from RAKR to air kerma strength was included in the appendix to this COP. It is recommended that the measured RAKR determined with a calibrated well chamber traceable to the NPL (192)Ir primary standard is used in the treatment planning system. The measurement uncertainty in the source calibration based on the system described in this COP has been reduced considerably compared to other methods based on interpolation techniques.

  13. A statistical approach to infer the minimum setup distance of a well chamber to the wall or to the floor for {sup 192}Ir HDR calibration

    SciTech Connect

    Chang Liyun; Ho, S.-Y.; Chui, C.-S.; Lee, J.-H.; Du Yichun; Chen Tainsong

    2008-06-15

    We propose a new method based on statistical analysis technique to determine the minimum setup distance of a well chamber used in the calibration of {sup 192}Ir high dose rate (HDR). The chamber should be placed at least this distance away from any wall or from the floor in order to mitigate the effect of scatter. Three different chambers were included in this study, namely, Sun Nuclear Corporation, Nucletron, and Standard Imaging. The results from this study indicated that the minimum setup distance varies depending on the particular chamber and the room architecture in which the chamber was used. Our result differs from that of a previous study by Podgorsak et al. [Med. Phys. 19, 1311-1314 (1992)], in which 25 cm was suggested, and also differs from that of the International Atomic Energy Agency (IAEA)-TECDOC-1079 report, which suggested 30 cm. The new method proposed in this study may be considered as an alternative approach to determine the minimum setup distance of a well-type chamber used in the calibration of {sup 192}Ir HDR.

  14. Comparison of air kerma standards of LNE-LNHB and NPL for 192Ir HDR brachytherapy sources: EUROMET project no 814.

    PubMed

    Douysset, Guilhem; Sander, Thorsten; Gouriou, Jean; Nutbrown, Rebecca

    2008-03-21

    An indirect comparison has been made in the air kerma standards for high dose rate (HDR) 192Ir brachytherapy sources at the Laboratoire National Henri Becquerel (LNHB) and the National Physical Laboratory (NPL). The measurements were carried out at both laboratories between November and December 2004. The comparison was based on measurements using well-type transfer ionization chambers and two different source types, Nucletron microSelectron HDR Classic and version 2. The results show the reported calibration coefficients to agree within 0.47% to 0.63%, which is within the overall standard uncertainty of 0.65% reported by both laboratories at the time of this comparison. Following this comparison, some of the NPL primary standard correction factors were re-evaluated resulting in a change of +0.17% in the overall correction factor. The new factor was implemented in May 2006. Applying the revised chamber factor to the measurements reported in this comparison report will reduce the difference between the two standards by 0.17%.

  15. 3D workflow for HDR image capture of projection systems and objects for CAVE virtual environments authoring with wireless touch-sensitive devices

    NASA Astrophysics Data System (ADS)

    Prusten, Mark J.; McIntyre, Michelle; Landis, Marvin

    2006-02-01

    A 3D workflow pipeline is presented for High Dynamic Range (HDR) image capture of projected scenes or objects for presentation in CAVE virtual environments. The methods of HDR digital photography of environments vs. objects are reviewed. Samples of both types of virtual authoring being the actual CAVE environment and a sculpture are shown. A series of software tools are incorporated into a pipeline called CAVEPIPE, allowing for high-resolution objects and scenes to be composited together in natural illumination environments [1] and presented in our CAVE virtual reality environment. We also present a way to enhance the user interface for CAVE environments. The traditional methods of controlling the navigation through virtual environments include: glove, HUD's and 3D mouse devices. By integrating a wireless network that includes both WiFi (IEEE 802.11b/g) and Bluetooth (IEEE 802.15.1) protocols the non-graphical input control device can be eliminated. Therefore wireless devices can be added that would include: PDA's, Smart Phones, TabletPC's, Portable Gaming consoles, and PocketPC's.

  16. Monte Carlo study of the impact of a magnetic field on the dose distribution in MRI-guided HDR brachytherapy using Ir-192

    NASA Astrophysics Data System (ADS)

    Beld, E.; Seevinck, P. R.; Lagendijk, J. J. W.; Viergever, M. A.; Moerland, M. A.

    2016-09-01

    In the process of developing a robotic MRI-guided high-dose-rate (HDR) prostate brachytherapy treatment, the influence of the MRI scanner’s magnetic field on the dose distribution needs to be investigated. A magnetic field causes a deflection of electrons in the plane perpendicular to the magnetic field, and it leads to less lateral scattering along the direction parallel with the magnetic field. Monte Carlo simulations were carried out to determine the influence of the magnetic field on the electron behavior and on the total dose distribution around an Ir-192 source. Furthermore, the influence of air pockets being present near the source was studied. The Monte Carlo package Geant4 was utilized for the simulations. The simulated geometries consisted of a simplified point source inside a water phantom. Magnetic field strengths of 0 T, 1.5 T, 3 T, and 7 T were considered. The simulation results demonstrated that the dose distribution was nearly unaffected by the magnetic field for all investigated magnetic field strengths. Evidence was found that, from a dose perspective, the HDR prostate brachytherapy treatment using Ir-192 can be performed safely inside the MRI scanner. No need was found to account for the magnetic field during treatment planning. Nevertheless, the presence of air pockets in close vicinity to the source, particularly along the direction parallel with the magnetic field, appeared to be an important point for consideration.

  17. The economics of heat mining: An analysis of design options and performance requirements of hot dry rock (HDR) geothermal power systems

    SciTech Connect

    Tester, Jefferson W.; Herzog, Howard J.

    1991-01-25

    A generalized economic model was developed to predict the breakeven price of HDR generated electricity. Important parameters include: (1) resource quality--average geothermal gradient ({sup o}C/km) and well depth, (2) reservoir performance--effective productivity, flow impedance, and lifetime (thermal drawdown rate), (3) cost components--drilling, reservoir formation, and power plant costs and (4) economic factors--discount and interest rates, taxes, etc. Detailed cost correlations based on historical data and results of other studies are presented for drilling, stimulation, and power plant costs. Results of the generalized model are compared to the results of several published economic assessments. Critical parameters affecting economic viability are drilling costs and reservoir performance. For example, high gradient areas are attractive because shallower well depths and/or lower reservoir production rates are permissible. Under a reasonable set of assumptions regarding reservoir impedance, accessible rock volumes and surface areas, and mass flow rates (to limit thermal drawdown rates to about 10 C per year), predictions for HDR-produced electricity result in competitive breakeven prices in the range of 5 to 9 cents/kWh for resources having average gradients above 50 C/km. Lower gradient areas require improved reservoir performance and/or lower well drilling costs.

  18. The effect of ambient pressure on well chamber response: Monte Carlo calculated results for the HDR 1000 plus.

    PubMed

    Bohm, Tim D; Griffin, Sheridan L; DeLuca, Paul M; DeWerd, Larry A

    2005-04-01

    The determination of the air kerma strength of a brachytherapy seed is necessary for effective treatment planning. Well ionization chambers are used on site at therapy clinics to determine the air kerma strength of seeds. In this work, the response of the Standard Imaging HDR 1000 Plus well chamber to ambient pressure is examined using Monte Carlo calculations. The experimental work examining the response of this chamber as well as other chambers is presented in a companion paper. The Monte Carlo results show that for low-energy photon sources, the application of the standard temperature pressure PTP correction factor produces an over-response at the reduced air densities/pressures corresponding to high elevations. With photon sources of 20 to 40 keV, the normalized PTP corrected chamber response is as much as 10% to 20% over unity for air densities/pressures corresponding to an elevation of 3048 m (10000 ft) above sea level. At air densities corresponding to an elevation of 1524 m (5000 ft), the normalized PTP-corrected chamber response is 5% to 10% over unity for these photon sources. With higher-energy photon sources (>100 keV), the normalized PTP corrected chamber response is near unity. For low-energy beta sources of 0.25 to 0.50 MeV, the normalized PTP-corrected chamber response is as much as 4% to 12% over unity for air densities/pressures corresponding to an elevation of 3048 m (10000 ft) above sea level. Higher-energy beta sources (>0.75 MeV) have a normalized PTP corrected chamber response near unity. Comparing calculated and measured chamber responses for common 103Pd- and 125I-based brachytherapy seeds show agreement to within 2.7% and 1.9%, respectively. Comparing MCNP calculated chamber responses with EGSnrc calculated chamber responses show agreement to within 3.1% at photon energies of 20 to 40 keV. We conclude that Monte Carlo transport calculations accurately model the response of this well chamber. Further, applying the standard PTP correction

  19. HDR prostate monotherapy: dosimetric effects of implant deformation due to posture change between TRUS- and CT-imaging.

    PubMed

    Seppenwoolde, Yvette; Kolkman-Deurloo, Inger-Karine; Sipkema, Dick; de Langen, Mark; Praag, John; Jansen, Peter; Heijmen, Ben

    2008-01-01

    HDR monotherapy for prostate cancer consists of four fractions. The first fraction is delivered with online TRUS-based treatment planning. For the last three fractions the treatment plan is based on a CT-scan acquired in between fractions 1 and 2. The patient position (high lithotomy, rectal US probe) during TRUS-guided catheter implantation and first fraction differs from the patient position in the CT-scan and the remaining three fractions (lowered legs, no TRUS probe). This study describes the effect of posture changes on dose distributions when a plan designed for the TRUS anatomy is applied to the CT-scan anatomy. The aim is to quantify dosimetrical errors that would result from skipping the use of a planning CT-scan, and rely for all fractions on the TRUS plan. Such a procedure would substantially reduce the involved workload, and would increase patient comfort. For three prostate cancer patients, images were acquired during TRUS-guided catheter implantation. Furthermore, a CT-scan (no US probe in rectum, different position of legs) was acquired and matched with the TRUS set. On both TRUS and CT, prostate, urethra and rectum were delineated and all catheters were traced. For each patient, an optimized treatment plan was designed using TRUS images and contours. Catheters with obtained dwell positions of the TRUS plan were transferred individually to the catheter positions in the CT. Changes in dose distribution due to relocation of catheters were evaluated using DVHs. For all patients the dose distributions changed significantly due to rearrangement of the catheters, having most impact on the urethra (maximum observed change: 32% volume receiving > or = 120% of the prescribed dose) and a reduction of PTV coverage (6-28%). Implant deformation when changing from TRUS patient set-up to CT set-up affected negatively the quality of optimized treatment plans. Inclusion of more patients in this study was planned, but because of the observed strong negative effects it

  20. SU-F-BRA-05: Utility of the Combined Use of Two Types of HDR Sources with the Direction Modulation Brachytherapy (DMBT) Tandem Applicator for Cervical Cancer Treatment

    SciTech Connect

    Safigholi, H; Soliman, A; Song, W; Han, D; Meigooni, A Soleimani; Scanderbeg, D

    2015-06-15

    Purpose: To maximize the dose to HRCTV while minimizing dose to the OARs, the combination of two HDR brachytherapy sources, 192-Ir and 169-Yb, used in combination with the recently-proposed novel direction modulated brachytherapy (DMBT) tandem applicator were examined. Methods: The DMBT tandem, made from nonmagnetic tungsten-alloy rod, with diameter of 5.4mm, has 6 symmetric peripheral holes of 1.3mm diameter. The 0.3mm thick bio-compatible plastic tubing wraps the tandem. MCNPX v.2.6 was used to simulate the mHDR 192-Ir V2 and 4140 HDR 169-Yb sources inside the DMBT applicator. Thought was by combining the higher energy 192-Ir (380keV) and lower energy 169-Yb (92.7keV) sources could create unprecedented level of dose conformality when combined with the high-degree intensity modulation capable DMBT tandem applicator. 3D dose matrices, with 1 mm3 resolution, were imported into an in-house-coded inverse optimization planning system to evaluate plan quality of 19 clinical patient cases. Prescription dose was 15Gy. All plans were normalized to receive the same HRCTV D90. Results: Generally, the use of dual sources produced better plans than using either of the sources alone, with significantly better performance in some patients. The mean D2cc for bladder, rectum, and sigmoid were 11.65±2.30Gy, 7.47±3.05Gy, and 9.84±2.48Gy for 192-Ir-only, respectively. For 169 -Yb-only, they were 11.67±2.26Gy, 7.44±3.02Gy, and 9.83±2.38Gy, respectively. The corresponding data for the dual sources were 11.51±2.24Gy, 7.30±3.00Gy, and 9.68 ±2.39Gy, respectively. The HRCTV D98 and V100 were 16.37±1.86Gy and 97.37±1.92Gy for Ir-192-only, respectively. For 169-Yb-only, they were 16.43±1.86Gy, and 97.51±1.91Gy, respectively. For the dual source, they were 16.42±1.87Gy and 97.47±1.93Gy, respectively. Conclusion: The plan quality improves, in some cases quite significantly, for when dual 192-Ir and 169-Yb sources are used in combination with highly intensity modulation capable

  1. SU-C-16A-01: In Vivo Source Position Verification in High Dose Rate (HDR) Prostate Brachytherapy Using a Flat Panel Imager: Initial Clinical Experience

    SciTech Connect

    Franich, R; Smith, R; Millar, J; Haworth, A; Taylor, M; McDermott, L

    2014-06-15

    Purpose: We report our initial clinical experience with a novel position-sensitive source-tracking system based on a flat panel imager. The system has been trialled with 4 prostate HDR brachytherapy patients (8 treatment fractions) in this initial study. Methods: The flat panel imaging system was mounted under a customised carbon fibre couch top assembly (Figure 1). Three gold fiducial markers were implanted into the prostate of each patient at the time of catheter placement. X-ray dwell position markers were inserted into three catheters and a radiograph acquired to locate the implant relative to the imaging device. During treatment, as the HDR source dwells were delivered, images were acquired and processed to determine the position of the source in the patient. Source positions measured by the imaging device were compared to the treatment plan for verification of treatment delivery. Results: Measured dwell positions provided verification of relative dwell spacing within and between catheters, in the coronal plane. Measurements were typically within 2.0mm (0.2mm – 3.3mm, s.d. 0.8mm) of the planned positions over 60 dwells (Figure 2). Discrimination between larger dwell intervals and catheter differentiation were clear. This confirms important delivery attributes such as correct transfer tube connection, source step size, relative catheter positions and therefore overall correct plan selection and delivery. The fiducial markers, visible on the radiograph, provided verification of treatment delivery to the correct anatomical location. The absolute position of the dwells was determined by comparing the measured dwell positions with the x-ray markers from the radiograph, validating the programmed treatment indexer length. The total impact on procedure time was less than 5 minutes. Conclusion: The novel, noninvasive HDR brachytherapy treatment verification system was used clinically with minor impact on workflow. The system allows verification of correct treatment

  2. Determination of absorbed dose in water at the reference point d(r0, theta0) for an 192Ir HDR brachytherapy source using a Fricke system.

    PubMed

    Austerlitz, C; Mota, H C; Sempau, J; Benhabib, S M; Campos, D; Allison, R; DeAlmeida, C E; Zhu, D; Sibata, C H

    2008-12-01

    A ring-shaped Fricke device was developed to measure the absolute dose on the transverse bisector of a 192Ir high dose rate (HDR) source at 1 cm from its center in water, D(r0, theta0). It consists of a polymethylmethacrylate (PMMA) rod (axial axis) with a cylindrical cavity at its center to insert the 192Ir radioactive source. A ring cavity around the source with 1.5 mm thickness and 5 mm height is centered at 1 cm from the central axis of the source. This ring cavity is etched in a disk shaped base with 2.65 cm diameter and 0.90 cm thickness. The cavity has a wall around it 0.25 cm thick. This ring is filled with Fricke solution, sealed, and the whole assembly is immersed in water during irradiations. The device takes advantage of the cylindrical geometry to measure D(r0, theta0). Irradiations were performed with a Nucletron microselectron HDR unit loaded with an 192Ir Alpha Omega radioactive source. A Spectronic 1001 spectrophotometer was used to measure the optical absorbance using a 1 mL quartz cuvette with 1.00 cm light pathlength. The PENELOPE Monte Carlo code (MC) was utilized to simulate the Fricke device and the 192Ir Alpha Omega source in detail to calculate the perturbation introduced by the PMMA material. A NIST traceable calibrated well type ionization chamber was used to determine the air-kerma strength, and a published dose-rate constant was used to determine the dose rate at the reference point. The time to deliver 30.00 Gy to the reference point was calculated. This absorbed dose was then compared to the absorbed dose measured by the Fricke solution. Based on MC simulation, the PMMA of the Fricke device increases the D(r0, theta0) by 2.0%. Applying the corresponding correction factor, the D(r0, theta0) value assessed with the Fricke device agrees within 2.0% with the expected value with a total combined uncertainty of 3.43% (k=1). The Fricke device provides a promising method towards calibration of brachytherapy radiation sources in terms of D(r0

  3. Objective method to report planner-independent skin/rib maximal dose in balloon-based high dose rate (HDR) brachytherapy for breast cancer

    SciTech Connect

    Kim, Yongbok; Trombetta, Mark G.

    2011-04-15

    Purpose: An objective method was proposed and compared with a manual selection method to determine planner-independent skin and rib maximal dose in balloon-based high dose rate (HDR) brachytherapy planning. Methods: The maximal dose to skin and rib was objectively extracted from a dose volume histogram (DVH) of skin and rib volumes. A virtual skin volume was produced by expanding the skin surface in three dimensions (3D) external to the breast with a certain thickness in the planning computed tomography (CT) images. Therefore, the maximal dose to this volume occurs on the skin surface the same with a conventional manual selection method. The rib was also delineated in the planning CT images and its maximal dose was extracted from its DVH. The absolute (Abdiff=|D{sub max}{sup Man}-D{sub max}{sup DVH}|) and relative (Rediff[%]=100x(|D{sub max}{sup Man}-D{sub max}{sup DVH}|)/D{sub max}{sup DVH}) maximal skin and rib dose differences between the manual selection method (D{sub max}{sup Man}) and the objective method (D{sub max}{sup DVH}) were measured for 50 balloon-based HDR (25 MammoSite and 25 Contura) patients. Results: The average{+-}standard deviation of maximal dose difference was 1.67%{+-}1.69% of the prescribed dose (PD). No statistical difference was observed between MammoSite and Contura patients for both Abdiff and Rediff[%] values. However, a statistically significant difference (p value <0.0001) was observed in maximal rib dose difference compared with maximal skin dose difference for both Abdiff (2.30%{+-}1.71% vs 1.05%{+-}1.43%) and Rediff[%] (2.32%{+-}1.79% vs 1.21%{+-}1.41%). In general, rib has a more irregular contour and it is more proximally located to the balloon for 50 HDR patients. Due to the inverse square law factor, more dose difference was observed in higher dose range (D{sub max}>90%) compared with lower dose range (D{sub max}<90%): 2.16%{+-}1.93% vs 1.19%{+-}1.25% with p value of 0.0049. However, the Rediff[%] analysis eliminated the

  4. Image-Guided High-Dose-Rate (HDR) Boost Localization Using MRI/MR Spectroscopy: A Correlation Study with Biopsy

    PubMed Central

    Mbodji, Khaly; Racine, Louis G; Chevrette, Eric; Lavallee, Marie C; Martin, André-Guy; Despres, Philippe; Beaulieu, Luc

    2016-01-01

    93.7% (84.5% - 98.2%) and 82.1% (66.5% - 92.5%), respectively, and a PPV and NPV of 89.4% (79.4% - 95.6%) and 88.9% (73.9% - 96.9%), respectively. Finally, after combining MRI, MRS, and DWI-ADC mapping, compared with biopsy, we obtained a Sn, Sp, PPV, and NPV of 100% (94.8% - 100%), 49% (34.8% - 63.4%), 72.6% (62.5% - 81.3%), and 100% (86.3% - 100%), respectively. Conclusions: The combination of MRI/MRS is a sensitive tool for both the structural and metabolic evaluation of prostate cancer location. MRI/MRS exams are useful to delineate a DIL for high-dose-rate (HDR) intraprostatic boost. PMID:27790388

  5. Imaging of implant needles for real-time HDR-brachytherapy prostate treatment using biplane ultrasound transducers.

    PubMed

    Siebert, Frank-André; Hirt, Markus; Niehoff, Peter; Kovács, György

    2009-08-01

    Ultrasound imaging is becoming increasingly important in prostate brachytherapy. In high-dose-rate (HDR) real-time planning procedures the definition of the implant needles is often performed by transrectal ultrasound. This article describes absolute measurements of the visibility and accuracy of manual detection of implant needle tips and compares measurement results of different biplane ultrasound systems in transversal and longitudinal (i.e., sagittal) ultrasound modes. To obtain a fixed coordinate system and stable conditions the measurements were carried out in a water tank using a dedicated marker system. Needles were manually placed in the phantom until the observer decided by the real-time ultrasound image that the zero position was reached. A comparison of three different ultrasound systems yielded an offset between 0.8 and 3.1 mm for manual detection of the needle tip in ultrasound images by one observer. The direction of the offset was discovered to be in the proximal direction, i.e., the actual needle position was located more distally compared to the ultrasound-based definition. In the second part of the study, the ultrasound anisotropy of trocar implant needles is reported. It was shown that the integrated optical density in a region of interest around the needle tip changes with needle rotation. Three peaks were observed with a phase angle of 120 degrees. Peaks appear not only in transversal but also in longitudinal ultrasound images, with a phase shift of 60 degrees. The third section of this study shows results of observer dependent influences on needle tip detection in sagittal ultrasound images considering needle rotation. These experiments were carried out using the marker system in a water tank. The needle tip was placed exactly at the position z=0 mm. It was found that different users tend to differently interpret the same ultrasound images. The needle tip was manually detected five times in the ultrasound images by three experienced observers

  6. A dual-plane co-RASOR technique for accurate and rapid tracking and position verification of an Ir-192 source for single fraction HDR brachytherapy

    NASA Astrophysics Data System (ADS)

    de Leeuw, Hendrik; Moerland, Marinus A.; van Vulpen, Marco; Seevinck, Peter R.; Bakker, Chris J. G.

    2013-11-01

    Effective high-dose-rate (HDR) treatment requires accurate and independent treatment verification to ensure that the treatment proceeds as prescribed, in particular if a high dose is given, as in single fraction therapy. Contrary to CT imaging and fluoroscopy, MR imaging provides high soft tissue contrast. Conventional MR techniques, however, do not offer the temporal resolution in combination with the 3D spatial resolution required for accurate brachytherapy source localization. We have developed an MR imaging method (center-out RAdial Sampling with Off-Resonance (co-RASOR)) that generates high positive contrast in the geometrical center of field perturbing objects, such as HDR brachytherapy sources. co-RASOR generates high positive contrast in the geometric center of an Ir-192 source by applying a frequency offset to center-out encoded data. To obtain high spatial accuracy in 3D with adequate temporal resolution, two orthogonal center-out encoded 2D images are applied instead of a full 3D acquisition. Its accuracy in 3D is demonstrated by 3D MRI and CT. The 2D images show high positive contrast in the geometric center of non-radioactive Ir-192 sources, with signal intensities up to 160% of the average signal intensity in the surrounding medium. The accuracy with which the center of the Ir-192 source is located by the dual-plane MRI acquisition corresponds closely to the accuracy obtained by 3D MRI and CT imaging. The positive contrast is shown to be obtained in homogeneous and in heterogeneous tissue. The dual-plane MRI technique allows the brachytherapy source to be tracked in 3D with millimeter accuracy with a temporal resolution of approximately 4 s.

  7. SU-E-T-615: Investigation of the Dosimetric Impact of Tandem Loading in the Treatment of Cervical Cancer for HDR Brachytherapy Procedures

    SciTech Connect

    Esquivel, C; Patton, L; Nelson, K; Lin, B

    2014-06-01

    Purpose: To quantify the dosimetric impact of the tandem loading in the treatment of cervical cancer for HDR brachytherapy procedures. Methods: Ten patients were evaluated, each of whom received 5 fractions of treatment. Tandem and ovoid sets were inserted into the uterine cavity based on institutional protocols and procedures. Following insertion and stabilization, CT image sets of 1.5mm slice thickness were acquired and sent to the Oncentra V4.3 Treatment Planning System. Critical structures such as the CTV, bladder, rectum, sigmoid, and bowel were contoured and a fractional dose of 5.5Gy was prescribed to Point A for each patient. Six different treatment plans were created for each fraction using varying tandem weightings; from 0.5 to 1.4 times that of the ovoids. Surface dose evaluation of various ovoid diameters, 2.0-3.5cm, at the vaginal fornices was also investigated. Results: Critical structures were evaluated based on varying dose and volume constraints, in particular the 2.0 cc volume recommendation cited by the gynecological GEC-ESTRO working group. Based on dose volume histogram evaluation, a reduction of dose to the critical structures was most often discovered when the tandem weighting was increased. CTV coverage showed little change as the tandem weighting was varied. Ovoid surface dose decreased by 50-65% as the tandem weighting increased. Conclusion: The advantage of 3D planning with HDR brachytherapy is the dose optimization for each individual treatment plan. This investigation shows that by utilizing large tandem weightings, 1.4 times greater than the ovoid, one can still achieve adequate coverage of the CTV and relatively low doses to the critical structures. In some cases, one would still have to optimize further per individual case. In addition, the ovoid surface dose was greatly decreased when large tandem weighting was utilized; especially for small ovoid diameters.

  8. SU-E-P-38: Comparison of Capri Applicator HDR Planning Methods to Meet the NCCN Uterine Neoplasm 2.2015 Guidelines

    SciTech Connect

    Klash, S; Steinman, J; Stanley, T; Kim, D; Yi, S; Yap, J

    2015-06-15

    Purpose: To establish a systematic planning approach for Capri intravaginal multichannel balloon applicators that meet updated Version 2.2015 NCCN guidelines for uterine neoplasms, which dictate delivery of 400 to 600 cGy in 2 to 3 fractions prescribed to the vaginal mucosa for HDR combined with EBRT as well as a regimen of 600 cGy x 5 (to the vaginal mucosa) for HDR brachytherapy alone. Methods: Studies have shown three different channel configurations of the Capri applicator are optimal for dosimetric conformity: central channel combined with the six inner ring channels (R12), all inner and outer ring channels (R23), or all thirteen channels (R123). To minimize the dose to the vaginal mucosa, a traditional 0.5cm expansion contour from the Capri surface was created. Optimization limits were set to push 600 cGy to 100% of the Capri volume, while simultaneously restricting dose to the expansion contour. Results: Plans were created using all three configurations (R12, R23, R123) and evaluated to determine which was best for delivering 600 cGy to the vaginal mucosa. Our criteria was: Capri V100 > 98%, Vaginal Mucosa Dmax < 125%, Bladder Dmax < 100%, Rectum Dmax < 100%. All configurations show Capri V100 values greater than 98.5%, with differences between plans varying by less than 1%. Vaginal mucosal Dmax values showed differences of roughly 5% of prescription. The R12 configuration proved the lowest vaginal mucosa Dmax, on average. The OAR Dmax values showed an average dose difference of roughly 2% of prescription, with the R23 configuration having the best results. Conclusion: The R12 channel configuration optimally fits our planning criteria and NCCN guidelines for 600 cGy prescribed to the vaginal mucosa. On average, it produced the highest Capri V100, the lowest vaginal mucosal Dmax, and a marginally higher OAR Dmax doses compared to the R23 and R123 plans.

  9. SU-E-T-795: Validations of Dose Calculation Accuracy of Acuros BV in High-Dose-Rate (HDR) Brachytherapy with a Shielded Cylinder Applicator Using Monte Carlo Simulation

    SciTech Connect

    Li, Y; Tian, Z; Hrycushko, B; Jiang, S; Jia, X

    2015-06-15

    Purpose: Acuros BV has become available to perform accurate dose calculations in high-dose-rate (HDR) brachytherapy with phantom heterogeneity considered by solving the Boltzmann transport equation. In this work, we performed validation studies regarding the dose calculation accuracy of Acuros BV in cases with a shielded cylinder applicator using Monte Carlo (MC) simulations. Methods: Fifteen cases were considered in our studies, covering five different diameters of the applicator and three different shielding degrees. For each case, a digital phantom was created in Varian BrachyVision with the cylinder applicator inserted in the middle of a large water phantom. A treatment plan with eight dwell positions was generated for these fifteen cases. Dose calculations were performed with Acuros BV. We then generated a voxelized phantom of the same geometry, and the materials were modeled according to the vendor’s specifications. MC dose calculations were then performed using our in-house developed fast MC dose engine for HDR brachytherapy (gBMC) on a GPU platform, which is able to simulate both photon transport and electron transport in a voxelized geometry. A phase-space file for the Ir-192 HDR source was used as a source model for MC simulations. Results: Satisfactory agreements between the dose distributions calculated by Acuros BV and those calculated by gBMC were observed in all cases. Quantitatively, we computed point-wise dose difference within the region that receives a dose higher than 10% of the reference dose, defined to be the dose at 5mm outward away from the applicator surface. The mean dose difference was ∼0.45%–0.51% and the 95-percentile maximum difference was ∼1.24%–1.47%. Conclusion: Acuros BV is able to accurately perform dose calculations in HDR brachytherapy with a shielded cylinder applicator.

  10. A multicenter study to quantify systematic variations and associated uncertainties in source positioning with commonly used HDR afterloaders and ring applicators for the treatment of cervical carcinomas

    SciTech Connect

    Awunor, O.; Berger, D.; Kirisits, C.

    2015-08-15

    Purpose: The reconstruction of radiation source position in the treatment planning system is a key part of the applicator reconstruction process in high dose rate (HDR) brachytherapy treatment of cervical carcinomas. The steep dose gradients, of as much as 12%/mm, associated with typical cervix treatments emphasize the importance of accurate and precise determination of source positions. However, a variety of methodologies with a range in associated measurement uncertainties, of up to ±2.5 mm, are currently employed by various centers to do this. In addition, a recent pilot study by Awunor et al. [“Direct reconstruction and associated uncertainties of {sup 192}Ir source dwell positions in ring applicators using gafchromic film in the treatment planning of HDR brachytherapy cervix patients,” Phys. Med. Biol. 58, 3207–3225 (2013)] reported source positional differences of up to 2.6 mm between ring sets of the same type and geometry. This suggests a need for a comprehensive study to assess and quantify systematic source position variations between commonly used ring applicators and HDR afterloaders across multiple centers. Methods: Eighty-six rings from 20 European brachytherapy centers were audited in the form of a postal audit with each center collecting the data independently. The data were collected by setting up the rings using a bespoke jig and irradiating gafchromic films at predetermined dwell positions using four afterloader types, MicroSelectron, Flexitron, GammaMed, and MultiSource, from three manufacturers, Nucletron, Varian, and Eckert & Ziegler BEBIG. Five different ring types in six sizes (Ø25–Ø35 mm) and two angles (45° and 60°) were used. Coordinates of irradiated positions relative to the ring center were determined and collated, and source position differences quantified by ring type, size, and angle. Results: The mean expanded measurement uncertainty (k = 2) along the direction of source travel was ±1.4 mm. The standard deviation

  11. SU-F-BRF-09: A Non-Rigid Point Matching Method for Accurate Bladder Dose Summation in Cervical Cancer HDR Brachytherapy

    SciTech Connect

    Chen, H; Zhen, X; Zhou, L; Zhong, Z; Pompos, A; Yan, H; Jiang, S; Gu, X

    2014-06-15

    Purpose: To propose and validate a deformable point matching scheme for surface deformation to facilitate accurate bladder dose summation for fractionated HDR cervical cancer treatment. Method: A deformable point matching scheme based on the thin plate spline robust point matching (TPSRPM) algorithm is proposed for bladder surface registration. The surface of bladders segmented from fractional CT images is extracted and discretized with triangular surface mesh. Deformation between the two bladder surfaces are obtained by matching the two meshes' vertices via the TPS-RPM algorithm, and the deformation vector fields (DVFs) characteristic of this deformation is estimated by B-spline approximation. Numerically, the algorithm is quantitatively compared with the Demons algorithm using five clinical cervical cancer cases by several metrics: vertex-to-vertex distance (VVD), Hausdorff distance (HD), percent error (PE), and conformity index (CI). Experimentally, the algorithm is validated on a balloon phantom with 12 surface fiducial markers. The balloon is inflated with different amount of water, and the displacement of fiducial markers is benchmarked as ground truth to study TPS-RPM calculated DVFs' accuracy. Results: In numerical evaluation, the mean VVD is 3.7(±2.0) mm after Demons, and 1.3(±0.9) mm after TPS-RPM. The mean HD is 14.4 mm after Demons, and 5.3mm after TPS-RPM. The mean PE is 101.7% after Demons and decreases to 18.7% after TPS-RPM. The mean CI is 0.63 after Demons, and increases to 0.90 after TPS-RPM. In the phantom study, the mean Euclidean distance of the fiducials is 7.4±3.0mm and 4.2±1.8mm after Demons and TPS-RPM, respectively. Conclusions: The bladder wall deformation is more accurate using the feature-based TPS-RPM algorithm than the intensity-based Demons algorithm, indicating that TPS-RPM has the potential for accurate bladder dose deformation and dose summation for multi-fractional cervical HDR brachytherapy. This work is supported in part by

  12. SU-E-T-509: Inter-Observer and Inter-Modality Contouring Analysis for Organs at Risk for HDR Gynecological Brachytherapy

    SciTech Connect

    Sadeghi, P; Smith, W; Banerjee, R; Alghamdi, M; Phan, T; Taggar, A

    2015-06-15

    Purpose This study quantifies errors associated with MR-guided High Dose Rate (HDR) gynecological brachytherapy. Uncertainties in this treatment results from contouring, organ motion between imaging and treatment delivery, dose calculation, and dose delivery. We focus on interobserver and inter-modality variability in contouring and the motion of organs at risk (OARs) in the time span between the MR and CT scans (∼1 hour). We report the change in organ volume and position of center of mass (CM) between the two imaging modalities. Methods A total of 8 patients treated with MR-guided HDR brachytherapy were included in this study. Two observers contoured the bladder and rectum on both MR and CT scans. The change in OAR volume and CM position between the MR and CT imaging sessions on both image sets were calculated. Results The absolute mean bladder volume change between the two imaging modalities is 67.1cc. The absolute mean inter-observer difference in bladder volume is much lower at 15.5cc (MR) and 11.0cc (CT). This higher inter-modality volume difference suggests a real change in the bladder filling between the two imaging sessions. Change in Rectum volume inter-observer standard error of means (SEM) is 3.18cc (MR) and 3.09cc (CT), while the inter-modality SEM is 3.65cc (observer 1), and 2.75cc (observer 2). The SEM for rectum CM position in the superior-inferior direction was approximately three times higher than in other directions for both the inter—observer (0.77 cm, 0.92 cm for observers 1 and 2, respectively) and inter-modality (0.91 cm, 0.95 cm for MR and CT, respectively) variability. Conclusion Bladder contours display good consistency between different observers on both CT and MR images. For rectum contouring the highest inconsistency stems from the observers’ choice of the superior-inferior borders. A complete analysis of a larger patient cohort will enable us to separate the true organ motion from the inter-observer variability.

  13. Treatment planning study of the 3D dosimetric differences between Co-60 and Ir-192 sources in high dose rate (HDR) brachytherapy for cervix cancer

    PubMed Central

    Hayman, Orla; Muscat, Sarah

    2012-01-01

    Purpose To evaluate whether Co-60 is equivalent to Ir-192 for HDR cervical brachytherapy, through 3D-DVH dose comparisons in standard and optimised plans. Previous studies have only considered 2D dosimetry, point dose comparisons or identical loading. Typical treatment times and economics are considered. Material and methods Plans were produced for eight cervix patients using Co-60 and Ir-192 sources, CT imaging and IU/two-channel-ring applicator (Eckert Ziegler BEBIG). The comparison was made under two conditions: (A) identical dwell positions and loading, prescribed to Point A and (B) optimised source dwells, prescribed to HR-CTV. This provided a direct comparison of inherent differences and residual differences under typical clinical plan optimisation. The DVH (target and OAR), ICRU reference points and isodose distributions were compared. Typical treatment times and source replacement costs were compared. Results Small differences (p < 0.01) in 3D dosimetry exist when using Co-60 compared to Ir-192, prescribed to Point A with identical loading patterns, particularly 3.3% increase in rectum D2cc. No significant difference was observed in this parameter when prescribing to the HR-CTV using dwell-time optimisation. There was no statistically significant difference in D90 between the two isotopes. Co-60 plans delivered consistently higher V150% (mean +4.4%, p = 0.03) and V400% (mean +11.6%, p < 0.01) compared to Ir-192 in optimised plans. Differences in physical source properties were overwhelmed by geometric effects. Conclusions Co-60 may be used as an effective alternative to Ir-192 for HDR cervix brachytherapy, producing similar plans of equivalent D90, but with logistical benefits. There is a small dose increase along the extension of the source axis when using Co-60 compared to Ir-192, leading to small rectal dose increases for identical loading patterns. This can be eliminated by planning optimisation techniques. Such optimisation may also be associated with

  14. Thermal dosimetry analysis combined with patient-specific thermal modeling of clinical interstitial ultrasound hyperthermia integrated within HDR brachytherapy for treatment of locally advanced prostate cancer

    NASA Astrophysics Data System (ADS)

    Salgaonkar, Vasant A.; Wootton, Jeff; Prakash, Punit; Scott, Serena; Hsu, I. C.; Diederich, Chris J.

    2017-03-01

    This study presents thermal dosimetry analysis from clinical treatments where ultrasound hyperthermia (HT) was administered following high-dose rate (HDR) brachytherapy treatment for locally advanced prostate cancer as part of a clinical pilot study. HT was administered using ultrasound applicators from within multiple 13-g brachytherapy catheters implanted along the posterior periphery of the prostate. The heating applicators were linear arrays of sectored tubular transducers (˜7 MHz), with independently powered array elements enabling energy deposition with 3D spatial control. Typical heat treatments employed time-averaged peak acoustic intensities of 1 - 3 W/cm2 and lasted for 60 - 70 minutes. Throughout the treatments, temperatures at multiple points were monitored using multi-junction thermocouples, placed within available brachytherapy catheters throughout mid-gland prostate and identified as the hyperthermia target volume (HTV). Clinical constraints allowed placement of 8 - 12 thermocouple sensors in the HTV and patient-specific 3D thermal modeling based on finite element methods (FEM) was used to supplement limited thermometry. Patient anatomy, heating device positions, orientations, and thermometry junction locations were obtained from patient CT scans and HDR and hyperthermia planning software. The numerical models utilized the applied power levels recorded during the treatments. Tissue properties such as perfusion and acoustic absorption were varied within physiological ranges such that squared-errors between measured and simulated temperatures were minimized. This data-fitting was utilized for 6 HT treatments to estimate volumetric temperature distributions achieved in the HTV and surrounding anatomy devoid of thermocouples. For these treatments, the measured and simulated T50 values in the hyperthermia target volume (HTV) were between 40.1 - 43.9 °C and 40.3 - 44.9 °C, respectively. Maximum temperatures between 46.8 - 49.8 °C were measured during

  15. Prostate Specific Antigen (PSA) as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT) in Combination with Additional External Beam Radiation Therapy (EBRT) for High Risk Prostate Cancer.

    PubMed

    Ecke, Thorsten H; Huang-Tiel, Hui-Juan; Golka, Klaus; Selinski, Silvia; Geis, Berit Christine; Koswig, Stephan; Bathe, Katrin; Hallmann, Steffen; Gerullis, Holger

    2016-11-10

    High-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT) is a common treatment option for locally advanced prostate cancer (PCa). Seventy-nine male patients (median age 71 years, range 50 to 79) with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval) with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA) value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index), Gleason score, D'Amico risk classification for PCa, digital rectal examination (DRE), PSA value after one/three/five year(s) follow-up (FU), time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis (p = 0.009), PSA on date of first HDR-BT (p = 0.033), and PSA on date of first follow-up after one year (p = 0.025) have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities.

  16. Prostate Specific Antigen (PSA) as Predicting Marker for Clinical Outcome and Evaluation of Early Toxicity Rate after High-Dose Rate Brachytherapy (HDR-BT) in Combination with Additional External Beam Radiation Therapy (EBRT) for High Risk Prostate Cancer

    PubMed Central

    Ecke, Thorsten H.; Huang-Tiel, Hui-Juan; Golka, Klaus; Selinski, Silvia; Geis, Berit Christine; Koswig, Stephan; Bathe, Katrin; Hallmann, Steffen; Gerullis, Holger

    2016-01-01

    High-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT) is a common treatment option for locally advanced prostate cancer (PCa). Seventy-nine male patients (median age 71 years, range 50 to 79) with high-risk PCa underwent HDR-BT following EBRT between December 2009 and January 2016 with a median follow-up of 21 months. HDR-BT was administered in two treatment sessions (one week interval) with 9 Gy per fraction using a planning system and the Ir192 treatment unit GammaMed Plus iX. EBRT was performed with CT-based 3D-conformal treatment planning with a total dose administration of 50.4 Gy with 1.8 Gy per fraction and five fractions per week. Follow-up for all patients was organized one, three, and five years after radiation therapy to evaluate early and late toxicity side effects, metastases, local recurrence, and prostate-specific antigen (PSA) value measured in ng/mL. The evaluated data included age, PSA at time of diagnosis, PSA density, BMI (body mass index), Gleason score, D’Amico risk classification for PCa, digital rectal examination (DRE), PSA value after one/three/five year(s) follow-up (FU), time of follow-up, TNM classification, prostate volume, and early toxicity rates. Early toxicity rates were 8.86% for gastrointestinal, and 6.33% for genitourinary side effects. Of all treated patients, 84.81% had no side effects. All reported complications in early toxicity were grade 1. PSA density at time of diagnosis (p = 0.009), PSA on date of first HDR-BT (p = 0.033), and PSA on date of first follow-up after one year (p = 0.025) have statistical significance on a higher risk to get a local recurrence during follow-up. HDR-BT in combination with additional EBRT in the presented design for high-risk PCa results in high biochemical control rates with minimal side-effects. PSA is a negative predictive biomarker for local recurrence during follow-up. A longer follow-up is needed to assess long-term outcome and toxicities. PMID:27834929

  17. High dynamic range subjective testing

    NASA Astrophysics Data System (ADS)

    Allan, Brahim; Nilsson, Mike

    2016-09-01

    This paper describes of a set of subjective tests that the authors have carried out to assess the end user perception of video encoded with High Dynamic Range technology when viewed in a typical home environment. Viewers scored individual single clips of content, presented in High Definition (HD) and Ultra High Definition (UHD), in Standard Dynamic Range (SDR), and in High Dynamic Range (HDR) using both the Perceptual Quantizer (PQ) and Hybrid Log Gamma (HLG) transfer characteristics, and presented in SDR as the backwards compatible rendering of the HLG representation. The quality of SDR HD was improved by approximately equal amounts by either increasing the dynamic range or increasing the resolution to UHD. A further smaller increase in quality was observed in the Mean Opinion Scores of the viewers by increasing both the dynamic range and the resolution, but this was not quite statistically significant.

  18. Comparison of organ doses for patients undergoing balloon brachytherapy of the breast with HDR {sup 192}Ir or electronic sources using Monte Carlo simulations in a heterogeneous human phantom

    SciTech Connect

    Mille, Matthew M.; Xu, X. George; Rivard, Mark J.

    2010-02-15

    Purpose: Accelerated partial breast irradiation via interstitial balloon brachytherapy is a fast and effective treatment method for certain early stage breast cancers. The radiation can be delivered using a conventional high-dose rate (HDR) {sup 192}Ir gamma-emitting source or a novel electronic brachytherapy (eBx) source which uses lower energy x rays that do not penetrate as far within the patient. A previous study [A. Dickler, M. C. Kirk, N. Seif, K. Griem, K. Dowlatshahi, D. Francescatti, and R. A. Abrams, ''A dosimetric comparison of MammoSite high-dose-rate brachytherapy and Xoft Axxent electronic brachytherapy,'' Brachytherapy 6, 164-168 (2007)] showed that the target dose is similar for HDR {sup 192}Ir and eBx. This study compares these sources based on the dose received by healthy organs and tissues away from the treatment site. Methods: A virtual patient with left breast cancer was represented by a whole-body, tissue-heterogeneous female voxel phantom. Monte Carlo methods were used to calculate the dose to healthy organs in a virtual patient undergoing balloon brachytherapy of the left breast with HDR {sup 192}Ir or eBx sources. The dose-volume histograms for a few organs which received large doses were also calculated. Additional simulations were performed with all tissues in the phantom defined as water to study the effect of tissue inhomogeneities. Results: For both HDR {sup 192}Ir and eBx, the largest mean organ doses were received by the ribs, thymus gland, left lung, heart, and sternum which were close to the brachytherapy source in the left breast. eBx yielded mean healthy organ doses that were more than a factor of {approx}1.4 smaller than for HDR {sup 192}Ir for all organs considered, except for the three closest ribs. Excluding these ribs, the average and median dose-reduction factors were {approx}28 and {approx}11, respectively. The volume distribution of doses in nearby soft tissue organs that were outside the PTV were also improved with e

  19. SU-F-19A-10: Recalculation and Reporting Clinical HDR 192-Ir Head and Neck Dose Distributions Using Model Based Dose Calculation

    SciTech Connect

    Carlsson Tedgren, A; Persson, M; Nilsson, J

    2014-06-15

    Purpose: To retrospectively re-calculate dose distributions for selected head and neck cancer patients, earlier treated with HDR 192Ir brachytherapy, using Monte Carlo (MC) simulations and compare results to distributions from the planning system derived using TG43 formalism. To study differences between dose to medium (as obtained with the MC code) and dose to water in medium as obtained through (1) ratios of stopping powers and (2) ratios of mass energy absorption coefficients between water and medium. Methods: The MC code Algebra was used to calculate dose distributions according to earlier actual treatment plans using anonymized plan data and CT images in DICOM format. Ratios of stopping power and mass energy absorption coefficients for water with various media obtained from 192-Ir spectra were used in toggling between dose to water and dose to media. Results: Differences between initial planned TG43 dose distributions and the doses to media calculated by MC are insignificant in the target volume. Differences are moderate (within 4–5 % at distances of 3–4 cm) but increase with distance and are most notable in bone and at the patient surface. Differences between dose to water and dose to medium are within 1-2% when using mass energy absorption coefficients to toggle between the two quantities but increase to above 10% for bone using stopping power ratios. Conclusion: MC predicts target doses for head and neck cancer patients in close agreement with TG43. MC yields improved dose estimations outside the target where a larger fraction of dose is from scattered photons. It is important with awareness and a clear reporting of absorbed dose values in using model based algorithms. Differences in bone media can exceed 10% depending on how dose to water in medium is defined.

  20. Application of a pelvic phantom in brachytherapy dosimetry for high-dose-rate (HDR) 192Ir source based on Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Ahn, Woo Sang; Choi, Wonsik; Shin, Seong Soo; Jung, Jinhong

    2014-08-01

    In this study, we evaluate how the radial dose function is influenced by the source position as well as the phantom size and shape. A pelvic water phantom similar to the pelvic shape of a human body was designed by averaging dimensions obtained from computed tomography (CT) images of patients treated with brachytherapy for cervical cancer. Furthermore, for the study of the effects of source position on the dose distribution, the position of the source in the water phantom was determined by using the center of mass of the gross target volume (GTV) in the CT images. To obtain the dosimetric parameter of a high-dose-rate (HDR) 192Ir source, we performed Monte Carlo simulations by using the Monte Carlo n-particle extended code (MCNPX). The radial dose functions obtained using the pelvic water phantom were compared with those of spherical phantom with different sizes, including the Monte Carlo (MC) results of Williamson and Li. Differences between the radial dose functions from this study and the data in the literature increased with the radial distances. The largest differences appeared for spherical phantom with the smallest size. In contrast to the published MC results, the radial dose function of the pelvic water phantom significantly decreased with radial distance in the vertical direction because full scattering was not possible. When the source was located in posterior position 2 cm from the center in the pelvic water phantom, the differences between the radial dose functions rapidly decreased with the radial distance in the lower vertical direction. If the International Commission on Radiation Units and Measurements bladder and rectum points are considered, doses to these reference points could be underestimated by up to 1%-2% at a distance of 3 to 6 cm. Our simulation results provide a valid clinical reference data and can used to improve the accuracy of the doses delivered during brachytherapy applied to patients with cervical cancer.

  1. SU-E-T-297: Dosimetric Assessment of An Air-Filled Balloon Applicator in HDR Vaginal Cuff Brachytherapy Using the Monte Carlo Method

    SciTech Connect

    Jiang, H; Lee, Y; Pokhrel, D; Badkul, R

    2015-06-15

    Purpose: As an alternative to cylindrical applicators, air inflated balloon applicators have been introduced into HDR vaginal cuff brachytherapy treatment to achieve sufficient dose to vagina mucosa as well as to spare rectum and bladder. In general, TG43 formulae based treatment planning systems do not take into account tissue inhomogeneity, and air in the balloon applicator can cause higher delivered dose to mucosa than treatment plan reported. We investigated dosimetric effect of air in balloon applicator using the Monte Carlo method. Methods: The thirteen-catheter Capri applicator with a Nucletron Ir-192 seed was modeled for various balloon diameters (2cm to 3.5cm) using the MCNP Monte Carlo code. Ir-192 seed was placed in both central and peripheral catheters to replicate real patient situations. Existence of charged particle equilibrium (CPE) with air balloon was evaluated by comparing kerma and dose at various distances (1mm to 70mm) from surface of air-filled applicator. Also mucosa dose by an air-filled applicator was compared with by a water-filled applicator to evaluate dosimetry accuracy of planning system without tissue inhomogeneity correction. Results: Beyond 1mm from air/tissue interface, the difference between kerma and dose was within 2%. CPE (or transient CPE) condition was deemed existent, and in this region no electron transport was necessary in Monte Carlo simulations. At 1mm or less, the deviation of dose from kerma became more apparent. Increase of dose to mucosa depended on diameter of air balloon. The increment of dose to mucosa was 2.5% and 4.3% on average for 2cm and 3.5cm applicators, respectively. Conclusion: After introduction of air balloon applicator, CPE fails only at the proximity of air/tissue interface. Although dose to mucosa is increased, there is no significant dosimetric difference (<5%) between air and water filled applicators. Tissue inhomogeneity correction is not necessary for air-filled applicators.

  2. SU-E-T-352: Effects of Skull Attenuation and Missing Backscatter On Brain Dose in HDR Treatment of the Head with Surface Applicators

    SciTech Connect

    Cifter, F; Dhou, S; Lewis, J; Cormack, R; Altundal, Y; Sajo, E

    2015-06-15

    Purpose: To calculate the effect of lack of backscatter from air and attenuation of bone on dose distributions in brachytherapy surface treatment of head. Existing treatment planning systems based on TG43 do not account for heterogeneities, and thus may overestimate the dose to the brain. While brachytherapy generally has rapid dose falloff, the dose to the deeper tissues (in this case, the brain) can become significant when treating large curved surfaces. Methods: Applicator geometries representing a range of clinical cases were simulated in MCNP5. An Ir-192 source was modeled using the energy spectrum presented by TG-43. The head phantom was modeled as a 7.5-cm radius water sphere, with a 7 -mm thick skull embedded 5-mm beneath the surface. Dose values were calculated at 20 points inside the head, in which 10 of them were on the central axis and the other 10 on the axis connecting the central of the phantom with the second to last source from the applicator edge. Results: Central and peripheral dose distributions for a range of applicator and head sizes are presented. The distance along the central axis at which the dose falls to 80% of the prescribed dose (D80) was 7 mm for a representative small applicator and 9 mm for a large applicator. Corresponding D50 and D30 for the same small applicator were 17 mm and 32 mm respectively. D50 and D30 for the larger applicator were 32 mm and 60 mm respectively. These results reflect the slower falloff expected for larger applicators on a curved surface. Conclusion: Our results can provide guidance for clinicians to calculate the dose reduction effect due to bone attenuation and the lack of backscatter from air to estimate the brain dose for the HDR treatments of surface lesions.

  3. SU-E-T-491: Influence of Applicator Dimensions On Doses to Bladder, Rectum and Sigmoid in HDR Brachytherapy for Cervical Cancer

    SciTech Connect

    Dumane, V; Rhome, R; Yuan, Y; Gupta, V

    2015-06-15

    Purpose: To study the influence of dimensions of the tandem and ring applicator on bladder D2cc, rectum D2cc and sigmoid D2cc in HDR treatment planning for cervical cancer. Methods: 53 plans from 13 patients treated at our institution with the tandem and ring applicator were retrospectively reviewed. Prescription doses were one of the following: 8 Gy x 3, 7 Gy x 4 and 5.5 Gy x 5. Doses to the D2ccs of the bladder, rectum and the sigmoid were recorded. These doses were normalized to their relative prescriptions doses. Correlations between the normalized bladder D2cc, rectum D2cc and sigmoid D2cc were investigated and linear regression models were developed to study the dependence of these doses on the ring diameter and the applicator angle. Results: Normalized doses to the D2cc of the bladder, rectum and sigmoid showed statistically significant correlation (P < 0.05) to the applicator angle. Significant correlation was also noted for the normalized D2cc of the rectum and the sigmoid with the ring diameter. The normalized bladder D2cc was found to decrease with applicator angle on an average by 22.65% ± 4.43% while the same for the rectum and sigmoid were found to increase on an average by 14.43% ± 1.65% and 14.01% ± 1.42% respectively. Both the rectum and sigmoid D2cc reduced with increasing ring diameter by 12.93% ± 1.95% and 11.27% ± 1.79%. No correlation was observed between the normalized bladder D2cc and the ring diameter. Conclusion: Preliminary regression models developed in this study can potentially aid in the choice of the appropriate applicator angle and ring diameter for tandem and ring implant so as to optimize doses to the bladder, rectum and sigmoid.

  4. 4D analysis of influence of patient movement and anatomy alteration on the quality of 3D U/S-based prostate HDR brachytherapy treatment delivery

    SciTech Connect

    Milickovic, Natasa; Mavroidis, Panayiotis; Tselis, Nikolaos; Nikolova, Iliyana; Katsilieri, Zaira; Kefala, Vasiliki; Zamboglou, Nikolaos; Baltas, Dimos

    2011-09-15

    Purpose: Modern HDR brachytherapy treatment for prostate cancer based on the 3D ultrasound (U/S) plays increasingly important role. The purpose of this study is to investigate possible patient movement and anatomy alteration between the clinical image set acquisition, made after the needle implantation, and the patient irradiation and their influence on the quality of treatment. Methods: The authors used 3D U/S image sets and the corresponding treatment plans based on a 4D-treatment planning procedure: plans of 25 patients are obtained right after the needle implantation (clinical plan is based on this 3D image set) and just before and after the treatment delivery. The authors notice the slight decrease of treatment quality with increase of time gap between the clinical image set acquisition and the patient irradiation. 4D analysis of dose-volume-histograms (DVHs) for prostate: CTV1 = PTV, and urethra, rectum, and bladder as organs at risk (OARs) and conformity index (COIN) is presented, demonstrating the effect of prostate, OARs, and needles displacement. Results: The authors show that in the case that the patient body movement/anatomy alteration takes place, this results in modification of DVHs and radiobiological parameters, hence the plan quality. The observed average displacement of needles (1 mm) and of prostate (0.57 mm) is quite small as compared with the average displacement noted in several other reports [A. A. Martinez et al., Int. J. Radiat. Oncol., Biol., Phys. 49(1), 61-69 (2001); S. J. Damore et al., Int. J. Radiat. Oncol., Biol., Phys. 46(5), 1205-1211 (2000); P. J. Hoskin et al., Radiotherm. Oncol. 68(3), 285-288 (2003); E. Mullokandov et al., Int. J. Radiat. Oncol., Biol., Phys. 58(4), 1063-1071 (2004)] in the literature. Conclusions: Although the decrease of quality of dosimetric and radiobiological parameters occurs, this does not cause clinically unacceptable changes to the 3D dose distribution, according to our clinical protocol.

  5. SU-F-19A-12: Split-Ring Applicator with Interstitial Needle for Improved Volumetric Coverage in HDR Brachytherapy for Cervical Cancer

    SciTech Connect

    Sherertz, T; Ellis, R; Colussi, V; Mislmani, M; Traughber, B; Herrmann, K; Podder, T

    2014-06-15

    Purpose: To evaluate volumetric coverage of a Mick Radionuclear titanium Split-Ring applicator (SRA) with/without interstitial needle compared to an intracavitary Vienna applicator (VA), interstitial-intracavitary VA, and intracavitary ring and tandem applicator (RTA). Methods: A 57 year-old female with FIGO stage IIB cervical carcinoma was treated following chemoradiotherapy (45Gy pelvic and 5.4Gy parametrial boost) with highdose- rate (HDR) brachytherapy to 30Gy in 5 fractions using a SRA. A single interstitial needle was placed using the Ellis Interstitial Cap for the final three fractions to increase coverage of left-sided gross residual disease identified on 3T-MRI. High-risk (HR) clinical target volume (CTV) and intermediate-risk (IR) CTV were defined using axial T2-weighted 2D and 3D MRI sequences (Philips PET/MRI unit). Organs-at-risks (OARs) were delineated on CT. Oncentra planning system was used for treatment optimization satisfying GEC-ESTRO guidelines for target coverage and OAR constraints. Retrospectively, treatment plans (additional 20 plans) were simulated using intracavitary SRA (without needle), intracavitary VA (without needle), interstitial-intracavitary VA, and intracavitary RTA with this same patient case. Plans were optimized for each fraction to maintain coverage to HR-CTV. Results: Interstitial-intracavitary SRA achieved the following combined coverage for external radiation and brachytherapy (EQD2): D90 HR-CTV =94.6Gy; Bladder-2cc =88.9Gy; Rectum-2cc =65.1Gy; Sigmoid-2cc =48.9Gy; Left vaginal wall (VW) =103Gy, Right VW =99.2Gy. Interstitial-intracavitary VA was able to achieve identical D90 HR-CTV =94.6Gy, yet Bladder-2cc =91.9Gy (exceeding GEC-ESTRO recommendations of 2cc<90Gy) and Left VW =120.8Gy and Right VW =115.5Gy. Neither the SRA nor VA without interstitial needle could cover HR-CTV adequately without exceeding dose to Bladder-2cc. Conventional RTA was unable to achieve target coverage for the HR-CTV >80Gy without severely

  6. SU-E-T-23: A Novel Two-Step Optimization Scheme for Tandem and Ovoid (T and O) HDR Brachytherapy Treatment for Locally Advanced Cervical Cancer

    SciTech Connect

    Sharma, M; Todor, D; Fields, E

    2014-06-01

    Purpose: To present a novel method allowing fast, true volumetric optimization of T and O HDR treatments and to quantify its benefits. Materials and Methods: 27 CT planning datasets and treatment plans from six consecutive cervical cancer patients treated with 4–5 intracavitary T and O insertions were used. Initial treatment plans were created with a goal of covering high risk (HR)-CTV with D90 > 90% and minimizing D2cc to rectum, bladder and sigmoid with manual optimization, approved and delivered. For the second step, each case was re-planned adding a new structure, created from the 100% prescription isodose line of the manually optimized plan to the existent physician delineated HR-CTV, rectum, bladder and sigmoid. New, more rigorous DVH constraints for the critical OARs were used for the optimization. D90 for the HR-CTV and D2cc for OARs were evaluated in both plans. Results: Two-step optimized plans had consistently smaller D2cc's for all three OARs while preserving good D90s for HR-CTV. On plans with “excellent” CTV coverage, average D90 of 96% (range 91–102), sigmoid D2cc was reduced on average by 37% (range 16–73), bladder by 28% (range 20–47) and rectum by 27% (range 15–45). Similar reductions were obtained on plans with “good” coverage, with an average D90 of 93% (range 90–99). For plans with inferior coverage, average D90 of 81%, an increase in coverage to 87% was achieved concurrently with D2cc reductions of 31%, 18% and 11% for sigmoid, bladder and rectum. Conclusions: A two-step DVH-based optimization can be added with minimal planning time increase, but with the potential of dramatic and systematic reductions of D2cc for OARs and in some cases with concurrent increases in target dose coverage. These single-fraction modifications would be magnified over the course of 4–5 intracavitary insertions and may have real clinical implications in terms of decreasing both acute and late toxicity.

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

    SciTech Connect

    Araki, Fujio; Kouno, Tomohiro; Ohno, Takeshi; Kakei, Kiyotaka; Yoshiyama, Fumiaki; Kawamura, Shinji

    2013-09-15

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

  8. HDR brachytherapy for anal cancer

    PubMed Central

    Kovács, Gyoergy

    2014-01-01

    The challenge of treating anal cancer is to preserve the anal sphincter function while giving high doses to the tumor and sparing the organ at risk. For that reason there has been a shift from radical surgical treatment with colostomy to conservative treatment. Radiotherapy combined with chemotherapy has an important role in the treatment of anal cancer patients. New techniques as intensity modulated radiotherapy (IMRT) have shown reduced acute toxicity and high rates of local control in combination with chemotherapy compared to conventional 3-D radiotherapy. Not only external beam radio-chemotherapy treatment (EBRT) is an established method for primary treatment of anal cancer, brachytherapy (BT) is also an approved method. BT is well known for boost irradiation in combination with EBRT (+/– chemotherapy). Because of technical developments like modern image based 3D treatment planning and the possibility of intensity modulation in brachytherapy (IMBT), BT today has even more therapeutic potential than it had in the era of linear sources. The combination of external beam radiotherapy (EBRT) and BT allows the clinician to deliver higher doses to the tumor and to reduce dose to the normal issue. Improvements in local control and reductions in toxicity therefore become possible. Various BT techniques and their results are discussed in this work. PMID:24982770

  9. Dosimetric analysis of 3D image-guided HDR brachytherapy planning for the treatment of cervical cancer: is point A-based dose prescription still valid in image-guided brachytherapy?

    PubMed

    Kim, Hayeon; Beriwal, Sushil; Houser, Chris; Huq, M Saiful

    2011-01-01

    The purpose of this study was to analyze the dosimetric outcome of 3D image-guided high-dose-rate (HDR) brachytherapy planning for cervical cancer treatment and compare dose coverage of high-risk clinical target volume (HRCTV) to traditional Point A dose. Thirty-two patients with stage IA2-IIIB cervical cancer were treated using computed tomography/magnetic resonance imaging-based image-guided HDR brachytherapy (IGBT). Brachytherapy dose prescription was 5.0-6.0 Gy per fraction for a total 5 fractions. The HRCTV and organs at risk (OARs) were delineated following the GYN GEC/ESTRO guidelines. Total doses for HRCTV, OARs, Point A, and Point T from external beam radiotherapy and brachytherapy were summated and normalized to a biologically equivalent dose of 2 Gy per fraction (EQD2). The total planned D90 for HRCTV was 80-85 Gy, whereas the dose to 2 mL of bladder, rectum, and sigmoid was limited to 85 Gy, 75 Gy, and 75 Gy, respectively. The mean D90 and its standard deviation for HRCTV was 83.2 ± 4.3 Gy. This is significantly higher (p < 0.0001) than the mean value of the dose to Point A (78.6 ± 4.4 Gy). The dose levels of the OARs were within acceptable limits for most patients. The mean dose to 2 mL of bladder was 78.0 ± 6.2 Gy, whereas the mean dose to rectum and sigmoid were 57.2 ± 4.4 Gy and 66.9 ± 6.1 Gy, respectively. Image-based 3D brachytherapy provides adequate dose coverage to HRCTV, with acceptable dose to OARs in most patients. Dose to Point A was found to be significantly lower than the D90 for HRCTV calculated using the image-based technique. Paradigm shift from 2D point dose dosimetry to IGBT in HDR cervical cancer treatment needs advanced concept of evaluation in dosimetry with clinical outcome data about whether this approach improves local control and/or decreases toxicities.

  10. WE-A-17A-06: Evaluation of An Automatic Interstitial Catheter Digitization Algorithm That Reduces Treatment Planning Time and Provide Means for Adaptive Re-Planning in HDR Brachytherapy of Gynecologic Cancers

    SciTech Connect

    Dise, J; Liang, X; Lin, L; Teo, B

    2014-06-15

    Purpose: To evaluate an automatic interstitial catheter digitization algorithm that reduces treatment planning time and provide means for adaptive re-planning in HDR Brachytherapy of Gynecologic Cancers. Methods: The semi-automatic catheter digitization tool utilizes a region growing algorithm in conjunction with a spline model of the catheters. The CT images were first pre-processed to enhance the contrast between the catheters and soft tissue. Several seed locations were selected in each catheter for the region growing algorithm. The spline model of the catheters assisted in the region growing by preventing inter-catheter cross-over caused by air or metal artifacts. Source dwell positions from day one CT scans were applied to subsequent CTs and forward calculated using the automatically digitized catheter positions. This method was applied to 10 patients who had received HDR interstitial brachytherapy on an IRB approved image-guided radiation therapy protocol. The prescribed dose was 18.75 or 20 Gy delivered in 5 fractions, twice daily, over 3 consecutive days. Dosimetric comparisons were made between automatic and manual digitization on day two CTs. Results: The region growing algorithm, assisted by the spline model of the catheters, was able to digitize all catheters. The difference between automatic and manually digitized positions was 0.8±0.3 mm. The digitization time ranged from 34 minutes to 43 minutes with a mean digitization time of 37 minutes. The bulk of the time was spent on manual selection of initial seed positions and spline parameter adjustments. There was no significance difference in dosimetric parameters between the automatic and manually digitized plans. D90% to the CTV was 91.5±4.4% for the manual digitization versus 91.4±4.4% for the automatic digitization (p=0.56). Conclusion: A region growing algorithm was developed to semi-automatically digitize interstitial catheters in HDR brachytherapy using the Syed-Neblett template. This automatic

  11. Dosimetric Analysis of 3D Image-Guided HDR Brachytherapy Planning for the Treatment of Cervical Cancer: Is Point A-Based Dose Prescription Still Valid in Image-Guided Brachytherapy?

    SciTech Connect

    Kim, Hayeon; Beriwal, Sushil; Houser, Chris; Huq, M. Saiful

    2011-07-01

    The purpose of this study was to analyze the dosimetric outcome of 3D image-guided high-dose-rate (HDR) brachytherapy planning for cervical cancer treatment and compare dose coverage of high-risk clinical target volume (HRCTV) to traditional Point A dose. Thirty-two patients with stage IA2-IIIB cervical cancer were treated using computed tomography/magnetic resonance imaging-based image-guided HDR brachytherapy (IGBT). Brachytherapy dose prescription was 5.0-6.0 Gy per fraction for a total 5 fractions. The HRCTV and organs at risk (OARs) were delineated following the GYN GEC/ESTRO guidelines. Total doses for HRCTV, OARs, Point A, and Point T from external beam radiotherapy and brachytherapy were summated and normalized to a biologically equivalent dose of 2 Gy per fraction (EQD2). The total planned D90 for HRCTV was 80-85 Gy, whereas the dose to 2 mL of bladder, rectum, and sigmoid was limited to 85 Gy, 75 Gy, and 75 Gy, respectively. The mean D90 and its standard deviation for HRCTV was 83.2 {+-} 4.3 Gy. This is significantly higher (p < 0.0001) than the mean value of the dose to Point A (78.6 {+-} 4.4 Gy). The dose levels of the OARs were within acceptable limits for most patients. The mean dose to 2 mL of bladder was 78.0 {+-} 6.2 Gy, whereas the mean dose to rectum and sigmoid were 57.2 {+-} 4.4 Gy and 66.9 {+-} 6.1 Gy, respectively. Image-based 3D brachytherapy provides adequate dose coverage to HRCTV, with acceptable dose to OARs in most patients. Dose to Point A was found to be significantly lower than the D90 for HRCTV calculated using the image-based technique. Paradigm shift from 2D point dose dosimetry to IGBT in HDR cervical cancer treatment needs advanced concept of evaluation in dosimetry with clinical outcome data about whether this approach improves local control and/or decreases toxicities.

  12. Determination of absorbed dose to water around a clinical HDR {sup 192}Ir source using LiF:Mg,Ti TLDs demonstrates an LET dependence of detector response

    SciTech Connect

    Carlsson Tedgren, Aasa; Elia, Rouba; Hedtjaern, Haakan; Olsson, Sara; Alm Carlsson, Gudrun

    2012-02-15

    Purpose: Experimental radiation dosimetry with thermoluminescent dosimeters (TLDs), calibrated in a {sup 60}Co or megavoltage (MV) photon beam, is recommended by AAPM TG-43U1for verification of Monte Carlo calculated absorbed doses around brachytherapy sources. However, it has been shown by Carlsson Tedgren et al.[Med. Phys. 38, 5539-5550 (2011)] that for TLDs of LiF:Mg,Ti, detector response was 4% higher in a {sup 137}Cs beam than in a {sup 60}Co one. The aim of this work was to investigate if similar over-response exists when measuring absorbed dose to water around {sup 192}Ir sources, using LiF:Mg,Ti dosimeters calibrated in a 6 MV photon beam. Methods: LiF dosimeters were calibrated to measure absorbed dose to water in a 6 MV photon beam and used to measure absorbed dose to water at distances of 3, 5, and 7 cm from a clinical high dose rate (HDR) {sup 192}Ir source in a polymethylmethacrylate (PMMA) phantom. Measured values were compared to values of absorbed dose to water calculated using a treatment planning system (TPS) including corrections for the difference in energy absorption properties between calibration quality and the quality in the users'{sup 192}Ir beam and for the use of a PMMA phantom instead of the water phantom underlying dose calculations in the TPS. Results: Measured absorbed doses to water around the {sup 192}Ir source were overestimated by 5% compared to those calculated by the TPS. Corresponding absorbed doses to water measured in a previous work with lithium formate electron paramagnetic resonance (EPR) dosimeters by Antonovic et al. [Med. Phys. 36, 2236-2247 (2009)], using the same irradiation setup and calibration procedure as in this work, were 2% lower than those calculated by the TPS. The results obtained in the measurements in this work and those obtained using the EPR lithium formate dosimeters were, within the expanded (k = 2) uncertainty, in agreement with the values derived by the TPS. The discrepancy between the results using

  13. SU-E-T-525: Dose Volume Histograms (DVH) Analysis and Comparison with ICRU Point Doses in MRI Guided HDR Brachytherapy for Cervical Cancer

    SciTech Connect

    Badkul, R; McClinton, C; Kumar, P; Mitchell, M

    2014-06-01

    .1 overestimated the bladder ICRU point dose up to 43% for conventional-techniques.Bladder-D2 provided a good estimation of ICRU bladder point-doses(within 3.6%) for conventional-techniques. This correlation is not observed for MGO plans perhaps due to steering of isodose line, leading to unpredictable dwell-weighting. Conclusion: MRI based HDR-planning provides accurate delineation of tumor volumes and normal structures, and optimized tumor-coverage can be achieved with acceptable normal-tissue doses. This study showed that for conventional techniques D0.1 rectum dose and D2 bladder dose are good representation of ICRU-reference-point doses.

  14. The energy-conserving electron transfer system used by Desulfovibrio alaskensis strain G20 during pyruvate fermentation involves reduction of endogenously formed fumarate and cytoplasmic and membrane-bound complexes, Hdr-Flox and Rnf.

    PubMed

    Meyer, Birte; Kuehl, Jennifer V; Price, Morgan N; Ray, Jayashree; Deutschbauer, Adam M; Arkin, Adam P; Stahl, David A

    2014-11-01

    The adaptation capability of Desulfovibrio to natural fluctuations in electron acceptor availability was evaluated by studying Desulfovibrio alaskensis strain G20 under varying respiratory, fermentative and methanogenic coculture conditions in chemostats. Transition from lactate to pyruvate in coculture resulted in a dramatic shift in the population structure and closer interspecies cell-to-cell interactions. Lower methane production rates in coculture than predicted from pyruvate input was attributed to redirection of electron flow to fumarate reduction. Without a methanogenic partner, accumulation of H₂and formate resulted in greater succinate production. Comparative transcript and gene fitness analysis in concert with physiological data of G20 wildtype and mutants demonstrated that pyruvate fermentation involves respiration of cytoplasmically formed fumarate using cytoplasmic and membrane-bound energy-conserving complexes, Rnf, Hdr-Flox-1 and Hmc. At the low H₂/formate levels maintained in coculture, Rnf likely functions as proton-pumping ferredoxin (Fd): type-I cytochrome c oxidoreductase, which transitions to a proton-pumping Fd(red):  nicotinamide adenine dinucleotide (NAD⁺) oxidoreductase at high H₂/formate levels during fermentation in monoculture. Hdr-Flox-1 is postulated to recycle Fd(red) via a flavin-based electron bifurcation involving NADH, Fdox and the thiol/disulphide-containing DsrC. In a menaquinone (MQ)-based electron confurcation reaction, the high-molecular-weight cytochrome-c₃complex, Hmc, is proposed to then couple DsrC(red) and periplasmic H₂/formate oxidation using the MQ pool to fuel a membrane-bound fumarate reductase.

  15. SU-E-T-263: Point Dose Variation Using a Single Ir-192 HDR Brachytherapy Plan for Two Treatments with a Single Tandem-Ovoid Insertion for Cervical Cancer

    SciTech Connect

    Liang, X; Morrill, S; Hardee, M; Han, E; Penagaricano, J; Zhang, X; Vaneerat, R

    2014-06-01

    Purpose: To evaluate the point dose variations between Ir-192 HDR treatments on two consecutive days using a single tandem-ovoid insertion without replanning in cervical cancer patients. Methods: This study includes eleven cervical cancer patients undergoing HDR brachytherapy with a prescribed dose of 28 Gy in 4 fractions. Each patient had two tandemovoid insertions one week apart. Each insertion was treated on consecutive days with rescanning and replanning prior to each treatment. To study the effect of no replanning for day 2 treatments, the day 1 plan dwell position and dwell time with decay were applied to the day 2 CT dataset. The point dose variations on the prescription point H (defined according to American Brachytherapy Society), and normal tissue doses at point B, bladder, rectum and vaginal mucosa (based on ICRU Report 38) were obtained. Results: Without replanning, the mean point H dose variation was 4.6 ± 10.7% on the left; 2.3 ± 2.9% on the right. The mean B point variation was 3.8 ± 4.9% on the left; 3.6 ± 4.7% on the right. The variation in the left vaginal mucosal point was 12.2 ± 10.7%; 9.5 ± 12.5% on the right; the bladder point 5.5 ± 7.4%; and the rectal point 7.9 ± 9.1%. Conclusion: Without replanning, there are variations both in the prescription point and the normal tissue point doses. The latter can vary as much as 10% or more. This is likely due to the steep dose gradient from brachytherapy compounded by shifts in the positions of the applicator in relationship to the patients anatomy. Imaging prior to each treatment and replanning ensure effective and safe brachytherapy are recommended.

  16. SU-E-T-787: Utility of the Two Candidate 192-Ir and 169-Yb HDR Sources for Use with a Novel Direction Modulated Brachytherapy Tandem Applicator for Cervical Cancer Treatment

    SciTech Connect

    Safigholi, H; Soliman, A; Song, W; Han, D; Meigooni, A Soleimani

    2015-06-15

    Purpose: A novel tungsten alloy shielded, MRI-compatible, direction modulated brachytherapy (DMBT) concept tandem applicator, which enables unprecedented intensity modulation, was used to evaluate treatment plan quality improvement over a conventional tandem. The utility of the 192-Ir and 169-Yb HDR sources, for use with the DMBT applicator, was evaluated. Methods: The total diameter of the DMBT tandem applicator is 6.0 mm, which consists of 5.4-mm diameter tungsten alloy and 0.3 mm thick plastic sheath. The tandem has 6 symmetric peripheral 1.3-mm diameter grooves for the source to travel. MCNPX v.2.6 was used to simulate the 192-Ir and 169-Yb sources inside the DMBT applicator. First, TG-43 source parameters were evaluated. Second, 3D dose matrix with 1 mm3 resolution were imported into an in-house-coded inverse optimization treatment planning program to obtain optimal plans for 19 clinical cases. All plans were compared with the standard tandem and ring plans. Prescription dose was 15.0 Gy. All plans were normalized to receive the same HRCTV D90. Results: Generally, the DMBT tandem (and ring) plans were better than the conventional tandem and ring plans for 192-Ir and 169-Yb HDR sources. The mean data of D2cc for bladder, rectum, and sigmoid were 11.65±2.30 Gy, 7.47±3.05 Gy, and 9.84±2.48 Gy for Ir-192 DMBT tandem, respectively. These data for Yb-169 were 11.67±2.26 Gy, 7.44±3.02 Gy, and 9.83±2.38 Gy, respectively. The HR-CTV D98 and V100 were 16.37±1.86 Gy and 97.37 ± 1.92 Gy for Ir-192 DMBT, respectively. The corresponding values for Yb-169 were 16.43±1.86 Gy, and 97.51 ± 1.91 Gy. Plans with the 169-Yb source generally produced more favorable results where V100 increased by 13.65% while D2cc across all OARs reduced by 0.54% compared with the 192-Ir plans. Conclusion: For the DMBT tandem applicator, 169-Yb source seems to produce more directional beams resulting in increased intensity modulation capacity, thus resulting in more conformal plans.

  17. A study of pumps for the Hot Dry Rock Geothermal Energy extraction experiment (LTFT (Long Term Flow Test))

    SciTech Connect

    Tatro, C.A.

    1986-10-01

    A set of specifications for the hot dry rock (HDR) Phase II circulation pumping system is developed from a review of basic fluid pumping mechanics, a technical history of the HDR Phase I and Phase II pumping systems, a presentation of the results from experiment 2067 (the Initial Closed-Loop Flow Test or ICFT), and consideration of available on-site electrical power limitations at the experiment site. For the Phase II energy extraction experiment (the Long Term Flow Test or LTFT) it is necessary to provide a continuous, low maintenance, and highly efficient pumping capability for a period of twelve months at variable flowrates up to 420 gpm and at surface injection pressures up to 5000 psi. The pumping system must successfully withstand attacks by corrosive and embrittling gases, erosive chemicals and suspended solids, and fluid pressure and temperature fluctuations. In light of presently available pumping hardware and electric power supply limitations, it is recommended that positive displacement multiplex plunger pumps, driven by variable speed control electric motors, be used to provide the necessary continuous surface injection pressures and flowrates for LTFT. The decision of whether to purchase the required circulation pumping hardware or to obtain contractor provided pumping services has not been made.

  18. Feasibility test of line sensors for optical tissue thickness estimation

    NASA Astrophysics Data System (ADS)

    Stüber, Patrick; Wissel, Tobias; Wagner, Benjamin; Schweikard, Achim; Ernst, Floris

    2015-05-01

    Purpose Line sensors are cheap, fast and have high quantum effciencies. Here, we investigate whether these sensors can replace an area image sensor for the purpose of tissue thickness measurements. Material and Methods As part of a subject study high dynamic range (HDR) images of three subjects were acquired with an area image sensor. To simulate a line sensor as realistic as possible single or multiple lines were extracted from these HDR images. Thereby, horizontally extracted lines correspond to a parallel orientation of the line sensor relative to the incident angle of a laser beam. Vertically extracted lines correspond to an orthogonal orientation. Then, optical features were determined and converted into a tissue thickness using a machine learning algorithm. Results For the tested subjects the worst root mean square error (RMSE) of the learning process was 0:385 mm. The best RMSE was 0:222 mm. For all subjects, the mean RMSE and the standard deviation of RMSE values decreases with a larger number of extracted lines. The orientation of the line sensor turned out to be important for the RMSE. Vertically oriented line sensors achieve lower RMSEs than horizontally oriented sensors because of the influence of the incident angle. Furthermore, the head-pose of the subject seems to be important for the accuracy. Conclusion Line sensors deliver comparable results to previously analysed area image sensors. Nevertheless, the scattering of the values is higher and the size and orientation of the sensor and the head-pose have an influence on the RMSE of the learning process. Therefore, line sensors are feasible for tissue thickness estimation but they are a trade-off between accuracy and speed.

  19. Field Observation of Joint Structures in Various Types of Igneous Rocks

    NASA Astrophysics Data System (ADS)

    Kano, Shingo; Tsuchiya, Noriyoshi

    2006-05-01

    In this study, field observations of natural fracture network systems in some intrusive and extrusive rocks were undertaken, to clarify the fracturing mechanism in the rocks. Shallow intrusives, whose depth of emplacement was less than several hundred metres, include the Momo-iwa Dacite dome on Rebun Island (Hokkaido), and Jodogahama Rhyolite in Iwate prefecture. Extrusive complexes studied include the Tojinbo Andesite and Ojima Rhyodacite in Fukui prefecture. Rocks of `granitic' composition were collected from the Takidani (Japan Alps) and Hijiori (Yamagata prefecture) plutons. The joint structure in Hijiori Granite was evaluated by analysis of core samples extracted from the HDR-3 geothermal production well. Based on detailed field observation, joint structures related to thermal contraction of a rock mass could be classified according to their inferred depth of formation. Joints from a near surface setting, such as shallow intrusive rocks and extrusives, tend to form pentagonal — hexagonal columnar structures (for a variety of rock types), whilst granitic rocks (from a deeper setting) typically exhibit a parallelepiped structure. The apparent differences in joint form are inferred to be dependent on the confining pressure, which acts on joint generation and propagation. In cases of non-confining pressure, such as the near-surface (shallow intrusive/extrusive) setting, joint networks typically form a columnar structure. On the contrary, confining pressure is considerably greater for deeper rock masses, and these form a parallelepiped joint structure.

  20. SU-E-J-103: Propagation of Rectum and Bladder Contours for Tandem and Ring (T&R) HDR Treatment Using Deformable Image Registration

    SciTech Connect

    Yuan, Y; Chao, M; Sheu, R; Dumane, V; Gupta, V; Lo, Y

    2015-06-15

    Purpose: To investigate the feasibility of using DIR to propagate the manually contoured rectum and bladder from the 1st insertion to the new CT images on subsequent insertions and evaluate the segmentation performance. Methods: Ten cervical cancer patients, who were treated by T&R brachytherapy in 3–4 insertions, were retrospectively collected. In each insertion, rectum and bladder were manually delineated on the planning CT by a physicist and verified by a radiation oncologist. Using VelocityAI (Velocity Medical Solutions, Atlanta, GA), a rigid registration was firstly employed to match the bony structures between the first insertion and each of the following insertions, then a multi-pass B-spine DIR was carried out to further map the sub volume that encompasses rectum and bladder. The resultant deformation fields propagated contours, and dice similarity coefficient (DSC) was used to quantitatively evaluate the agreement between the propagated contours and the manually-delineated organs. For the 3rd insertion, we also evaluated if the segmentation performance could be improved by propagating the contours from the most recent insertion, i.e., the 2nd insertion. Results: On average, the contour propagation took about 1 minute. The average and standard deviation of DSC over all insertions and patients was 0.67±0.10 (range: 0.44–0.81) for rectum, and 0.78±0.07 (range: 0.63–0.87) for bladder. For the 3rd insertion, propagating contours from the 2nd insertion could improve the segmentation performance in terms of DSC from 0.63±0.10 to 0.72±0.08 for rectum, and from 0.77±0.07 to 0.79±0.06 for bladder. A Wilcoxon signed rank test indicated that the improvement was statistically significant for rectum (p = 0.004). Conclusion: The preliminary results demonstrate that deformable image registration could efficiently and accurately propagate rectum and bladder contours between CT images in different T&R brachytherapy fractions. We are incorporating the propagated

  1. Energy Conservation Designed into HDR's New Building

    ERIC Educational Resources Information Center

    Jenkins, Larry

    1974-01-01

    A new building has been engineered by its engineer-owner tenants with provisions for two gas-oil hot water generators and for an electric boiler, so that operating personnel could switch to whatever fuel is available. (Author/MLF)

  2. Test Architecture, Test Retrofit

    ERIC Educational Resources Information Center

    Fulcher, Glenn; Davidson, Fred

    2009-01-01

    Just like buildings, tests are designed and built for specific purposes, people, and uses. However, both buildings and tests grow and change over time as the needs of their users change. Sometimes, they are also both used for purposes other than those intended in the original designs. This paper explores architecture as a metaphor for language…

  3. Test plan :

    SciTech Connect

    Dwyer, Stephen F.

    2013-05-01

    This test plan is a document that provides a systematic approach to the planned testing of rooftop structures to determine their actual load carrying capacity. This document identifies typical tests to be performed, the responsible parties for testing, the general feature of the tests, the testing approach, test deliverables, testing schedule, monitoring requirements, and environmental and safety compliance.

  4. Pinworm test

    MedlinePlus

    Oxyuriasis test; Enterobiasis test; Tape test ... diagnose this infection is to do a tape test. The best time to do this is in ... lay their eggs at night. Steps for the test are: Firmly press the sticky side of a ...

  5. Thyroid Tests

    MedlinePlus

    ... calories and how fast your heart beats. Thyroid tests check how well your thyroid is working. They ... thyroid diseases such as hyperthyroidism and hypothyroidism. Thyroid tests include blood tests and imaging tests. Blood tests ...

  6. Susceptibility Testing

    MedlinePlus

    ... Also known as: Sensitivity Testing; Drug Resistance Testing; Culture and Sensitivity; C & S; Antimicrobial Susceptibility Formal name: Bacterial and Fungal Susceptibility Testing Related tests: Urine Culture ; Blood Culture ; Bacterial Wound Culture ; AFB Testing ; MRSA ; ...

  7. Tracer experiment results during the Long-Term Flow Test of the Fenton Hill reservoir

    SciTech Connect

    Rodrigues, N.E.V.; Robinson, B.A.; Counce, D.A.

    1993-02-01

    Three chemical tracer experiments and one extended injection of fluid low in concentration of dissolved species have been carried out during the Long Term Flow Test (LTFT) of the Fenton Hill Hot Dry Rock (HDR) reservoir. The tracer tests,results illustrate the dynamic nature of the flow system, with more fluid traveling through longer residence time paths as heat is extracted. The total fracture volumes calculated from these tests allow us to determine the fate of unrecovered injection fluid, examine the pressure-dependence of fracture volume, and, through a comparison to the hydraulic performance, postulate a model for the nature of the pressure drops through the system. The Fresh Water Flush (FWF) test showed that while no dissolved specie behavior is truly conservative (no sources or sinks), several breakthrough curves are well explained with a pore fluid displacement model. Other dissolved components are clearly influenced by dissolution or precipitation reactions. Finally, the transient response of the chemistry during the FWF to an increase in production well pressure showed that some fractures connected to the production well preferentially open when pressure is raised.

  8. Pharmacogenomic Testing

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  9. Predictive Testing

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  10. Pregnancy Tests

    MedlinePlus

    ... Us Home A-Z Health Topics Pregnancy tests Pregnancy tests > A-Z Health Topics Pregnancy test fact ... To receive Publications email updates Enter email Submit Pregnancy tests If you think you may be pregnant , ...

  11. VDRL test

    MedlinePlus

    ... The VDRL test is a screening test for syphilis. It measures substances (proteins), called antibodies, that your ... come in contact with the bacteria that cause syphilis. How the Test is Performed The test is ...

  12. Coombs test

    MedlinePlus

    Direct antiglobulin test; Indirect antiglobulin test; Anemia - hemolytic ... No special preparation is necessary for this test. ... There are 2 types of the Coombs test: Direct Indirect The direct ... that are stuck to the surface of red blood cells. Many diseases ...

  13. Ham test

    MedlinePlus

    Acid hemolysin test; Paroxysmal nocturnal hemoglobinuria - Ham test; PNH - Ham test ... BJ. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures . 6th ed. Philadelphia, PA: Elsevier ...

  14. Trichomonas Testing

    MedlinePlus

    ... Trichomonas vaginalis by Amplified Detection; Trichomonas vaginalis by Direct Fluorescent Antibody (DFA) Related tests: Pap Test , Chlamydia ... by one of the following methods: Molecular testing, direct DNA probes, or nucleic acid amplification tests (NAATs)— ...

  15. Thyroid Tests

    MedlinePlus

    ... the thyroid, a computerized tomography (CT) scan, or nuclear medicine tests, to diagnose and find the cause ... is having the scan for other health problems. Nuclear medicine tests. Nuclear medicine tests of the thyroid ...

  16. Laboratory Tests

    MedlinePlus

    Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor ... compare your results to results from previous tests. Laboratory tests are often part of a routine checkup ...

  17. Lipase Test

    MedlinePlus

    ... known as: LPS Formal name: Lipase Related tests: Amylase , Trypsin , Trypsinogen At a Glance Test Sample The ... lipase is most often used, along with an amylase test , to help diagnose and monitor acute pancreatitis . ...

  18. IQ testing

    MedlinePlus

    IQ (intelligence quotient) testing is a series of exams used to determine your general intelligence in relation ... Many IQ tests are used today. Whether they measure actual intelligence or simply certain abilities is controversial. IQ tests ...

  19. Test Madness

    ERIC Educational Resources Information Center

    Hedrick, Wanda B., Ed.

    2007-01-01

    There's accountability and then there's the testing craze an iatrogenic practice that undermines real learning. Hedrick documents the negative effects of testing, giving teachers another weapon in their arsenal against mindless preparation for high-stakes tests.

  20. Chlamydia Testing

    MedlinePlus

    ... of testing for chlamydia. NAAT is a molecular test that detects the genetic material ( DNA ) of Chlamydia trachomatis . It is generally more sensitive and specific than other chlamydia tests and can be performed on a vaginal swab ...

  1. Testing Services

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Trace Laboratories is an independent testing laboratory specializing in testing printed circuit boards, automotive products and military hardware. Technical information from NASA Tech Briefs and two subsequent JPL Technical Support packages have assisted Trace in testing surface insulation resistance on printed circuit board materials. Testing time was reduced and customer service was improved because of Jet Propulsion Laboratory technical support packages.

  2. RPR test

    MedlinePlus

    ... more specific test for syphilis, such as FTA-ABS . The FTA-ABS test will help distinguish between syphilis and other ... Elsevier Saunders; 2015:chap 239. Read More FTA-ABS test VDRL test Review Date 9/10/2015 ...

  3. Composite Testing

    DTIC Science & Technology

    2007-01-01

    Impact Test Matrix for Each Team Impact Tests Qty. Reqd. Per Team Dimensions Steel- GFRP Hybrid Specimen 3 40” x 12” GFRP Control...5: Tension Test Specimen Details Table 2: Tension Test Matrix for Each Team Tension Tests Qty. Reqd. Per Team Dimensions Steel- GFRP Hybrid...Specimen 6 12” L x 1-2” W GFRP Control Specimen 3 12” L x 1-2” W Numerical Modelling A detailed numerical model

  4. Pregnancy test

    MedlinePlus

    ... eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 22nd ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 25. Read More Ectopic pregnancy HCG blood test - qualitative HCG blood test - quantitative HCG in urine Miscarriage ...

  5. Prenatal Tests

    MedlinePlus

    ... may recommend you have an invasive test, like amniocentesis , to confirm the results. Chorionic villus sampling (also ... done at 15 to 22 weeks of pregnancy. Amniocentesis (also called amnio). Tests the amniotic fluid from ...

  6. Procalcitonin Test

    MedlinePlus

    ... Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & ... Complete Blood Count , Blood Culture , CSF Analysis All content on Lab Tests Online ...

  7. HPV Test

    MedlinePlus

    ... test for wider range of HPV types. 2009 Mar 13. US Food and Drug Administration. Available online ... approves two DNA tests to detect HPV. 2009 Mar 17. Infectious Disease News. Available online at http:// ...

  8. Potassium test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003484.htm Potassium test To use the sharing features on this ... enable JavaScript. This test measures the amount of potassium in the fluid portion (serum) of the blood. ...

  9. Kidney Tests

    MedlinePlus

    ... taking out waste products and making urine. Kidney tests check to see how well your kidneys are working. They include blood, urine, and imaging tests. Early kidney disease usually does not have signs ...

  10. Urodynamic Testing

    MedlinePlus

    ... the ability or inability to stop the urine flow in midstream. For precise measurements, imaging equipment takes pictures of the bladder filling ... postvoid residual measurement cystometric test leak point pressure measurement pressure flow ... urodynamic tests Uroflowmetry Uroflowmetry is ...

  11. Pertussis Tests

    MedlinePlus

    ... as: Whooping Cough Tests Formal name: Bordetella pertussis Culture; Bordetella pertussis by PCR; Bordetella pertussis Antibodies (IgA, ... outbreak, at least one case be confirmed using culture. Culture – this test was the "gold standard" for ...

  12. Syphilis Test

    MedlinePlus

    ... been developed, making them convenient for screening purposes. Direct detection of bacteria —these tests are less commonly ... highly sensitive; can be used to exclude neurosyphilis. Direct detection tests (much less common): Microscopic Exam, Darkfield ...

  13. Seismic testing

    SciTech Connect

    Knott, S.

    1981-10-01

    Electric Power Research Institute (EPRI) research programs in seismic testing to improve earthquake design guidelines lowers the safety-design costs of nuclear power plants. Explosive tests that simulate earthquakes help to determine how structures respond to ground motion and how these are related to soil and geologic conditions at a specific site. Explosive tests develop data for simulation using several computer codes. Photographs illustrate testing techniques. 6 references. (DCK)

  14. Tested Demonstrations.

    ERIC Educational Resources Information Center

    Gilbert, George L., Ed.

    1988-01-01

    Describes three flame test demonstrations including "Student-Presented Demonstrations on the Colors of Transition Metal Complexes,""A Flame Test Demonstration Device," and "Vivid Flame Tests." Preparation and procedures are discussed. Included in the first demonstration is an evaluation scheme for grading student…

  15. Teacher Testing.

    ERIC Educational Resources Information Center

    Dunn, Judy; And Others

    1987-01-01

    A one-page introduction is followed by summaries of articles and documents on teacher competency testing. George F. Madaus argues that, although tests serve some useful functions, treating them as a major mechanism for reforming education is questionable. Peter A. Garcia examines the negative impact of testing on minority teachers and minorities…

  16. Analytical testing

    NASA Technical Reports Server (NTRS)

    Flannelly, W. G.; Fabunmi, J. A.; Nagy, E. J.

    1981-01-01

    Analytical methods for combining flight acceleration and strain data with shake test mobility data to predict the effects of structural changes on flight vibrations and strains are presented. This integration of structural dynamic analysis with flight performance is referred to as analytical testing. The objective of this methodology is to analytically estimate the results of flight testing contemplated structural changes with minimum flying and change trials. The category of changes to the aircraft includes mass, stiffness, absorbers, isolators, and active suppressors. Examples of applying the analytical testing methodology using flight test and shake test data measured on an AH-1G helicopter are included. The techniques and procedures for vibration testing and modal analysis are also described.

  17. Testing Relativity

    NASA Astrophysics Data System (ADS)

    Hentschel, Klaus

    in chapter 7 of this book, Klaus Hentschel first reviews Einstein's general attitude towards experiments, much more positive than generally believed, then reviews experimental tests of both special and general relativity, focussing on tests during Einstein's lifetime, incl. gravitational redshift, light deflection, perihelion motion. Among the non-standard tests, time-delay measurements, gyroscope experiments, the Nordtvedt effect, and gravitational waves are also discussed.

  18. Performance tests.

    PubMed Central

    Wetherell, A

    1996-01-01

    This paper discusses the use of psychological performance tests to assess the effects of environmental stressors. The large number and the variety of performance tests are illustrated, and the differences between performance tests and other psychological tests are described in terms of their design, construction, use, and purpose. The stressor emphasis is on the effects of drugs since that is where most performance tests have found their main application, although other stressors, e.g., fatigue, toxic chemicals, are mentioned where appropriate. Diazepam is used as an example. There is no particular performance emphasis since the tests are intended to have wide applicability. However, vehicle-driving performance is discussed because it has been the subject of a great deal of research and is probably one of the most important areas of application. Performance tests are discussed in terms of the four main underlying models--factor analysis, general information processing, multiple resource and strategy models, and processing-stage models--and in terms of their psychometric properties--sensitivity, reliability, and content, criterion, construct, and face validity. Some test taxonomies are presented. Standardization is also discussed with reference to the reaction time, mathematical processing, memory search, spatial processing, unstable tracking, verbal processing, and dual task tests used in the AGARD STRES battery. Some comments on measurement strengths and appropriate study designs and methods are included. PMID:9182033

  19. Rubella Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  20. Malnutrition Tests

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  1. RSV Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  2. PTH Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  3. Progesterone Test

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  4. Testing Speaking.

    ERIC Educational Resources Information Center

    Kitao, S. Kathleen; Kitao, Kenji

    Speaking a second language is probably the most difficult skill to test in that it involves a combination of skills that may have no correlation with each other, and which do not lend themselves to objective testing. In addition, what can be understood is a function of the listener's background and ability as well as those of the speaker. Another…

  5. Microalbumin Test

    MedlinePlus

    ... test to detect very small levels of a blood protein (albumin) in your urine. A microalbumin test is used ... kidney disease. Healthy kidneys filter waste from your blood and hang on to the healthy components, including proteins such as albumin. Kidney damage can cause proteins to leak through ...

  6. Testing Behavior.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.

    2003-01-01

    Analyzes Georgia high-stakes testing case involving administrative law judge's recommendation (subsequently approved) that fifth-grade science teacher's teaching certificate be suspended for giving his students pretest copies of the Iowa Tests of Basic Skills. Suggests No Child Left Behind Act will spawn similar litigation in the future. (PKP)

  7. Strength Testing.

    ERIC Educational Resources Information Center

    Londeree, Ben R.

    1981-01-01

    Postural deviations resulting from strength and flexibility imbalances include swayback, scoliosis, and rounded shoulders. Screening tests are one method for identifying strength problems. Tests for the evaluation of postural problems are described, and exercises are presented for the strengthening of muscles. (JN)

  8. Allogeneic stem cell transplantation after reduced intensity conditioning in patients with relapsed or refractory Hodgkin’s lymphoma. Results of the HDR-ALLO study – a prospective clinical trial by the Grupo Español de Linfomas/Trasplante de Médula Osea (GEL/TAMO) and the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

    PubMed Central

    Sureda, Anna; Canals, Carme; Arranz, Reyes; Caballero, Dolores; Ribera, Josep Maria; Brune, Mats; Passweg, Jacob; Martino, Rodrigo; Valcárcel, David; Besalduch, Joan; Duarte, Rafael; León, Angel; Pascual, Maria Jesus; García-Noblejas, Ana; Corral, Lucia López; Xicoy, Bianca; Sierra, Jordi; Schmitz, Norbert

    2012-01-01

    the major remaining challenge in this setting. The HDR-Allo trial was registered in the European Clinical Trials Database (EUDRACT, https://eudract.ema.europa.eu/) with number 02-0036 PMID:21993674

  9. Optical testing

    NASA Technical Reports Server (NTRS)

    Wyant, James; Hochberg, Eric; Breault, Robert; Greivenkamp, John; Hunt, Gary; Mason, Pete; Mcguire, James; Meinel, Aden; Morris, Mike; Scherr, Larry

    1992-01-01

    Optical testing is one of the most vital elements in the process of preparing an optical instrument for launch. Without well understood, well controlled, and well documented test procedures, current and future mission goals will be jeopardized. We should keep in mind that the reason we test is to provide an opportunity to catch errors, oversights, and problems on the ground, where solutions are possible and difficulties can be rectified. Consequently, it is necessary to create tractable test procedures that truly provide a measure of the performance of all optical elements and systems under conditions which are close to those expected in space. Where testing is not feasible, accurate experiments are required in order to perfect models that can exactly predict the optical performance. As we stretch the boundaries of technology to perform more complex space and planetary investigations, we must expand the technology required to test the optical components and systems which we send into space. As we expand the observational wavelength ranges, so must we expand our range of optical sources and detectors. As we increase resolution and sensitivity, our understanding of optical surfaces to accommodate more stringent figure and scatter requirements must expand. Only with research and development in these areas can we hope to achieve success in the ever increasing demands made on optical testing by the highly sophisticated missions anticipated over the next two decades. Technology assessment and development plan for surface figure, surface roughness, alignment, image quality, radiometric quantities, and stray light measurement are presented.

  10. Patch tests*

    PubMed Central

    Lazzarini, Rosana; Duarte, Ida; Ferreira, Alessandra Lindmayer

    2013-01-01

    Patch tests were introduced as a diagnostic tool in the late nineteenth century. Since then, they have improved considerably becoming what they are today. Patch tests are used in the diagnostic investigation of contact dermatitis worldwide. Batteries or series previously studied and standardized should be used in patch testing. The methodology is simple, but it requires adequate training for the results to be correctly interpreted and used. Despite having been used for over a century, it needs improvement like all other diagnostic techniques in the medical field. PMID:24474094

  11. Misconceptions Tests or Misconceived Tests?

    ERIC Educational Resources Information Center

    Griggs, Richard A.; Ransdell, Sarah E.

    1987-01-01

    States that taking a high school psychology course did not improve the performance of college students in an introductory psychology class on a modified version of Vaughan's misconceptions test (Test of Common Beliefs). Concludes that while college experience did lead to some improvement, comparison with other studies indicates that perhaps the…

  12. Cholesterol Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Cholesterol Share this page: Was this page helpful? Also known as: Blood Cholesterol Formal name: Total Cholesterol Related tests: HDL Cholesterol , ...

  13. VMA Test

    MedlinePlus

    ... is primarily used to detect and rule out neuroblastomas in children with an abdominal mass or other ... homovanillic acid (HVA) test to help diagnose a neuroblastoma, to monitor the effectiveness of treatment, and to ...

  14. Neuropathy Tests

    MedlinePlus

    ... strength and tone, and the ability to sense vibration, light touch, body position, temperature, and pain. Depending ... tests that record the ability to sense touch, vibration, cooling, and heat Nerve biopsy – to evaluate damage ...

  15. Runflat Testing

    DTIC Science & Technology

    2015-09-09

    tire assembly tread life combat flat central tire inflation system (CTIS) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...2 2. FACILITIES AND INSTRUMENTATION ......................... 2 2.1 Facilities...2 2.2 Instrumentation ...................................................................... 3 3. REQUIRED TEST

  16. Iron Test

    MedlinePlus

    ... detect and help diagnose iron deficiency or iron overload. In people with anemia , these tests can help ... also be ordered when iron deficiency or iron overload is suspected. Early iron deficiency often goes unnoticed. ...

  17. Albumin Test

    MedlinePlus

    ... may also be ordered to evaluate a person's nutritional status. ^ Back to top When is it ordered? An ... albumin test to check or monitor a person's nutritional status. However, since albumin concentrations respond to a variety ...

  18. Trypsinogen Test

    MedlinePlus

    ... of some newborn screening programs to screen for cystic fibrosis (CF) . It may be used in conjunction with a sweat chloride test and/or a cystic fibrosis gene mutation panel to help identify CF. IRT ...

  19. Amylase Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Amylase Share this page: Was this page helpful? Also known as: Amy Formal name: Amylase Related tests: Lipase , Trypsin , Trypsinogen At a Glance ...

  20. AMA Test

    MedlinePlus

    ... M2 test may be ordered to help diagnose primary biliary cirrhosis (PBC) . PBC is a serious condition in which ... be performed to look for characteristic signs of primary biliary cirrhosis in the liver tissue and to confirm the ...

  1. Sodium Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Sodium Share this page: Was this page helpful? Also known as: Na Formal name: Sodium Related tests: Chloride , Bicarbonate , Potassium , Electrolytes , Osmolality , Basic ...

  2. Fungal Tests

    MedlinePlus

    ... diagnosis is needed, as in cases of persistent, deep, or systemic infections, more extensive testing may be ... mouth (thrush) Vaginal itching and discharge (yeast infection) Deep and systemic fungal infections may cause a variety ...

  3. ACT Test

    MedlinePlus

    Advertisement Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: Policy | Opportunities PLEASE NOTE: Your web browser ...

  4. Troponins Test

    MedlinePlus

    ... affected by damage to skeletal muscles, so injections, accidents, and drugs that can damage muscle do not ... Learn more about ... Understanding Your Tests Inside the Lab In the News Article Index About This Site ...

  5. Test report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-08-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratory (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors have supplied their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and a subset of these systems were selected for performance evaluation at the BCIL. The technologies tested were electro-chemical energy storage systems comprised of lead acid, lithium-ion or zinc-bromide. MILSPRAY Military Technologies has developed an energy storage system that utilizes lead acid batteries to save fuel on a military microgrid. This report contains the testing results and some limited assessment of the Milspray Scorpion Energy Storage Device.

  6. Test Anxiety

    MedlinePlus

    ... for Parents for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q& ... Like other anxiety reactions, test anxiety affects the body and the mind. When you're under stress, your body releases ...

  7. Lactate Test

    MedlinePlus

    ... oxygen delivered to cells and tissues, such as shock or congestive heart failure , this test can be ... treated for an acute condition, such as sepsis, shock or heart attack , or a chronic condition, such ...

  8. Tested Demonstrations.

    ERIC Educational Resources Information Center

    Gilbert, George L.

    1990-01-01

    Included are three demonstrations that include the phase change of ice when under pressure, viscoelasticity and colloid systems, and flame tests for metal ions. The materials, procedures, probable results, and applications to real life situations are included. (KR)

  9. Ammonia Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Ammonia Share this page: Was this page helpful? Also known as: NH3 Formal name: Ammonia, plasma Related tests: Liver Panel , ALT , AST , ALP , ...

  10. Test report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-10-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratories (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprising of lead acid, lithium-ion or zinc-bromide. Raytheon/KTech has developed an energy storage system that utilizes zinc-bromide flow batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the Raytheon/KTech Zinc-Bromide Energy Storage System.

  11. Test Report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-10-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratories (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprising of lead acid, lithium-ion or zinc-bromide. GS Battery and EPC Power have developed an energy storage system that utilizes zinc-bromide flow batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the GS Battery, EPC Power HES RESCU.

  12. Genomic Testing

    MedlinePlus

    ... Services released a report identifying gaps in the regulation, oversight, and usefulness of genetic testing. They expressed ... December 20, 2016 Content source: Center for Surveillance, Epidemiology and Laboratory Services (CSELS) , Public Health Genomics Email ...

  13. Test report :

    SciTech Connect

    Rose, David Martin; Schenkman, Benjamin L.; Borneo, Daniel R.

    2013-08-01

    The Department of Energy Office of Electricity (DOE/OE), Sandia National Laboratory (SNL) and the Base Camp Integration Lab (BCIL) partnered together to incorporate an energy storage system into a microgrid configured Forward Operating Base to reduce the fossil fuel consumption and to ultimately save lives. Energy storage vendors will be sending their systems to SNL Energy Storage Test Pad (ESTP) for functional testing and then to the BCIL for performance evaluation. The technologies that will be tested are electro-chemical energy storage systems comprised of lead acid, lithium-ion or zinc-bromide. Princeton Power Systems has developed an energy storage system that utilizes lithium ion phosphate batteries to save fuel on a military microgrid. This report contains the testing results and some limited analysis of performance of the Princeton Power Systems Prototype Energy Storage System.

  14. Digoxin test

    MedlinePlus

    Heart failure - digoxin test ... Mann DL. Management of patients with heart failure with reduced ejection fraction. In: Mann DL, Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of ...

  15. Bilirubin Test

    MedlinePlus

    ... Also known as: Total Bilirubin; TBIL; Neonatal Bilirubin; Direct Bilirubin; Conjugated Bilirubin; Indirect Bilirubin; Unconjugated Bilirubin Formal ... Hepatitis B ; Hepatitis C ; Complete Blood Count ; Urinalysis ; Direct Antiglobulin Test ; Haptoglobin ; Reticulocyte Count All content on ...

  16. Testing technology

    SciTech Connect

    Not Available

    1993-10-01

    This bulletin from Sandia National Laboratories presents current research highlights in testing technology. Ion microscopy offers new nondestructive testing technique that detects high resolution invisible defects. An inexpensive thin-film gauge checks detonators on centrifuge. Laser trackers ride the range and track helicopters at low-level flights that could not be detected by radar. Radiation transport software predicts electron/photon effects via cascade simulation. Acoustic research in noise abatement will lead to quieter travelling for Bay Area Rapid Transport (BART) commuters.

  17. Estrogen Test

    MedlinePlus

    ... and Men Estradiol (E2) and/or estrone (E1) testing in boys and men may be ordered when: A boy has delayed puberty, characterized by delayed development of muscle mass, lack of deepening of the voice or growth of body hair, slow or delayed growth of testicles and penis ...

  18. Homocysteine Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  19. Phosphorus Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  20. Chymotrypsin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  1. AMA Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  2. TORCH Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  3. Gonorrhea Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  4. Triglycerides Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  5. Electrolytes Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  6. Myoglobin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  7. Toxoplasmosis Testing

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  8. Prealbumin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  9. Serotonin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  10. Lead Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  11. Prolactin Test

    MedlinePlus

    PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be limited. ... Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization and does not endorse non-AACC products and services. Advertising & Sponsorship: ...

  12. Prenatal Tests

    MedlinePlus

    ... baby with a birth defect — especially heart or genetic problems are carrying more than one baby have high blood pressure , diabetes , lupus , heart disease, ... A Week-by-Week Pregnancy Calendar Birth Plans Genetic Testing Staying Healthy During ... Having a Healthy Pregnancy Contact Us Print ...

  13. Rotational testing.

    PubMed

    Furman, J M

    2016-01-01

    The natural stimulus for the semicircular canals is rotation of the head, which also might stimulate the otolith organs. Vestibular stimulation usually induces eye movements via the vestibulo-ocular reflex (VOR). The orientation of the subject with respect to the axis of rotation and the orientation of the axis of rotation with respect to gravity together determine which labyrinthine receptors are stimulated for particular motion trajectories. Rotational testing usually includes the measurement of eye movements via a video system but might use a subject's perception of motion. The most common types of rotational testing are whole-body computer-controlled sinusoidal or trapezoidal stimuli during earth-vertical axis rotation (EVAR), which stimulates primarily the horizontal semicircular canals bilaterally. Recently, manual impulsive rotations, known as head impulse testing (HIT), have been developed to assess individual horizontal semicircular canals. Most types of rotational stimuli are not used routinely in the clinical setting but may be used in selected research environments. This chapter will discuss clinically relevant rotational stimuli and several types of rotational testing that are used primarily in research settings.

  14. Mono Test

    MedlinePlus

    ... services. Advertising & Sponsorship: Policy | Opportunities PLEASE NOTE: Your web browser does not have JavaScript enabled. Unless you enable Javascript , your ability to navigate and access the features of this website will be ... Mononucleosis (Mono) Test Share this page: Was this page helpful? Also ...

  15. HDR intraluminal brachytherapy for lung tumours--a case report.

    PubMed

    Wee, J T; Yang, E T; Lim, Y C

    1994-06-01

    The lung is a common site for cancer to occur, for both primary as well as metastases. The presence of such tumours can give rise to symptoms such as haemoptysis, cough, breathlessness and pneumonia. In most cases, treatment is strictly for palliation. We present a case report of a patient with an endobronchial metastasis from a primary hypernephroma which recurred following external beam radiotherapy. He was treated with a single fraction of intraluminal brachytherapy to a dose of 10Gy at 1 cm from the axis on a High Dose Rate Ir192 Remote Afterloading Machine. There were no adverse effects following treatment. On follow-up 7 months later, the patient did not have any further recurrence of breathlessness although his disease had progressed at other sites.

  16. Using HDR (Hot Dry Rock) technology to recharge The Geysers

    SciTech Connect

    Brown, D.W.; Robinson, B.A.

    1990-01-01

    The main reason for the productivity decline at The Geysers geothermal field is obvious: more fluid is being withdrawn from the reservoir than is being returned by reinjection and natural recharge. However, there is another factor that may be contributing to this decline --- the method of reinjection. By reinjecting cold condensate directly into the steam dome as is the current practice, the very large pressure difference between the injected condensate and the underpressured reservoir guarantees that the reinjected fluid will fall rapidly to the bottom of the reservoir, with very little residence time for heat transfer. This point is very important since the vast majority of the heat contained in The Geysers geothermal field is stored in the hot rock comprising the reservoir. 10 refs., 4 figs.

  17. Spatial imaging in color and HDR: prometheus unchained

    NASA Astrophysics Data System (ADS)

    McCann, John J.

    2013-03-01

    The Human Vision and Electronic Imaging Conferences (HVEI) at the IS and T/SPIE Electronic Imaging meetings have brought together research in the fundamentals of both vision and digital technology. This conference has incorporated many color disciplines that have contributed to the theory and practice of today's imaging: color constancy, models of vision, digital output, high-dynamic-range imaging, and the understanding of perceptual mechanisms. Before digital imaging, silver halide color was a pixel-based mechanism. Color films are closely tied to colorimetry, the science of matching pixels in a black surround. The quanta catch of the sensitized silver salts determines the amount of colored dyes in the final print. The rapid expansion of digital imaging over the past 25 years has eliminated the limitations of using small local regions in forming images. Spatial interactions can now generate images more like vision. Since the 1950's, neurophysiology has shown that post-receptor neural processing is based on spatial interactions. These results reinforced the findings of 19th century experimental psychology. This paper reviews the role of HVEI in color, emphasizing the interaction of research on vision and the new algorithms and processes made possible by electronic imaging.

  18. Dosimetric equivalence of nonstandard HDR brachytherapy catheter patterns

    SciTech Connect

    Cunha, J. A. M.; Hsu, I-C.; Pouliot, J.

    2009-01-15

    Purpose: To determine whether alternative high dose rate prostate brachytherapy catheter patterns can result in similar or improved dose distributions while providing better access and reducing trauma. Materials and Methods: Standard prostate cancer high dose rate brachytherapy uses a regular grid of parallel needle positions to guide the catheter insertion. This geometry does not easily allow the physician to avoid piercing the critical structures near the penile bulb nor does it provide position flexibility in the case of pubic arch interference. This study used CT datasets with 3 mm slice spacing from ten previously treated patients and digitized new catheters following three hypothetical catheter patterns: conical, bi-conical, and fireworks. The conical patterns were used to accommodate a robotic delivery using a single entry point. The bi-conical and fireworks patterns were specifically designed to avoid the critical structures near the penile bulb. For each catheter distribution, a plan was optimized with the inverse planning algorithm, IPSA, and compared with the plan used for treatment. Irrelevant of catheter geometry, a plan must fulfill the RTOG-0321 dose criteria for target dose coverage (V{sub 100}{sup Prostate}>90%) and organ-at-risk dose sparing (V{sub 75}{sup Bladder}<1 cc, V{sub 75}{sup Rectum}<1 cc, V{sub 125}{sup Urethra}<<1 cc). Results: The three nonstandard catheter patterns used 16 nonparallel, straight divergent catheters, with entry points in the perineum. Thirty plans from ten patients with prostate sizes ranging from 26 to 89 cc were optimized. All nonstandard patterns fulfilled the RTOG criteria when the clinical plan did. In some cases, the dose distribution was improved by better sparing the organs-at-risk. Conclusion: Alternative catheter patterns can provide the physician with additional ways to treat patients previously considered unsuited for brachytherapy treatment (pubic arch interference) and facilitate robotic guidance of catheter insertion. In addition, alternative catheter patterns may decrease toxicity by avoidance of the critical structures near the penile bulb while still fulfilling the RTOG criteria.

  19. Microgrid Testing

    SciTech Connect

    Shirazi, M.; Kroposki, B.

    2012-01-01

    With the publication of IEEE 1574.4 Guide for Design, Operation, and Integration of Distributed Resource Island Systems with Electric Power Systems, there is an increasing amount of attention on not only the design and operations of microgrids, but also on the proper operation and testing of these systems. This standard provides alternative approaches and good practices for the design, operation, and integration of microgrids. This includes the ability to separate from and reconnect to part of the utility grid while providing power to the islanded power system. This presentation addresses the industry need to develop standardized testing and evaluation procedures for microgrids in order to assure quality operation in the grid connected and islanded modes of operation.

  20. test title

    DTIC Science & Technology

    2015-12-01

    expectations by experimenters and testbed system managers, with minor automation from the testbed. We include design hooks for the system to use...scripting environment whose syntax enables specification of control flows that depend on controlled program outputs, thus automating system testing...Homeland Security and the Space and Naval Warfare Systems Center, San Diego, under contract No. N66001-07-C-2001, and by the National Science

  1. Earthquake Testing

    NASA Technical Reports Server (NTRS)

    1979-01-01

    During NASA's Apollo program, it was necessary to subject the mammoth Saturn V launch vehicle to extremely forceful vibrations to assure the moonbooster's structural integrity in flight. Marshall Space Flight Center assigned vibration testing to a contractor, the Scientific Services and Systems Group of Wyle Laboratories, Norco, California. Wyle-3S, as the group is known, built a large facility at Huntsville, Alabama, and equipped it with an enormously forceful shock and vibration system to simulate the liftoff stresses the Saturn V would encounter. Saturn V is no longer in service, but Wyle-3S has found spinoff utility for its vibration facility. It is now being used to simulate earthquake effects on various kinds of equipment, principally equipment intended for use in nuclear power generation. Government regulations require that such equipment demonstrate its ability to survive earthquake conditions. In upper left photo, Wyle3S is preparing to conduct an earthquake test on a 25ton diesel generator built by Atlas Polar Company, Ltd., Toronto, Canada, for emergency use in a Canadian nuclear power plant. Being readied for test in the lower left photo is a large circuit breaker to be used by Duke Power Company, Charlotte, North Carolina. Electro-hydraulic and electro-dynamic shakers in and around the pit simulate earthquake forces.

  2. Testing Understanding and Understanding Testing.

    ERIC Educational Resources Information Center

    Pedersen, Jean; Ross, Peter

    1985-01-01

    Provides examples in which graphs are used in the statements of problems or in their solutions as a means of testing understanding of mathematical concepts. Examples (appropriate for a beginning course in calculus and analytic geometry) include slopes of lines and curves, quadratic formula, properties of the definite integral, and others. (JN)

  3. Tauwer Test

    SciTech Connect

    Russ, James; Iori, Maurizio; Ronzhin, Anatoly; /Fermilab

    2011-01-24

    TAUWER is a proposed astroparticle experiment to detect ultrahigh energy TAU neutrinos, using detector towers arrayed on a mountainside looking down into a valley. This test is to study the possibility of replacing Hamamatsu miniature PMTs with SiPMs for readout by determining the response of scintillation detectors with SiPM readout to low energy electrons, 2 GeV or lower, as the beam will provide. The detector itself is a compact package shown in the picture on the cover. it was used in a parasitic test beam run on December 15, 2010, to compare the relative timing of the signals from three counters for MIPs. The only change for this new run is the insertion of 1.5 cm of Pb in front of counter 2 or counter 3 during most of the running. The experiment takes some electron data without Pb for calibration purposes. The apparatus will be mounted on the moving table in MT6.2B.

  4. Nuclear stress test

    MedlinePlus

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  5. Performance Testing

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Systems Technology, Inc., Hawthorne, CA, developed an electronic Critical Tracking Task (CTT) system that analyzes and rates a subject's visual/motor responses for Ames Research Center. Originally applied to measuring the effects of long term confinement in the mid 1960's, the CTT system is now marketed as FACTOR 1000 by Performance Factors, Inc. Alameda, CA, under a licensing agreement with Systems Technology. The system is a non-invasive, self-administered test that takes less than a minute and detects impairment from a broad range of causes, including stress, fatigue, illness, drugs, or alcohol. It is used daily by Old Town Trolley Tours, San Diego, CA, to assess each driver's physical coordination skills prior to the start of each shift. FACTOR 1000 reduces liabilities and costs related to accidents, and costs less than one dollar per day per employee. Performance Factors is now BioFactors, Inc.

  6. Orchestrated Testing.

    PubMed

    Pallotto, Eugenia K; Chuo, John; Piazza, Anthony J; Provost, Lloyd; Grover, Theresa R; Smith, Joan R; Mingrone, Teresa; Moran, Susan; Morelli, Lorna; Zaniletti, Isabella; Brozanski, Beverly

    Health care quality improvement collaboratives implement care bundles to target critical parts of a complex system to improve a specific health outcome. The quantitative impact of each component of the care bundle is often unknown. Orchestrated testing (OT) is an application of planned experimentation that allows simultaneous examination of multiple practices (bundle elements) to determine which intervention or combination of interventions affects the outcome. The purpose of this article is to describe the process needed to design and implement OT methodology for improvement collaboratives. Examples from a multicenter collaborative to reduce central line-associated bloodstream infections highlight the practical application of this approach. The key components for implementation of OT are the following: (1) define current practice and evidence, (2) develop a factorial matrix and calculate power, (3) formulate structure for engagement, (4) analyze results, and (5) replicate findings.

  7. Drug testing.

    PubMed

    Cowan, David A

    2008-01-01

    The analysis of sports samples for prohibited substances began in the 1960s and has developed since then using modern technologies close to the latest scientific discoveries. In this chapter the latest techniques and applications are described as well as the role of the World Anti-Doping Agency as the controlling body for the implementation of these tests. For small molecules, apart from the routine use of GC-MS, the newer techniques include the use of isotope ratio MS to detect testosterone and nandrolone administration and LC-MS/MS (liquid chromatography-tandem MS) to detect diuretics. For large molecules, several applications of LC-MS/MS are described as well as immunoprocedures for erythropoietin and human growth hormone. Finally, the latest method to detect homologous blood transfusion is briefly described.

  8. Heliostat tested

    NASA Astrophysics Data System (ADS)

    1984-12-01

    An enormous glint of sunlight darted over gently sloping summits and the hairpin curves of the mountain road. Mirrors concentrated this glint into a single beam, which then shot through a thick sheet of aluminum. Such was the result of the first test run on heliostats of the unique Solntse scientific-production complex being erected in Tashkent Oblast. There will be 62 such heliostats, each with an area of 50 square meters. Hot beams will be transmitted to the concave mirror of a concentrator (2,000 square meters). And the glint that shoots from it effortlessly melts not only aluminum but also almost all known materials. A special melting furnace toward which the concentractor directs hundreds of kilowatts of energy, burns brighter than a thousand suns. The complex presently under construction is intended for acquisition of ultrahigh-heat and concurrently ultrapure materials needed by many industrial sectors. This is extremely difficult to do by traditional chemical methods and even by the most modern methods--ultrahigh frequency and cathode ray methods.

  9. APU diaphragm testing. Test plan

    NASA Technical Reports Server (NTRS)

    Shelley, Richard

    1992-01-01

    Auxiliary Power Unit (APU) fuel (hydrazine) tanks have had to be removed from the Columbia Shuttle (OV-102) because they have been in service for 11 years, which is the limit of their useful life. As part of an effort to determine whether the useful life of the fuel tanks can be extended, examination of the ethylene propylene rubber (EPR) diaphragm and the metal from one of the APU tanks is required. The JSC Propulsion and Power Division has requested White Sands Test Facility (WSTF) to examine the EPR diaphragm thoroughly and the metal casing generally from one tank. The objective is to examine the EPR diaphragm for signs of degradation that may limit the life of its function in the APU propellant tank. The metal casing will also be examined for signs of surface corrosion.

  10. Computer-Based Testing: Test Site Security.

    ERIC Educational Resources Information Center

    Rosen, Gerald A.

    Computer-based testing places great burdens on all involved parties to ensure test security. A task analysis of test site security might identify the areas of protecting the test, protecting the data, and protecting the environment as essential issues in test security. Protecting the test involves transmission of the examinations, identifying the…

  11. Mononucleosis spot test

    MedlinePlus

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  12. Dengue Fever Testing

    MedlinePlus

    ... name: Dengue Antibodies (IgG, IgM); Dengue Virus by PCR Related tests: Arbovirus Testing , West Nile Virus Testing , ... testing are available: Molecular testing ( polymerase chain reaction, PCR )—this type of test detects the genetic material ...

  13. Context-dependent JPEG backward-compatible high-dynamic range image compression

    NASA Astrophysics Data System (ADS)

    Korshunov, Pavel; Ebrahimi, Touradj

    2013-10-01

    High-dynamic range (HDR) imaging is expected, together with ultrahigh definition and high-frame rate video, to become a technology that may change photo, TV, and film industries. Many cameras and displays capable of capturing and rendering both HDR images and video are already available in the market. The popularity and full-public adoption of HDR content is, however, hindered by the lack of standards in evaluation of quality, file formats, and compression, as well as large legacy base of low-dynamic range (LDR) displays that are unable to render HDR. To facilitate the wide spread of HDR usage, the backward compatibility of HDR with commonly used legacy technologies for storage, rendering, and compression of video and images are necessary. Although many tone-mapping algorithms are developed for generating viewable LDR content from HDR, there is no consensus of which algorithm to use and under which conditions. We, via a series of subjective evaluations, demonstrate the dependency of the perceptual quality of the tone-mapped LDR images on the context: environmental factors, display parameters, and image content itself. Based on the results of subjective tests, it proposes to extend JPEG file format, the most popular image format, in a backward compatible manner to deal with HDR images also. An architecture to achieve such backward compatibility with JPEG is proposed. A simple implementation of lossy compression demonstrates the efficiency of the proposed architecture compared with the state-of-the-art HDR image compression.

  14. Cholesterol testing and results

    MedlinePlus

    Cholesterol test results; LDL test results; VLDL test results; HDL test results; Coronary risk profile results; Hyperlipidemia- ... Some cholesterol is considered good and some is considered bad. Different blood tests can be done to measure each ...

  15. Growth hormone suppression test

    MedlinePlus

    GH suppression test; Glucose loading test; Acromegaly - blood test; Gigantism - blood test ... At least 3 blood samples are taken. The test is done in the following way: The first blood sample is collected between 6 ...

  16. Heart failure - tests

    MedlinePlus

    CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... An echocardiogram (Echo) is a test that uses sound waves to create a moving picture of the heart. The picture is much more detailed than a plain ...

  17. Turbine blade testing methods

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Testing procedures which could be used to model test turbine blades are developed. The methods studied were methods which used and extended current modal testing procedures. An acoustical impacting testing method was perfected for testing small turbine blades.

  18. HIV Antibody Test

    MedlinePlus

    ... test is performed that detects the genetic material ( RNA ) of the virus. An HIV RNA test will detect HIV in most people by ... next test to perform is an HIV-1 RNA test (nucleic acid amplification test, NAAT). If the ...

  19. Glucose urine test

    MedlinePlus

    Urine sugar test; Urine glucose test; Glucosuria test; Glycosuria test ... After you provide a urine sample, it is tested right away. The health care provider uses a dipstick made with a color-sensitive pad. The ...

  20. Draft Test Guideline: Gammarid Acute Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  1. Draft Test Guideline: Penaeid Acute Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  2. Tests, Testing, and Genuine School Reform

    ERIC Educational Resources Information Center

    Walberg, Herbert J., Ed.

    2011-01-01

    The pressing need to improve achievement in American schools is widely recognized. In "Tests, Testing, and Genuine School Reform," Herbert J. Walberg draws on scientific studies of tests and their uses to inform citizens, educators, and policy makers about well-established principles of testing, current problems, and promising evidence-based…

  3. Draft Test Guideline: Daphnid Chronic Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  4. Draft Test Guideline: Chironomid Sediment Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  5. Draft Test Guideline: Mysid Chronic Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  6. Draft Test Guideline: Mysid Acute Toxicity Test

    EPA Pesticide Factsheets

    The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

  7. What Is Diagnostic Testing?

    MedlinePlus

    ... Primary care providers Specialists Getting covered Research Basic science research Research in people ... screening Diagnostic testing Direct-to-consumer genetic testing Newborn screening Pharmacogenomic testing ...

  8. Listening: Who's Testing What?

    ERIC Educational Resources Information Center

    Watson, Kittie W.

    1984-01-01

    Discusses how listening is now being tested as three separate abilities, how test validity is affected by administration factors, criticisms of listening skills tests currently available, and criteria for development of reliable and valid listening tests. (MBR)

  9. Ketones urine test

    MedlinePlus

    Ketone bodies - urine; Urine ketones; Ketoacidosis - urine ketones test; Diabetic ketoacidosis - urine ketones test ... Urine ketones are usually measured as a "spot test." This is available in a test kit that ...

  10. Coccidioides precipitin test

    MedlinePlus

    Coccidioidomycosis antibody test ... There is no special preparation for the test. ... The precipitin test is one of several tests that can be done to determine if you are infected with the fungus ...

  11. Blood sugar test - blood

    MedlinePlus

    ... sugar; Blood sugar level; Fasting blood sugar; Glucose test; Diabetic screening - blood sugar test; Diabetes - blood sugar test ... The test may be done in the following ways: After you have not eaten anything for at least 8 ...

  12. Sweat electrolytes test

    MedlinePlus

    Sweat test; Sweat chloride; Iontophoretic sweat test ... No special steps are needed before this test. ... The test is not painful. Some people have a tingling feeling at the site of the electrode. This feeling ...

  13. Lactose tolerance tests

    MedlinePlus

    Hydrogen breath test for lactose tolerance ... Two common methods include: Lactose tolerance blood test Hydrogen breath test The hydrogen breath test is the preferred method. It measures the amount of hydrogen in the air you breathe out. ...

  14. Allergy Skin Tests

    MedlinePlus

    ... allergic rhinitis) Allergic asthma Dermatitis (eczema) Food allergies Penicillin allergy Bee venom allergy Latex allergy Skin tests are ... may recommend this test to check for an allergy to insect venom or penicillin. Patch test Patch testing is generally done to ...

  15. Strep Throat Test

    MedlinePlus

    ... Was this page helpful? Also known as: Throat Culture; Culture, Throat; Rapid Strep Test; Rapid Antigen Detection Test; ... beta hemolytic streptococcus Related tests: Influenza Tests ; Blood Culture ; ASO ; Anti-DNase B All content on Lab ...

  16. Prenatal Genetic Screening Tests

    MedlinePlus

    ... Education & Events Advocacy For Patients About ACOG Prenatal Genetic Screening Tests Home For Patients Search FAQs Prenatal ... Screening Tests FAQ165, September 2016 PDF Format Prenatal Genetic Screening Tests Pregnancy What is prenatal genetic testing? ...

  17. Genetic Testing (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Genetic Testing KidsHealth > For Parents > Genetic Testing Print A ... blood, skin, bone, or other tissue is needed. Genetic Testing During Pregnancy For genetic testing before birth, ...

  18. CRYSTAL FILTER TEST SET

    DTIC Science & Technology

    CRYSTAL FILTERS, *HIGH FREQUENCY, *RADIOFREQUENCY FILTERS, AMPLIFIERS, ELECTRIC POTENTIAL, FREQUENCY, IMPEDANCE MATCHING , INSTRUMENTATION, RADIOFREQUENCY, RADIOFREQUENCY AMPLIFIERS, TEST EQUIPMENT, TEST METHODS

  19. Automatic Test Program Generation.

    DTIC Science & Technology

    1978-03-01

    presents a test description language, NOPAL , in which a user may describe diagnostic tests, and a software system which automatically generates test...programs for an automatic test equipment based on the descriptions of tests. The software system accepts as input the tests specified in NOPAL , performs

  20. Intelligent test integration system

    NASA Technical Reports Server (NTRS)

    Sztipanovits, J.; Padalkar, S.; Rodriguez-Moscoso, J.; Kawamura, K.; Purves, B.; Williams, R.; Biglari, H.

    1988-01-01

    A new test technology is described which was developed for space system integration. The ultimate purpose of the system is to support the automatic generation of test systems in real time, distributed computing environments. The Intelligent Test Integration System (ITIS) is a knowledge based layer above the traditional test system components which can generate complex test configurations from the specification of test scenarios.

  1. GED Testing Fact Sheet

    ERIC Educational Resources Information Center

    GED Testing Service, 2009

    2009-01-01

    This GED Testing fact sheet provides information on: (1) GED[R] Tests; (2) Versions and Editions of the GED Tests; (3) Earning a Credential; (4) GED Testing Service[R]; (5) History of the GED Tests; (6) Who Accepts the GED Credential; (7) Public/Private Partnership of GEDTS; (8) Renowned GED Credential Recipients; (9) GED Testing Numbers for 2008;…

  2. Professional Issues in Testing.

    ERIC Educational Resources Information Center

    Pryor, Robert G. L.

    1991-01-01

    The following issues in psychological testing in Australia are reviewed: (1) commercialization of testing; (2) test user qualifications; and (3) computerization of testing. Proposed solutions include development of user guidelines, accreditation standards, test standards, and a network of test data information; and regulation by a professional…

  3. Transient Pressure Test Article test program

    NASA Technical Reports Server (NTRS)

    Vibbart, Charles M.

    1988-01-01

    The Transient Pressure Test Article test program being conducted at NASA-Marshall is described. The main goal of the TPTA test program is to provide data to verify the sealing capability of the redesigned SRM field joints, the nozzle-to-case joint, and the igniter joint. The TPTA test program can be used to demonstrate the assembly/disassembly and reusability of the redesigned joints along with the adequacy of assembly/disassembly tooling, procedures, and inspections.

  4. Boilerplate Test Article (BTA) Modal Test Correlation

    NASA Technical Reports Server (NTRS)

    Vassilakos, Gregory J.; Corliss, James M.; Mark, Stephen D.

    2017-01-01

    Modal testing of the Boilerplate Test Article (BTA) was performed to obtain data to determine the accuracy of the BTA LS- DYNA model in determining the structural response. The BTA is a full-scale steel and aluminum test article that is representative of the Orion Crew Module (CM), with similar outer-mold-line geometry, mass properties, and some similar structural features, including an internal pressure vessel connected to a backshell and heatshield via longerons, Retention and Release (R&R) brackets, and an aft ring. The structural design of the Orion CM is being developed based on LS-DYNA water landing simulations. To obtain data to evaluate the accuracy of LS-DYNA water impact landing simulations, a series of BTA water impacts was conducted at NASA Langley Research Center (LaRC). Discrepancies between test and simulation data are attributed to three causes:(1) Test data variability and uncertainty, (2) LS-DYNA water model and fluid-structure coupling approximations; and (3) LS-DYNA structural modeling approximations. Two activities have been undertaken to assess the accuracy of the BTA LS-DYNA structural model separately from the fluid-structure coupling portion of the water landing simulations: 1) modal testing, and 2) static load testing. The results from the static load tests are documented in a separate report. For the modal test series, the following tests were performed: (1) BTA Fully-Assembled Model Test, (2) BTA Backshell Removed Modal Test, (3) Standalone Heatshield Modal Test, (4) Standalone Windward Backshell Panel Modal Test; and (5) Standalone Leeward Backshell Panel Modal Test. This report documents findings from correlation of modal test data with LS-DYNA modal analysis results. The following figures illustrate the correlation of the modal frequencies. Where multiple closely spaced modes have been identified, the points representing the upper and lower frequencies are shown connected by a dotted line.

  5. From Test Takers to Test Makers

    ERIC Educational Resources Information Center

    Smith, Kari

    2009-01-01

    As a classroom teacher, Kari Smith realized that traditional objective tests don't always assess what students actually know. But tests are so deeply embedded in the education system that it would be difficult to do away with them entirely. Smith decided to make tests into learning tools. In this article, Smith describes three strategies for…

  6. Test Technical Manual 2014 GED® Test

    ERIC Educational Resources Information Center

    GED Testing Service, 2014

    2014-01-01

    This manual was written to provide technical information regarding the General Educational Development (GED®) test as evidence that the GED® test is technically sound. Throughout this manual, documentation is provided regarding the development of the GED® test and data collection activities, as well as evidence of reliability and validity. This…

  7. Sonar Test and Test Instrumentation Support.

    DTIC Science & Technology

    1976-11-10

    6487 < rM SEL ECTE CO, BU 9 1 Approved for public release;distribution unlimited. 611 095 A DNAR IA ST WI EST INSTRUMENTATIONJUPPORT.J ) Quaterly ...INSTRUMENTATION TEST AND EVALUATION 17 A. Introduction 17 B. Operational Testing of the AN/WQM-7 Sonar Test Set 17 C. AN/SQM-( ) Feasibility Study 19 VII. STUDY ...AN/WQM-5 Sonar Test Set Field Support IV. Special Purpose Passive Sonar Systems Support V. Sonar Instrumentation Test and Evaluation VI. Study of

  8. Satellite battery testing status

    NASA Technical Reports Server (NTRS)

    Haag, R.; Hall, S.

    1986-01-01

    Because of the large numbers of satellite cells currently being tested and anticipated at the Naval Weapons Support Center (NAVWPNSUPPCEN) Crane, Indiana, satellite cell testing is being integrated into the Battery Test Automation Project (BTAP). The BTAP, designed to meet the growing needs for battery testing at the NAVWPNSUPPCEN Crane, will consist of several Automated Test Stations (ATSs) which monitor batteries under test. Each ATS will interface with an Automation Network Controller (ANC) which will collect test data for reduction.

  9. Transient Pressure Test Article (TPTA) Test Firing

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The Marshall Space Flight Center (MSFC) successfully test fired the third in a series of Transient Pressure Test Articles (TPTA) in its east test area. The test article was a short-stack solid rocket motor 52-feet long and 12-feet in diameter. The TPTA tests were designed to evaluate the effects of temperature, pressure and external loads encountered by the SRM, primarily during ignition transients. Instrumentation on the motor recorded approximately 1,000 charnels of data to verify the structural performance, thermal response, sealing capability of the redesign field, and case-to-nozzle joints. The TPTA test stand, 14-feet wide by 26-feet long by 33-feet high, was built in 1987. The TPTA series was a joint effort among Morton Thiokol, Inc., United Space Boosters, Inc., Wyle Laboratories, and MSFC. Wyle Laboratories conducted the tests for the MSFC, which manages the redesigned SRM program for NASA.

  10. Test chip assembler and test program generator

    NASA Technical Reports Server (NTRS)

    Pina, C. A.

    1985-01-01

    One of the major problems in working at the geometry level for the generation of either test structure or functional circuit designs is the amount of labor involved in the design phase. To reduce the amount of labor involved in both the design and test of the structures used, JPL has developed a design and test program consisting of a Test Chip Assembler (TCA) and a Test Program Generator (TPG), which creates the geometrical description of the structures and generates the necessary test information using a high-level language. This system reduces the design time for a test chip by a factor of 30. To analyze the data obtained from wafer probing, a statistical package called STMJPL was developed. Some of the capabilities of the JPL software (STMJPL) are described.

  11. Test Anxiety, Test Comfort and Student Achievement Test Performance.

    ERIC Educational Resources Information Center

    Fyans, Leslie J., Jr.

    The Illinois Inventory of Educational Progress (IIEP) Test Comfort Scale was administered and test results were studied in terms of student achievement and correlates of achievement. Using the revised, seven-item scale, it was determined that: in grade 4, there was no main significant effect for sex or ethnic differences, although Orientals and…

  12. Balloon launched decelerator test program: Post-test test report

    NASA Technical Reports Server (NTRS)

    Dickinson, D.; Schlemmer, J.; Hicks, F.; Michel, F.; Moog, R. D.

    1972-01-01

    Balloon Launched Decelerator Test (BLDT) flights were conducted during the summer of 1972 over the White Sands Missile Range. The purpose of these tests was to qualify the Viking disk-gap band parachute system behind a full-scale simulator of the Viking Entry Vehicle over the maximum range of entry conditions anticipated in the Viking '75 soft landing on Mars. Test concerns centered on the ability of a minimum weight parachute system to operate without structural damage in the turbulent wake of the blunt-body entry vehicle (140 deg, 11.5 diameter cone). This is the first known instance of parachute operation at supersonic speeds in the wake of such a large blunt body. The flight tests utilized the largest successful balloon-payload weight combination known to get to high altitude (120kft) where rocket engines were employed to boost the test vehicle to supersonic speeds and dynamic pressures simulating the range of conditions on Mars.

  13. Cumulative experience of the US Hot Dry Rock Program

    SciTech Connect

    Brown, D.W.

    1993-01-01

    In over 20 years of research on the Hot Dry Rock (HDR) geothermal energy concept at Los Alamos National Laboratory, no obstacle has yet been found that would prevent its development as a major new energy source for the nation. To put the continuing development of the HDR concept in perspective, the most appropriate comparison is with fusion energy, the only other nonrenewable energy resource of the magnitude of HDR geothermal energy. In this context, research on fusion energy is currently so far from the demonstration stage that obstacles to its ultimate commercial development, such as induced radiation or neutron damage to structural materials, cannot yet be addressed from the standpoint of engineered solutions. For the commercialization of the HDR concept, on the other hand, we know what technical problems remain and are presently developing engineered solutions to address each of them. This document presents learned information on: the formation of HDR reservoirs; the structure of the deep precambrian basement; the mechanics of creating an HDR geothermal reservoir; peripheral water loss from deep HDR reservoirs; the determination of the size, orientation, and internal structure of the stimulated HDR region; and results from geochemical analyses and tracer testing.

  14. Cumulative experience of the US Hot Dry Rock Program

    SciTech Connect

    Brown, D.W.

    1993-04-01

    In over 20 years of research on the Hot Dry Rock (HDR) geothermal energy concept at Los Alamos National Laboratory, no obstacle has yet been found that would prevent its development as a major new energy source for the nation. To put the continuing development of the HDR concept in perspective, the most appropriate comparison is with fusion energy, the only other nonrenewable energy resource of the magnitude of HDR geothermal energy. In this context, research on fusion energy is currently so far from the demonstration stage that obstacles to its ultimate commercial development, such as induced radiation or neutron damage to structural materials, cannot yet be addressed from the standpoint of engineered solutions. For the commercialization of the HDR concept, on the other hand, we know what technical problems remain and are presently developing engineered solutions to address each of them. This document presents learned information on: the formation of HDR reservoirs; the structure of the deep precambrian basement; the mechanics of creating an HDR geothermal reservoir; peripheral water loss from deep HDR reservoirs; the determination of the size, orientation, and internal structure of the stimulated HDR region; and results from geochemical analyses and tracer testing.

  15. Gene conversion is strongly induced in human cells by double-strand breaks and is modulated by the expression of BCL-x(L)

    NASA Technical Reports Server (NTRS)

    Wiese, Claudia; Pierce, Andrew J.; Gauny, Stacey S.; Jasin, Maria; Kronenberg, Amy; Chatterjee, A. (Principal Investigator)

    2002-01-01

    Homology-directed repair (HDR) of DNA double-strand breaks (DSBs) contributes to the maintenance of genomic stability in rodent cells, and it has been assumed that HDR is of similar importance in DSB repair in human cells. However, some outcomes of homologous recombination can be deleterious, suggesting that factors exist to regulate HDR. We demonstrated previously that overexpression of BCL-2 or BCL-x(L) enhanced the frequency of X-ray-induced TK1 mutations, including loss of heterozygosity events presumed to arise by mitotic recombination. The present study was designed to test whether HDR is a prominent DSB repair pathway in human cells and to determine whether ectopic expression of BCL-x(L) affects HDR. Using TK6-neo cells, we find that a single DSB in an integrated HDR reporter stimulates gene conversion 40-50-fold, demonstrating efficient DSB repair by gene conversion in human cells. Significantly, DSB-induced gene conversion events are 3-4-fold more frequent in TK6 cells that stably overexpress the antiapoptotic protein BCL-X(L). Thus, HDR plays an important role in maintaining genomic integrity in human cells, and ectopic expression of BCL-x(L) enhances HDR of DSBs. This is the first study to highlight a function for BCL-x(L) in modulating DSB repair in human cells.

  16. Criteria for structural test

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The results of a study to define criteria and techniques of design, analysis and test which permit the use of a single major structural test article for performing dynamic, fatigue, and static testing are presented. The criteria developed is applicable to both space vehicles and aircraft structures operating in the subsonic or supersonic regime. The feasibility of such an approach was demonstrated by defining test interactions, compatibilities and incompatibilities between the three different types of tests. The results of the study indicate that the single test article concept is feasible with a testing sequence of dynamic test followed by a fatigue and static test.

  17. Cumulative achievement testing: progress testing in reverse.

    PubMed

    Swanson, D B; Holtzman, K Z; Butler, A

    2010-01-01

    This collaborative project between the National Board of Medical Examiners (NBME) and Case Western Reserve University (CWRU) School of Medicine explored the design and use of cumulative achievement tests in basic science education. In cumulative achievement testing, integrative end-of-unit tests are deliberately constructed to systematically retest topics covered in previous units as well as material from the just-completed unit. CWRU faculty developed and administered a series of six web-based cumulative achievement tests using retired United States Medical Licensing Examination (USMLE) step 1 test material and tools provided by NBME's Customized Assessment Services, and trends in student performance were examined as the new CWRU basic science curriculum unfolded. This article provides the background information about test design and administration, as well as samples of score reporting information for students and faculty. While firm conclusions about the effectiveness of cumulative achievement testing are not warranted after a pilot test at a single school, preliminary results suggest that cumulative achievement testing may be an effective complement to progress testing, with the former used to encourage retention of already-covered material and the latter used to assess growth toward the knowledge and skills expected of a graduating student.

  18. Transient Pressure Test Article Test Program

    NASA Technical Reports Server (NTRS)

    Vibbart, Charles M.

    1989-01-01

    The Transient Pressure Test Article (TPTA) test program is being conducted at a new test facility located in the East Test Area at the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This facility, along with the special test equipment (STE) required for facility support, was constructed specifically to test and verify the sealing capability of the Redesigned Solid Rocket Motor (RSRM) field, igniter, and nozzle joints. The test article consists of full scale RSRM hardware loaded with inert propellant and assembled in a short stack configuration. The TPTA is pressurized by igniting a propellant cartridge capable of inducing a pressure rise rate which stimulates the ignition transient that occurs during launch. Dynamic loads are applied during the pressure cycle to simulate external tank attach (ETA) strut loads present on the ETA ring. Sealing ability of the redesigned joints is evaluated under joint movement conditions produced by these combined loads since joint sealing ability depends on seal resilience velocity being greater than gap opening velocity. Also, maximum flight dynamic loads are applied to the test article which is either pressurized to 600 psia using gaseous nitrogen (GN2) or applied to the test article as the pressure decays inside the test article on the down cycle after the ignition transient cycle. This new test facility is examined with respect to its capabilities. In addition, both the topic of test effectiveness versus space vehicle flight performance and new aerospace test techniques, as well as a comparison between the old SRM design and the RSRM are presented.

  19. Teaching to the Test.

    ERIC Educational Resources Information Center

    Powell, Sara Davis

    1999-01-01

    Academically sound methods for preparing students for standardized tests include establishing tests' importance, forming preparation teams, gathering information, aligning curricular and test objectives, teaching test-wiseness skills, informing stakeholders, involving students in preparation plans, infusing curriculum with test content, and…

  20. Longitudinal Multistage Testing

    ERIC Educational Resources Information Center

    Pohl, Steffi

    2013-01-01

    This article introduces longitudinal multistage testing (lMST), a special form of multistage testing (MST), as a method for adaptive testing in longitudinal large-scale studies. In lMST designs, test forms of different difficulty levels are used, whereas the values on a pretest determine the routing to these test forms. Since lMST allows for…

  1. Test vs. simulation

    NASA Technical Reports Server (NTRS)

    Wood, Charles C.

    1991-01-01

    The following topics are presented in tabular form: (1) simulation capability assessments (no propulsion system test); (2) advanced vehicle simulation capability assessment; (3) systems tests identified events; (4) main propulsion test article (MPTA) testing evaluation; (5) Saturn 5, 1B, and 1 testing evaluation. Special vehicle simulation issues that are propulsion related are briefly addressed.

  2. Stool guaiac test

    MedlinePlus

    gFOBT; Guaiac smear test; Fecal occult blood test - guaiac smear; Stool occult blood test - guaiac smear ... This test detects blood in the digestive tract. It may be done if: You are being screened or tested for colon cancer You ...

  3. Growth hormone stimulation test

    MedlinePlus

    Arginine test; Arginine-GHRH test ... of re-inserting the needle each time. The test takes between 2 to 5 hours. The procedure ... eat for 10 to 12 hours before the test. Eating food can change the test results. Some ...

  4. CO2 blood test

    MedlinePlus

    Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2; CO2 test - serum ... Many medicines can interfere with blood test results. Your health care provider will tell you if you need to stop taking any medicines before you have this test. DO ...

  5. Vendor System Vulnerability Testing Test Plan

    SciTech Connect

    James R. Davidson

    2005-01-01

    The Idaho National Laboratory (INL) prepared this generic test plan to provide clients (vendors, end users, program sponsors, etc.) with a sense of the scope and depth of vulnerability testing performed at the INL’s Supervisory Control and Data Acquisition (SCADA) Test Bed and to serve as an example of such a plan. Although this test plan specifically addresses vulnerability testing of systems applied to the energy sector (electric/power transmission and distribution and oil and gas systems), it is generic enough to be applied to control systems used in other critical infrastructures such as the transportation sector, water/waste water sector, or hazardous chemical production facilities. The SCADA Test Bed is established at the INL as a testing environment to evaluate the security vulnerabilities of SCADA systems, energy management systems (EMS), and distributed control systems. It now supports multiple programs sponsored by the U.S. Department of Energy, the U.S. Department of Homeland Security, other government agencies, and private sector clients. This particular test plan applies to testing conducted on a SCADA/EMS provided by a vendor. Before performing detailed vulnerability testing of a SCADA/EMS, an as delivered baseline examination of the system is conducted, to establish a starting point for all-subsequent testing. The series of baseline tests document factory delivered defaults, system configuration, and potential configuration changes to aid in the development of a security plan for in depth vulnerability testing. The baseline test document is provided to the System Provider,a who evaluates the baseline report and provides recommendations to the system configuration to enhance the security profile of the baseline system. Vulnerability testing is then conducted at the SCADA Test Bed, which provides an in-depth security analysis of the Vendor’s system.b a. The term System Provider replaces the name of the company/organization providing the system

  6. Transient Pressure Test Article (TPTA) Test

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A forward segment is being lowered into the Transient Pressure Test Article (TPTA) test stand at the Marshall Space Flight Center (MSFC) east test area. The TPTA test stand, 14-feet wide, 27-feet long, and 33-feet high, was built in 1987 to provide data to verify the sealing capability of the redesign solid rocket motor (SRM) field and nozzle joints. The test facility applies pressure, temperature, and external loads to a short stack of solid rocket motor hardware. The simulated SRM ignition pressure and temperature transients are achieved by firing a small amount of specially configured solid propellant. The pressure transient is synchronized with external programmable dynamic loads that simulate lift off loads at the external tank attach points. Approximately one million pounds of dead weight on top of the test article simulates the weight of the other Shuttle elements.

  7. Transient Pressure Test Article (TPTA) Test Stand

    NASA Technical Reports Server (NTRS)

    1987-01-01

    A forward segment is being lowered into the Transient Pressure Test Article (TPTA) test stand at thw Marshall Space Flight Center (MSFC) east test area. The TPTA test stand, 14-feet wide, 27-feet long, and 33-feet high, was built in 1987 to provide data to verify the sealing capability of the redesign solid rocket motor (SRM) field and nozzle joints. The test facility applies pressure, temperature, and external loads to a short stack of solid rocket motor hardware. The simulated SRM ignition pressure and temperature transients are achieved by firing a small amount of specially configured solid propellant. The pressure transient is synchronized with external programmable dynamic loads that simulate lift off loads at the external tank attach points. Approximately one million pounds of dead weight on top of the test article simulates the weight of the other Shuttle elements.

  8. Tests Related to Pregnancy

    MedlinePlus

    ... testing also happens before you are pregnant, but embryos are tested instead of the parents. Eggs from ... called in-vitro fertilization, or IVF. The resulting embryos are then tested for increased risk of genetic ...

  9. Anthrax - blood test

    MedlinePlus

    ... The anthrax blood test looks for antibodies against Bacillus anthracis , the bacteria that cause anthrax. How the ... Serologic test for B anthracis Images Blood test Bacillus anthracis References Hall GS, Woods GL. Medical bacteriology. ...

  10. Urine concentration test

    MedlinePlus

    ... Test is Performed For this test, the specific gravity of urine , urine electrolytes , and/or urine osmolality ... it is tested right away. For urine specific gravity, the health care provider uses a dipstick made ...

  11. Screening Tests for Women

    MedlinePlus

    ... All people should know their HIV status. This Web page from womenshealth.gov talks about how to get tested for HIV, types of HIV tests, and confidential versus anonymous testing. Gonorrhea Fact Sheet - ...

  12. Color vision test

    MedlinePlus

    ... from birth) color vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling ... test - color; Ishihara color vision test Images Color blindness tests References Adams AJ, Verdon WA, Spivey BE. ...

  13. Testing and the Law.

    ERIC Educational Resources Information Center

    Bersoff, Donald N.

    1981-01-01

    Examines the legal issues concerning (1) cultural bias in educational tests; (2) the validity of employment tests; and (3) the disclosure of test materials. Discusses the legal interpretations of psychometric concepts that have arisen from recent litigation. (Author/GC)

  14. Common Tests for Arrhythmia

    MedlinePlus

    ... Venous Thromboembolism Aortic Aneurysm More Common Tests for Arrhythmia Updated:Dec 21,2016 Several tests can help ... View an animation of arrhythmia . Common Tests for Arrhythmia Holter monitor (continuous ambulatory electrocardiographic monitor) Suspected arrhythmias ...

  15. Home blood sugar testing

    MedlinePlus

    Diabetes - home glucose testing; Diabetes - home blood sugar testing ... Usual times to test your blood sugar are before meals and at bedtime. Your provider may ask you to check your blood sugar 2 hours after a ...

  16. Glucagon blood test

    MedlinePlus

    ... type I - glucagon test; Hypoglycemia - glucagon test; Low blood sugar - glucagon test ... A blood sample is needed . ... When the needle is inserted to draw blood, some people feel ... Afterward, there may be some throbbing or a slight bruise. This ...

  17. PBG urine test

    MedlinePlus

    Porphobilinogen test ... temporarily stop taking medicines that may affect the test results. Be sure to tell your provider about ... This test involves only normal urination, and there is no discomfort.

  18. Creatine phosphokinase test

    MedlinePlus

    CPK test ... vein. The procedure is called a venipuncture . This test may be repeated over 2 or 3 days ... helps determine which tissue has been damaged. This test may be used to: Diagnose heart attack Evaluate ...

  19. Sickle cell test

    MedlinePlus

    Sickledex; Hgb S test ... This test is done to tell if a person has abnormal hemoglobin that causes sickle cell disease and sickle ... and no symptoms, or only mild ones. This test does not tell the difference between these two ...

  20. Methylene blue test

    MedlinePlus

    Methemoglobinemia - methylene blue test ... No special preparation is required for this test. ... which are genetic (problem with your genes). This test is used to tell the difference between methemoglobinemia ...

  1. ALP isoenzyme test

    MedlinePlus

    Alkaline phosphatase isoenzyme test ... anything for 10 to 12 hours before the test, unless your health care provider tells you to do so. Many medicines can interfere with blood test results. Your health care provider will tell you ...

  2. Liver Function Tests

    MedlinePlus

    ... food, store energy, and remove poisons. Liver function tests are blood tests that check to see how well your liver ... hepatitis and cirrhosis. You may have liver function tests as part of a regular checkup. Or you ...

  3. Dexamethasone suppression test

    MedlinePlus

    DST; ACTH suppression test; Cortisol suppression test ... During this test, you will receive dexamethasone. This is a strong man-made (synthetic) glucocorticoid medication. Afterward, your blood is drawn ...

  4. Home Use Tests

    MedlinePlus

    ... C Human Immunodeficiency Virus (HIV) Menopause Fecal Occult Blood Ovulation (Saliva Test) Ovulation (Urine Test) Pregnancy Prothrombin Vaginal pH Resources for You Home Use Tests: Glossary Page ...

  5. Hepatitis A Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Hepatitis A Testing Share this page: Was this page ... HAV-Ab total; Anti-HAV Formal name: Viral Hepatitis A Antibody Related tests: Hepatitis B Testing ; Hepatitis ...

  6. Exams and Test Descriptions

    MedlinePlus

    ... spread, and to monitor it during treatment. Imaging (Radiology) Tests Doctors use imaging tests to make pictures ( ... help determine if cancer treatment is working. Imaging (Radiology) Tests for Cancer Understanding Radiation Risk from Imaging ...

  7. Blood Test: Testosterone

    MedlinePlus

    ... Test: Estradiol Precocious Puberty Understanding Puberty Endocrine System Male Reproductive System Getting a Blood Test (Video) All About Puberty Blood Test (Video) Male Reproductive System Contact Us Print Resources Send to a Friend ...

  8. PPD skin test

    MedlinePlus

    ... is a method used to diagnose silent (latent) tuberculosis (TB) infection. PPD stands for purified protein derivative. ... skin test; Tuberculin skin test; Mantoux test Images Tuberculosis in the kidney Tuberculosis in the lung Positive ...

  9. Prenatal Genetic Diagnostic Tests

    MedlinePlus

    ... Education & Events Advocacy For Patients About ACOG Prenatal Genetic Diagnostic Tests Home For Patients Search FAQs Prenatal ... Pamphlets - Spanish FAQ164, September 2016 PDF Format Prenatal Genetic Diagnostic Tests Pregnancy What is prenatal genetic testing? ...

  10. Home vision tests

    MedlinePlus

    ... testing. AMSLER GRID TEST This test helps detect macular degeneration . This is a disease that causes blurred vision, ... eye exam. People who are at risk of macular degeneration may be told by their ophthalmologist to perform ...

  11. Direct Antiglobulin Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Direct Antiglobulin Test Share this page: Was this page helpful? Also known as: DAT; Direct Coombs Test; Direct Anti-human Globulin Test Formal ...

  12. Liver function tests

    MedlinePlus

    Liver function tests are common tests that are used to see how well the liver is working. Tests include: ... M, Bowne WB, Bluth MH. Evaluation of liver function. In: McPherson RA, Pincus MR, eds. Henry's Clinical ...

  13. hCG Test (Pregnancy Test)

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? Advertisement Proceeds from website advertising help sustain Lab Tests ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  14. Test Analysis Guidelines

    NASA Technical Reports Server (NTRS)

    Jeng, Frank F.

    2007-01-01

    Development of analysis guidelines for Exploration Life Support (ELS) technology tests was completed. The guidelines were developed based on analysis experiences gained from supporting Environmental Control and Life Support System (ECLSS) technology development in air revitalization systems and water recovery systems. Analyses are vital during all three phases of the ELS technology test: pre-test, during test and post test. Pre-test analyses of a test system help define hardware components, predict system and component performances, required test duration, sampling frequencies of operation parameters, etc. Analyses conducted during tests could verify the consistency of all the measurements and the performance of the test system. Post test analyses are an essential part of the test task. Results of post test analyses are an important factor in judging whether the technology development is a successful one. In addition, development of a rigorous model for a test system is an important objective of any new technology development. Test data analyses, especially post test data analyses, serve to verify the model. Test analyses have supported development of many ECLSS technologies. Some test analysis tasks in ECLSS technology development are listed in the Appendix. To have effective analysis support for ECLSS technology tests, analysis guidelines would be a useful tool. These test guidelines were developed based on experiences gained through previous analysis support of various ECLSS technology tests. A comment on analysis from an experienced NASA ECLSS manager (1) follows: "Bad analysis was one that bent the test to prove that the analysis was right to begin with. Good analysis was one that directed where the testing should go and also bridged the gap between the reality of the test facility and what was expected on orbit."

  15. Titanium Honeycomb Panel Testing

    NASA Technical Reports Server (NTRS)

    Richards, W. Lance; Thompson, Randolph C.

    1996-01-01

    Thermal-mechanical tests were performed on a titanium honeycomb sandwich panel to experimentally validate the hypersonic wing panel concept and compare test data with analysis. Details of the test article, test fixture development, instrumentation, and test results are presented. After extensive testing to 900 deg. F, non-destructive evaluation of the panel has not detected any significant structural degradation caused by the applied thermal-mechanical loads.

  16. Strapdown gyro test program

    NASA Technical Reports Server (NTRS)

    Irvine, R. B.; Vanalstine, R.

    1977-01-01

    The power spectral noise characteristic performance of the Teledyne two-degree-of-freedom dry tuned gimbal gyroscope was determined. Tests were conducted using a current configuration SDG-5 gyro in conjunction with test equipment with minor modification. Long term bias stability tests were conducted as well as some first difference performance tests. The gyro, test equipment, and the tests performed are described. Results are presented.

  17. Test Response Patterning,

    DTIC Science & Technology

    REACTION(PSYCHOLOGY), PATTERN RECOGNITION), (*PERFORMANCE TESTS , STATISTICAL ANALYSIS), PSYCHOMETRICS, NUMERICAL METHODS AND PROCEDURES, ERRORS, TEST CONSTRUCTION(PSYCHOLOGY), MATHEMATICAL PREDICTION, PERSONALITY, BEHAVIOR

  18. CEQATR Thermal Test Overview

    NASA Technical Reports Server (NTRS)

    Balusek, Alan R.

    2009-01-01

    A thermal test overview of the Constellation Environmental Qualification and Acceptance Test Requirement (CEQATR) is presented. The contents include: 1) CEQATR Thermal Test Overview; 2) CxP Environments; 3) CEQATR Table 1.2-1; 4) Levels of Assembly; 5) Definitions for Levels of Assembly; 6) Hardware Applicability; 7) CEQATR Thermal-Related Definitions; 8) Requirements for unit-level thermal testing; 9) Requirements for major assembly level thermal testing; 10) General thermal testing requirements; 11) General thermal cycle, thermal vacuum profiles; 12) Test tolerances; 13) Vacuum vs Ambient; 14) Thermal Gradient; 15) Sequence of Testing; 16) Alternative Strategies; 17) Protoflight; 18) Halt/Hass; 19) Humidity; and 20) Tailoring.

  19. Testing for Software Safety

    NASA Technical Reports Server (NTRS)

    Chen, Ken; Lee, Yann-Hang; Wong, W. Eric; Xu, Dianxiang

    2007-01-01

    This research focuses on testing whether or not the hazardous conditions identified by design-level fault tree analysis will occur in the target implementation. Part 1: Integrate fault tree models into functional specifications so as to identify testable interactions between intended behaviors and hazardous conditions. Part 2: Develop a test generator that produces not only functional tests but also safety tests for a target implementation in a cost-effective way. Part 3: Develop a testing environment for executing generated functional and safety tests and evaluating test results against expected behaviors or hazardous conditions. It includes a test harness as well as an environment simulation of external events and conditions.

  20. Computerized Testing: The Hidden Figures Test.

    ERIC Educational Resources Information Center

    Jacobs, Ronald L.; And Others

    1985-01-01

    This study adapted the Hidden Figures Test for use on PLATO and determined the reliability of the computerized version compared to the paper and pencil version. Results indicate the test was successfully adapted with some modifications, and it was judged reliable although it may be measuring additional constructs. (MBR)

  1. Test plan for Simulated Saltcake Retrieval Test

    SciTech Connect

    HERTING, D.L.

    2000-07-19

    This document describes the plan for a bench-scale laboratory test to evaluate physical and chemical parameters associated with dissolution of a simulated saltcake waste. Parameters to be measured during the test include water addition rate, liquid drainage rate, visual observations of flow patterns, physical appearance and volume of dissolving saltcake, chemical composition of drained liquid, and polarized light microscopy analysis of solids.

  2. PACS component testing: beta and acceptance testing

    NASA Astrophysics Data System (ADS)

    Honeyman-Buck, Janice C.; Frost, Meryll M.; Staab, Edward V.

    1997-05-01

    The functionality and performance expectations of all PACS components must be specified at the time of purchase and tested completely upon delivery to assure customer satisfaction and successful adoption of the new technology. This process may be more elaborate if the customer agrees to serve as a Beta test site for a new component or a new revision of an existing component.A carefully designed test plan will save time at installation, will allow the customer and vendor to agree on expectations, and will assure that the installation will proceed as planned. This paper describes the test procedure used at the University of Florida to accept each PACS component, either a commercial product, or one developed in house. A set of documents contain descriptions of the pre-installation environment, sets of studies to be used in the test, installation checklist, functional usage reports, subjective evaluations, and problem reporting forms. Training and user documentation is also reviewed and 'help lists' are created to help users perform the most common functions. Although details in the documents are changed to match the type of component being tested, the general form of the test remains the same. A formal procedure for testing the functionality and performance of new equipment can save time for both the vendor and the customer and, if specified at the time of purchase, can serve to document the expectations of the customer. Following these procedures will assure a successful installation and improve customer satisfaction.

  3. Digface characterization test plan (remote testing)

    SciTech Connect

    Croft, K.; Hyde, R.; Allen, S.

    1993-08-01

    The objective of the Digface Characterization (DFC) Remote Testing project is to remotely deploy a sensor head (Mini-Lab) across a digface to determine if it can characterize the contents below the surface. The purpose of this project is to provide a robotics technology that allows removal of workers from hazards, increases speed of operations, and reduces life cycle costs compared to alternate methods and technologies. The Buried Waste Integrated Demonstration (BWID) is funding the demonstration, testing, and evaluation of DFC. This document describes the test plan for the DFC remote deployment demonstration for the BWID. The purposes of the test plan are to establish test parameters so that the demonstration results are deemed useful and usable and perform the demonstration in a safe manner and within all regulatory requirements.

  4. Integrated Test and Evaluation Flight Test 3 Flight Test Plan

    NASA Technical Reports Server (NTRS)

    Marston, Michael Lawrence

    2015-01-01

    The desire and ability to fly Unmanned Aircraft Systems (UAS) in the National Airspace System (NAS) is of increasing urgency. The application of unmanned aircraft to perform national security, defense, scientific, and emergency management are driving the critical need for less restrictive access by UAS to the NAS. UAS represent a new capability that will provide a variety of services in the government (public) and commercial (civil) aviation sectors. The growth of this potential industry has not yet been realized due to the lack of a common understanding of what is required to safely operate UAS in the NAS. NASA's UAS Integration into the NAS Project is conducting research in the areas of Separation Assurance/Sense and Avoid Interoperability, Human Systems Integration (HSI), and Communication to support reducing the barriers of UAS access to the NAS. This research is broken into two research themes namely, UAS Integration and Test Infrastructure. UAS Integration focuses on airspace integration procedures and performance standards to enable UAS integration in the air transportation system, covering Sense and Avoid (SAA) performance standards, command and control performance standards, and human systems integration. The focus of Test Infrastructure is to enable development and validation of airspace integration procedures and performance standards, including the integrated test and evaluation. In support of the integrated test and evaluation efforts, the Project will develop an adaptable, scalable, and schedulable relevant test environment capable of evaluating concepts and technologies for unmanned aircraft systems to safely operate in the NAS. To accomplish this task, the Project will conduct a series of Human-in-the-Loop and Flight Test activities that integrate key concepts, technologies and/or procedures in a relevant air traffic environment. Each of the integrated events will build on the technical achievements, fidelity and complexity of the previous tests and

  5. Bone Density Test

    MedlinePlus

    Tests and Procedures Bone density test By Mayo Clinic Staff A bone density test determines if you have osteoporosis — a disease that causes bones to ... your bones could be quite weak. A bone density test enhances the accuracy of calculating your risk ...

  6. Color identification testing device

    NASA Technical Reports Server (NTRS)

    Brawner, E. L.; Martin, R.; Pate, W.

    1970-01-01

    Testing device, which determines ability of a technician to identify color-coded electric wires, is superior to standard color blindness tests. It tests speed of wire selection, detects partial color blindness, allows rapid testing, and may be administered by a color blind person.

  7. Rh Factor Blood Test

    MedlinePlus

    Tests and Procedures Rh factor blood test By Mayo Clinic Staff Rhesus (Rh) factor is an inherited protein found on the surface of red ... positive. Your health care provider will recommend an Rh factor test during your first prenatal visit. This test ...

  8. Psychological Tests and Minorities.

    ERIC Educational Resources Information Center

    Wright, Brenda Johnson; Isenstein, Vivian R.

    The problems with traditional testing, particularly as they relate to minorities, are discussed; and psychological tests designed specifically for Blacks are reviewed. Considered are general problems, problems with testing at the higher education level and for employment, and moral and legal implications of the testing controversy. The rationale…

  9. Liquid Rocket Engine Testing

    NASA Technical Reports Server (NTRS)

    Rahman, Shamim

    2005-01-01

    Comprehensive Liquid Rocket Engine testing is essential to risk reduction for Space Flight. Test capability represents significant national investments in expertise and infrastructure. Historical experience underpins current test capabilities. Test facilities continually seek proactive alignment with national space development goals and objectives including government and commercial sectors.

  10. Test Preparation: Your Role

    MedlinePlus

    ... information about preparations needed for specific tests on web sites like Lab Tests Online. However, you should always follow your healthcare ... may sometimes be elaborated on further on "The Test" tab. However, be sure ... on this or any other web site, as different labs may have varying testing ...

  11. Flight Test Techniques

    DTIC Science & Technology

    2009-07-01

    Fort Rucker, AL 36362-5276 8. PERFORMING ORGANIZATION REPORT NUMBER TOP 7-4-020 9. SPONSORING/ MONITORING AGENCY NAME(S) AND ADDRESS(ES...2 3. REQUIRED TEST CONDITIONS ............................................. 3 3.1...3. REQUIRED TEST CONDITIONS . 3.1 Air Vehicle Flight Test Techniques. Many different flight test techniques are in existence. As technology

  12. Deconstructing Test Anxiety

    ERIC Educational Resources Information Center

    Putwain, David William

    2008-01-01

    Recent changes to educational policy which have focused attention on the use of high stakes testing as performance and accountability measures have renewed interest in test anxiety both in the UK and the USA. The aim of this paper is to provide a critical examination of the test anxiety construct, and explore the ways in which test anxiety is…

  13. Testing Our Limits

    ERIC Educational Resources Information Center

    Tempel, Melissa Bollow

    2012-01-01

    Computerized testing, including the widely used MAP test, has infiltrated the public schools in Milwaukee and across the nation, bringing with it a frightening future for public education. High-stakes standardized tests can be scored almost immediately via the internet, and testing companies can now easily link districts to their online data…

  14. Testing. Occasional Papers 21.

    ERIC Educational Resources Information Center

    Culhane, P. T., Ed.; White, J., Ed.

    Five papers on testing in English as a second language are included in this volume. "A Preliminary Diagnostic Test for Adult Immigrants" by Johan I. Arthur presents the first stage in a project to develop a test for limited English speaking adults in the Colchester, Essex area. "An Initial Testing Battery on a Course for Air Traffic…

  15. Regulation of Genetic Tests

    MedlinePlus

    ... En Español: Regulación de pruebas genéticas Regulation of Genetic Tests Overview of Genetic Testing Introduction to Genetic ... Statements Congressional Activity Genetic Testing Resources Overview of Genetic Testing As the science of genomics advances, genetic ...

  16. Pre-Test Assessment

    ERIC Educational Resources Information Center

    Berry, Thomas

    2008-01-01

    Pre-tests are a non-graded assessment tool used to determine pre-existing subject knowledge. Typically pre-tests are administered prior to a course to determine knowledge baseline, but here they are used to test students prior to topical material coverage throughout the course. While counterintuitive, the pre-tests cover material the student is…

  17. Dtest Testing Software

    NASA Technical Reports Server (NTRS)

    Jain, Abhinandan; Cameron, Jonathan M.; Myint, Steven

    2013-01-01

    This software runs a suite of arbitrary software tests spanning various software languages and types of tests (unit level, system level, or file comparison tests). The dtest utility can be set to automate periodic testing of large suites of software, as well as running individual tests. It supports distributing multiple tests over multiple CPU cores, if available. The dtest tool is a utility program (written in Python) that scans through a directory (and its subdirectories) and finds all directories that match a certain pattern and then executes any tests in that directory as described in simple configuration files.

  18. Flight Test Engineering

    NASA Technical Reports Server (NTRS)

    Pavlock, Kate Maureen

    2013-01-01

    Although the scope of flight test engineering efforts may vary among organizations, all point to a common theme: flight test engineering is an interdisciplinary effort to test an asset in its operational flight environment. Upfront planning where design, implementation, and test efforts are clearly aligned with the flight test objective are keys to success. This chapter provides a top level perspective of flight test engineering for the non-expert. Additional research and reading on the topic is encouraged to develop a deeper understanding of specific considerations involved in each phase of flight test engineering.

  19. Pancreatic exocrine function testing

    SciTech Connect

    Goff, J.S.

    1981-11-01

    It is important to understand which pancreatic function tests are available and how to interpret them when evaluating patients with malabsorption. Available direct tests are the secretin stimulation test, the Lundh test meal, and measurement of serum or fecal enzymes. Indirect tests assess pancreatic exocrine function by measuring the effect of pancreatic secretion on various nutrients. These include triglycerides labeled with carbon 14, cobalamin labeled with cobalt 57 and cobalt 58, and para-aminobenzoic acid bound to a dipeptide. Of all these tests the secretin stimulation test is the most accurate and reliable if done by experienced personnel. However, the indirect tests are simpler to do and appear to be comparable to the secretin test at detecting pancreatic exocrine insufficiency. These indirect tests are becoming clinically available and clinicians should familiarize themselves with the strengths and weaknesses of each.

  20. Entry/Exit Port testing, test report

    SciTech Connect

    Winkelman, R.H.

    1993-05-01

    The Waste Receiving and Processing Module I (WRAP-1) facility must have the ability to allow 55-gallon drums to enter and exit glovebox enclosures. An Entry/Exit Port (Appendix 1, Figure 1), designed by United Engineers and Constructors (UE&C), is one method chosen for drum transfer. The Entry/Exit Port is to be used for entry of 55-gallon drums into both process entry gloveboxes, exit of 55-gallon drum waste pucks from the low-level waste (LLW) glovebox, and loadout of waste from the restricted waste management glovebox. The Entry/Exit Port relies on capture velocity air flow and a neoprene seal to provide alpha confinement when the Port is in the open and closed positions, respectively. Since the glovebox is in a slight vacuum, air flow is directed into the glovebox through the space between the overpack drum and glovebox floor. The air flow is to direct any airborne contamination into the glovebox. A neoprene seal is used to seal the Port door to the glovebox floor, thus maintaining confinement in the closed position. Entry/Exit Port testing took place February 17, 1993, through April 14, 1993, in the 305 building of Westinghouse Hanford Company. Testing was performed in accordance with the Entry/Exit Port Testing Test Plan, document number WHC-SD-WO26-TP-005. A prototype Entry/Exit Port built at the Hanford Site was tested using fluorescent paint pigment and smoke candles as simulant contaminants. This test report is an interim test report. Further developmental testing is required to test modifications made to the Port as the original design of the Port did not provide complete confinement during all stages of operation.

  1. Flight Test Series 3: Flight Test Report

    NASA Technical Reports Server (NTRS)

    Marston, Mike; Sternberg, Daniel; Valkov, Steffi

    2015-01-01

    This document is a flight test report from the Operational perspective for Flight Test Series 3, a subpart of the Unmanned Aircraft System (UAS) Integration in the National Airspace System (NAS) project. Flight Test Series 3 testing began on June 15, 2015, and concluded on August 12, 2015. Participants included NASA Ames Research Center, NASA Armstrong Flight Research Center, NASA Glenn Research Center, NASA Langley Research center, General Atomics Aeronautical Systems, Inc., and Honeywell. Key stakeholders analyzed their System Under Test (SUT) in two distinct configurations. Configuration 1, known as Pairwise Encounters, was subdivided into two parts: 1a, involving a low-speed UAS ownship and intruder(s), and 1b, involving a high-speed surrogate ownship and intruder. Configuration 2, known as Full Mission, involved a surrogate ownship, live intruder(s), and integrated virtual traffic. Table 1 is a summary of flights for each configuration, with data collection flights highlighted in green. Section 2 and 3 of this report give an in-depth description of the flight test period, aircraft involved, flight crew, and mission team. Overall, Flight Test 3 gathered excellent data for each SUT. We attribute this successful outcome in large part from the experience that was acquired from the ACAS Xu SS flight test flown in December 2014. Configuration 1 was a tremendous success, thanks to the training, member participation, integration/testing, and in-depth analysis of the flight points. Although Configuration 2 flights were cancelled after 3 data collection flights due to various problems, the lessons learned from this will help the UAS in the NAS project move forward successfully in future flight phases.

  2. Test Control Center exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Have you ever wondered how the engineers at John C. Stennis Space Center in Hancock County, Miss., test fire a Space Shuttle Main Engine? The Test Control Center exhibit at StenniSphere can answer your questions by simulating the test firing of a Space Shuttle Main Engine. A recreation of one of NASA's test control centers, the exhibit explains and portrays the 'shake, rattle and roar' that happens during a real test firing.

  3. Solderability test system

    DOEpatents

    Yost, F.; Hosking, F.M.; Jellison, J.L.; Short, B.; Giversen, T.; Reed, J.R.

    1998-10-27

    A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time. 11 figs.

  4. Solderability test system

    DOEpatents

    Yost, Fred; Hosking, Floyd M.; Jellison, James L.; Short, Bruce; Giversen, Terri; Reed, Jimmy R.

    1998-01-01

    A new test method to quantify capillary flow solderability on a printed wiring board surface finish. The test is based on solder flow from a pad onto narrow strips or lines. A test procedure and video image analysis technique were developed for conducting the test and evaluating the data. Feasibility tests revealed that the wetted distance was sensitive to the ratio of pad radius to line width (l/r), solder volume, and flux predry time.

  5. NGST Optical Testing

    NASA Technical Reports Server (NTRS)

    Keski-Kuha, Ritva

    1999-01-01

    An Integrated Product Team (IPT) was formed to develop a detailed optical test methodology for testing of the Next Generation Space Telescope (NGST) mirrors and the optical system on the ground. Optical testing is a significant cost driver therefore the testing has to be planned in detailed fashion early. This paper will discuss the preliminary metrology test plan at the mirror component and telescope system level. Instrumentation, facilities and schedule will also be addressed.

  6. Solid Propellant Test Article (SPTA) Test Stand

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This photograph shows the Solid Propellant Test Article (SPTA) test stand with the Modified Nasa Motor (M-NASA) test article at the Marshall Space Flight Center (MSFC). The SPTA test stand, 12-feet wide by 12-feet long by 24-feet high, was built in 1989 to provide comparative performance data on nozzle and case insulation material and to verify thermostructural analysis models. A modified NASA 48-inch solid motor (M-NASA motor) with a 12-foot blast tube and 10-inch throat makes up the SPTA. The M-NASA motor is being used to evaluate solid rocket motor internal non-asbestos insulation materials, nozzle designs, materials, and new inspection techniques. New internal motor case instrumentation techniques are also being evaluated.

  7. Antimicrobials Products Tested or Pending Testing

    EPA Pesticide Factsheets

    The agency has completed testing of the majority of registered hospital disinfectants and tuberculocide products. The list of products can assist users in making informed choices regarding infection control in their facilities.

  8. Letter Directionality Test, Word Directionality Test, and Sentence Directionality Test.

    ERIC Educational Resources Information Center

    Twohig, Brian T.

    Designed to measure the subject's ability to discriminate among alphabetic letters varied over three spatial dimensions (left-right, vertical, and combination left-right and vertical), the tests can be administered in groups and take about twenty minutes to complete. Ten letters of the alphabet were selected for assymetry (for example, b-d) and…

  9. Dynamic Testing: Toward a Multiple Exciter Test

    DTIC Science & Technology

    2015-04-01

    sinusoidal motion is not sufficient to characterize such environments. Even though random vibration testing were then feasible, the initial limi...wheeled vehicles, which tend to be dominated by pre- dominantly low-frequency random vibrations , and aircraft and space vehicles that tend to be... random environments was a giant leap forward, the limitation continued of conducting vibration tests in one mechanical DOF at a time. The limitations

  10. Wolf Testing: Open Source Testing Software

    NASA Astrophysics Data System (ADS)

    Braasch, P.; Gay, P. L.

    2004-12-01

    Wolf Testing is software for easily creating and editing exams. Wolf Testing allows the user to create an exam from a database of questions, view it on screen, and easily print it along with the corresponding answer guide. The questions can be multiple choice, short answer, long answer, or true and false varieties. This software can be accessed securely from any location, allowing the user to easily create exams from home. New questions, which can include associated pictures, can be added through a web-interface. After adding in questions, they can be edited, deleted, or duplicated into multiple versions. Long-term test creation is simplified, as you are able to quickly see what questions you have asked in the past and insert them, with or without editing, into future tests. All tests are archived in the database. Written in PHP and MySQL, this software can be installed on any UNIX / Linux platform, including Macintosh OS X. The secure interface keeps students out, and allows you to decide who can create tests and who can edit information already in the database. Tests can be output as either html with pictures or rich text without pictures, and there are plans to add PDF and MS Word formats as well. We would like to thank Dr. Wolfgang Rueckner and the Harvard University Science Center for providing incentive to start this project, computers and resources to complete this project, and inspiration for the project's name. We would also like to thank Dr. Ronald Newburgh for his assistance in beta testing.

  11. Test Methods for Acceptance Testing of Telescopes

    DTIC Science & Technology

    1993-07-01

    instrument. Although various interferometer configurations are used, they all basically operate on the same principle. The beam from a stable continuous...a Goerz with a nominal focal length of 92 inches. This lens has been recoated and carefully aligned to produce excellent image quality. The focus...test. Such requirements are necessary when the procuring agency has no facilities for performing adequate tests. It is also an excellent policy even

  12. Nevada Test Site Sensor Test Facility

    SciTech Connect

    Gomez, B.J.; Boyer, W.B.

    1996-12-01

    A Sensor Test Facility (STF) was recently established at the Department of Energy`s Nevada Test Site (NTS). It has been used for a series of sensor tests that have demonstrated the usefulness of the testbed. The facility consists of a cut-and-cover bunker complex and the two square mile surrounding area. The STF was developed as a scientific testbed optimized for the development and evaluation of advanced sensor systems, including ground sensor systems designed to identify and detect hardened underground facilities. This was accomplished by identifying a facility in a remote location where seismic, acoustic, and electromagnetic interference would be minimal, establishing a testbed that would be accommodating to field testing, and conducting a thorough geophysical characterization of the area surrounding the facility in order to understand the local geology and its effects on geophysical signals emanating from the facility. The STF is representative of a number of cut-and-cover bunkers around the world that are used for the manufacture and/or storage of weapons of mass destruction. This paper provides a general description of the Nevada Test Site, the Sensor Test Facility, and the Geophysical Site Characterization.

  13. Morpheus Vertical Test Bed Flight Testing

    NASA Technical Reports Server (NTRS)

    Hart, Jeremy; Devolites, Jennifer

    2014-01-01

    NASA's Morpheus Project has developed and tested a prototype planetary lander capable of vertical takeoff and landing, that is designed to serve as a testbed for advanced spacecraft technologies. The lander vehicle, propelled by a LOX/Methane engine and sized to carry a 500kg payload to the lunar surface, provides a platform for bringing technologies from the laboratory into an integrated flight system at relatively low cost. Morpheus onboard software is autonomous from ignition all the way through landing, and is designed to be capable of executing a variety of flight trajectories, with onboard fault checks and automatic contingency responses. The Morpheus 1.5A vehicle performed 26 integrated vehicle test flights including hot-fire tests, tethered tests, and two attempted freeflights between April 2011 and August 2012. The final flight of Morpheus 1.5A resulted in a loss of the vehicle. In September 2012, development began on the Morpheus 1.5B vehicle, which subsequently followed a similar test campaign culminating in free-flights at a simulated planetary landscape built at Kennedy Space Center's Shuttle Landing Facility. This paper describes the integrated test campaign, including successes and setbacks, and how the system design for handling faults and failures evolved over the course of the project.

  14. Testing Tests on Active Galactic Nucleus Microvariability

    NASA Astrophysics Data System (ADS)

    de Diego, José A.

    2010-03-01

    Literature on optical and infrared microvariability in active galactic nuclei (AGNs) reflects a diversity of statistical tests and strategies to detect tiny variations in the light curves of these sources. Comparison between the results obtained using different methodologies is difficult, and the pros and cons of each statistical method are often badly understood or even ignored. Even worse, improperly tested methodologies are becoming more and more common, and biased results may be misleading with regard to the origin of the AGN microvariability. This paper intends to point future research on AGN microvariability toward the use of powerful and well-tested statistical methodologies, providing a reference for choosing the best strategy to obtain unbiased results. Light curves monitoring has been simulated for quasars and for reference and comparison stars. Changes for the quasar light curves include both Gaussian fluctuations and linear variations. Simulated light curves have been analyzed using χ2 tests, F tests for variances, one-way analyses of variance and C-statistics. Statistical Type I and Type II errors, which indicate the robustness and the power of the tests, have been obtained in each case. One-way analyses of variance and χ2 prove to be powerful and robust estimators for microvariations, while the C-statistic is not a reliable methodology and its use should be avoided.

  15. TESTING TESTS ON ACTIVE GALACTIC NUCLEI MICROVARIABILITY

    SciTech Connect

    De Diego, Jose A.

    2010-03-15

    Literature on optical and infrared microvariability in active galactic nuclei (AGNs) reflects a diversity of statistical tests and strategies to detect tiny variations in the light curves of these sources. Comparison between the results obtained using different methodologies is difficult, and the pros and cons of each statistical method are often badly understood or even ignored. Even worse, improperly tested methodologies are becoming more and more common, and biased results may be misleading with regard to the origin of the AGN microvariability. This paper intends to point future research on AGN microvariability toward the use of powerful and well-tested statistical methodologies, providing a reference for choosing the best strategy to obtain unbiased results. Light curves monitoring has been simulated for quasars and for reference and comparison stars. Changes for the quasar light curves include both Gaussian fluctuations and linear variations. Simulated light curves have been analyzed using {chi}{sup 2} tests, F tests for variances, one-way analyses of variance and C-statistics. Statistical Type I and Type II errors, which indicate the robustness and the power of the tests, have been obtained in each case. One-way analyses of variance and {chi}{sup 2} prove to be powerful and robust estimators for microvariations, while the C-statistic is not a reliable methodology and its use should be avoided.

  16. Wire Test Grip Fixture

    NASA Technical Reports Server (NTRS)

    Burke, Christopher S.

    2011-01-01

    Wire-testing issues, such as the gripping strains imposed on the wire, play a critical role in obtaining clean data. In a standard test frame fitted with flat wedge grips, the gripping action alone creates stresses on the wire specimen that cause the wire to fail at the grip location. A new test frame, which is outfitted with a vacuum chamber, negated the use of any conventional commercially available wire test fixtures, as only 7 in. (17.8 cm) existed between the grip faces. An innovative grip fixture was designed to test thin gauge wire for a variety of applications in an existing Instron test frame outfitted with a vacuum chamber.

  17. Metamorphic Testing for Cybersecurity.

    PubMed

    Chen, Tsong Yueh; Kuo, Fei-Ching; Ma, Wenjuan; Susilo, Willy; Towey, Dave; Voas, Jeffrey; Zhou, Zhi Quan

    2016-06-01

    Testing is a major approach for the detection of software defects, including vulnerabilities in security features. This article introduces metamorphic testing (MT), a relatively new testing method, and discusses how the new perspective of MT can help to conduct negative testing as well as to alleviate the oracle problem in the testing of security-related functionality and behavior. As demonstrated by the effectiveness of MT in detecting previously unknown bugs in real-world critical applications such as compilers and code obfuscators, we conclude that software testing of security-related features should be conducted from diverse perspectives in order to achieve greater cybersecurity.

  18. Testing technology, January 1993

    SciTech Connect

    Goetsch, B.

    1993-01-01

    This bulletin from Sandia Laboratories presents current research on testing technology. Fiber optics systems at the Nevada Test Site is replacing coaxial cables. The hypervelocity launcher is being used to test orbital debris impacts with space station shielding. A digital recorder makes testing of high-speed water entries possible. Automobile engine design is aided by an instrumented head gasket that detects the combustion zone. And composite-to-metal strength and fatigue tests provide new data on joint failures in wind turbine joint tests.

  19. Rules for Optical Testing

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2014-01-01

    Based on 30 years of optical testing experience, a lot of mistakes, a lot of learning and a lot of experience, I have defined seven guiding principles for optical testing - regardless of how small or how large the optical testing or metrology task: Fully Understand the Task, Develop an Error Budget, Continuous Metrology Coverage, Know where you are, Test like you fly, Independent Cross-Checks, Understand All Anomalies. These rules have been applied with great success to the inprocess optical testing and final specification compliance testing of the JWST mirrors.

  20. Materials Test Branch

    NASA Technical Reports Server (NTRS)

    Gordon, Gail

    2012-01-01

    The Materials Test Branch resides at Marshall Space Flight Center's Materials and Processing laboratory and has a long history of supporting NASA programs from Mercury to the recently retired Space Shuttle. The Materials Test Branch supports its customers by supplying materials testing expertise in a wide range of applications. The Materials Test Branch is divided into three Teams, The Chemistry Team, The Tribology Team and the Mechanical Test Team. Our mission and goal is to provide world-class engineering excellence in materials testing with a special emphasis on customer service.

  1. Gas Test Loop Booster Fuel Hydraulic Testing

    SciTech Connect

    Gas Test Loop Hydraulic Testing Staff

    2006-09-01

    The Gas Test Loop (GTL) project is for the design of an adaptation to the Advanced Test Reactor (ATR) to create a fast-flux test space where fuels and materials for advanced reactor concepts can undergo irradiation testing. Incident to that design, it was found necessary to make use of special booster fuel to enhance the neutron flux in the reactor lobe in which the Gas Test Loop will be installed. Because the booster fuel is of a different composition and configuration from standard ATR fuel, it is necessary to qualify the booster fuel for use in the ATR. Part of that qualification is the determination that required thermal hydraulic criteria will be met under routine operation and under selected accident scenarios. The Hydraulic Testing task in the GTL project facilitates that determination by measuring flow coefficients (pressure drops) over various regions of the booster fuel over a range of primary coolant flow rates. A high-fidelity model of the NW lobe of the ATR with associated flow baffle, in-pile-tube, and below-core flow channels was designed, constructed and located in the Idaho State University Thermal Fluids Laboratory. A circulation loop was designed and constructed by the university to provide reactor-relevant water flow rates to the test system. Models of the four booster fuel elements required for GTL operation were fabricated from aluminum (no uranium or means of heating) and placed in the flow channel. One of these was instrumented with Pitot tubes to measure flow velocities in the channels between the three booster fuel plates and between the innermost and outermost plates and the side walls of the flow annulus. Flow coefficients in the range of 4 to 6.5 were determined from the measurements made for the upper and middle parts of the booster fuel elements. The flow coefficient for the lower end of the booster fuel and the sub-core flow channel was lower at 2.3.

  2. Smart HIV testing system.

    PubMed

    El Kateeb, Ali; Law, Peter; Chan, King

    2005-06-01

    The quick HIV testing method called "MiraWell Rapid HIV Test" uses a specialized testing kit to determine whether an individual's blood is contaminated with the HIV virus or not. When a drop of blood is placed on the center of the testing kit, a simple pattern will appear in the middle of the kit to indicate the test status, i.e., positive or negative. This HIV test should be done in a small clinic or in a lab and the test must be conducted by a trained technician. A smart HIV testing system was developed through this research to eliminate the human error that is associated with the use of the quick HIV testing kits. Also, the smart HIV system will improve the testing productivity in comparison to those achieved by the trained technicians. In this research, we have developed a cost-effective system that analyzes the image produced by the HIV kits. We have used a System-On-Chip (SOC) design approach based on the Field Programmable Gate Array (FPGA) technology and the Xilinx Virtex SOC chip in building the system's prototype. The system used a CMOS digital camera to capture the image and an FPGA chip to process the captured image and send the testing results to the display unit. The system can be used in small clinics and pharmacies and eliminates the need for trained technicians. The system has been tested successfully and 98% of the tests were correct.

  3. ECN Pressure Test

    SciTech Connect

    Dixon, K.; /Fermilab

    1991-07-18

    This note describes: the rationale for the test pressure of the inner ECN cryostat vessel, the equipment to be used in this test, the test procedure, the status of the vessel prior to the test, the actual test results, and a schematic diagram of the testing set up and the pressure testing permit. The test, performed in the evening of July 17, 1991, was a major success. Based on a neglible pressure drop indicated on the pressure gages (1/4 psi), the vessel appeared to be structurally sound throughout the duration of the test (approx. 1.5 hrs.). No pressure increases were observed on the indicators looking at the beam tube bellows volumes. There was no indication of bubbles form the soap test on the welds and most of the fittings that were checked. There were some slight deviations in the actual procedure used. The UO filter was removed after the vessel had bled down to about 18 psig in order to speed up that aspect of the test. The rationale was that the higher velocity gas had already passed through at the higher pressures and there was no visible traces of the black uo particles. The rate of 4 psi/10 minutes seemed incredibly slow and often that time was reduced to just over half that rate. The testing personnel was allowed to stay in the pit throughout the duration of the test; this was a slight relaxation of the rules.

  4. VIEW OF EAST TEST SITE FROM TOP OF STATIC TEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF EAST TEST SITE FROM TOP OF STATIC TEST TOWER VIEW INCLUDES STRUCTURAL DYNAMICS TEST STAND COLD CALIBRATION TEST STAND AND COMPONENTS TEST LAB. - Marshall Space Flight Center, East Test Area, Dodd Road, Huntsville, Madison County, AL

  5. Urine specific gravity test

    MedlinePlus

    ... medlineplus.gov/ency/article/003587.htm Urine specific gravity test To use the sharing features on this page, please enable JavaScript. Urine specific gravity is a laboratory test that shows the concentration ...

  6. GI Radiographic Tests

    MedlinePlus

    ... noninvasive technique that is very sensitive in detecting gastrointestinal cancer. This test is increasingly ordered for this purpose ... distant spread of a tumor (metastasis). Examples of gastrointestinal tumors for which this test ... C Inflammatory Bowel Disease Irritable Bowel Syndrome ...

  7. Blood Test: Testosterone

    MedlinePlus

    ... Estradiol Precocious Puberty Understanding Puberty Endocrine System Male Reproductive System Getting a Blood Test (Video) All About Puberty Blood Test (Video) Male Reproductive System Contact Us Print Resources Send to a friend ...

  8. Test Control Center

    NASA Technical Reports Server (NTRS)

    2000-01-01

    At the test observation periscope in the Test Control Center exhibit in StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., visitors can observe a test of a Space Shuttle Main Engine exactly as test engineers might see it during a real engine test. The Test Control Center exhibit exactly simulates not only the test control environment, but also the procedure of testing a rocket engine. Designed to entertain while educating, StenniSphere includes informative dispays and exhibits from NASA's lead center for rocket propulsion and remote sensing applications. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  9. Testing for HIV

    MedlinePlus

    ... Medical Devices Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Vaccines, Blood & Biologics Home Vaccines, Blood & Biologics Safety & Availability (Biologics) HIV Home Test Kits Testing for HIV Share Tweet Linkedin Pin it More ...

  10. Visual acuity test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003396.htm Visual acuity test To use the sharing features on this page, please enable JavaScript. The visual acuity test is used to determine the smallest ...

  11. Screening Tests and Vaccines

    MedlinePlus

    ... Contact Us Text size | Print | Screening Tests and Vaccines This information in Spanish ( en español ) Getting important screening tests and vaccines can save your life. Check this section of ...

  12. Breath alcohol test

    MedlinePlus

    ... muscle coordination A longer reaction time Impaired judgment Driving and operating machinery when you're drunk (intoxicated) ... test. Considerations The test does not measure the driving abilities of a person. Driving abilities vary among ...

  13. Vitamin A Test

    MedlinePlus

    ... Vitamin A testing is used to help diagnose vitamin A deficiency in people with symptoms, such as night blindness, ... of nutrients and who are at risk of vitamin A deficiency. Testing for this purpose is not common because ...

  14. Your Kidney Test Results

    MedlinePlus

    ... blood vessels healthy. Vitamin D is important for bones and heart health. 1 Your Kidney Test Results Other Important Tests, continued A1C (for patients with diabetes) Results Goal: Your Result: Total Cholesterol Normal: Less ...

  15. Chloride - urine test

    MedlinePlus

    ... a condition that affects body fluids or acid-base balance. ... slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test result.

  16. Blood Count Tests

    MedlinePlus

    ... white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in ... helps doctors check on your overall health. The tests can also help to diagnose diseases and conditions ...

  17. Sediment Toxicity Testing

    EPA Science Inventory

    Sediment toxicity testing has become a fundamental component of regulatory frameworks for assessing the risks posed by contaminated sediments and for development of chemical sediment quality guidelines. Over the past two decades, sediment toxicity testing methods have advanced co...

  18. The first PANDA tests

    SciTech Connect

    Dreier, J.; Huggenberger, M.; Aubert, C.

    1996-08-01

    The PANDA test facility at PSI in Switzerland is used to study the long-term Simplified Boiling Water Reactor (SBWR) Passive Containment Cooling System (PCCS) performance. The PANDA tests demonstrate performance on a larger scale than previous tests and examine the effects of any non-uniform spatial distributions of steam and non-condensables in the system. The PANDA facility has a 1:1 vertical scale, and 1:25 ``system`` scale (volume, power, etc.). Steady-state PCCS condenser performance tests and extensive facility characterization tests have been completed. Transient system behavior tests were conducted late in 1995; results from the first three transient tests (M3 series) are reviewed. The first PANDA tests showed that the overall global behavior of the SBWR containment was globally repeatable and very favorable; the system exhibited great ``robustness.``

  19. Hepatitis B Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Hepatitis B Testing Share this page: Was this page ... known as: HBV Tests; Hep B; anti-HBs; Hepatitis B Surface Antibody; HBsAg; Hepatitis B Surface Antigen; ...

  20. Chloride test - blood

    MedlinePlus

    ... of body fluids and maintain the body's acid-base balance. This article is about the laboratory test ... signs that your body's fluid level or acid-base balance is disturbed. This test is most often ...

  1. ISS Update: Suitport Testing

    NASA Video Gallery

    ISS Update commentator Lynnette Madison interviews Joel Maganza, Test Director, about thermal vacuum chambers and unmanned and human-testing with the Suitport. Questions? Ask us on Twitter @NASA_Jo...

  2. Phosphorus blood test

    MedlinePlus

    ... II Osteomalacia Parathyroid hormone (PTH) blood test Rickets Sarcoidosis Review Date 11/1/2015 Updated by: Laura ... Balance Kidney Tests Liver Diseases Malnutrition Parathyroid Disorders Sarcoidosis Ulcerative Colitis Browse the Encyclopedia A.D.A. ...

  3. Toddler test (image)

    MedlinePlus

    With proper preparation prior to a test or procedure, a toddler's fear and anxiety may be reduced. Preparing a child for a test may include going through the steps of the procedure, explaining the body part ...

  4. Follow-Up Testing

    MedlinePlus

    ... the test is not important. The University of Chicago Celiac Disease Center recommends additional testing, because the ... well. For more information contact the University of Chicago Celiac Disease Center at 773.702.7593 or ...

  5. Lyme Disease Tests

    MedlinePlus

    ... Borrelia Antibodies, IgM/IgG; Borrelia DNA Detection by PCR Related tests: CSF Analysis All content on Lab ... fluid (CSF) . In special cases, polymerase chain reaction (PCR) testing may be performed on a sample because ...

  6. Growth hormone test

    MedlinePlus

    ... under the skin) Infection (a slight risk any time the skin is broken) Alternative Names GH test Images Growth hormone stimulation test - series References Ali O. Hyperpituitarism, tall stature, and overgrowth ...

  7. Latex agglutination test

    MedlinePlus

    ... the results of this test. Normal Results Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider ...

  8. Rotavirus antigen test

    MedlinePlus

    ... is not found in the stool. Note: Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your health care provider about the meaning of your specific test results.

  9. TB Screening Tests

    MedlinePlus

    ... known as: Purified Protein Derivative; PPD; Mantoux; Latent Tuberculosis Infection Test; Interferon-gamma Release Assays; IGRA; T- ... else I should know? How is it used? Tuberculosis (TB) screening tests are not used as general ...

  10. Pleural Fluid Analysis Test

    MedlinePlus

    ... and susceptibility testing Adenosine deaminase – may help detect tuberculosis (TB) Less commonly, tests for infectious diseases, such ... of lymphocytes may be seen with cancers and tuberculosis . Cytology—a cytocentrifuged sample is treated with a ...

  11. Prenatal Genetic Testing Chart

    MedlinePlus

    ... Education & Events Advocacy For Patients About ACOG Prenatal Genetic Testing Chart (Infographic) Home For Patients Search FAQs Prenatal Genetic Testing Chart (Infographic) PFSI010 ››› Weeks 1–4 Weeks ...

  12. Liver Function Tests

    MedlinePlus

    ... Your Liver > Liver Disease Information > Liver Function Tests Liver Function Tests Explore this section to learn more ... including a description and diagnosis. Why is the liver important? The liver is the second largest organ ...

  13. Vitamin A blood test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003570.htm Vitamin A blood test To use the sharing features on this page, please enable JavaScript. The vitamin A test measures the level of vitamin A ...

  14. Control system testing

    NASA Astrophysics Data System (ADS)

    Whittler, W. H.; Collart, R. E.

    1984-08-01

    A three stage process of ground testing of the Space Telescope Pointing Control System is used for verification prior to on-orbit operation. First, development tests are conducted in a laboratory environment using flight/engineering model control sensor and actuators configured with an engineering model of the flight computer and data management system breadboards. These development tests validate the results of computer simulations predicting control system performance. Integration tests bring together flight system elements and software interfaced to a software simulation of vehicle dynamics to confirm closed loop performance. The final ground test phase, flight systems testing, is conducted on the fully assembled Space Telescope, verifies interfaces with the Fine Guidance Sensors and includes a thermal vacuum testing period. During the final test phase, the Point Control System is exercised with the dynamics simulator running in real time.

  15. 17-Ketosteroids urine test

    MedlinePlus

    ... 6 to 12 mg per 24 hr Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

  16. Who Trusts the Tests?

    ERIC Educational Resources Information Center

    Gurney, Roger

    1978-01-01

    The author reviews the advantages and disadvantages of standardized reading tests, with special reference to the new national reading tests designed by the Assessment of Performance Unit of the Department of Education and Science. (SJL)

  17. Ovulation home test

    MedlinePlus

    ... women to help determine the time in the menstrual cycle when getting pregnant is most likely. The test ... start testing depends on the length of your menstrual cycle. For example, if your normal cycle is 28 ...

  18. Ethylene glycol blood test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003564.htm Ethylene glycol blood test To use the sharing features ... enable JavaScript. This test measures the level of ethylene glycol in the blood. Ethylene glycol is a ...

  19. Lactic acid test

    MedlinePlus

    Lactate test ... test. Exercise can cause a temporary increase in lactic acid levels. ... not getting enough oxygen. Conditions that can increase lactic acid levels include: Heart failure Liver disease Lung disease ...

  20. Methylmalonic acid blood test

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003565.htm Methylmalonic acid blood test To use the sharing features on this page, please enable JavaScript. The methylmalonic acid blood test measures the amount of methylmalonic acid ...