WorldWideScience

Sample records for plan background volume

  1. Federal Facility Compliance Act, Proposed Site Treatment Plan: Background Volume. Executive Summary

    International Nuclear Information System (INIS)

    1995-01-01

    This Federal Facility Compliance Act Site Treatment Plan discusses the options of radioactive waste management for Ames Laboratory. This is the background volume which discusses: site history and mission; framework for developing site treatment plans; proposed plan organization and related activities; characterization of mixed waste and waste minimization; low level mixed waste streams and the proposed treatment approach; future generation of TRU and mixed wastes; the adequacy of mixed waste storage facilities; and a summary of the overall DOE activity in the area of disposal of mixed waste treatment residuals

  2. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site.

  3. Draft Site Treatment Plan (DSTP), Volumes I and II

    International Nuclear Information System (INIS)

    D'Amelio, J.

    1994-01-01

    Site Treatment Plans (STP) are required for facilities at which the DOE generates or stores mixed waste. This Draft Site Treatment Plan (DSTP) the second step in a three-phase process, identifies the currently preferred options for treating mixed waste at the Savannah River Site (SRS) or for developing treatment technologies where technologies do not exist or need modification. The DSTP reflects site-specific preferred options, developed with the state's input and based on existing available information. To the extent possible, the DSTP identifies specific treatment facilities for treating the mixed waste and proposes schedules. Where the selection of specific treatment facilities is not possible, schedules for alternative activities such as waste characterization and technology assessment are provided. All schedule and cost information presented is preliminary and is subject to change. The DSTP is comprised of two volumes: this Compliance Plan Volume and the Background Volume. This Compliance Plan Volume proposes overall schedules with target dates for achieving compliance with the land disposal restrictions (LDR) of RCRA and procedures for converting the target dates into milestones to be enforced under the Order. The more detailed discussion of the options contained in the Background Volume is provided for informational purposes only

  4. Leak testing plan for the Oak Ridge National Laboratory liquid low-level waste systems (active tanks): Revision 2. Volume 1: Regulatory background and plan approach; Volume 2: Methods, protocols, and schedules; Volume 3: Evaluation of the ORNL/LT-823DP differential pressure leak detection method; Appendix to Revision 2: DOE/EPA/TDEC correspondence

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, D.G.; Wise, R.F.; Starr, J.W.; Maresca, J.W. Jr. [Vista Research, Inc., Mountain View, CA (United States)

    1994-11-01

    This document, the Leak Testing Plan for the Oak Ridge National Laboratory Liquid Low-Level Waste System (Active Tanks), comprises three volumes. The first two volumes address the component-based leak testing plan for the liquid low-level waste system at Oak Ridge, while the third volume describes the performance evaluation of the leak detection method that will be used to test this system. Volume 1, describes that portion of the liquid low-level waste system at that will be tested; it provides the regulatory background, especially in terms of the requirements stipulated in the Federal Facilities Agreement, upon which the leak testing plan is based. Volume 1 also describes the foundation of the plan, portions of which were abstracted from existing federal documents that regulate the petroleum and hazardous chemicals industries. Finally, Volume 1 gives an overview the plan, describing the methods that will be used to test the four classes of components in the liquid low-level waste system. Volume 2 takes the general information on component classes and leak detection methods presented in Volume 1 and shows how it applies particularly to each of the individual components. A complete test plan for each of the components is presented, with emphasis placed on the methods designated for testing tanks. The protocol for testing tank systems is described, and general leak testing schedules are presented. Volume 3 describes the results of a performance evaluation completed for the leak testing method that will be used to test the small tanks at the facility (those less than 3,000 gal in capacity). Some of the details described in Volumes 1 and 2 are expected to change as additional information is obtained, as the viability of candidate release detection methods is proven in the Oak Ridge environment, and as the testing program evolves.

  5. Leak testing plan for the Oak Ridge National Laboratory liquid low-level waste systems (active tanks): Revision 2. Volume 1: Regulatory background and plan approach; Volume 2: Methods, protocols, and schedules; Volume 3: Evaluation of the ORNL/LT-823DP differential pressure leak detection method; Appendix to Revision 2: DOE/EPA/TDEC correspondence

    International Nuclear Information System (INIS)

    Douglas, D.G.; Wise, R.F.; Starr, J.W.; Maresca, J.W. Jr.

    1994-11-01

    This document, the Leak Testing Plan for the Oak Ridge National Laboratory Liquid Low-Level Waste System (Active Tanks), comprises three volumes. The first two volumes address the component-based leak testing plan for the liquid low-level waste system at Oak Ridge, while the third volume describes the performance evaluation of the leak detection method that will be used to test this system. Volume 1, describes that portion of the liquid low-level waste system at that will be tested; it provides the regulatory background, especially in terms of the requirements stipulated in the Federal Facilities Agreement, upon which the leak testing plan is based. Volume 1 also describes the foundation of the plan, portions of which were abstracted from existing federal documents that regulate the petroleum and hazardous chemicals industries. Finally, Volume 1 gives an overview the plan, describing the methods that will be used to test the four classes of components in the liquid low-level waste system. Volume 2 takes the general information on component classes and leak detection methods presented in Volume 1 and shows how it applies particularly to each of the individual components. A complete test plan for each of the components is presented, with emphasis placed on the methods designated for testing tanks. The protocol for testing tank systems is described, and general leak testing schedules are presented. Volume 3 describes the results of a performance evaluation completed for the leak testing method that will be used to test the small tanks at the facility (those less than 3,000 gal in capacity). Some of the details described in Volumes 1 and 2 are expected to change as additional information is obtained, as the viability of candidate release detection methods is proven in the Oak Ridge environment, and as the testing program evolves

  6. Savannah River Site Approved Site Treatment Plan, 2001 Annual Update (Volumes I and II)

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, B.

    2001-04-30

    The Compliance Plan Volume (Volume I) identifies project activity scheduled milestones for achieving compliance with Land Disposal Restrictions. Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume II) and is provided for information.

  7. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    1993-04-01

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site

  8. Approved Site Treatment Plan, Volumes 1 and 2. Revision 4

    Energy Technology Data Exchange (ETDEWEB)

    Helmich, E.H.; Molen, G.; Noller, D.

    1996-03-22

    The US Department of Energy, Savannah River Operations Office (DOE-SR), has prepared the Site Treatment Plan (STP) for Savannah River Site (SRS) mixed wastes in accordance with RCRA Section 3021(b), and SCDHEC has approved the STP (except for certain offsite wastes) and issued an order enforcing the STP commitments in Volume 1. DOE-SR and SCDHEC agree that this STP fulfills the requirements contained in the FFCAct, RCRA Section 3021, and therefore, pursuant to Section 105(a) of the FFCAct (RCRA Section 3021(b)(5)), DOE`s requirements are to implement the plan for the development of treatment capacities and technologies pursuant to RCRA Section 3021. Emerging and new technologies not yet considered may be identified to manage waste more safely, effectively, and at lower cost than technologies currently identified in the plan. DOE will continue to evaluate and develop technologies that offer potential advantages in public acceptance, privatization, consolidation, risk abatement, performance, and life-cycle cost. Should technologies that offer such advantages be identified, DOE may request a revision/modification of the STP in accordance with the provisions of Consent Order 95-22-HW. The Compliance Plan Volume (Volume 1) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions (LDR). Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume 2) and is provided for information.

  9. Approved Site Treatment Plan, Volumes 1 and 2. Revision 4

    International Nuclear Information System (INIS)

    Helmich, E.H.; Molen, G.; Noller, D.

    1996-01-01

    The US Department of Energy, Savannah River Operations Office (DOE-SR), has prepared the Site Treatment Plan (STP) for Savannah River Site (SRS) mixed wastes in accordance with RCRA Section 3021(b), and SCDHEC has approved the STP (except for certain offsite wastes) and issued an order enforcing the STP commitments in Volume 1. DOE-SR and SCDHEC agree that this STP fulfills the requirements contained in the FFCAct, RCRA Section 3021, and therefore, pursuant to Section 105(a) of the FFCAct (RCRA Section 3021(b)(5)), DOE's requirements are to implement the plan for the development of treatment capacities and technologies pursuant to RCRA Section 3021. Emerging and new technologies not yet considered may be identified to manage waste more safely, effectively, and at lower cost than technologies currently identified in the plan. DOE will continue to evaluate and develop technologies that offer potential advantages in public acceptance, privatization, consolidation, risk abatement, performance, and life-cycle cost. Should technologies that offer such advantages be identified, DOE may request a revision/modification of the STP in accordance with the provisions of Consent Order 95-22-HW. The Compliance Plan Volume (Volume 1) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions (LDR). Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume 2) and is provided for information

  10. Proposed Site Treatment Plan (PSTP). Volumes 1 and 2 and Reference Document

    Energy Technology Data Exchange (ETDEWEB)

    Helmich, E.; Noller, D.K.; Wierzbicki, K.S.; Bailey, L.L.

    1994-12-22

    The Compliance Plan Volume provides overall schedules with target dates for achieving compliance with the land disposal restrictions (LDR) and contains procedures to establish milestones to be enforced under the Order. Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume and is provided for informational purposes only.

  11. Improved robotic stereotactic body radiation therapy plan quality and planning efficacy for organ-confined prostate cancer utilizing overlap-volume histogram-driven planning methodology

    International Nuclear Information System (INIS)

    Wu, Binbin; Pang, Dalong; Lei, Siyuan; Gatti, John; Tong, Michael; McNutt, Todd; Kole, Thomas; Dritschilo, Anatoly; Collins, Sean

    2014-01-01

    Background and purpose: This study is to determine if the overlap-volume histogram (OVH)-driven planning methodology can be adapted to robotic SBRT (CyberKnife Robotic Radiosurgery System) to further minimize the bladder and rectal doses achieved in plans manually-created by clinical planners. Methods and materials: A database containing clinically-delivered, robotic SBRT plans (7.25 Gy/fraction in 36.25 Gy) of 425 patients with localized prostate cancer was used as a cohort to establish an organ’s distance-to-dose model. The OVH-driven planning methodology was refined by adding the PTV volume factor to counter the target’s dose fall-off effect and incorporated into Multiplan to automate SBRT planning. For validation, automated plans (APs) for 12 new patients were generated, and their achieved dose/volume values were compared to the corresponding manually-created, clinically-delivered plans (CPs). A two-sided, Wilcoxon rank-sum test was used for statistical comparison with a significance level of p < 0.05. Results: PTV’s V(36.25 Gy) was comparable: 95.6% in CPs comparing to 95.1% in APs (p = 0.2). On average, the refined approach lowered V(18.12 Gy) to the bladder and rectum by 8.2% (p < 0.05) and 6.4% (p = 0.14). A physician confirmed APs were clinically acceptable. Conclusions: The improvements in APs could further reduce toxicities observed in SBRT for organ-confined prostate cancer

  12. The spill prevention, control, and countermeasures (SPCC) plan for the Y-12 Plant. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    This spill prevention, control and countermeasures (SPCC) Plan is divided into two volumes. Volume I addresses Y-12`s compliance with regulations pertinent to the content of SPCC Plans. Volume II is the SPCC Hazardous Material Storage Data Base, a detailed tabulation of facility-specific information and data on potential spill sources at the Y-12 Plant. Volume I follows the basic format and subject sequence specified in 40 CFR 112.7. This sequence is prefaced by three additional chapters, including this introduction and brief discussions of the Y-12 Plant`s background/environmental setting and potential spill source categories. Two additional chapters on containers and container storage areas and PCB and PCB storage for disposal facilities are inserted into the required sequence. The following required subjects are covered in this volume: Spill history, site drainage; secondary containment/diversion structures and equipment; contingency plans; notification and spill response procedures; facility drainage; bulk storage tanks; facility transfer operations, pumping, and in-plant processes; transfer stations (facility tank cars/tank tracks); inspections and records; security, and personnel, training, and spill prevention procedures.

  13. Target volume definition with 18F-FDG PET-CT in radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Carson, K. J.; Hanna, G. G.; Hounsell, A. R.

    2011-01-01

    There is considerable interest in using 18F -Fluorodeoxyglucose (FDG) positron emission tomography (PET) images for radiotherapy treatment planning (RTF) purposes, and in particular for defining target volumes. This is a rapidly evolving subject and this review describes the background to this application of PET imaging and discusses the issues involved. (authors)

  14. Federal Facilities Compliance Act, Draft Site Treatment Plan: Background Volume, Part 2, Volume 1

    International Nuclear Information System (INIS)

    1994-01-01

    This Draft Site Treatment Plan was prepared by Ames Laboratory to meet the requirements of the Federal Facilities Compliance Act. Topics discussed include: purpose and scope of the plan; site history and mission; draft plant organization; waste minimization; waste characterization; preferred option selection process; technology for treating low-level radioactive wastes and TRU wastes; future generation of mixed waste streams; funding; and process for evaluating disposal issues in support of the site treatment plan

  15. CT-guided intracavitary radiotherapy for cervical cancer: Comparison of conventional point A plan with clinical target volume-based three-dimensional plan using dose-volume parameters

    International Nuclear Information System (INIS)

    Shin, Kyung Hwan; Kim, Tae Hyun; Cho, Jung Keun; Kim, Joo-Young; Park, Sung Yong; Park, Sang-Yoon; Kim, Dae Yong; Chie, Eui Kyu; Pyo, Hong Ryull; Cho, Kwan Ho

    2006-01-01

    Purpose: To perform an intracavitary radiotherapy (ICR) plan comparison between the conventional point A plan (conventional plan) and computed tomography (CT)-guided clinical target volume-based plan (CTV plan) by analysis of the quantitative dose-volume parameters and irradiated volumes of organs at risk in patients with cervical cancer. Methods and Materials: Thirty plans for 192 Ir high-dose-rate ICR after 30-40-Gy external beam radiotherapy were investigated. CT images were acquired at the first ICR session with artifact-free applicators in place. The gross tumor volume, clinical target volume (CTV), point A, and International Commission on Radiation Units and Measurements Report 38 rectal and bladder points were defined on reconstructed CT images. A fractional 100% dose was prescribed to point A in the conventional plan and to the outermost point to cover all CTVs in the CTV plan. The reference volume receiving 100% of the prescribed dose (V ref ), and the dose-volume parameters of the coverage index, conformal index, and external volume index were calculated from the dose-volume histogram. The bladder, rectal point doses, and percentage of volumes receiving 50%, 80%, and 100% of the prescribed dose were also analyzed. Results: Conventional plans were performed, and patients were categorized on the basis of whether the 100% isodose line of point A prescription dose fully encompassed the CTV (Group 1, n = 20) or not (Group 2, n = 10). The mean gross tumor volume (11.6 cm 3 ) and CTV (24.9 cm 3 ) of Group 1 were smaller than the corresponding values (23.7 and 44.7 cm 3 , respectively) for Group 2 (p = 0.003). The mean V ref for all patients was 129.6 cm 3 for the conventional plan and 97.0 cm 3 for the CTV plan (p = 0.003). The mean V ref in Group 1 decreased markedly with the CTV plan (p < 0.001). For the conventional and CTV plans in all patients, the mean coverage index, conformal index, and external volume index were 0.98 and 1.0, 0.23 and 0.34, and 3.86 and

  16. The relationship between the bladder volume and optimal treatment planning in definitive radiotherapy for localized prostate cancer

    International Nuclear Information System (INIS)

    Nakamura, Naoki; Sekiguchi, Kenji; Akahane, Keiko; Shikama, Naoto; Takahashi, Osamu; Hama, Yukihiro; Nakagawa, Keiichi

    2012-01-01

    Background and purpose: There is no current consensus regarding the optimal bladder volumes in definitive radiotherapy for localized prostate cancer. The aim of this study was to clarify the relationship between the bladder volume and optimal treatment planning in radiotherapy for localized prostate cancer. Material and methods: Two hundred and forty-three patients underwent definitive radiotherapy with helical tomotherapy for intermediate- and high-risk localized prostate cancer. The prescribed dose defined as 95 % of the planning target volume (PTV) receiving 100 % of the prescription dose was 76 Gy in 38 fractions. The clinical target volume (CTV) was defined as the prostate with a 5-mm margin and 2 cm of the proximal seminal vesicle. The PTV was defined as the CTV with a 5-mm margin. Treatment plans were optimized to satisfy the dose constraints defined by in-house protocols for PTV and organs at risk (rectum wall, bladder wall, sigmoid colon and small intestine). If all dose constraints were satisfied, the plan was defined as an optimal plan (OP). Results: An OP was achieved with 203 patients (84%). Mean bladder volume (± 1 SD) was 266 ml (± 130 ml) among those with an OP and 214 ml (±130 ml) among those without an OP (p = 0.02). Logistic regression analysis also showed that bladder volumes below 150 ml decreased the possibility of achieving an OP. However, the percentage of patients with an OP showed a plateau effect at bladder volumes above 150 ml. Conclusions. Bladder volume is a significant factor affecting OP rates. However, our results suggest that bladder volumes exceeding 150 ml may not help meet planning dose constraints

  17. Automated planning volume definition in soft-tissue sarcoma adjuvant brachytherapy

    International Nuclear Information System (INIS)

    Lee, Eva K.; Fung, Albert Y.C.; Zaider, Marco; Brooks, J. Paul

    2002-01-01

    In current practice, the planning volume for adjuvant brachytherapy treatment for soft-tissue sarcoma is either not determined a priori (in this case, seed locations are selected based on isodose curves conforming to a visual estimate of the planning volume), or it is derived via a tedious manual process. In either case, the process is subjective and time consuming, and is highly dependent on the human planner. The focus of the work described herein involves the development of an automated contouring algorithm to outline the planning volume. Such an automatic procedure will save time and provide a consistent and objective method for determining planning volumes. In addition, a definitive representation of the planning volume will allow for sophisticated brachytherapy treatment planning approaches to be applied when designing treatment plans, so as to maximize local tumour control and minimize normal tissue complications. An automated tumour volume contouring algorithm is developed utilizing computational geometry and numerical interpolation techniques in conjunction with an artificial intelligence method. The target volume is defined to be the slab of tissue r cm perpendicularly away from the curvilinear plane defined by the mesh of catheters. We assume that if adjacent catheters are over 2r cm apart, the tissue between the two catheters is part of the tumour bed. Input data consist of the digitized coordinates of the catheter positions in each of several cross-sectional slices of the tumour bed, and the estimated distance r from the catheters to the tumour surface. Mathematically, one can view the planning volume as the volume enclosed within a minimal smoothly-connected surface which contains a set of circles, each circle centred at a given catheter position in a given cross-sectional slice. The algorithm performs local interpolation on consecutive triplets of circles. The effectiveness of the algorithm is evaluated based on its performance on a collection of

  18. Automated planning volume definition in soft-tissue sarcoma adjuvant brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eva K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Fung, Albert Y.C.; Zaider, Marco [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY (United States); Brooks, J. Paul [School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

    2002-06-07

    In current practice, the planning volume for adjuvant brachytherapy treatment for soft-tissue sarcoma is either not determined a priori (in this case, seed locations are selected based on isodose curves conforming to a visual estimate of the planning volume), or it is derived via a tedious manual process. In either case, the process is subjective and time consuming, and is highly dependent on the human planner. The focus of the work described herein involves the development of an automated contouring algorithm to outline the planning volume. Such an automatic procedure will save time and provide a consistent and objective method for determining planning volumes. In addition, a definitive representation of the planning volume will allow for sophisticated brachytherapy treatment planning approaches to be applied when designing treatment plans, so as to maximize local tumour control and minimize normal tissue complications. An automated tumour volume contouring algorithm is developed utilizing computational geometry and numerical interpolation techniques in conjunction with an artificial intelligence method. The target volume is defined to be the slab of tissue r cm perpendicularly away from the curvilinear plane defined by the mesh of catheters. We assume that if adjacent catheters are over 2r cm apart, the tissue between the two catheters is part of the tumour bed. Input data consist of the digitized coordinates of the catheter positions in each of several cross-sectional slices of the tumour bed, and the estimated distance r from the catheters to the tumour surface. Mathematically, one can view the planning volume as the volume enclosed within a minimal smoothly-connected surface which contains a set of circles, each circle centred at a given catheter position in a given cross-sectional slice. The algorithm performs local interpolation on consecutive triplets of circles. The effectiveness of the algorithm is evaluated based on its performance on a collection of

  19. Plan for studies of subsurface radionuclide migration at the Radioactive Waste Management Complex of the Idaho National Engineering Laboratory. Volume 1 of 2

    International Nuclear Information System (INIS)

    1983-11-01

    This document describes planned studies of subsurface radionuclide migration at the Radioactive Waste Management Complex of the Idaho National Engineering Laboratory. A plan is provided for each proposed study. The rational for arriving at the list of proposed studies is also presented. This document consists of two volumes. In the first volume, Sections 1 through 5 contain the introduction, the objectives of the proposed studies, and background information. The discussion is not comprehensive in detail; documents are referenced that discuss the background material in greater detail. Sections 6 through 9 identify and select the group of studies to be performed and discuss the peer review process. The second volume contains Appendices A and B, which present the assignment of responsibilities and the detailed plans, schedules, and costs for the proposed program

  20. Is pregnancy planning associated with background characteristics and pregnancy-planning behavior?

    DEFF Research Database (Denmark)

    Stern, Jenny; Salih Joelsson, Lana; Tydén, Tanja

    2016-01-01

    household income, to be currently working (≥50%) and to have longer relationships than women with unplanned pregnancies. The level of pregnancy planning was associated with planning behavior, such as information-seeking and intake of folic acid, but without a reduction in alcohol consumption. One......-third of all women took folic acid 1 month prior to conception, 17% used tobacco daily and 11% used alcohol weekly 3 months before conception. Conclusions A majority rated their pregnancy as very or fairly planned, with socio-economic factors as explanatory variables. The level of pregnancy planning should......Introduction Prevalence of planned pregnancies varies between countries but is often measured in a dichotomous manner. The aim of this study was to investigate to what level pregnant women had planned their pregnancies and whether pregnancy planning was associated with background characteristics...

  1. Plan for studies of subsurface radionuclide migration at the Radioactive Waste Management Complex of the Idaho National Engineering Laboratory. Volume 2 of 2. Appendices

    International Nuclear Information System (INIS)

    1983-11-01

    This document describes planned studies of subsurface radionuclide migration at the Radioactive Waste Management Complex of the Idaho National Engineering Laboratory. A plan is provided for each proposed study. The rational for arriving at the list of proposed studies is also presented. This document consists of two volumes. In the first volume, Sections 1 through 5 contain the introduction, the objectives of the proposed studies, and background information. The discussion is not comprehensive in detail; documents are referenced that discuss the background material in greater detail. Sections 6 through 9 identify and select the group of studies to be performed and discuss the peer review process. The second volume contains Appendices A and B, which present the assignment of responsibilities and the detailed plans, schedules, and costs for the proposed program

  2. Savannah River Site mixed waste Proposed Site Treatment Plan (PSTP). Volumes 1 and 2 and reference document: Revision 2

    International Nuclear Information System (INIS)

    Helmich, E.; Noller, D.K.; Wierzbicki, K.S.; Bailey, L.L.

    1995-01-01

    The DOE is required by the Resource Conservation and Recovery Act to prepare site treatment plans describing the development of treatment capacities and technologies for treating mixed waste. This proposed plan contains Savannah River Site's preferred options and schedules for constructing new facilities, and otherwise obtaining treatment for mixed wastes. The proposed plan consists of 2 volumes. Volume 1, Compliance Plan, identifies the capacity to be developed and the schedules as required. Volume 2, Background, provides a detailed discussion of the preferred options with technical basis, plus a description of the specific waste streams. Chapters are: Introduction; Methodology; Mixed low level waste streams; Mixed transuranic waste; High level waste; Future generation of mixed waste streams; Storage; Process for evaluation of disposal issues in support of the site treatment plans discussions; Treatment facilities and treatment technologies; Offsite waste streams for which SRS treatment is the Preferred Option (Naval reactor wastes); Summary information; and Acronyms and glossary. This revision does not contain the complete revised report, but only those pages that have been revised

  3. Treatment plan evaluation using dose-volume histogram (DVH) and spatial dose-volume histogram (zDVH)

    International Nuclear Information System (INIS)

    Cheng, C.-W.; Das, Indra J.

    1999-01-01

    Objective: The dose-volume histogram (DVH) has been accepted as a tool for treatment-plan evaluation. However, DVH lacks spatial information. A new concept, the z-dependent dose-volume histogram (zDVH), is presented as a supplement to the DVH in three-dimensional (3D) treatment planning to provide the spatial variation, as well as the size and magnitude of the different dose regions within a region of interest. Materials and Methods: Three-dimensional dose calculations were carried out with various plans for three disease sites: lung, breast, and prostate. DVHs were calculated for the entire volume. A zDVH is defined as a differential dose-volume histogram with respect to a computed tomographic (CT) slice position. In this study, zDVHs were calculated for each CT slice in the treatment field. DVHs and zDVHs were compared. Results: In the irradiation of lung, DVH calculation indicated that the treatment plan satisfied the dose-volume constraint placed on the lung and zDVH of the lung revealed that a sizable fraction of the lung centered about the central axis (CAX) received a significant dose, a situation that warranted a modification of the treatment plan due to the removal of one lung. In the irradiation of breast with tangential fields, the DVH showed that about 7% of the breast volume received at least 110% of the prescribed dose (PD) and about 11% of the breast received less than 98% PD. However, the zDVHs of the breast volume in each of seven planes showed the existence of high-dose regions of 34% and 15%, respectively, of the volume in the two caudal-most planes and cold spots of about 40% in the two cephalic planes. In the treatment planning of prostate, DVHs showed that about 15% of the bladder and 40% of the rectum received 102% PD, whereas about 30% of the bladder and 50% of the rectum received the full dose. Taking into account the hollow structure of both the bladder and the rectum, the dose-surface histograms (DSH) showed larger hot-spot volume, about

  4. OCCUPATIONAL EDUCATION--PLANNING AND PROGRAMMING. VOLUME TWO.

    Science.gov (United States)

    KOTZ, ARNOLD

    ADDITIONAL POSITION PAPERS BASED ON INFORMATION GATHERED IN THE RECONNAISSANCE SURVEYS OF PLANNING AND PROGRAMING IN OCCUPATIONAL EDUCATION, REPORTED IN VOLUME ONE (VT 005 041), ARE PRESENTED. PART IV, CONCERNED WITH PROGRAM STRUCTURE AND BUDGETING AND THEIR RELATION TO THE PLANNING PROCESS, INCLUDES THE PAPERS--(1) "CURRENT POLICIES AND…

  5. Limitations of the planning organ at risk volume (PRV) concept.

    Science.gov (United States)

    Stroom, Joep C; Heijmen, Ben J M

    2006-09-01

    Previously, we determined a planning target volume (PTV) margin recipe for geometrical errors in radiotherapy equal to M(T) = 2 Sigma + 0.7 sigma, with Sigma and sigma standard deviations describing systematic and random errors, respectively. In this paper, we investigated margins for organs at risk (OAR), yielding the so-called planning organ at risk volume (PRV). For critical organs with a maximum dose (D(max)) constraint, we calculated margins such that D(max) in the PRV is equal to the motion averaged D(max) in the (moving) clinical target volume (CTV). We studied margins for the spinal cord in 10 head-and-neck cases and 10 lung cases, each with two different clinical plans. For critical organs with a dose-volume constraint, we also investigated whether a margin recipe was feasible. For the 20 spinal cords considered, the average margin recipe found was: M(R) = 1.6 Sigma + 0.2 sigma with variations for systematic and random errors of 1.2 Sigma to 1.8 Sigma and -0.2 sigma to 0.6 sigma, respectively. The variations were due to differences in shape and position of the dose distributions with respect to the cords. The recipe also depended significantly on the volume definition of D(max). For critical organs with a dose-volume constraint, the PRV concept appears even less useful because a margin around, e.g., the rectum changes the volume in such a manner that dose-volume constraints stop making sense. The concept of PRV for planning of radiotherapy is of limited use. Therefore, alternative ways should be developed to include geometric uncertainties of OARs in radiotherapy planning.

  6. Background and planning requirements for spent fuel shipments to DOE

    Energy Technology Data Exchange (ETDEWEB)

    Ravenscroft, Norman [Edlow International Company, 1666 Connecticut Avenue, NW, Suite 201, Washington, DC 20009 (United States)

    1996-10-01

    Information is provided on the planning required and the factors that must be included in the planning process for spent fuel shipments to DOE. A summary is also provided on the background concerning renewal of the DOE spent fuel acceptance policy in May 1996. (author)

  7. Final Sampling and Analysis Plan for Background Sampling, Fort Sheridan, Illinois

    National Research Council Canada - National Science Library

    1995-01-01

    .... This Background Sampling and Analysis Plan (BSAP) is designed to address this issue through the collection of additional background samples at Fort Sheridan to support the statistical analysis and the Baseline Risk Assessment (BRA...

  8. Subseabed Disposal Program Plan. Volume II. FY80 budget and subtask work plans

    International Nuclear Information System (INIS)

    1980-01-01

    This volume of the Subseabed Disposal Program Plan presents a breakdown of the master program structure by major activity. Each activity is described and accompanied by a specific cost plan schedule and a milestone plan. The costs have been compiled in the Cost Plan Schedules attached to each Subtask Work Plan. The FY 1980 budget for the Subseabed Disposal Program is summarized at the second level of the Work Breakdown Structure. The milestone plans for FY 80 are presented. The milestones can be changed only with the concurrence of the Sandia Subseabed Program Manager

  9. International Photovoltaic Program Plan. Volume II. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Costello, D.; Koontz, R.; Posner, D.; Heiferling, P.; Carpenter, P.; Forman, S.; Perelman, L.

    1979-12-01

    This second volume of a two-part report on the International Photovoltaic Program Plan contains appendices summarizing the results of analyses conducted in preparation of the plan. These analyses include compilations of relevant statutes and existing Federal programs; strategies designed to expand the use of photovoltaics abroad; information on the domestic photovoltaic plan and its impact on the proposed international plan; perspectives on foreign competition; industry views on the international photovoltaic market and ideas about how US government actions could affect this market; international financing issues; and information on issues affecting foreign policy and developing countries.

  10. Integrated operations plan for the MFTF-B Mirror Fusion Test Facility. Volume I. Organization plan

    International Nuclear Information System (INIS)

    1981-12-01

    This plan and the accompanying MFTF-B Integrated Operations Plan are submitted in response to UC/LLNL Purchase Order 3883801, dated July 1981. The organization plan also addresses the specific tasks and trade studies directed by the scope of work. The Integrated Operations Plan, which includes a reliability, quality assurance, and safety plan and an integrated logistics plan, comprises the burden of the report. In the first section of this volume, certain underlying assumptions and observations are discussed setting the requirements and limits for organization. Section B presents the recommended structure itself. Section C Device Availability vs Maintenance and Support Efforts and Section D Staffing Levels and Skills provide backup detail and justification. Section E is a trade study on maintenance and support by LLNL staff vs subcontract and Section F is a plan for transitioning from the construction phase into operation. A brief summary of schedules and estimated costs concludes the volume

  11. Nuclear power enterprise tax planning strategy in the background of reform

    International Nuclear Information System (INIS)

    Wu Yimin

    2012-01-01

    The success of tax planning can be converted into enterprise's productivity, tax planning strategy can maximize the desired effects and bring out its full play to tax planning. Taking new round of tax reform in 12th five-year-plan and the reformation of professional groups as the background, the author detailedly conceived a frame of corporate tax planning strategy for nuclear power enterprises of China National Nuclear Corporation at the forefront of reformation from an all-round comprehensive view and multi-angle stand. (author)

  12. Impact of 18FDG-PET/CT on biological target volume (BTV) definition for treatment planning for non-small cell lung cancer patients

    International Nuclear Information System (INIS)

    Devic, Slobodan; Tomic, Nada; Faria, Sergio; Dean, Geoffrey; Lisbona, Robert; Parker, William; Kaufman, Chris; Podgorsak, Ervin B.

    2007-01-01

    This work represents our effort to test feasibility of FDG-based PET/CT on target volume delineation in radiotherapy treatment planning of NSCLC patients. Different methods have been developed to enable more precise target outlining using PET: Qualitative Visual Method, CTV=2.5 SUV units, linear SUV threshold function method, and CTV=40% Iso of Maximum Uptake Value. We are proposing reconstruction of three biological target volumes: necrotic BTV (same as PTV created by radiation oncologist using CT data), proliferating BTV (based on PET signal to background ratio 1:3) and hypoxic BTV (based on PET signal to background ratio of 1:19). Two IMRT plans were created and compared to the conventional treatment plan: 'conservative' IMRT plan delivers 52.5 Gy to the necrotic BTV and 65 Gy to the hypoxic BTV; 'radical' IMRT plan delivers 30 Gy to necrotic BTV, 52.5 Gy to proliferating BTV and 65 Gy to hypoxic BTV. Use of BTVs in IMRT plans is attractive because it increases dose to targets considered to need higher doses. It reduces considerably dose to heart and spinal cord, organs considered to limit dose escalation approaches in NSCLC treatment. 'Conservative' IMRT approach can be understood as a PET/CT-based concomitant boost to the tumor expressing the highest FDG uptake. 'Radical' plan implies deviation from the traditional uniform dose target coverage approach, with the intention of achieving better surrounding tissue sparing and ultimately allowing for dose escalation protocols relying on biologically based treatment planning

  13. The potential advantages of (18)FDG PET/CT-based target volume delineation in radiotherapy planning of head and neck cancer.

    Science.gov (United States)

    Moule, Russell N; Kayani, Irfan; Moinuddin, Syed A; Meer, Khalda; Lemon, Catherine; Goodchild, Kathleen; Saunders, Michele I

    2010-11-01

    This study investigated two fixed threshold methods to delineate the target volume using (18)FDG PET/CT before and during a course of radical radiotherapy in locally advanced squamous cell carcinoma of the head and neck. Patients were enrolled into the study between March 2006 and May 2008. (18)FDG PET/CT scans were carried out 72h prior to the start of radiotherapy and then at 10, 44 and 66Gy. Functional volumes were delineated according to the SUV Cut Off (SUVCO) (2.5, 3.0, 3.5, and 4.0bwg/ml) and percentage of the SUVmax (30%, 35%, 40%, 45%, and 50%) thresholds. The background (18)FDG uptake and the SUVmax within the volumes were also assessed. Primary and lymph node volumes for the eight patients significantly reduced with each increase in the delineation threshold (for example 2.5-3.0bwg/ml SUVCO) compared to the baseline threshold at each imaging point. There was a significant reduction in the volume (p⩽0.0001-0.01) after 36Gy compared to the 0Gy by the SUVCO method. There was a negative correlation between the SUVmax within the primary and lymph node volumes and delivered radiation dose (p⩽0.0001-0.011) but no difference in the SUV within the background reference region. The volumes delineated by the PTSUVmax method increased with the increase in the delivered radiation dose after 36Gy because the SUVmax within the region of interest used to define the edge of the volume was equal or less than the background (18)FDG uptake and the software was unable to effectively differentiate between tumour and background uptake. The changes in the target volumes delineated by the SUVCO method were less susceptible to background (18)FDG uptake compared to those delineated by the PTSUVmax and may be more helpful in radiotherapy planning. The best method and threshold have still to be determined within institutions, both nationally and internationally. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  14. Optimized Planning Target Volume for Intact Cervical Cancer

    International Nuclear Information System (INIS)

    Khan, Alvin; Jensen, Lindsay G.; Sun Shuai; Song, William Y.; Yashar, Catheryn M.; Mundt, Arno J.; Zhang Fuquan; Jiang, Steve B.; Mell, Loren K.

    2012-01-01

    Purpose: To model interfraction clinical target volume (CTV) variation in patients with intact cervical cancer and design a planning target volume (PTV) that minimizes normal tissue dose while maximizing CTV coverage. Methods and Materials: We analyzed 50 patients undergoing external-beam radiotherapy for intact cervical cancer using daily online cone-beam computed tomography (CBCT). The CBCTs (n = 972) for each patient were rigidly registered to the planning CT. The CTV was delineated on the planning CT (CTV 0 ) and the set of CBCTs ({CTV 1 –CTV 25 }). Manual (n = 98) and automated (n = 668) landmarks were placed over the surface of CTV 0 with reference to defined anatomic structures. Normal vectors were extended from each landmark, and the minimum length required for a given probability of encompassing CTV 1 –CTV 25 was computed. The resulting expansions were used to generate an optimized PTV. Results: The mean (SD; range) normal vector length to ensure 95% coverage was 4.3 mm (2.7 mm; 1–16 mm). The uniform expansion required to ensure 95% probability of CTV coverage was 13 mm. An anisotropic margin of 20 mm anteriorly and posteriorly and 10 mm superiorly, inferiorly, and laterally also would have ensured a 95% probability of CTV coverage. The volume of the 95% optimized PTV (1470 cm 3 ) was significantly lower than both the anisotropic PTV (2220 cm 3 ) and the uniformly expanded PTV (2110 cm 3 ) (p 0 , 5–10 mm along the interfaces of CTV 0 with the bladder and rectum, and 10–14 mm along the anterior surface of CTV 0 at the level of the uterus. Conclusion: Optimizing PTV definition according to surface landmarking resulted in a high probability of CTV coverage with reduced PTV volumes. Our results provide data justifying planning margins to use in practice and clinical trials.

  15. DNFSB Recommendation 94-1 Hanford Site Integrated Stabilization Management Plan. Volume 2

    International Nuclear Information System (INIS)

    Gerber, E.W.

    1995-10-01

    The Hanford Site Integrated Stabilization Management Plan (SISMP) was developed in support of the US Department of Energy's (DOE) Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 94-1 Integrated Program Plan (IPP). Volume 1 of the SISMP identifies the technical scope and costs associated with Hanford Site plans to resolve concerns identified in DNFSB Recommendation 94-1. Volume 2 of the SISMP provides the Resource Loaded Integrated Schedules for Spent Nuclear Fuel Project and Plutonium Finishing Plant activities identified in Volume 1 of the SISMP. Appendix A provides the schedules and progress curves related to spent nuclear fuel management. Appendix B provides the schedules and progress curves related to plutonium-bearing material management. Appendix C provides programmatic logic diagrams that were referenced in Volume 1 of the SISMP

  16. Split-Volume Treatment Planning of Multiple Consecutive Vertebral Body Metastases for Cyberknife Image-Guided Robotic Radiosurgery

    International Nuclear Information System (INIS)

    Sahgal, Arjun; Chuang, Cynthia; Larson, David; Huang, Kim; Petti, Paula; Weinstein, Phil; Ma Lijun

    2008-01-01

    Cyberknife treatment planning of multiple consecutive vertebral body metastases is challenging due to large target volumes adjacent to critical normal tissues. A split-volume treatment planning technique was developed to improve the treatment plan quality of such lesions. Treatment plans were generated for 1 to 5 consecutive thoracic vertebral bodies (CVBM) prescribing a total dose of 24 Gy in 3 fractions. The planning target volume (PTV) consisted of the entire vertebral body(ies). Treatment plans were generated considering both the de novo clinical scenario (no prior radiation), imposing a dose limit of 8 Gy to 1 cc of spinal cord, and the retreatment scenario (prior radiation) with a dose limit of 3 Gy to 1 cc of spinal cord. The split-volume planning technique was compared with the standard full-volume technique only for targets ranging from 2 to 5 CVBM in length. The primary endpoint was to obtain best PTV coverage by the 24 Gy prescription isodose line. A total of 18 treatment plans were generated (10 standard and 8 split-volume). PTV coverage by the 24-Gy isodose line worsened consistently as the number of CVBM increased for both the de novo and retreatment scenario. Split-volume planning was achieved by introducing a 0.5-cm gap, splitting the standard full-volume PTV into 2 equal length PTVs. In every case, split-volume planning resulted in improved PTV coverage by the 24-Gy isodose line ranging from 4% to 12% for the de novo scenario and, 8% to 17% for the retreatment scenario. We did not observe a significant trend for increased monitor units required, or higher doses to spinal cord or esophagus, with split-volume planning. Split-volume treatment planning significantly improves Cyberknife treatment plan quality for CVBM, as compared to the standard technique. This technique may be of particular importance in clinical situations where stringent spinal cord dose limits are required

  17. Volume rendering in treatment planning for moving targets

    Energy Technology Data Exchange (ETDEWEB)

    Gemmel, Alexander [GSI-Biophysics, Darmstadt (Germany); Massachusetts General Hospital, Boston (United States); Wolfgang, John A.; Chen, George T.Y. [Massachusetts General Hospital, Boston (United States)

    2009-07-01

    Advances in computer technologies have facilitated the development of tools for 3-dimensional visualization of CT-data sets with volume rendering. The company Fovia has introduced a high definition volume rendering engine (HDVR trademark by Fovia Inc., Palo Alto, USA) that is capable of representing large CT data sets with high user interactivity even on standard PCs. Fovia provides a software development kit (SDK) that offers control of all the features of the rendering engine. We extended the SDK by functionalities specific to the task of treatment planning for moving tumors. This included navigation of the patient's anatomy in beam's eye view, fast point-and-click measurement of lung tumor trajectories as well as estimation of range perturbations due to motion by calculation of (differential) water equivalent path lengths for protons and carbon ions on 4D-CT data sets. We present patient examples to demonstrate the advantages and disadvantages of volume rendered images as compared to standard 2-dimensional axial plane images. Furthermore, we show an example of a range perturbation analysis. We conclude that volume rendering is a powerful technique for the representation and analysis of large time resolved data sets in treatment planning.

  18. An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions.

    Science.gov (United States)

    Hummelink, S; Verhulst, Arico C; Maal, Thomas J J; Hoogeveen, Yvonne L; Schultze Kool, Leo J; Ulrich, Dietmar J O

    2017-07-01

    Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available nowadays, we can combine information to preoperatively plan the optimal flap volume to be harvested. In this proof-of-concept, we investigated whether projection of a virtual flap planning onto the patient's abdomen using a projection method could result in harvesting the correct flap volume. In six patients (n = 9 breasts), 3D stereophotogrammetry and CTA data were combined from which a virtual flap planning was created comprising perforator locations, blood vessel trajectory and flap size. All projected perforators were verified with Doppler ultrasound. Intraoperative flap measurements were collected to validate the determined flap delineation volume. The measured breast volume using 3D stereophotogrammetry was 578 ± 127 cc; on CTA images, 527 ± 106 cc flap volumes were planned. The nine harvested flaps weighed 533 ± 109 g resulting in a planned versus harvested flap mean difference of 5 ± 27 g (flap density 1.0 g/ml). In 41 out of 42 projected perforator locations, a Doppler signal was audible. This proof-of-concept shows in small numbers that flap volumes can be included into a virtual DIEP flap planning, and transferring the virtual planning to the patient through a projection method results in harvesting approximately the same volume during surgery. In our opinion, this innovative approach is the first step in consequently achieving symmetric breast volumes in DIEP flap breast reconstructions. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. Mitochondrial genetic background modulates bioenergetics and susceptibility to acute cardiac volume overload.

    Science.gov (United States)

    Fetterman, Jessica L; Zelickson, Blake R; Johnson, Larry W; Moellering, Douglas R; Westbrook, David G; Pompilius, Melissa; Sammy, Melissa J; Johnson, Michelle; Dunham-Snary, Kimberly J; Cao, Xuemei; Bradley, Wayne E; Zhang, Jinju; Wei, Chih-Chang; Chacko, Balu; Schurr, Theodore G; Kesterson, Robert A; Dell'italia, Louis J; Darley-Usmar, Victor M; Welch, Danny R; Ballinger, Scott W

    2013-10-15

    Dysfunctional bioenergetics has emerged as a key feature in many chronic pathologies such as diabetes and cardiovascular disease. This has led to the mitochondrial paradigm in which it has been proposed that mtDNA sequence variation contributes to disease susceptibility. In the present study we show a novel animal model of mtDNA polymorphisms, the MNX (mitochondrial-nuclear exchange) mouse, in which the mtDNA from the C3H/HeN mouse has been inserted on to the C57/BL6 nuclear background and vice versa to test this concept. Our data show a major contribution of the C57/BL6 mtDNA to the susceptibility to the pathological stress of cardiac volume overload which is independent of the nuclear background. Mitochondria harbouring the C57/BL6J mtDNA generate more ROS (reactive oxygen species) and have a higher mitochondrial membrane potential relative to those with C3H/HeN mtDNA, independent of nuclear background. We propose this is the primary mechanism associated with increased bioenergetic dysfunction in response to volume overload. In summary, these studies support the 'mitochondrial paradigm' for the development of disease susceptibility, and show that the mtDNA modulates cellular bioenergetics, mitochondrial ROS generation and susceptibility to cardiac stress.

  20. Salt Repository Project site study plan for background environmental radioactivity: Revision 1

    International Nuclear Information System (INIS)

    1987-12-01

    The Site Study Plan for Background Environmental Radioactivity describes a field program consisting of an initial radiological survey and a radiological sampling program. The field program includes measurement of direct radiation and collection and analysis of background radioactivity samples of air, precipitation, soil, water, milk, pasture grass, food crops, meat, poultry, game, and eggs. The plan describes for each study the need for the study, the study design, data management, and use, schedule of proposed activities, and quality assurance requirements. These studies will provide data needed to satisfy requirements contained in, or derived from, the Salt Repository Project Requirements Document. 43 refs., 10 figs., 7 tabs

  1. A treatment planning comparison of four target volume contouring guidelines for locally advanced pancreatic cancer radiotherapy

    International Nuclear Information System (INIS)

    Fokas, Emmanouil; Eccles, Cynthia; Patel, Neel; Chu, Kwun-Ye; Warren, Samantha; McKenna, W. Gillies; Brunner, Thomas B.

    2013-01-01

    Background and purpose: Contouring of target volumes varies significantly in radiotherapy of pancreatic ductal adenocarcinoma (PDAC). There is a lack of consensus as to whether elective lymph nodes (eLN’s) should be included or not in the planning target volume (PTV). In the present study we analyzed the dosimetric coverage of the eLN’s and organs at risk (OAR) by comparing four different contouring guidelines. Methods and materials: PTVs were delineated with (Oxford and RTOG guidelines) or without (Michigan and SCALOP guidelines) including the eLNs in eleven patients with PDAC. eLNs included the peripancreatic, paraaortic, paracaval, celiac trunk, superior mesenteric and portal vein clinical target volumes (CTVs). A 3D-CRT plan (50.40 Gy in 28 fractions) was performed to analyze and compare the dosimetric coverage of all eLNs and OAR between the 4 contouring guidelines. Results: The size of Oxford and RTOG PTVs was comparable and significantly larger than the SCALOP and Michigan PTVs. Interestingly the eLNs received a significant amount of incidental dose irradiation by PTV-based plans that only aimed to treat the tumor without the eLNs. The dosimetric coverage of eLN presented a large variability according to the respective contouring methods. The difference in the size of the 4 PTVs was reflected to the dose distribution at the OAR. Conclusions: Our study provides important information regarding the impact of different contouring guidelines on the dose distribution to the eLNs and the OAR in patients with locally advanced PDAC treated with radiotherapy

  2. Volume definition system for treatment planning

    International Nuclear Information System (INIS)

    Alakuijala, Jyrki; Pekkarinen, Ari; Puurunen, Harri

    1997-01-01

    Purpose: Volume definition is a difficult and time consuming task in 3D treatment planning. We have studied a systems approach for constructing an efficient and reliable set of tools for volume definition. Our intent is to automate body outline, air cavities and bone volume definition and accelerate definition of other anatomical structures. An additional focus is on assisting in definition of CTV and PTV. The primary goals of this work are to cut down the time used in contouring and to improve the accuracy of volume definition. Methods: We used the following tool categories: manual, semi-automatic, automatic, structure management, target volume definition, and visualization tools. The manual tools include mouse contouring tools with contour editing possibilities and painting tools with a scaleable circular brush and an intelligent brush. The intelligent brush adapts its shape to CT value boundaries. The semi-automatic tools consist of edge point chaining, classical 3D region growing of single segment and competitive volume growing of multiple segments. We tuned the volume growing function to take into account both local and global region image values, local volume homogeneity, and distance. Heuristic seeding followed with competitive volume growing finds the body outline, couch and air automatically. The structure management tool stores ICD-O coded structures in a database. The codes have predefined volume growing parameters and thus are able to accommodate the volume growing dissimilarity function for different volume types. The target definition tools include elliptical 3D automargin for CTV to PTV transformation and target volume interpolation and extrapolation by distance transform. Both the CTV and the PTV can overlap with anatomical structures. Visualization tools show the volumes as contours or color wash overlaid on an image and displays voxel rendering or translucent triangle mesh rendering in 3D. Results: The competitive volume growing speeds up the

  3. Motion and operation planning of robotic systems background and practical approaches

    CERN Document Server

    Gomez-Barvo, Fernando

    2015-01-01

    This book addresses the broad multi-disciplinary topic of robotics, and presents the basic techniques for motion and operation planning in robotics systems. Gathering contributions from experts in diverse and wide ranging fields, it offers an overview of the most recent and cutting-edge practical applications of these methodologies. It covers both theoretical and practical approaches, and elucidates the transition from theory to implementation. An extensive analysis is provided, including humanoids, manipulators, aerial robots and ground mobile robots. ‘Motion and Operation Planning of Robotic Systems’ addresses the following topics: *The theoretical background of robotics. *Application of motion planning techniques to manipulators, such as serial and parallel manipulators. *Mobile robots planning, including robotic applications related to aerial robots, large scale robots and traditional wheeled robots. *Motion planning for humanoid robots. An invaluable reference text for graduate students and researche...

  4. Northwest conservation and electric power plan 1986. Volume I

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This 20 year plan is prepared in accordance with the Pacific Northwest Electric Power Planning and Conservation Act - Public Law 96-501, of 1980. This Act required the Council to develop and adopt a 20-year electrical power plan for the region with a program to protect, mitigate and enhance the fish and wildlife affected by hydroelectric development in the Columbia River Basin. The plan provides a 25 year history of the regions power development and comments on its unique features and changing nature. Presentations covers problems, solutions and the planning strategy for risk management. The existing electrical power system is discussed along with future electricity needs, generating resources, conservation of resources, regional needs and resources, and the 1986 action plan. Underlying details are provided in Volume II

  5. A patient-specific planning target volume used in 'plan of the day' adaptation for interfractional motion mitigation

    International Nuclear Information System (INIS)

    Chen, Wenjing; Gemmel, Alexander; Rietzel, Eike

    2013-01-01

    We propose a patient-specific planning target volume (PTV) to deal with interfractional variations, and test its feasibility in a retrospective treatment-planning study. Instead of using one planning image only, multiple scans are taken on different days. The target and organs at risk (OARs) are delineated on each images. The proposed PTV is generated from a union of those target contours on the planning images, excluding voxels of the OARs, and is denoted the PTV 'GP-OAR' (global prostate-organs at risk). The study is performed using 'plan of the day' adaptive workflow, which selects a daily plan from a library of plans based on a similarity comparison between the daily scan and planning images. The daily plans optimized for GP-OAR volumes are compared with those optimized for PTVs generated from a single prostate contour (PTV SP). Four CT serials of prostate cancer patient datasets are included in the test, and in total 28 fractions are simulated. The results show that the daily chosen GP-OAR plans provide excellent target coverage, with V95 values of the prostate mostly >95%. In addition, dose delivered to the OARs as calculated from applying daily chosen GP-OAR plans is slightly increased but comparable to that calculated from applying daily SP plans. In general, the PTV GP-OARs are able to cover possible target variations while keeping dose delivered to the OARs at a similar level to that of the PTV SPs. (author)

  6. Background Information for the Nevada National Security Site Integrated Sampling Plan, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Farnham, Irene; Marutzky, Sam

    2014-12-01

    This document describes the process followed to develop the Nevada National Security Site (NNSS) Integrated Sampling Plan (referred to herein as the Plan). It provides the Plan’s purpose and objectives, and briefly describes the Underground Test Area (UGTA) Activity, including the conceptual model and regulatory requirements as they pertain to groundwater sampling. Background information on other NNSS groundwater monitoring programs—the Routine Radiological Environmental Monitoring Plan (RREMP) and Community Environmental Monitoring Program (CEMP)—and their integration with the Plan are presented. Descriptions of the evaluations, comments, and responses of two Sampling Plan topical committees are also included.

  7. Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress

    Science.gov (United States)

    2017-02-02

    international relations and strategy of basic world geographic features such as the size and location of continents, oceans, and individual countries. From...Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress Ronald O’Rourke Specialist in Naval Affairs February 2, 2017...

  8. Savannah River Site approved site treatment plan, 2000 annual update

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, B.

    2000-04-20

    The Compliance Plan Volume (Volume 1) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions. Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume 2) and is provided for information.

  9. Savannah River Site Approved Site Treatment Plan, 1998 Annual Update

    International Nuclear Information System (INIS)

    Lawrence, B.

    1999-01-01

    The Compliance Plan Volume (Volume I) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions. Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume II) and is provided for information

  10. Savannah River Site approved site treatment plan, 2000 annual update

    International Nuclear Information System (INIS)

    Lawrence, B.

    2000-01-01

    The Compliance Plan Volume (Volume 1) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions. Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume 2) and is provided for information

  11. Savannah River Site Environmental Implementation Plan. Volume 2, Protection programs

    Energy Technology Data Exchange (ETDEWEB)

    1989-08-01

    Formal sitewide environmental planning at the . Savannah River Site (SRS) began in 1986 with the development and adoption of the Strategic Environmental Plan. The Strategic Environmental Plan describes the philosophy, policy, and overall program direction of environmental programs for the operation of the SRS. The Strategic Environmental Plan (Volume 2) provided the basis for development of the Environmental Implementation Plan (EIP). The EIP is the detailed, comprehensive environmental master plan for operating contractor organizations at the SRS. The EIP provides a process to ensure that all environmental requirements and obligations are being met by setting specific measurable goals and objectives and strategies for implementation. The plan is the basis for justification of site manpower and funding requests for environmental projects and programs over a five-year planning period.

  12. Mitochondrial Genetic Background Modulates Bioenergetics and Susceptibility to Acute Cardiac Volume – Overload

    Science.gov (United States)

    Fetterman, Jessica L.; Zelickson, Blake R.; Johnson, Larry W.; Moellering, Douglas R.; Westbrook, David G.; Pompilius, Melissa; Sammy, Melissa J.; Johnson, Michelle; Dunham-Snary, Kimberly J.; Cao, Xuemei; Bradley, Wayne E.; Zhang, Jinju; Wei, Chih-Chang; Chacko, Balu; Schurr, Theodore G.; Kesterson, Robert A.; Dell’Italia, Louis J.; Darley-Usmar, Victor M.; Welch, Danny R.; Ballinger, Scott W.

    2013-01-01

    Synopsis Dysfunctional bioenergetics has emerged as a key feature in many chronic pathologies such as diabetes and cardiovascular disease. This has led to the mitochondrial paradigm in which it has been proposed that mitochondrial DNA (mtDNA) sequence variation contributes to disease susceptibility. In this study we present a novel animal model of mtDNA polymorphisms, the mitochondrial nuclear exchange mouse (MNX), in which the mtDNA from C3H/HeN mouse has been inserted onto the C57/BL6 nuclear background and vice versa to test this concept. Our data show a major contribution of the C57/BL6 mtDNA to the susceptibility to the pathological stress of cardiac volume overload which is independent of the nuclear background. Mitochondria harboring the C57/BL6J mtDNA generate more reactive oxygen species (ROS) and have a higher mitochondrial membrane potential relative to those having the C3H/HeN mtDNA, independent of nuclear background. We propose this is the primary mechanism associated with increased bioenergetic dysfunction in response to volume overload. In summary, these studies support the “mitochondrial paradigm” for the development of disease susceptibility, and show that the mtDNA modulates, cellular bioenergetics, mitochondrial reactive oxygen species generation and susceptibility to cardiac stress. PMID:23924350

  13. Dosimetric impact of the variation of the prostate volume and shape between pretreatment planning and treatment procedure

    International Nuclear Information System (INIS)

    Beaulieu, Luc; Aubin, Sylviane; Taschereau, Richard; Pouliot, Jean; Vigneault, Eric

    2002-01-01

    Purpose: The goal of this study is to evaluate the dosimetric impact on a pretreatment planning of prostatic volume and shape variations occurring between the moment of the volume study (preplanning) and just before a transperineal permanent seed implant procedure. Such variations could be an obvious source of misplacement of the seeds relative to the prostate gland and organs at risk. Other sources of dosimetric uncertainties, such as misplacement due to the procedure itself or edema, are eliminated by looking at these variations before the implant procedure. Methods and Materials: For 35 clinical cases, prostate contours were taken at preplanning time as well as in the operating room (OR) minutes before the procedure. Comparison of shape and volume between the two sets was made. The impact on V100 was evaluated by placing the seeds in their planned positions in the new volume (clinical situation) and also by performing a new plan with the second set of contours to simulate an intraoperative approach. Results: The volume taken in the OR remained unchanged compared to the pretreatment planning volume in only 37% of the cases. While on average the dose coverage loss from pretreatment planning due to a combination of variations of volume and shape was small at 5.7%, a V100 degradation of up to 20.9% was observed in extreme cases. Even in cases in which no changes in volume were observed, changes in shape occurred and strongly affected implant dosimetry. Conclusions: Variations of volume and shape between pretreatment planning and the implant procedure can have a strong impact on the dosimetry if the planning and the implant procedure are not performed on the same day. This is an argument in favor of performing implant dosimetry in the OR

  14. The minimum knowledge base for predicting organ-at-risk dose-volume levels and plan-related complications in IMRT planning

    International Nuclear Information System (INIS)

    Zhang, Hao H; D'Souza, Warren D; Meyer, Robert R; Shi Leyuan

    2010-01-01

    IMRT treatment planning requires consideration of two competing objectives: achieving the required amount of radiation for the planning target volume and minimizing the amount of radiation delivered to all other tissues. It is important for planners to understand the tradeoff between competing factors so that the time-consuming human interaction loop (plan-evaluate-modify) can be eliminated. Treatment-plan-surface models have been proposed as a decision support tool to aid treatment planners and clinicians in choosing between rival treatment plans in a multi-plan environment. In this paper, an empirical approach is introduced to determine the minimum number of treatment plans (minimum knowledge base) required to build accurate representations of the IMRT plan surface in order to predict organ-at-risk (OAR) dose-volume (DV) levels and complications as a function of input DV constraint settings corresponding to all involved OARs in the plan. We have tested our approach on five head and neck patients and five whole pelvis/prostate patients. Our results suggest that approximately 30 plans were sufficient to predict DV levels with less than 3% relative error in both head and neck and whole pelvis/prostate cases. In addition, approximately 30-60 plans were sufficient to predict saliva flow rate with less than 2% relative error and to classify rectal bleeding with an accuracy of 90%.

  15. Integrating respiratory-gated PET-based target volume delineation in liver SBRT planning, a pilot study

    International Nuclear Information System (INIS)

    Riou, Olivier; Thariat, Juliette; Serrano, Benjamin; Azria, David; Paulmier, Benoit; Villeneuve, Remy; Fenoglietto, Pascal; Artenie, Antonella; Ortholan, Cécile; Faraggi, Marc

    2014-01-01

    To assess the feasibility and benefit of integrating four-dimensional (4D) Positron Emission Tomography (PET) – computed tomography (CT) for liver stereotactic body radiation therapy (SBRT) planning. 8 patients with 14 metastases were accrued in the study. They all underwent a non-gated PET and a 4D PET centered on the liver. The same CT scan was used for attenuation correction, registration, and considered the planning CT for SBRT planning. Six PET phases were reconstructed for each 4D PET. By applying an individualized threshold to the 4D PET, a Biological Internal Target Volume (BITV) was generated for each lesion. A gated Planning Target Volume (PTVg) was created by adding 3 mm to account for set-up margins. This volume was compared to a manual Planning Target Volume (PTV) delineated with the help of a semi-automatic Biological Target Volume (BTV) obtained from the non-gated exam. A 5 mm radial and a 10 mm craniocaudal margins were applied to account for tumor motion and set-up margins to create the PTV. One undiagnosed liver metastasis was discovered thanks to the 4D PET. The semi-automatic BTV were significantly smaller than the BITV (p = 0.0031). However, after applying adapted margins, 4D PET allowed a statistically significant decrease in the PTVg as compared to the PTV (p = 0.0052). In comparison to non-gated PET, 4D PET may better define the respiratory movements of liver targets and improve SBRT planning for liver metastases. Furthermore, non respiratory-gated PET exams can both misdiagnose liver metastases and underestimate the real internal target volumes

  16. 18F-fluorodeoxyglucose PET in definition of target volumes and radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Qiao Wenli; Zhao Jinhua

    2007-01-01

    PET is a functional imaging modality, which can give some biological information of tumor. PET is more and more important in the definition of target volumes and radiotherapy treatment planning. Depending on its sensitivity and specificity, 18 F-fluorideoxyglucose 18 F-FDG PET has been shown to influence the selection of target volumes and radiotherapy treatment planning for non-small cell lung cancers, for head and neck squamous cell carcinomas or for esophageal tumors. On the other hand, for tumors such as rectal carcinomas, convincing data on the value of 18 F-FDG PET for target volume selection are still lacking. However, the application of 18 F-FDG PET in many aspects of radiotherapy is still controversy. Further researches in its clinical application are still needed to investigate whether 18 F-FDG PET for treatment planning should be routine because of the lack of prospective studies. (authors)

  17. Kilowatt isotope power system. Phase II plan. Volume I. Phase II program plan

    International Nuclear Information System (INIS)

    1978-01-01

    The development of a Kilowatt Isotope Power System (KIPS) was begun in 1975 for the purpose of satisfying the power requirements of satellites in the 1980's. The KIPS is a 238 PuO 2 -fueled organic Rankine cycle turbine power system to provide a design output of 500 to 2000 W. Phase II of the overall 3-phase KIPS program is described. This volume presents a program plan for qualifying the organic Rankine power system for flight test in 1982. The program plan calls for the design and fabrication of the proposed flight power system; conducting a development and a qualification program including both environmental and endurance testing, using an electrical and a radioisotope heat source; planning for flight test and spacecraft integration; and continuing ground demonstration system testing to act as a flight system breadboard and to accumulate life data

  18. Background, Personal, and Environmental Influences on the Career Planning of Adolescent Girls

    Science.gov (United States)

    Novakovic, Alexandra; Fouad, Nadya A.

    2013-01-01

    This study investigated the influence of background variables (age, race/ethnicity, mother's work status outside of the home, and socioeconomic status), personal variables (anticipatory role conflict and academic self-efficacy), and environmental variables (parental attachment and parental support) on aspects of adolescent girls' career planning.…

  19. NRC action plan developed as a result of the TMI-2 accident. Volume 2

    International Nuclear Information System (INIS)

    1980-05-01

    The Action Plan provides a comprehensive and integrated plan for all actions judged necessary by the Nuclear Regulatory Commission to correct or improve the regulation and operation of nuclear facilities based on the experience from the accident at the Three Mile Island, Unit 2, nuclear facility and the official studies and investigations of the accident. The tables included in this volume list the recommendations from the various organizations and task forces investigating the accident at Three Mile Island. The tables are annotated to provide easy references to the associated parts of the Action Plan in Volume 1. The tables are also annotated to provide a shorthand indication of how the various recommendations are treated in the Action Plan

  20. SU-F-T-378: Evaluation of Dose-Volume Variability and Parameters Between Prostate IMRT and VMAT Plans

    Energy Technology Data Exchange (ETDEWEB)

    Chow, J [Princess Margaret Cancer Centre, Toronto, ON (Canada); Jiang, R [Grand River Regional Cancer Centre, Kitchener, ON (Canada); Kiciak, A [University of Waterloo, Waterloo, ON (Canada)

    2016-06-15

    Purpose: This study compared the rectal dose-volume consistency, equivalent uniform dose (EUD) and normal tissue complication probability (NTCP) in prostate intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Methods: For forty prostate IMRT and fifty VMAT patients treated using the same dose prescription (78 Gy/39 fraction) and dose-volume criteria in inverse planning optimization, the rectal EUD and NTCP were calculated for each patient. The rectal dose-volume consistency, showing the variability of dose-volume histogram (DVH) among patients, was defined and calculated based on the deviation between the mean and corresponding rectal DVH. Results: From both the prostate IMRT and VMAT plans, the rectal EUD and NTCP were found decreasing with the rectal volume. The decrease rates for the IMRT plans (EUD = 0.47 × 10{sup −3} Gy cm{sup −3} and NTCP = 3.94 × 10{sup −2} % cm{sup −3}) were higher than those for the VMAT (EUD = 0.28 × 10{sup −3} Gy cm{sup −3} and NTCP = 2.61 × 10{sup −2} % cm{sup −3}). In addition, the dependences of the rectal EUD and NTCP on the dose-volume consistency were found very similar between the prostate IMRT and VMAT plans. This shows that both delivery techniques have similar variations of the rectal EUD and NTCP on the dose-volume consistency. Conclusion: Dependences of the dose-volume consistency on the rectal EUD and NTCP were compared between the prostate IMRT and VMAT plans. It is concluded that both rectal EUD and NTCP decreased with an increase of the rectal volume. The variation rates of the rectal EUD and NTCP on the rectal volume were higher for the IMRT plans than VMAT. However, variations of the rectal dose-volume consistency on the rectal EUD and NTCP were found not significant for both delivery techniques.

  1. Space Assembly, Maintenance and Servicing Study. Volume 4: Concept Development Plan

    National Research Council Canada - National Science Library

    1986-01-01

    .... This concept development program (CDP), Volume IV of the SAMS final report, contains a summary of the selection of CDP candidates and a plan for completing the required analysis, tests and demonstrations...

  2. Tumor and normal structures volume localization and quantitation in 3D radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Anselmi, R.; Andreucci, L.

    1995-01-01

    Improvements in imaging technology have significantly enhanced the ability of the radiation oncologist to stage and to evaluate the response of tumor during and after treatment. Over the last few year, in fact, computed tomography (CT), magnetic resonance spectroscopy (MRS), positron emission tomography (PET), single photon emission computed tomography (SPECT) imaging radiolabelled monoclonal tumor antibodies have allowed tumor definition and evaluation. Concerning the above mentioned techniques accurate methods for the integration of morphological (CT, MRI) and functional (PET, SPECT, MRS) information can be very useful for volumes definition. In fact three-dimensional treatment planning depends heavily on volume displays and calculation based on volumes to convey information to the radiation oncologist, physicist and dosimetrist. The accuracy and reproducibility of the methods for creating these volumes are fundamental limitations of current treatment planning systems. Slice by slice manual contouring, which is extremely labor-intensive, and automatic edge detection, which has a high failure rate and requires human intervention are representative of the current standard of practice. The aim of our work is both to develop methods of image data integration and automatic segmentation, and to make the treatment planning system able to combine these multiple information in unified data set in order to get a better tumor volume definition and dose distribution calculation. Then the possibility of using morphological and functional images and other information coming from MR spectroscopy and electronic or confocal microscopy can allow the development into the treatment planning system of biological calculation models for evaluating tumor and normal tissue control probabilities (TCP, NTCP). The definitive use of these models into the 3-D treatment plannings will offer a considerable improvement in the biological efficacy of radiotherapy and it will constitute the object

  3. Navy Force Structure and Shipbuilding Plans: Background and Issues for Congress

    Science.gov (United States)

    2016-03-17

    industrial base. Detailed coverage of certain individual Navy shipbuilding programs can be found in the following CRS reports:  CRS Report RS20643...U.S. Offset Strategy and its Implications for Partners and Allies, As Delivered by Deputy Secretary of Defense Bob Work, Willard Hotel , January 28...Contracting in Defense Acquisition : Background and Issues for Congress, by Ronald O’Rourke and Moshe Schwartz. Navy Force Structure and Shipbuilding Plans

  4. Management plan documentation standard and Data Item Descriptions (DID). Volume of the information system life-cycle and documentation standards, volume 2

    Science.gov (United States)

    Callender, E. David; Steinbacher, Jody

    1989-01-01

    This is the second of five volumes of the Information System Life-Cycle and Documentation Standards. This volume provides a well-organized, easily used standard for management plans used in acquiring, assuring, and developing information systems and software, hardware, and operational procedures components, and related processes.

  5. Guidance and Control Software Project Data - Volume 1: Planning Documents

    Science.gov (United States)

    Hayhurst, Kelly J. (Editor)

    2008-01-01

    The Guidance and Control Software (GCS) project was the last in a series of software reliability studies conducted at Langley Research Center between 1977 and 1994. The technical results of the GCS project were recorded after the experiment was completed. Some of the support documentation produced as part of the experiment, however, is serving an unexpected role far beyond its original project context. Some of the software used as part of the GCS project was developed to conform to the RTCA/DO-178B software standard, "Software Considerations in Airborne Systems and Equipment Certification," used in the civil aviation industry. That standard requires extensive documentation throughout the software development life cycle, including plans, software requirements, design and source code, verification cases and results, and configuration management and quality control data. The project documentation that includes this information is open for public scrutiny without the legal or safety implications associated with comparable data from an avionics manufacturer. This public availability has afforded an opportunity to use the GCS project documents for DO-178B training. This report provides a brief overview of the GCS project, describes the 4-volume set of documents and the role they are playing in training, and includes the planning documents from the GCS project. Volume 1 contains five appendices: A. Plan for Software Aspects of Certification for the Guidance and Control Software Project; B. Software Development Standards for the Guidance and Control Software Project; C. Software Verification Plan for the Guidance and Control Software Project; D. Software Configuration Management Plan for the Guidance and Control Software Project; and E. Software Quality Assurance Activities.

  6. Dose-volume histograms for optimization of treatment plans illustrated by the example of oesophagus carcinoma

    International Nuclear Information System (INIS)

    Roth, J.; Huenig, R.; Huegli, C.

    1995-01-01

    Using the example of oesophagus carcinoma, dose-volume histograms for diverse treatment techniques are calculated and judged by means of multiplanar isodose representations. The selected treatment plans are ranked with the aid of the dose-volume histograms. We distinguish the tissue inside and outside of the target volume. The description of the spatial dose distribution in dependence of the different volumes and the respective fractions of the tumor dose therein with the help of dose-volume histograms brings about a correlation between the physical parameters and the biological effects. In addition one has to bear in mind the consequences of measures that influence the reaction and the side-effects of radiotherapy (e.g. chemotherapy), i.e. the recuperation of the tissues that were irradiated intentionally or inevitably. Taking all that into account it is evident that the dose-volume histograms are a powerful tool for assessing the quality of treatment plans. (orig./MG) [de

  7. Defining internal target volume (ITV) for hepatocellular carcinoma using four-dimensional CT

    International Nuclear Information System (INIS)

    X, Mian; Liu Mengzhong; Deng Xiaowu; Zhang Li; Huang Xiaoyan; Liu Hui; Li Qiaoqiao; Hu Yonghong; Cai Ling; Cui Nianji

    2007-01-01

    Background and purpose: To define individualized internal target volume (ITV) for hepatocellular carcinoma using four-dimensional computed tomography (4DCT). Materials and methods: Gross tumor volumes (GTVs) and clinical target volumes (CTVs) were contoured on all 10 respiratory phases of 4DCT scans in 10 patients with hepatocellular carcinoma. The 3D and 4D treatment plans were performed for each patient using two different planning target volumes (PTVs): (1) PTV 3D was derived from a single CTV plus conventional margins; (2) PTV 4D was derived from ITV 4D , which encompassed all 10 CTVs plus setup margins (SMs). The volumes of PTVs and dose distribution were compared between the two plans. Results: The average PTV volume of the 4D plans (328.4 ± 152.2 cm 3 ) was less than 3D plans (407.0 ± 165.6 cm 3 ). The 4D plans spared more surrounding normal tissues than 3D plans, especially normal liver. Compared with 3D plans, the mean dose to normal liver (MDTNL) decreased from 22.7 to 20.3 Gy. Without increasing the normal tissue complication probability (NTCP), the 4D plans allowed for increasing the calculated dose from 50.4 ± 1.3 to 54.2 ± 2.6 Gy, an average increase of 7.5% (range 4.0-16.0%). Conclusions: The conventional 3D plans can result in geometric miss and include excess normal tissues. The 4DCT-based plans can reduce the target volumes to spare more normal tissues and allow dose escalation compared with 3D plans

  8. IMRT treatment plans and functional planning with functional lung imaging from 4D-CT for thoracic cancer patients

    Directory of Open Access Journals (Sweden)

    Huang Tzung-Chi

    2013-01-01

    Full Text Available Abstract Background and purpose Currently, the inhomogeneity of the pulmonary function is not considered when treatment plans are generated in thoracic cancer radiotherapy. This study evaluates the dose of treatment plans on highly-functional volumes and performs functional treatment planning by incorporation of ventilation data from 4D-CT. Materials and methods Eleven patients were included in this retrospective study. Ventilation was calculated using 4D-CT. Two treatment plans were generated for each case, the first one without the incorporation of the ventilation and the second with it. The dose of the first plans was overlapped with the ventilation and analyzed. Highly-functional regions were avoided in the second treatment plans. Results For small targets in the first plans (PTV  Conclusion Radiation treatments affect functional lung more seriously in large tumor cases. With compromise of dose to other critical organs, functional treatment planning to reduce dose in highly-functional lung volumes can be achieved

  9. Draft Strategic Laboratory Missions Plan. Volume II

    International Nuclear Information System (INIS)

    1996-03-01

    This volume described in detail the Department's research and technology development activities and their funding at the Department's laboratories. It includes 166 Mission Activity Profiles, organized by major mission area, with each representing a discrete budget function called a Budget and Reporting (B ampersand R) Code. The activities profiled here encompass the total research and technology development funding of the laboratories from the Department. Each profile includes a description of the activity and shows how the funding for that activity is distributed among the DOE laboratories as well as universities and industry. The profiles also indicate the principal laboratories for each activity, as well as which other laboratories are involved. The information in this volume is at the core of the Strategic Laboratory Mission Plan. It enables a reader to follow funds from the Department's appropriation to a specific activity description and to specific R ampersand D performing institutions. This information will enable the Department, along with the Laboratory Operations Board and Congress, to review the distribution of R ampersand D performers chosen to execute the Department's missions

  10. Draft Strategic Laboratory Missions Plan. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This volume described in detail the Department`s research and technology development activities and their funding at the Department`s laboratories. It includes 166 Mission Activity Profiles, organized by major mission area, with each representing a discrete budget function called a Budget and Reporting (B & R) Code. The activities profiled here encompass the total research and technology development funding of the laboratories from the Department. Each profile includes a description of the activity and shows how the funding for that activity is distributed among the DOE laboratories as well as universities and industry. The profiles also indicate the principal laboratories for each activity, as well as which other laboratories are involved. The information in this volume is at the core of the Strategic Laboratory Mission Plan. It enables a reader to follow funds from the Department`s appropriation to a specific activity description and to specific R & D performing institutions. This information will enable the Department, along with the Laboratory Operations Board and Congress, to review the distribution of R & D performers chosen to execute the Department`s missions.

  11. Universal field matching in craniospinal irradiation by a background-dose gradient-optimized method.

    Science.gov (United States)

    Traneus, Erik; Bizzocchi, Nicola; Fellin, Francesco; Rombi, Barbara; Farace, Paolo

    2018-01-01

    The gradient-optimized methods are overcoming the traditional feathering methods to plan field junctions in craniospinal irradiation. In this note, a new gradient-optimized technique, based on the use of a background dose, is described. Treatment planning was performed by RayStation (RaySearch Laboratories, Stockholm, Sweden) on the CT scans of a pediatric patient. Both proton (by pencil beam scanning) and photon (by volumetric modulated arc therapy) treatments were planned with three isocenters. An 'in silico' ideal background dose was created first to cover the upper-spinal target and to produce a perfect dose gradient along the upper and lower junction regions. Using it as background, the cranial and the lower-spinal beams were planned by inverse optimization to obtain dose coverage of their relevant targets and of the junction volumes. Finally, the upper-spinal beam was inversely planned after removal of the background dose and with the previously optimized beams switched on. In both proton and photon plans, the optimized cranial and the lower-spinal beams produced a perfect linear gradient in the junction regions, complementary to that produced by the optimized upper-spinal beam. The final dose distributions showed a homogeneous coverage of the targets. Our simple technique allowed to obtain high-quality gradients in the junction region. Such technique universally works for photons as well as protons and could be applicable to the TPSs that allow to manage a background dose. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  12. IMRT: Improvement in treatment planning efficiency using NTCP calculation independent of the dose-volume-histogram

    International Nuclear Information System (INIS)

    Grigorov, Grigor N.; Chow, James C.L.; Grigorov, Lenko; Jiang, Runqing; Barnett, Rob B.

    2006-01-01

    The normal tissue complication probability (NTCP) is a predictor of radiobiological effect for organs at risk (OAR). The calculation of the NTCP is based on the dose-volume-histogram (DVH) which is generated by the treatment planning system after calculation of the 3D dose distribution. Including the NTCP in the objective function for intensity modulated radiation therapy (IMRT) plan optimization would make the planning more effective in reducing the postradiation effects. However, doing so would lengthen the total planning time. The purpose of this work is to establish a method for NTCP determination, independent of a DVH calculation, as a quality assurance check and also as a mean of improving the treatment planning efficiency. In the study, the CTs of ten randomly selected prostate patients were used. IMRT optimization was performed with a PINNACLE3 V 6.2b planning system, using planning target volume (PTV) with margins in the range of 2 to 10 mm. The DVH control points of the PTV and OAR were adapted from the prescriptions of Radiation Therapy Oncology Group protocol P-0126 for an escalated prescribed dose of 82 Gy. This paper presents a new model for the determination of the rectal NTCP ( R NTCP). The method uses a special function, named GVN (from Gy, Volume, NTCP), which describes the R NTCP if 1 cm 3 of the volume of intersection of the PTV and rectum (R int ) is irradiated uniformly by a dose of 1 Gy. The function was 'geometrically' normalized using a prostate-prostate ratio (PPR) of the patients' prostates. A correction of the R NTCP for different prescribed doses, ranging from 70 to 82 Gy, was employed in our model. The argument of the normalized function is the R int , and parameters are the prescribed dose, prostate volume, PTV margin, and PPR. The R NTCPs of another group of patients were calculated by the new method and the resulting difference was <±5% in comparison to the NTCP calculated by the PINNACLE3 software where Kutcher's dose

  13. Dose-volume and biological-model based comparison between helical tomotherapy and (inverse-planned) IMAT for prostate tumours

    International Nuclear Information System (INIS)

    Iori, Mauro; Cattaneo, Giovanni Mauro; Cagni, Elisabetta; Fiorino, Claudio; Borasi, Gianni; Riccardo, Calandrino; Iotti, Cinzia; Fazio, Ferruccio; Nahum, Alan E.

    2008-01-01

    Background and purpose: Helical tomotherapy (HT) and intensity-modulated arc therapy (IMAT) are two arc-based approaches to the delivery of intensity-modulated radiotherapy (IMRT). Through plan comparisons we have investigated the potential of IMAT, both with constant (conventional or IMAT-C) and variable (non-conventional or IMAT-NC, a theoretical exercise) dose-rate, to serve as an alternative to helical tomotherapy. Materials and methods: Six patients with prostate tumours treated by HT with a moderately hypo-fractionated protocol, involving a simultaneous integrated boost, were re-planned as IMAT treatments. A method for IMAT inverse-planning using a commercial module for static IMRT combined with a multi-leaf collimator (MLC) arc-sequencing was developed. IMAT plans were compared to HT plans in terms of dose statistics and radiobiological indices. Results: Concerning the planning target volume (PTV), the mean doses for all PTVs were similar for HT and IMAT-C plans with minimum dose, target coverage, equivalent uniform dose (EUD) and tumour control probability (TCP) values being generally higher for HT; maximum dose and degree of heterogeneity were instead higher for IMAT-C. In relation to organs at risk, mean doses and normal tissue complication probability (NTCP) values were similar between the two modalities, except for the penile bulb where IMAT was significantly better. Re-normalizing all plans to the same rectal toxicity (NTCP = 5%), the HT modality yielded higher TCP than IMAT-C but there was no significant difference between HT and IMAT-NC. The integral dose with HT was higher than that for IMAT. Conclusions: with regards to the plan analysis, the HT is superior to IMAT-C in terms of target coverage and dose homogeneity within the PTV. Introducing dose-rate variation during arc-rotation, not deliverable with current linac technology, the simulations result in comparable plan indices between (IMAT-NC) and HT

  14. Research program plan: piping. Volume 3

    International Nuclear Information System (INIS)

    Vagins, M.; Strosnider, J.

    1985-07-01

    Regulatory issues related to piping can be divided into the three areas of pipe cracking, postulated design basis pipe breaks, and design of piping for seismic and other dynamic loads. The first two of these issues are in the domain of the Materials Engineering Branch (MEBR), while the last of the three issues is the responsibility of the Mechanical/Structural Engineering Branch. This volume of the MEBR Research Plan defines the critical aspects of the pipe cracking and postulated design basis pipe break issues and identifies those research efforts and results necessary for their resolution. In general, the objectives of the MERB Piping Research Program are to provide experimentally validated analytic techniques and appropriate material properties characterization methods and data to support regulatory activities related to evaluating and ensuring piping integrity

  15. Comparison of different application systems and CT- assisted treatment planning procedures in primary endometrium cancer: Is it technically possible to include the whole uterus volume in the volume treated by brachytherapy

    International Nuclear Information System (INIS)

    Mock, U.; Knocke, Th.; Fellner, C.; Poetter, R.

    1996-01-01

    Purpose: Brachytherapy is regarded as the definitive component of treatment for inoperable patients with endometrium cancer. In published series the whole uterus has been claimed to represent the target volume independently of the individual tumor spread. The purpose of this work is to compare different planning and application procedures and to analyze the target volumes (whole uterus), treatment volumes and their respective relation for the given various conditions. Material and Methods: In ten patients with primary endometrium cancer the correlation between target- and treatment volume was analysed based on standard one-channel applicators or individual Heyman applicators. A comparative analysis of target volumes resulting from two different planning procedures of Heyman applications was performed. CT was carried out after insertion of the Heyman ovoids. Target volume was estimated by measuring the uterus size at different cross sections of the CT images. Dose calculation was performed with (PLATO-system) or without (NPS-system) transferring these data directly to the planning system. We report on the differences in treatment volumes resulting from the two application and planning systems. Results: The mean value of the uterus volume was 180 ccm (range 57 ccm to 316 ccm). Four out of 10 patients had an asymmetric uterus configuration with a side-difference (in longitudinal or transversal direction) of more than 1 cm. On average 70% (range 48-95%) of the uterus volume was included by the treatment volume when Heymann applicators were used compared to 45 % (range 25-89%) when standard one channel applicators were used. This represents an improvement of 25% (range from 11%-35%). By utilizing the more sophisticated way of treatment planning a more adequate coverage of the uterus volume was achieved in five out of ten patients. The treated volume increased on the average by 20 % (range 11 %-32%). In three cases changes in the irradiation volume were less than 5%. In

  16. Inverse optimization of objective function weights for treatment planning using clinical dose-volume histograms

    Science.gov (United States)

    Babier, Aaron; Boutilier, Justin J.; Sharpe, Michael B.; McNiven, Andrea L.; Chan, Timothy C. Y.

    2018-05-01

    We developed and evaluated a novel inverse optimization (IO) model to estimate objective function weights from clinical dose-volume histograms (DVHs). These weights were used to solve a treatment planning problem to generate ‘inverse plans’ that had similar DVHs to the original clinical DVHs. Our methodology was applied to 217 clinical head and neck cancer treatment plans that were previously delivered at Princess Margaret Cancer Centre in Canada. Inverse plan DVHs were compared to the clinical DVHs using objective function values, dose-volume differences, and frequency of clinical planning criteria satisfaction. Median differences between the clinical and inverse DVHs were within 1.1 Gy. For most structures, the difference in clinical planning criteria satisfaction between the clinical and inverse plans was at most 1.4%. For structures where the two plans differed by more than 1.4% in planning criteria satisfaction, the difference in average criterion violation was less than 0.5 Gy. Overall, the inverse plans were very similar to the clinical plans. Compared with a previous inverse optimization method from the literature, our new inverse plans typically satisfied the same or more clinical criteria, and had consistently lower fluence heterogeneity. Overall, this paper demonstrates that DVHs, which are essentially summary statistics, provide sufficient information to estimate objective function weights that result in high quality treatment plans. However, as with any summary statistic that compresses three-dimensional dose information, care must be taken to avoid generating plans with undesirable features such as hotspots; our computational results suggest that such undesirable spatial features were uncommon. Our IO-based approach can be integrated into the current clinical planning paradigm to better initialize the planning process and improve planning efficiency. It could also be embedded in a knowledge-based planning or adaptive radiation therapy framework to

  17. Recommended criteria for the evaluation of on-site nuclear power plant emergency plans, volume II: criteria

    International Nuclear Information System (INIS)

    1997-01-01

    A critical review of existing Canadian and international nuclear power plant (NPP) emergency plans, evaluation criteria, and approaches has been conducted to provide AECB staff with information which can be used to assess the adequacy of NPP on-site emergency response plans. The results of this work are published in two volumes. Volume I, Basis Document, provides the reasons why certain requirements are in place. It also gives comprehensive references to various standards.Volume II, Criteria, contains the criteria which relate to on-site actions and their integration with control room activities and the roles of off-site responsible organizations. The recommended criteria provide information on what is required, and not on how to accomplish the requirements. The licensees are given the latitude to decide on the methods and processes needed to meet the requirements. The documents do not address NPP off-site plans and response capability, or the control room emergency operating procedures and response capability. This report contains only Volume II: Criteria. 55 refs., 2 tabs., 1 fig

  18. Does the IMRT technique allow improvement of treatment plans (e.g. lung sparing) for lung cancer patients with small lung volume: a planning study

    International Nuclear Information System (INIS)

    Komosinska, K.; Kepka, L.; Gizynska, M.; Zawadzka, A.

    2008-01-01

    Aim: We evaluated whether intensity-modulated radiation therapy (IMRT) may offer any advantages in comparison with three-dimensional conformal radiotherapy (3D-CRT) for patients with small lung volume (SLV). Methods: Treatment planning was performed for 10 NSCLC patients with the smallest lung volume (mean: 2241 cc) among 200 patients from our database. For each patient 3D-CRT and IMRT plans were prepared. The goal was to deliver 66 Gy/33 fractions, with dose constraints: mean lung dose (MLD) < 20 Gy, V20 < 35%; spinal cord - Dmax < 45 Gy. When the plan could not meet these criteria, total dose was reduced. The 3D-CRT and IMRT plans were compared. We investigated: prescribed dose, coverage and conformity indices, MLD, V5-V65 in the lung. Results: In 4 out of 10 plans, 3D-CRT did not allow 66 Gy to be delivered, because of predicted pulmonary toxicity. These 4 cases included 3 for which we did not reach 66 Gy with IMRT; still, for these 3 plans the total dose was increased by an average of 9 Gy with IMRT in comparison with 3D-CRT. Coverage indices were similar for both techniques. Conformity indices were better for IMRT plans. MLD was lower in five IMRT and two 3D-CRT plans if equal doses were delivered. The decrease in MLD was seen for cases with large PTV and high PTV/lung volume ratio. Lung V5 was lower for all 3D-CRT plans, 47% vs. 57% for IMRT; V15 and above were larger for 3D-CRT Conclusion: In the planning study, IMRT seems to be a promising technique for cases with SLV, especially when associated with large PT V. (authors)

  19. Target volume delineation and treatment planning for particle therapy a practical guide

    CERN Document Server

    Leeman, Jonathan E; Cahlon, Oren; Sine, Kevin; Jiang, Guoliang; Lu, Jiade J; Both, Stefan

    2018-01-01

    This handbook is designed to enable radiation oncologists to treat patients appropriately and confidently by means of particle therapy. The orientation and purpose are entirely practical, in that the focus is on the physics essentials of delivery and treatment planning , illustration of the clinical target volume (CTV) and associated treatment planning for each major malignancy when using particle therapy, proton therapy in particular. Disease-specific chapters provide guidelines and concise knowledge on CTV selection and delineation and identify aspects that require the exercise of caution during treatment planning. The treatment planning techniques unique to proton therapy for each disease site are clearly described, covering beam orientation, matching/patching field techniques, robustness planning, robustness plan evaluation, etc. The published data on the use of particle therapy for a given disease site are also concisely reported. In addition to fully meeting the needs of radiation oncologists, this "kn...

  20. Site Study Plan for background environmental radioactivity, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    International Nuclear Information System (INIS)

    1987-06-01

    The Background Environmental Radioactivity Site Study Plan describes a field program consisting of an initial radiological survey and a radiological sampling program. The field program includes measurement of direct radiation and collection and analysis of background radioactivity samples of air, precipitation, soil, water, milk, pasture grass, food crops, meat, poultry, game, and eggs. The plan describes for each study: the need for the study, the study design, data management and use, schedule of proposed activities, and quality assurance requirements. These studies will provide data needed to satisfy requirements contained in, or derived from, the Salt Repository Project (SRP) Requirements Document. 50 refs., 11 figs., 7 tabs

  1. Surfaced-based investigations plan, Volume 4: Yucca Mountain Project

    International Nuclear Information System (INIS)

    1988-12-01

    This document represents a detailed summary of design plans for surface-based investigations to be conducted for site characterization of the Yucca Mountain site. These plans are current as of December 1988. The description of surface-based site characterization activities contained in this document is intended to give all interested parties an understanding of the current plans for site characterization of Yucca Mountain. The maps presented in Volume 4 are products of the Geographic Information System (GIS) being used by the Yucca Mountain Project. The ARC/INFO GIS software, developed by Environmental Systems Research Institute, was used to digitize and process these SBIP maps. The maps were prepared using existing US Geological Survey (USGS) maps as a planimetric base. Roads and other surface features were interpreted from a variety of sources and entered into the GIS. Sources include the USGS maps, 1976 USGS orthophotoquads and aerial photography, 1986 and 1987 aerial photography, surveyed coordinates of field sites, and a combination of various maps, figures, descriptions and approximate coordinates of proposed locations for future activities

  2. WE-B-304-02: Treatment Planning Evaluation and Optimization Should Be Biologically and Not Dose/volume Based

    International Nuclear Information System (INIS)

    Deasy, J.

    2015-01-01

    The ultimate goal of radiotherapy treatment planning is to find a treatment that will yield a high tumor control probability (TCP) with an acceptable normal tissue complication probability (NTCP). Yet most treatment planning today is not based upon optimization of TCPs and NTCPs, but rather upon meeting physical dose and volume constraints defined by the planner. It has been suggested that treatment planning evaluation and optimization would be more effective if they were biologically and not dose/volume based, and this is the claim debated in this month’s Point/Counterpoint. After a brief overview of biologically and DVH based treatment planning by the Moderator Colin Orton, Joseph Deasy (for biological planning) and Charles Mayo (against biological planning) will begin the debate. Some of the arguments in support of biological planning include: this will result in more effective dose distributions for many patients DVH-based measures of plan quality are known to have little predictive value there is little evidence that either D95 or D98 of the PTV is a good predictor of tumor control sufficient validated outcome prediction models are now becoming available and should be used to drive planning and optimization Some of the arguments against biological planning include: several decades of experience with DVH-based planning should not be discarded we do not know enough about the reliability and errors associated with biological models the radiotherapy community in general has little direct experience with side by side comparisons of DVH vs biological metrics and outcomes it is unlikely that a clinician would accept extremely cold regions in a CTV or hot regions in a PTV, despite having acceptable TCP values Learning Objectives: To understand dose/volume based treatment planning and its potential limitations To understand biological metrics such as EUD, TCP, and NTCP To understand biologically based treatment planning and its potential limitations

  3. IMRT treatment planning-A comparative inter-system and inter-centre planning exercise of the ESTRO QUASIMODO group

    International Nuclear Information System (INIS)

    Bohsung, Joerg; Gillis, Sofie; Arrans, Rafael; Bakai, Annemarie; De Wagter, Carlos; Knoeoes, Tommy; Mijnheer, Ben J.; Paiusco, Marta; Perrin, Bruce A.; Welleweerd, Hans; Williams, Peter

    2005-01-01

    Background and purpose: The purpose of this work was a comparison of realistic IMRT plans based on the same CT-image data set and a common predefined set of dose objectives for the planning target volume and the organs at risk. This work was part of the larger European QUASIMODO IMRT verification project. Materials and methods: Eleven IMRT plans were produced by nine different European groups, each applying a representative set of clinically used IMRT treatment planning systems. The plans produced were to be deliverable in a clinically acceptable treatment time with the local technical equipment. All plans were characterized using a set of different quality measures such as dose-volume histograms, number of monitor units and treatment time. Results: Only one plan was able to fulfil all dose objectives strictly; six plans failed some of the objectives but were still considered to be clinically acceptable; four plans were not able to reach the objectives. Additional quality scores such as the number of monitor units and treatment time showed large variations, which mainly depend on the delivery technique. Conclusion: The presented planning study showed that with nearly all presently available IMRT planning and delivery systems comparable dose distributions could be achieved if the planning goals are clearly defined in advance

  4. Density overwrites of internal tumor volumes in intensity modulated proton therapy plans for mobile lung tumors

    Science.gov (United States)

    Botas, Pablo; Grassberger, Clemens; Sharp, Gregory; Paganetti, Harald

    2018-02-01

    The purpose of this study was to investigate internal tumor volume density overwrite strategies to minimize intensity modulated proton therapy (IMPT) plan degradation of mobile lung tumors. Four planning paradigms were compared for nine lung cancer patients. Internal gross tumor volume (IGTV) and internal clinical target volume (ICTV) structures were defined encompassing their respective volumes in every 4DCT phase. The paradigms use different planning CT (pCT) created from the average intensity projection (AIP) of the 4DCT, overwriting the density within the IGTV to account for movement. The density overwrites were: (a) constant filling with 100 HU (C100) or (b) 50 HU (C50), (c) maximum intensity projection (MIP) across phases, and (d) water equivalent path length (WEPL) consideration from beam’s-eye-view. Plans were created optimizing dose-influence matrices calculated with fast GPU Monte Carlo (MC) simulations in each pCT. Plans were evaluated with MC on the 4DCTs using a model of the beam delivery time structure. Dose accumulation was performed using deformable image registration. Interplay effect was addressed applying 10 times rescanning. Significantly less DVH metrics degradation occurred when using MIP and WEPL approaches. Target coverage (D99≥slant 70 Gy(RBE)) was fulfilled in most cases with MIP and WEPL (D{{99}WEPL}=69.2+/- 4.0 Gy (RBE)), keeping dose heterogeneity low (D5-D{{95}WEPL}=3.9+/- 2.0 Gy(RBE)). The mean lung dose was kept lowest by the WEPL strategy, as well as the maximum dose to organs at risk (OARs). The impact on dose levels in the heart, spinal cord and esophagus were patient specific. Overall, the WEPL strategy gives the best performance and should be preferred when using a 3D static geometry for lung cancer IMPT treatment planning. Newly available fast MC methods make it possible to handle long simulations based on 4D data sets to perform studies with high accuracy and efficiency, even prior to individual treatment planning.

  5. An improved distance-to-dose correlation for predicting bladder and rectum dose-volumes in knowledge-based VMAT planning for prostate cancer

    Science.gov (United States)

    Wall, Phillip D. H.; Carver, Robert L.; Fontenot, Jonas D.

    2018-01-01

    The overlap volume histogram (OVH) is an anatomical metric commonly used to quantify the geometric relationship between an organ at risk (OAR) and target volume when predicting expected dose-volumes in knowledge-based planning (KBP). This work investigated the influence of additional variables contributing to variations in the assumed linear DVH-OVH correlation for the bladder and rectum in VMAT plans of prostate patients, with the goal of increasing prediction accuracy and achievability of knowledge-based planning methods. VMAT plans were retrospectively generated for 124 prostate patients using multi-criteria optimization. DVHs quantified patient dosimetric data while OVHs quantified patient anatomical information. The DVH-OVH correlations were calculated for fractional bladder and rectum volumes of 30, 50, 65, and 80%. Correlations between potential influencing factors and dose were quantified using the Pearson product-moment correlation coefficient (R). Factors analyzed included the derivative of the OVH, prescribed dose, PTV volume, bladder volume, rectum volume, and in-field OAR volume. Out of the selected factors, only the in-field bladder volume (mean R  =  0.86) showed a strong correlation with bladder doses. Similarly, only the in-field rectal volume (mean R  =  0.76) showed a strong correlation with rectal doses. Therefore, an OVH formalism accounting for in-field OAR volumes was developed to determine the extent to which it improved the DVH-OVH correlation. Including the in-field factor improved the DVH-OVH correlation, with the mean R values over the fractional volumes studied improving from  -0.79 to  -0.85 and  -0.82 to  -0.86 for the bladder and rectum, respectively. A re-planning study was performed on 31 randomly selected database patients to verify the increased accuracy of KBP dose predictions by accounting for bladder and rectum volume within treatment fields. The in-field OVH led to significantly more precise

  6. Considerations on the calculation of volumes in two planning systems; Consideraciones sobre el calculo de volumenes en dos sistemas de planificacion

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Tenedor Alonso, S.; Rincon Perez, M.; Penedo Cobos, J. M.; Garcia Castejon, M. A.

    2011-07-01

    The discrepancies in the calculation of the same volume between different planning systems impact on dose-volume histograms and therefore clinical assessment of dosimetry for patients. The transfer, by a local network, tomographic study (CT) and contours of critical organs of patients, between our two planning systems allows us to evaluate the calculation of identical volumes.

  7. Treatment planning evaluation of non-coplanar techniques for conformal radiotherapy of the prostate

    International Nuclear Information System (INIS)

    Bedford, James L.; Henrys, Anthony J.; Dearnaley, David P.; Khoo, Vincent S.

    2005-01-01

    Background and purpose: To evaluate the benefit of using non-coplanar treatment plans for irradiation of two different clinical treatment volumes: prostate only (PO) and the prostate plus seminal vesicles (PSV). Material and methods: An inverse planning algorithm was used to produce three-field, four-field, five-field and six-field non-coplanar treatment plans without intensity-modulation in ten patients. These were compared against a three-field coplanar plan. A dose of 74 Gy was prescribed to the isocentre. Plans were compared using the minimum dose to the planning target volume (PTV), maximum dose to the small bowel, and irradiated volumes of rectum, bladder and femoral head. Biological indices were also evaluated. Results: For the PO group, volume of rectum irradiated to 60 Gy (V 60 ) was 22.5±3.7% for the coplanar plan, and 21.5±5.3% for the five-field non-coplanar plan, which was the most beneficial (p=0.3). For the PSV group, the five-field non-coplanar plan was again the most beneficial. Rectal V 60 was in this case reduced from 41.5±10.4% for the coplanar plan to 35.2±9.3% for the non-coplanar plan (p=0.02). Conclusions: The use of non-coplanar beams in conformal prostate radiotherapy provides a small increase in rectal sparing, more significantly with PSV volumes than for PO volumes

  8. The dose-volume constraint satisfaction problem for inverse treatment planning with field segments

    International Nuclear Information System (INIS)

    Michalski, Darek; Xiao, Ying; Censor, Yair; Galvin, James M

    2004-01-01

    The prescribed goals of radiation treatment planning are often expressed in terms of dose-volume constraints. We present a novel formulation of a dose-volume constraint satisfaction search for the discretized radiation therapy model. This approach does not rely on any explicit cost function. Inverse treatment planning uses the aperture-based approach with predefined, according to geometric rules, segmental fields. The solver utilizes the simultaneous version of the cyclic subgradient projection algorithm. This is a deterministic iterative method designed for solving the convex feasibility problems. A prescription is expressed with the set of inequalities imposed on the dose at the voxel resolution. Additional constraint functions control the compliance with selected points of the expected cumulative dose-volume histograms. The performance of this method is tested on prostate and head-and-neck cases. The relationships with other models and algorithms of similar conceptual origin are discussed. The demonstrated advantages of the method are: the equivalence of the algorithmic and prescription parameters, the intuitive setup of free parameters, and the improved speed of the method as compared to similar iterative as well as other techniques. The technique reported here will deliver approximate solutions for inconsistent prescriptions

  9. Kilowatt isotope power system, Phase II Plan. Volume IV. Teledyne FSCD vs GDS

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-15

    This Volume contains Teledyne's input to the Kilowatt Isotope Power System Phase II Plan. Included is a description of the Flight System Heat Generation System, Flight System Radiator, Thermal Insulation Stability, GDS Heat Generation System and GDS Radiator.

  10. Inverse planning IMRT

    International Nuclear Information System (INIS)

    Rosenwald, J.-C.

    2008-01-01

    The lecture addressed the following topics: Optimizing radiotherapy dose distribution; IMRT contributes to optimization of energy deposition; Inverse vs direct planning; Main steps of IMRT; Background of inverse planning; General principle of inverse planning; The 3 main components of IMRT inverse planning; The simplest cost function (deviation from prescribed dose); The driving variable : the beamlet intensity; Minimizing a 'cost function' (or 'objective function') - the walker (or skier) analogy; Application to IMRT optimization (the gradient method); The gradient method - discussion; The simulated annealing method; The optimization criteria - discussion; Hard and soft constraints; Dose volume constraints; Typical user interface for definition of optimization criteria; Biological constraints (Equivalent Uniform Dose); The result of the optimization process; Semi-automatic solutions for IMRT; Generalisation of the optimization problem; Driving and driven variables used in RT optimization; Towards multi-criteria optimization; and Conclusions for the optimization phase. (P.A.)

  11. Volume reduction of low-level contaminated metal waste by melting: selection of method and conceptual plan

    International Nuclear Information System (INIS)

    Copeland, G.L.; Heestand, R.L.; Mateer, R.S.

    1978-06-01

    A review of the literature and prior experience led to selection of induction melting as the most promising method for volume reduction of low-level transuranic contaminated metal waste. The literature indicates that melting with the appropriate slags significantly lowers the total contamination level of the metals by preferentially concentrating contaminants in the smaller volume of slag. Surface contamination not removed to the slag is diluted in the ingot and is contained uniformly in the metal. This dilution and decontamination offers the potential of lower cost disposal such as shallow burial rather than placement in a national repository. A processing plan is proposed as a model for economic analysis of the collection and volume reduction of contaminated metals. Further development is required to demonstrate feasibility of the plan

  12. Impact of the accuracy of automatic tumour functional volume delineation on radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Le Maitre, Amandine; Hatt, Mathieu; Pradier, Olivier; Cheze-le Rest, Catherine; Visvikis, Dimitris

    2012-01-01

    Over the past few years several automatic and semi-automatic PET segmentation methods for target volume definition in radiotherapy have been proposed. The objective of this study is to compare different methods in terms of dosimetry. For such a comparison, a gold standard is needed. For this purpose, realistic GATE-simulated PET images were used. Three lung cases and three H and N cases were designed with various shapes, contrasts and heterogeneities. Four different segmentation approaches were compared: fixed and adaptive thresholds, a fuzzy C-mean and the fuzzy locally adaptive Bayesian method. For each of these target volumes, an IMRT treatment plan was defined. The different algorithms and resulting plans were compared in terms of segmentation errors and ground-truth volume coverage using different metrics (V 95 , D 95 , homogeneity index and conformity index). The major differences between the threshold-based methods and automatic methods occurred in the most heterogeneous cases. Within the two groups, the major differences occurred for low contrast cases. For homogeneous cases, equivalent ground-truth volume coverage was observed for all methods but for more heterogeneous cases, significantly lower coverage was observed for threshold-based methods. Our study demonstrates that significant dosimetry errors can be avoided by using more advanced image-segmentation methods. (paper)

  13. Sodium fast reactor safety and licensing research plan - Volume II

    International Nuclear Information System (INIS)

    Ludewig, H.; Powers, D.A.; Hewson, John C.; LaChance, Jeffrey L.; Wright, A.; Phillips, J.; Zeyen, R.; Clement, B.; Garner, Frank; Walters, Leon; Wright, Steve; Ott, Larry J.; Suo-Anttila, Ahti Jorma; Denning, Richard; Ohshima, Hiroyuki; Ohno, S.; Miyhara, S.; Yacout, Abdellatif; Farmer, M.; Wade, D.; Grandy, C.; Schmidt, R.; Cahalen, J.; Olivier, Tara Jean; Budnitz, R.; Tobita, Yoshiharu; Serre, Frederic; Natesan, Ken; Carbajo, Juan J.; Jeong, Hae-Yong; Wigeland, Roald; Corradini, Michael; Thomas, Justin; Wei, Tom; Sofu, Tanju; Flanagan, George F.; Bari, R.; Porter D.

    2012-01-01

    Expert panels comprised of subject matter experts identified at the U.S. National Laboratories (SNL, ANL, INL, ORNL, LBL, and BNL), universities (University of Wisconsin and Ohio State University), international agencies (IRSN, CEA, JAEA, KAERI, and JRC-IE) and private consultation companies (Radiation Effects Consulting) were assembled to perform a gap analysis for sodium fast reactor licensing. Expert-opinion elicitation was performed to qualitatively assess the current state of sodium fast reactor technologies. Five independent gap analyses were performed resulting in the following topical reports: (1) Accident Initiators and Sequences (i.e., Initiators/Sequences Technology Gap Analysis), (2) Sodium Technology Phenomena (i.e., Advanced Burner Reactor Sodium Technology Gap Analysis), (3) Fuels and Materials (i.e., Sodium Fast Reactor Fuels and Materials: Research Needs), (4) Source Term Characterization (i.e., Advanced Sodium Fast Reactor Accident Source Terms: Research Needs), and (5) Computer Codes and Models (i.e., Sodium Fast Reactor Gaps Analysis of Computer Codes and Models for Accident Analysis and Reactor Safety). Volume II of the Sodium Research Plan consolidates the five gap analysis reports produced by each expert panel, wherein the importance of the identified phenomena and necessities of further experimental research and code development were addressed. The findings from these five reports comprised the basis for the analysis in Sodium Fast Reactor Research Plan Volume I.

  14. Sodium fast reactor safety and licensing research plan. Volume II.

    Energy Technology Data Exchange (ETDEWEB)

    Ludewig, H. (Brokhaven National Laboratory, Upton, NY); Powers, D. A.; Hewson, John C.; LaChance, Jeffrey L.; Wright, A. (Argonne National Laboratory, Argonne, IL); Phillips, J.; Zeyen, R. (Institute for Energy Petten, Saint-Paul-lez-Durance, France); Clement, B. (IRSN/DPAM.SEMIC Bt 702, Saint-Paul-lez-Durance, France); Garner, Frank (Radiation Effects Consulting, Richland, WA); Walters, Leon (Advanced Reactor Concepts, Los Alamos, NM); Wright, Steve; Ott, Larry J. (Oak Ridge National Laboratory, Oak Ridge, TN); Suo-Anttila, Ahti Jorma; Denning, Richard (Ohio State University, Columbus, OH); Ohshima, Hiroyuki (Japan Atomic Energy Agency, Ibaraki, Japan); Ohno, S. (Japan Atomic Energy Agency, Ibaraki, Japan); Miyhara, S. (Japan Atomic Energy Agency, Ibaraki, Japan); Yacout, Abdellatif (Argonne National Laboratory, Argonne, IL); Farmer, M. (Argonne National Laboratory, Argonne, IL); Wade, D. (Argonne National Laboratory, Argonne, IL); Grandy, C. (Argonne National Laboratory, Argonne, IL); Schmidt, R.; Cahalen, J. (Argonne National Laboratory, Argonne, IL); Olivier, Tara Jean; Budnitz, R. (Lawrence Berkeley National Laboratory, Berkeley, CA); Tobita, Yoshiharu (Japan Atomic Energy Agency, Ibaraki, Japan); Serre, Frederic (Centre d' %C3%94etudes nucl%C3%94eaires de Cadarache, Cea, France); Natesan, Ken (Argonne National Laboratory, Argonne, IL); Carbajo, Juan J. (Oak Ridge National Laboratory, Oak Ridge, TN); Jeong, Hae-Yong (Korea Atomic Energy Research Institute, Daejeon, Korea); Wigeland, Roald (Idaho National Laboratory, Idaho Falls, ID); Corradini, Michael (University of Wisconsin-Madison, Madison, WI); Thomas, Justin (Argonne National Laboratory, Argonne, IL); Wei, Tom (Argonne National Laboratory, Argonne, IL); Sofu, Tanju (Argonne National Laboratory, Argonne, IL); Flanagan, George F. (Oak Ridge National Laboratory, Oak Ridge, TN); Bari, R. (Brokhaven National Laboratory, Upton, NY); Porter D. (Idaho National Laboratory, Idaho Falls, ID); Lambert, J. (Argonne National Laboratory, Argonne, IL); Hayes, S. (Idaho National Laboratory, Idaho Falls, ID); Sackett, J. (Idaho National Laboratory, Idaho Falls, ID); Denman, Matthew R.

    2012-05-01

    Expert panels comprised of subject matter experts identified at the U.S. National Laboratories (SNL, ANL, INL, ORNL, LBL, and BNL), universities (University of Wisconsin and Ohio State University), international agencies (IRSN, CEA, JAEA, KAERI, and JRC-IE) and private consultation companies (Radiation Effects Consulting) were assembled to perform a gap analysis for sodium fast reactor licensing. Expert-opinion elicitation was performed to qualitatively assess the current state of sodium fast reactor technologies. Five independent gap analyses were performed resulting in the following topical reports: (1) Accident Initiators and Sequences (i.e., Initiators/Sequences Technology Gap Analysis), (2) Sodium Technology Phenomena (i.e., Advanced Burner Reactor Sodium Technology Gap Analysis), (3) Fuels and Materials (i.e., Sodium Fast Reactor Fuels and Materials: Research Needs), (4) Source Term Characterization (i.e., Advanced Sodium Fast Reactor Accident Source Terms: Research Needs), and (5) Computer Codes and Models (i.e., Sodium Fast Reactor Gaps Analysis of Computer Codes and Models for Accident Analysis and Reactor Safety). Volume II of the Sodium Research Plan consolidates the five gap analysis reports produced by each expert panel, wherein the importance of the identified phenomena and necessities of further experimental research and code development were addressed. The findings from these five reports comprised the basis for the analysis in Sodium Fast Reactor Research Plan Volume I.

  15. Clinical variability of target volume description and treatment plans in conformal radiotherapy in muscle invasive bladder cancer

    International Nuclear Information System (INIS)

    Logue, John P; Sharrock, Carole L; Cowan, Richard A.; Read, Graham; Marrs, Julie; Mott, David

    1996-01-01

    Purpose/Objective: The delineation of tumor and the production of a treatment plan to encompass this is the prime step in radiotherapy planning. Conformal radiotherapy is developing rapidly and although plentiful research has addressed the implementation of the radiotherapy prescription, scant attention has been made to the fundamental step of production, by the clinician, of an appropriate target volume. As part of an ongoing randomized trial of conformal radiotherapy, in bladder cancer, we have therefore assessed the interphysician variability of radiologists and radiation oncologists (RO) in assessing Gross Tumor Volume(GTV) (ICRU 50) and the adherence of the radiation oncologists to the study protocol of producing a Planning Target Volume (PTV). Materials and Methods: Four patients with T3 carcinoma of bladder who had been entered into the trial were identified. The clinical details, MR scans and CT scans were made available. Eight RO and 3 dedicated diagnostic oncology radiologists were invited to directly outline the GTV onto CT images on a planning computer consul. The RO in addition created a PTV following the trial protocol of 15mm margin around the GTV. Three RO sub-specialized in Urological radiotherapy; all RO had completed training. Volumes were produced, for each clinician, and comparison of these volumes and their isocenters were analyzed. In addition the margins allowed were measured and compared. Results: There was a maximum variation ratio (largest to smallest volume outlined) of the GTV in the four cases of 1.74 among radiologists and 3.74 among oncologists. There was a significant difference (p=0.01) in mean GTV between RO and the radiologists. The mean GTV of the RO exceeded the radiologists by a factor of 1.29 with a mean difference of 13.4 cm 3 The between observer variance within speciality comprised only 9.9% of the total variance in the data having accounted for case and observers speciality. The variation ratio in PTV among oncologists

  16. Background based Gaussian mixture model lesion segmentation in PET

    Energy Technology Data Exchange (ETDEWEB)

    Soffientini, Chiara Dolores, E-mail: chiaradolores.soffientini@polimi.it; Baselli, Giuseppe [DEIB, Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133 (Italy); De Bernardi, Elisabetta [Department of Medicine and Surgery, Tecnomed Foundation, University of Milano—Bicocca, Monza 20900 (Italy); Zito, Felicia; Castellani, Massimo [Nuclear Medicine Department, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, via Francesco Sforza 35, Milan 20122 (Italy)

    2016-05-15

    Purpose: Quantitative {sup 18}F-fluorodeoxyglucose positron emission tomography is limited by the uncertainty in lesion delineation due to poor SNR, low resolution, and partial volume effects, subsequently impacting oncological assessment, treatment planning, and follow-up. The present work develops and validates a segmentation algorithm based on statistical clustering. The introduction of constraints based on background features and contiguity priors is expected to improve robustness vs clinical image characteristics such as lesion dimension, noise, and contrast level. Methods: An eight-class Gaussian mixture model (GMM) clustering algorithm was modified by constraining the mean and variance parameters of four background classes according to the previous analysis of a lesion-free background volume of interest (background modeling). Hence, expectation maximization operated only on the four classes dedicated to lesion detection. To favor the segmentation of connected objects, a further variant was introduced by inserting priors relevant to the classification of neighbors. The algorithm was applied to simulated datasets and acquired phantom data. Feasibility and robustness toward initialization were assessed on a clinical dataset manually contoured by two expert clinicians. Comparisons were performed with respect to a standard eight-class GMM algorithm and to four different state-of-the-art methods in terms of volume error (VE), Dice index, classification error (CE), and Hausdorff distance (HD). Results: The proposed GMM segmentation with background modeling outperformed standard GMM and all the other tested methods. Medians of accuracy indexes were VE <3%, Dice >0.88, CE <0.25, and HD <1.2 in simulations; VE <23%, Dice >0.74, CE <0.43, and HD <1.77 in phantom data. Robustness toward image statistic changes (±15%) was shown by the low index changes: <26% for VE, <17% for Dice, and <15% for CE. Finally, robustness toward the user-dependent volume initialization was

  17. Navigator channel adaptation to reconstruct three dimensional heart volumes from two dimensional radiotherapy planning data

    International Nuclear Information System (INIS)

    Ng, Angela; Nguyen, Thao-Nguyen; Moseley, Joanne L; Hodgson, David C; Sharpe, Michael B; Brock, Kristy K

    2012-01-01

    Biologically-based models that utilize 3D radiation dosimetry data to estimate the risk of late cardiac effects could have significant utility for planning radiotherapy in young patients. A major challenge arises from having only 2D treatment planning data for patients with long-term follow-up. In this study, we evaluate the accuracy of an advanced deformable image registration (DIR) and navigator channels (NC) adaptation technique to reconstruct 3D heart volumes from 2D radiotherapy planning images for Hodgkin's Lymphoma (HL) patients. Planning CT images were obtained for 50 HL patients who underwent mediastinal radiotherapy. Twelve image sets (6 male, 6 female) were used to construct a male and a female population heart model, which was registered to 23 HL 'Reference' patients' CT images using a DIR algorithm, MORFEUS. This generated a series of population-to-Reference patient specific 3D deformation maps. The technique was independently tested on 15 additional 'Test' patients by reconstructing their 3D heart volumes using 2D digitally reconstructed radiographs (DRR). The technique involved: 1) identifying a matching Reference patient for each Test patient using thorax measurements, 2) placement of six NCs on matching Reference and Test patients' DRRs to capture differences in significant heart curvatures, 3) adapting the population-to-Reference patient-specific deformation maps to generate population-to-Test patient-specific deformation maps using linear and bilinear interpolation methods, 4) applying population-to-Test patient specific deformation to the population model to reconstruct Test-patient specific 3D heart models. The percentage volume overlap between the NC-adapted reconstruction and actual Test patient's true heart volume was calculated using the Dice coefficient. The average Dice coefficient expressed as a percentage between the NC-adapted and actual Test model was 89.4 ± 2.8%. The modified NC adaptation

  18. A dose-volume histogram based decision-support system for dosimetric comparison of radiotherapy treatment plans

    International Nuclear Information System (INIS)

    Alfonso, J. C. L.; Herrero, M. A.; Núñez, L.

    2015-01-01

    The choice of any radiotherapy treatment plan is usually made after the evaluation of a few preliminary isodose distributions obtained from different beam configurations. Despite considerable advances in planning techniques, such final decision remains a challenging task that would greatly benefit from efficient and reliable assessment tools. For any dosimetric plan considered, data on dose-volume histograms supplied by treatment planning systems are used to provide estimates on planning target coverage as well as on sparing of organs at risk and the remaining healthy tissue. These partial metrics are then combined into a dose distribution index (DDI), which provides a unified, easy-to-read score for each competing radiotherapy plan. To assess the performance of the proposed scoring system, DDI figures for fifty brain cancer patients were retrospectively evaluated. Patients were divided in three groups depending on tumor location and malignancy. For each patient, three tentative plans were designed and recorded during planning, one of which was eventually selected for treatment. We thus were able to compare the plans with better DDI scores and those actually delivered. When planning target coverage and organs at risk sparing are considered as equally important, the tentative plan with the highest DDI score is shown to coincide with that actually delivered in 32 of the 50 patients considered. In 15 (respectively 3) of the remaining 18 cases, the plan with highest DDI value still coincides with that actually selected, provided that organs at risk sparing is given higher priority (respectively, lower priority) than target coverage. DDI provides a straightforward and non-subjective tool for dosimetric comparison of tentative radiotherapy plans. In particular, DDI readily quantifies differences among competing plans with similar-looking dose-volume histograms and can be easily implemented for any tumor type and localization, irrespective of the planning system and

  19. Definition of gross tumor volume in lung cancer: inter-observer variability

    NARCIS (Netherlands)

    van de Steene, Jan; Linthout, Nadine; de Mey, Johan; Vinh-Hung, Vincent; Claassens, Cornelia; Noppen, Marc; Bel, Arjan; Storme, Guy

    2002-01-01

    BACKGROUND AND PURPOSE: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance. MATERIALS AND METHODS: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were

  20. An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions

    NARCIS (Netherlands)

    Hummelink, S.L.; Verhulst, A.C.; Maal, T.J.J.; Hoogeveen, Y.L.; Schultze Kool, L.J.; Ulrich, D.J.O.

    2017-01-01

    BACKGROUND: Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available

  1. Savannah River Site Environmental Monitoring Plan. Volume 1, Section 1000 Addendum: Revision 3

    International Nuclear Information System (INIS)

    Jannik, G.T.

    1994-01-01

    This document -- the Savannah River Site Environmental Monitoring Plan (SRS EM Plan) -- has been prepared according to guidance contained in the DOE 5400 Series orders, in 10 CFR 834, and in DOE/EH-0173T, Environmental Regulatory Guide for Radiological Effluent Monitoring and environmental Surveillance [DOE, 1991]. The SRS EM Plan's purpose is to define the criteria, regulations, and guideline requirements with which SRS will comply. These criteria and requirements are applicable to environmental monitoring activities performed in support of the SRS Environmental Monitoring Program (SRS EM Program), WSRC-3Q1-2, Volume 1, Section 1100. They are not applicable to monitoring activities utilized exclusively for process monitoring/control. The environmental monitoring program requirements documented in the SRS EM Plan incorporate all applicable should requirements of DOE/EH-0173T and expand upon them to include nonradiological environmental monitoring program requirements

  2. Poster - 36: Effect of Planning Target Volume Coverage on the Dose Delivered in Lung Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dekker, Chris; Wierzbicki, Marcin [McMaster University, Juravinski Cancer Centre (Canada)

    2016-08-15

    Purpose: In lung radiotherapy, breathing motion may be encompassed by contouring the internal target volume (ITV). Remaining uncertainties are included in a geometrical expansion to the planning target volume (PTV). In IMRT, the treatment is then optimized until a desired PTV fraction is covered by the appropriate dose. The resulting beams often carry high fluence in the PTV margin to overcome low lung density and to generate steep dose gradients. During treatment, the high density tumour can enter the PTV margin, potentially increasing target dose. Thus, planning lung IMRT with a reduced PTV dose may still achieve the desired ITV dose during treatment. Methods: A retrospective analysis was carried out with 25 IMRT plans prescribed to 63 Gy in 30 fractions. The plans were re-normalized to cover various fractions of the PTV by different isodose lines. For each case, the isocentre was moved using 125 shifts derived from all 3D combinations of 0 mm, (PTV margin - 1 mm), and PTV margin. After each shift, the dose was recomputed to approximate the delivered dose. Results and Conclusion: Our plans typically cover 95% of the PTV by 95% of the dose. Reducing the PTV covered to 94% did not significantly reduce the delivered ITV doses for (PTV margin - 1 mm) shifts. Target doses were reduced significantly for all other shifts and planning goals studied. Thus, a reduced planning goal will likely deliver the desired target dose as long as the ITV rarely enters the last mm of the PTV margin.

  3. Influence of volumes of prostate, rectum, and bladder on treatment planning CT on interfraction prostate shifts during ultrasound image-guided IMRT

    International Nuclear Information System (INIS)

    Reddy, Nandanuri M. S.; Nori, Dattatreyudu; Sartin, William; Maiorano, Samuel; Modena, Jennifer; Mazur, Andrej; Osian, Adrian; Sood, Brijmohan; Ravi, Akkamma; Sampath, Seshadri; Lange, Christopher S.

    2009-01-01

    Purpose: The purpose of this study was to analyze the relationship between prostate, bladder, and rectum volumes on treatment planning CT day and prostate shifts in the XYZ directions on treatment days. Methods: Prostate, seminal vesicles, bladder, and rectum were contoured on CT images obtained in supine position. Intensity modulated radiation therapy plans was prepared. Contours were exported to BAT-ultrasound imaging system. Patients were positioned on the couch using skin marks. An ultrasound probe was used to obtain ultrasound images of prostate, bladder, and rectum, which were aligned with CT images. Couch shifts in the XYZ directions as recommended by BAT system were made and recorded. 4698 couch shifts for 42 patients were analyzed to study the correlations between interfraction prostate shifts vs bladder, rectum, and prostate volumes on planning CT. Results: Mean and range of volumes (cc): Bladder: 179 (42-582), rectum: 108 (28-223), and prostate: 55 (21-154). Mean systematic prostate shifts were (cm, ±SD) right and left lateral: -0.047±0.16 (-0.361-0.251), anterior and posterior: 0.14±0.3 (-0.466-0.669), and superior and inferior: 0.19±0.26 (-0.342-0.633). Bladder volume was not correlated with lateral, anterior/posterior, and superior/inferior prostate shifts (P>0.2). Rectal volume was correlated with anterior/posterior (P 0.2). The smaller the rectal volume or cross sectional area, the larger was the prostate shift anteriorly and vice versa (P 0.2). The smaller the prostate volume, the larger was prostate shift superiorly and vice versa (P<0.05). Conclusions: Prostate and rectal volumes, but not bladder volumes, on treatment planning CT influenced prostate position on treatment fractions. Daily image-guided adoptive radiotherapy would be required for patients with distended or empty rectum on planning CT to reduce rectal toxicity in the case of empty rectum and to minimize geometric miss of prostate.

  4. Viability Assessment of a Repository at Yucca Mountain. Volume 4: License Application Plan and Costs

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-01

    Volume 4 provides the DOE plan and cost estimate for the remaining work necessary to proceed from completing this VA to submitting an LA to NRC. This work includes preparing an EIS and evaluating the suitability of the site. Both items are necessary components of the documentation required to support a decision in 2001 by the Secretary of Energy on whether or not to recommend that the President approve the site for development as a repository. If the President recommends the site to Congress and the site designation becomes effective, then DOE will submit the LA to NRC in 2002 for authorization to construct the repository. The work described in Volume 4 constitutes the last step in the characterization of the Yucca Mountain site and the design and evaluation of the performance of a repository system in the geologic setting of this site. The plans in this volume for the next 4 years' work are based on the results of the previous 15 years' work, as reported in Volumes 1, 2, and 3 of this VA. Volume 1 summarizes what DOE has learned to date about the Yucca Mountain site. Volume 2 describes the current, reference repository design, several design options that might enhance the performance of the reference design, and several alternative designs that represent substantial departures from the reference design. Volume 2 also summarizes the results of tests of candidate materials for waste packages and for support of the tunnels into which waste would be emplaced. Volume 3 provides the results of the latest performance assessments undertaken to evaluate the performance of the design in the geologic setting of Yucca Mountain. The results described in Volumes 1, 2, and 3 provide the basis for identifying and prioritizing the work described in this volume. DOE believes that the planned work, together with the results of previous work, will be sufficient to support a site suitability evaluation for site recommendation and, if the site is recommended and designated, a

  5. Optimization of stereotactically-guided conformal treatment planning of sellar and parasellar tumors, based on normal brain dose volume histograms

    International Nuclear Information System (INIS)

    Perks, Julian R.; Jalali, Rakesh; Cosgrove, Vivian P.; Adams, Elizabeth J.; Shepherd, Stephen F.; Warrington, Alan P.; Brada, Michael

    1999-01-01

    Purpose: To investigate the optimal treatment plan for stereo tactically-guided conformal radiotherapy (SCRT) of sellar and parasellar lesions, with respect to sparing normal brain tissue, in the context of routine treatment delivery, based on dose volume histogram analysis. Methods and Materials: Computed tomography (CT) data sets for 8 patients with sellar- and parasellar-based tumors (6 pituitary adenomas and 2 meningiomas) have been used in this study. Treatment plans were prepared for 3-coplanar and 3-, 4-, 6-, and 30-noncoplanar-field arrangements to obtain 95% isodose coverage of the planning target volume (PTV) for each plan. Conformal shaping was achieved by customized blocks generated with the beams eye view (BEV) facility. Dose volume histograms (DVH) were calculated for the normal brain (excluding the PTV), and comparisons made for normal tissue sparing for all treatment plans at ≥80%, ≥60%, and ≥40% of the prescribed dose. Results: The mean volume of normal brain receiving ≥80% and ≥60% of the prescribed dose decreased by 22.3% (range 14.8-35.1%, standard deviation σ = 7.5%) and 47.6% (range 25.8-69.1%, σ 13.2%), respectively, with a 4-field noncoplanar technique when compared with a conventional 3-field coplanar technique. Adding 2 further fields, from 4-noncoplanar to 6-noncoplanar fields reduced the mean normal brain volume receiving ≥80% of the prescribed dose by a further 4.1% (range -6.5-11.8%, σ = 6.4%), and the volume receiving ≥60% by 3.3% (range -5.5-12.2%, σ = 5.4%), neither of which were statistically significant. Each case must be considered individually however, as a wide range is seen in the volume spared when increasing the number of fields from 4 to 6. Comparing the 4- and 6-field noncoplanar techniques to a 30-field conformal field approach (simulating a dynamic arc plan) revealed near-equivalent normal tissue sparing. Conclusion: Four to six widely spaced, fixed-conformal fields provide the optimum class solution

  6. Endoscopic clipping for gastrointestinal tumors. A method to define the target volume more precisely

    International Nuclear Information System (INIS)

    Riepl, M.; Klautke, G.; Fehr, R.; Fietkau, R.; Pietsch, A.

    2000-01-01

    Background: In many cases it is not possible to exactly define the extension of carcinoma of the gastrointestinal tract with the help of computertomography scans made for 3-D-radiation treatment planning. Consequently, the planning of external beam radiotherapy is made more difficult for the gross tumor volume as well as, in some cases, also for the clinical target volume. Patients and Methods: Eleven patients with macrosocpic tumors (rectal cancer n = 5, cardiac cancer n = 6) were included. Just before 3-D planning, the oral and aboral border of the tumor was marked endoscopically with hemoclips. Subsequently, CT scans for radiotherapy planning were made and the clinical target volume was defined. Five to 6 weeks thereafter, new CT scans were done to define the gross tumor volume for boost planning. Two investigators independently assessed the influence of the hemoclips on the different planning volumes, and whether the number of clips was sufficient to define the gross tumor volume. Results: In all patients, the implantation of the clips was done without complications. Start of radiotherapy was not delayed. With the help of the clips it was possible to exactly define the position and the extension of the primary tumor. The clinical target volume was modified according to the position of the clips in 5/11 patients; the gross tumor volume was modified in 7/11 patients. The use of the clips made the documentation and verification of the treatment portals by the simulator easier. Moreover, the clips helped the surgeon to define the primary tumor region following marked regression after neoadjuvant therapy in 3 patients. Conclusions: Endoscopic clipping of gastrointestinal tumors helps to define the tumor volumes more precisely in radiation therapy. The clips are easily recognized on the portal films and, thus, contribute to quality control. (orig.) [de

  7. Federal Facilities Compliance Act, Draft Site Treatment Plan: Compliance Plan Volume. Part 2, Volume 2

    International Nuclear Information System (INIS)

    1994-01-01

    This document presents the details of the implementation of the Site Treatment Plan developed by Ames Laboratory in compliance with the Federal Facilities Compliance Act. Topics discussed in this document include: implementation of the plan; milestones; annual updates to the plan; inclusion of new waste streams; modifications of the plan; funding considerations; low-level mixed waste treatment plan and schedules; and TRU mixed waste streams

  8. An investigation into positron emission tomography contouring methods across two treatment planning systems

    International Nuclear Information System (INIS)

    Young, Tony; Som, Seu; Sathiakumar, Chithradevi; Holloway, Lois

    2013-01-01

    Positron emission tomography (PET) imaging has been used to provide additional information regarding patient tumor location, size, and staging for radiotherapy treatment planning purposes. This additional information reduces interobserver variability and produces more consistent contouring. It is well recognized that different contouring methodology for PET data results in different contoured volumes. The goal of this study was to compare the difference in PET contouring methods for 2 different treatment planning systems using a phantom dataset and a series of patient datasets. Contouring methodology was compared on the ADAC Pinnacle Treatment Planning System and the CMS XiO Treatment Planning System. Contours were completed on the phantom and patient datasets using a number of PET contouring methods—the standardized uptake value 2.5 method, 30%, 40%, and 50% of the maximum uptake method and the signal to background ratio method. Differences of >15% were observed for PET-contoured volumes between the different treatment planning systems for the same data and the same PET contouring methodology. Contoured volume differences between treatment planning systems were caused by differences in data formatting and display and the different contouring tools available. Differences in treatment planning system as well as contouring methodology should be considered carefully in dose-volume contouring and reporting, especially between centers that may use different treatment planning systems or those that have several different treatment planning systems

  9. Computer-generated display system guidelines. Volume 2. Developing an evaluation plan

    International Nuclear Information System (INIS)

    1984-09-01

    Volume 1 of this report provides guidance to utilities on the design of displays and the selection and retrofit of a computer-generated display system in the control room of an operating nuclear power plant. Volume 2 provides guidance on planning and managing empirical evaluation of computer-generated display systems, particularly when these displays are primary elements of computer-based operator aids. The guidance provided is in terms of a multilevel evaluation methodology that enables sequential consideration of three primary issues: (1) compatibility; (2) understandability; and (3) effectiveness. The evaluation process approaches these three issues with a top-down review of system objectives, functions, tasks, and information requirements. The process then moves bottom-up from lower-level to higher-level issues, employing different evaluation methods at each level in order to maximize the efficiency and effectiveness of the evaluation process

  10. Planning target volume (PTV) definition and its effects in the radiotherapy

    International Nuclear Information System (INIS)

    Poli, Maria Esmeralda Ramos

    2007-01-01

    Tills work intends to study the margins required to define a planning target volume (PTV) for adequate treatment of the mobile tumors such as prostate or those located in areas with less mobility as the ones in head and neck region, in the absence of daily localization imaging based. It is also intends to evaluate the impact caused by the PTV, in terms of dose, to the critical structures surrounding the PTV and its influence when inverse planning is used in the intensity-modulated radiation therapy (IMRT). Data from 387 prostate patients were analyzed retrospectively. Every patient in the study received daily pre-treatment localization with 2D ultrasound resulting in a total of 10,327 localizations, each comprising of an isocenter displacement in 3 directions: anterior-posterior (AP), right-left lateral (RL), and superior-inferior (SI). The mean displacement and standard deviation (SD) for each direction for each patient was computed from daily treatment records. The uncertainties (SD) in the target position were 4.4 mm (AP), 3.6 mm (RL), and 4.5 mm (SI). A study of the uncertainties in the daily positioning of 78 head and neck patients who used thermoplastic mask to immobilize them, evaluated with electronic portal imaging device (EPID), showed variations (SD) in the isocenter treatment position of 3.1 mm (AP), 1.5 mm (RL), and 4.5 mm (SI). By applying these shifts in an anthropomorphic phantom it was studied the dose-volume histograms resultant of the isocenter displacement in the daily treatment. The result showed the importance of putting margins in the clinical target volume to assure an adequate treatment and also showed that isocenter daily variation can cause an increase to the dose greater than the tolerance level to the critical organs. (author)

  11. Testing the new ICRU 62 'Planning Organ at Risk Volume' concept for the rectum

    International Nuclear Information System (INIS)

    Muren, Ludvig Paul; Karlsdottir, Asa; Kvinnsland, Yngve; Wentzel-Larsen, Tore; Dahl, Olav

    2005-01-01

    Background and purpose: To study the impact of the new ICRU 62 'Planning organ at Risk Volume' (PRV) concept on the relationship between rectum dose-volume histogram (DVH) data and toxicity. Patients and methods: The acute gastro-intestinal (GI) RTOG toxicity in 127 prostate cancer patients prescribed a total dose of 70 Gy with conformal irradiation to either the prostate, the prostate and seminal vesicles or the whole pelvis (initial 50 Gy only) were analysed. DVHs were derived for the rectum only and for rectum extended with six PRV margin sets (narrow/intermediate/wide; anterior/anterior and posterior). The data was analysed using permutation tests, logistic regression and effective uniform dose (EUD) calculations. Results: Acute Grade 2 GI toxicity was seen in 22 of 127 cases (17%). Permutation tests showed that the difference between DVHs for patients with and without Grade 2 effects was significant, both for rectum only and rectum PRVs (P-value range: 0.02-0.04), with generally lower P-values for the PRVs. In the logistic regression, the fractional DVH variables (i.e. volumes) were significantly related to toxicity, with approximately 2-3 times as many significant dose levels for the PRVs as for rectum only. E.g. with wide anterior and posterior margins (16 and 11 mm, respectively) the relation was significant at 26 different dose levels (6-7, 13-14, 35-43, 60-71 and 73 Gy), compared to nine levels (38-40, 43-44 and 71-74 Gy) for rectum only. EUDs were significantly different for patients with and without Grade 2 effects both for rectum only and the PRVs (95% confidence interval for EUD increase with Grade 2 effects: 0.1-3.1 Gy). Conclusions: All statistical methods applied indicated a small, but definite difference in DVH parameters between patients with versus those without Grade 2 effects. The difference was most pronounced when margins of 16 mm anterior and 11 mm posterior were applied

  12. ICPP tank farm closure study. Volume III: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

    International Nuclear Information System (INIS)

    1998-02-01

    This volume contains information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the six options described in Volume 1, Section 2: Option 1 -- Total removal clean closure; No subsequent use; Option 2 -- Risk-based clean closure; LLW fill; Option 3 -- Risk-based clean closure; CERCLA fill; Option 4 -- Close to RCRA landfill standards; LLW fill; Option 5 -- Close to RCRA landfill standards; CERCLA fill; and Option 6 -- Close to RCRA landfill standards; Clean fill. This volume is divided into two portions. The first portion contains the cost and planning schedule estimates while the second portion contains life-cycle costs and yearly cash flow information for each option

  13. Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-01

    Volume 1 is comprised of chapters on: background and description; environmental impacts of add-on gaseous diffusion plant; unavoidable adverse environmental effects; alternatives; relationship between short-term uses and long-term productivity; relationship of program to land-use plans, policies, and controls; irreversible and irretrievable commitments of resources; cost-benefit analysis; and response to comment letters. (LK)

  14. Portsmouth Gaseous Diffusion Plant expansion: final environmental statement. Volume 1

    International Nuclear Information System (INIS)

    1977-09-01

    Volume 1 is comprised of chapters on: background and description; environmental impacts of add-on gaseous diffusion plant; unavoidable adverse environmental effects; alternatives; relationship between short-term uses and long-term productivity; relationship of program to land-use plans, policies, and controls; irreversible and irretrievable commitments of resources; cost-benefit analysis; and response to comment letters

  15. Fusion Engineering Device. Volume VI. Complementary development plan for engineering development

    International Nuclear Information System (INIS)

    1981-10-01

    The basic approach followed in this volume is to define key technical issues for several fusion reactor technologies and to device program strategies to resolve each of these issues. Particular attention has been paid to elucidating the role of FED vis-a-vis complementary (non-FED) facilities in this process. The remainder of this chapter consists of summaries of the major conclusions of the technology plans in each of the areas studied, i.e., plasma heating, magnetics, nuclear, and systems considerations

  16. Optimal grasp planning for a dexterous robotic hand using the volume of a generalized force ellipsoid during accepted flattening

    Directory of Open Access Journals (Sweden)

    Peng Jia

    2017-01-01

    Full Text Available A grasp planning method based on the volume and flattening of a generalized force ellipsoid is proposed to improve the grasping ability of a dexterous robotic hand. First, according to the general solution of joint torques for a dexterous robotic hand, a grasping indicator for the dexterous hand—the maximum volume of a generalized external force ellipsoid and the minimum volume of a generalized contact internal force ellipsoid during accepted flattening—is proposed. Second, an optimal grasp planning method based on a task is established using the grasping indicator as an objective function. Finally, a simulation analysis and grasping experiment are performed. Results show that when the grasping experiment is conducted with the grasping configuration and positions of contact points optimized using the proposed grasping indicator, the root-mean-square values of the joint torques and contact internal forces of the dexterous hand are at a minimum. The effectiveness of the proposed grasping planning method is thus demonstrated.

  17. The spill prevention, control, and countermeasures (SPCC) plan for the Y-12 Plant

    International Nuclear Information System (INIS)

    1992-08-01

    This spill prevention, control and countermeasures (SPCC) Plan is divided into two volumes. Volume I addresses Y-12's compliance with regulations pertinent to the content of SPCC Plans. Volume II is the SPCC Hazardous Material Storage Data Base, a detailed tabulation of facility-specific information and data on potential spill sources at the Y-12 Plant. Volume I follows the basic format and subject sequence specified in 40 CFR 112.7. This sequence is prefaced by three additional chapters, including this introduction and brief discussions of the Y-12 Plant's background/environmental setting and potential spill source categories. Two additional chapters on containers and container storage areas and PCB and PCB storage for disposal facilities are inserted into the required sequence. The following required subjects are covered in this volume: Spill history, site drainage; secondary containment/diversion structures and equipment; contingency plans; notification and spill response procedures; facility drainage; bulk storage tanks; facility transfer operations, pumping, and in-plant processes; transfer stations (facility tank cars/tank tracks); inspections and records; security, and personnel, training, and spill prevention procedures

  18. Utility of Quantitative Tc-MAA SPECT/CT for yttrium-Labelled Microsphere Treatment Planning: Calculating Vascularized Hepatic Volume and Dosimetric Approach.

    Science.gov (United States)

    Garin, Etienne; Rolland, Yan; Lenoir, Laurence; Pracht, Marc; Mesbah, Habiba; Porée, Philippe; Laffont, Sophie; Clement, Bruno; Raoul, Jean-Luc; Boucher, Eveline

    2011-01-01

    Objectives. The aim of this study was to assess the effectiveness of SPECT/CT for volume measurements and to report a case illustrating the major impact of SPECT/CT in calculating the vascularized liver volume and dosimetry prior to injecting radiolabelled yttrium-90 microspheres (Therasphere). Materials and Methods. This was a phantom study, involving volume measurements carried out by two operators using SPECT and SPECT/CT images. The percentage of error for each method was calculated, and interobserver reproducibility was evaluated. A treatment using Therasphere was planned in a patient with three hepatic arteries, and the quantitative analysis of SPECT/CT for this patient is provided. Results. SPECT/CT volume measurements proved to be accurate (mean error Therasphere used. Conclusions. MAA SPECT/CT is accurate for vascularized liver volume measurements, providing a valuable contribution to the therapeutic planning of patients with complex hepatic vascularization.

  19. First impressions of 3D visual tools and dose volume histograms for plan evaluation

    International Nuclear Information System (INIS)

    Rattray, G.; Simitcioglu, A.; Parkinson, M.; Biggs, J.

    1999-01-01

    Converting from 2D to 3D treatment planning offers numerous challenges. The practices that have evolved in the 2D environment may not be applicable when translated into the 3D environment. One such practice is the methods used to evaluate a plan. In 2D planning a plane by plane comparison method is generally practiced. This type of evaluation method would not be appropriate for plans produced by a 3D planning system. To this end 3D dose displays and Dose Volume Histograms (DVHs) have been developed to facilitate the evaluation of such plans. A survey was conducted to determine the impressions of Radiation Therapists as they used these tools for the first time. The survey involved comparing a number of plans for a small group of patients and selecting the best plan for each patient. Three evaluation methods were assessed. These included the traditional plane by plane, 3D dose display, and DVHs. Those surveyed found the DVH to be the easiest of the three methods to use, with the 3D display being the next easiest. Copyright (1999) Blackwell Science Pty Ltd

  20. A case study of IMRT planning (Plan B) subsequent to a previously treated IMRT plan (Plan A)

    International Nuclear Information System (INIS)

    2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" data-affiliation=" (Department of Medical Physics and 2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" >Cao, F; 2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" data-affiliation=" (Department of Medical Physics and 2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" >Leong, C; 2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" data-affiliation=" (Department of Medical Physics and 2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" >Schroeder, J; 2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" data-affiliation=" (Department of Medical Physics and 2Department of Radiation Oncology, Fraser Valley Centre, BC Cancer Agency, Surrey, British Columbia (Canada))" >Lee, B

    2014-01-01

    Background and purpose: Treatment of the contralateral neck after previous ipsilateral intensity modulated radiation therapy (IMRT) for head and neck cancer is a challenging problem. We have developed a technique that limits the cumulative dose to the spinal cord and brainstem while maximizing coverage of a planning target volume (PTV) in the contralateral neck. Our case involves a patient with right tonsil carcinoma who was given ipsilateral IMRT with 70Gy in 35 fractions (Plan A). A left neck recurrence was detected 14 months later. The patient underwent a neck dissection followed by postoperative left neck radiation to a dose of 66 Gy in 33 fractions (Plan B). Materials and Methods: The spinal cord-brainstem margin (SCBM) was defined as the spinal cord and brainstem with a 1.0 cm margin. Plan A was recalculated on the postoperative CT scan but the fluence outside of SCBM was deleted. A further modification of Plan A resulted in a base plan that was summed with Plan B to evaluate the cumulative dose received by the spinal cord and brainstem. Plan B alone was used to evaluate for coverage of the contralateral neck PTV. Results: The maximum cumulative doses to the spinal cord with 0.5cm margin and brainstem with 0.5cm margin were 51.96 Gy and 45.60 Gy respectively. For Plan B, 100% of the prescribed dose covered 95% of PTVb1. Conclusion: The use of a modified ipsilateral IMRT plan as a base plan is an effective way to limit the cumulative dose to the spinal cord and brainstem while enabling coverage of a PTV in the contralateral neck.

  1. Functional image-based radiotherapy planning for non-small cell lung cancer: A simulation study

    International Nuclear Information System (INIS)

    Bates, Emma L.; Bragg, Christopher M.; Wild, Jim M.; Hatton, Matthew Q.F.; Ireland, Rob H.

    2009-01-01

    Background and purpose: To investigate the incorporation of data from single-photon emission computed tomography (SPECT) or hyperpolarized helium-3 magnetic resonance imaging ( 3 He-MRI) into intensity-modulated radiotherapy (IMRT) planning for non-small cell lung cancer (NSCLC). Material and methods: Seven scenarios were simulated that represent cases of NSCLC with significant functional lung defects. Two independent IMRT plans were produced for each scenario; one to minimise total lung volume receiving ≥20 Gy (V 20 ), and the other to minimise only the functional lung volume receiving ≥20 Gy (FV 20 ). Dose-volume characteristics and a plan quality index related to planning target volume coverage by the 95% isodose (V PTV95 /FV 20 ) were compared between anatomical and functional plans using the Wilcoxon signed ranks test. Results: Compared to anatomical IMRT plans, functional planning reduced FV 20 (median 2.7%, range 0.6-3.5%, p = 0.02), and total lung V 20 (median 1.5%, 0.5-2.7%, p = 0.02), with a small reduction in mean functional lung dose (median 0.4 Gy, 0-0.7 Gy, p = 0.03). There were no significant differences in target volume coverage or organ-at-risk doses. Plan quality index was improved for functional plans (median increase 1.4, range 0-11.8, p = 0.02). Conclusions: Statistically significant reductions in FV 20 , V 20 and mean functional lung dose are possible when IMRT planning is supplemented by functional information derived from SPECT or 3 He-MRI.

  2. Climate change in Nova Scotia : a background paper to guide Nova Scotia's climate change action plan

    International Nuclear Information System (INIS)

    2007-10-01

    Climate change causes changes in the temperature of the earth, the level of the sea, and the frequency of extreme weather conditions. The province of Nova Scotia recently released an act related to environmental goals and sustainable prosperity. Addressing climate change is a key element in achieving Nova Scotia's sustainable prosperity goals outlined in the act. The Nova Scotia Department of Energy is working towards developing both policy and action, to help meet its target of a 10 per cent reduction in greenhouse gases from 1990 levels by the year 2020. Two major plans are underway, notably a climate change action plan and a renewed energy strategy. This report provided background information on Nova Scotia's climate change action plan. It discussed climate change issues affecting Nova Scotia, air pollutants, energy sources in Nova Scotia, energy consumers in the province, and Nova Scotia's approach to climate change. The report also discussed actions underway and funding sources. It was concluded that in order for the climate change action plan to be successful, Nova Scotians must use energy more efficiently; use renewable energy; use cleaner energy; and plan for change. 13 refs., 2 tabs., 6 figs., 4 appendices

  3. The development of mentoring-relationship quality, future-planning style, and career goal setting among adolescents from a disadvantaged background.

    Science.gov (United States)

    Lau, Wendy S Y; Zhou, Xiao-Chun; Lai, Simon M K

    2017-03-01

    Our behaviors are regulated by our perception of the future based on past experiences and knowledge. Children from a disadvantaged background might encounter obstacles more frequently when they plan their future. It is possible that a good relationship with an adult volunteer who provides assistance and guidance in the disadvantaged youth's development may facilitate their future-planning style and career goal setting. The present study investigated the role of a good mentoring relationship in promoting a disadvantaged youth's future-planning style and goal-setting ability. It focused on children from a disadvantaged background who participated in the Child Development Fund (CDF) in Hong Kong. In the study, 187 CDF participants (93 with high mentoring-relationship quality [MRQ] and 94 with low MRQ) and 208 comparison group participants were able to complete all four times of the survey. Repeated-measures analyses of covariance showed that Group main effects were observed for both future-planning style, F(2, 374) = 5.92, p career goal-setting self-efficacy, F(2, 376) = 6.07, p planning style only, F(5.78, 1081.21) = 2.17, p planning style and career goal-setting self-efficacy. Multiple regression analyses revealed that mean MRQ score accounted for 3.9% (p planning style and 4.1% (p career goal-setting self-efficacy, supporting the role of a good mentoring relationship. Mentors have introduced new resources to the disadvantaged youths with high MRQ and have promoted the development of various skills through modeling. © 2017 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  4. Savannah River Site Approved Site Treatment Plan, 1998 Annual Update (U)

    International Nuclear Information System (INIS)

    Lawrence, B.; Berry, M.

    1998-03-01

    The U.S. Department of Energy, Savannah River Operations Office (DOE- SR),has prepared the Site Treatment Plan (STP) for Savannah River Site (SRS) mixed wastes in accordance with RCRA Section 3021(b), and SCDHEC has approved the STP (except for certain offsite wastes) and issued an order enforcing the STP commitments in Volume I. DOE-SR and SCDHEC agree that this STP fulfills the requirements contained in the FFCAct, RCRA Section 3021, and therefore,pursuant to Section 105(a) of the FFCAct (RCRA Section 3021(b)(5)), DOE's requirements are to implement the plan for the development of treatment capacities and technologies pursuant to RCRA Section 3021.Emerging and new technologies not yet considered may be identified to manage waste more safely, effectively, and at lower cost than technologies currently identified in the plan. DOE will continue to evaluate and develop technologies that offer potential advantages in public acceptance, privatization, consolidation, risk abatement, performance, and life-cycle cost. Should technologies that offer such advantages be identified, DOE may request a revision/modification of the STP in accordance with the provisions of Consent Order 95-22-HW.The Compliance Plan Volume (Volume I) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions (LDR). Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume II) and is provided for information

  5. Prescribing and evaluating target dose in dose-painting treatment plans

    DEFF Research Database (Denmark)

    Håkansson, Katrin; Specht, Lena; Aznar, Marianne C

    2014-01-01

    BACKGROUND: Assessment of target dose conformity in multi-dose-level treatment plans is challenging due to inevitable over/underdosage at the border zone between dose levels. Here, we evaluate different target dose prescription planning aims and approaches to evaluate the relative merit of such p......-painting and multi-dose-level plans. The tool can be useful for quality assurance of multi-center trials, and for visualizing the development of treatment planning in routine clinical practice....... of such plans. A quality volume histogram (QVH) tool for history-based evaluation is proposed. MATERIAL AND METHODS: Twenty head and neck cancer dose-painting plans with five prescription levels were evaluated, as well as clinically delivered simultaneous integrated boost (SIB) plans from 2010 and 2012. The QVH...

  6. Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

    Directory of Open Access Journals (Sweden)

    Korevaar Erik W

    2008-01-01

    Full Text Available Abstract Background The shift from conventional two-dimensional (2D to three-dimensional (3D-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT-based breast and boost planning target volumes (PTV, absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Methods Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. Results With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. Conclusion The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on

  7. Characterisation of radiotherapy planning volumes using textural analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nailon, William H.; Redpath, Anthony T.; McLaren, Duncan B. (Dept. of Oncology Physics, Edinburgh Cancer Centre, Western General Hospital, Edinburgh (United Kingdom))

    2008-08-15

    Computer-based artificial intelligence methods for classification and delineation of the gross tumour volume (GTV) on computerised tomography (CT) and magnetic resonance (MR) images do not, at present, provide the accuracy required for radiotherapy applications. This paper describes an image analysis method for classification of distinct regions within the GTV, and other clinically relevant regions, on CT images acquired on eight bladder cancer patients at the radiotherapy planning stage and thereafter at regular intervals during treatment. Statistical and fractal textural features (N=27) were calculated on the bladder, rectum and a control region identified on axial, coronal and sagittal CT images. Unsupervised classification results demonstrate that with a reduced feature set (N=3) the approach offers significant classification accuracy on axial, coronal and sagittal CT image planes and has the potential to be developed further for radiotherapy applications, particularly towards an automatic outlining approach

  8. Characterisation of radiotherapy planning volumes using textural analysis

    International Nuclear Information System (INIS)

    Nailon, William H.; Redpath, Anthony T.; McLaren, Duncan B.

    2008-01-01

    Computer-based artificial intelligence methods for classification and delineation of the gross tumour volume (GTV) on computerised tomography (CT) and magnetic resonance (MR) images do not, at present, provide the accuracy required for radiotherapy applications. This paper describes an image analysis method for classification of distinct regions within the GTV, and other clinically relevant regions, on CT images acquired on eight bladder cancer patients at the radiotherapy planning stage and thereafter at regular intervals during treatment. Statistical and fractal textural features (N=27) were calculated on the bladder, rectum and a control region identified on axial, coronal and sagittal CT images. Unsupervised classification results demonstrate that with a reduced feature set (N=3) the approach offers significant classification accuracy on axial, coronal and sagittal CT image planes and has the potential to be developed further for radiotherapy applications, particularly towards an automatic outlining approach

  9. Savannah River Site Approved Site Treatment Plan, 1998 Annual Update

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, B. [Westinghouse Savannah River Company, AIKEN, SC (United States); Berry, M.

    1998-03-01

    The U.S. Department of Energy, Savannah River Operations Office (DOE- SR),has prepared the Site Treatment Plan (STP) for Savannah River Site (SRS) mixed wastes in accordance with RCRA Section 3021(b), and SCDHEC has approved the STP (except for certain offsite wastes) and issued an order enforcing the STP commitments in Volume I. DOE-SR and SCDHEC agree that this STP fulfills the requirements contained in the FFCAct, RCRA Section 3021, and therefore,pursuant to Section 105(a) of the FFCAct (RCRA Section 3021(b)(5)), DOE`s requirements are to implement the plan for the development of treatment capacities and technologies pursuant to RCRA Section 3021.Emerging and new technologies not yet considered may be identified to manage waste more safely, effectively, and at lower cost than technologies currently identified in the plan. DOE will continue to evaluate and develop technologies that offer potential advantages in public acceptance, privatization, consolidation, risk abatement, performance, and life-cycle cost. Should technologies that offer such advantages be identified, DOE may request a revision/modification of the STP in accordance with the provisions of Consent Order 95-22-HW.The Compliance Plan Volume (Volume I) identifies project activity schedule milestones for achieving compliance with Land Disposal Restrictions (LDR). Information regarding the technical evaluation of treatment options for SRS mixed wastes is contained in the Background Volume (Volume II) and is provided for information.

  10. ICRU reference dose in an era of intensity-modulated radiation therapy clinical trials: Correlation with planning target volume mean dose and suitability for intensity-modulated radiation therapy dose prescription

    International Nuclear Information System (INIS)

    Yaparpalvi, Ravindra; Hong, Linda; Mah, Dennis; Shen Jin; Mutyala, Subhakar; Spierer, Marnee; Garg, Madhur; Guha, Chandan; Kalnicki, Shalom

    2008-01-01

    Background and Purpose: IMRT clinical trials lack dose prescription and specification standards similar to ICRU standards for two- and three-dimensional external beam planning. In this study, we analyzed dose distributions for patients whose treatment plans incorporated IMRT, and compared the dose determined at the ICRU reference point to the PTV doses determined from dose-volume histograms. Additionally, we evaluated if ICRU reference type single-point dose prescriptions are suitable for IMRT dose prescriptions. Materials and methods: For this study, IMRT plans of 117 patients treated at our institution were randomly selected and analyzed. The treatment plans were clinically applied to the following disease sites: abdominal (11), anal (10), brain (11), gynecological (15), head and neck (25), lung (15), male pelvis (10) and prostate (20). The ICRU reference point was located in each treatment plan following ICRU Report 50 guidelines. The reference point was placed in the central part of the PTV and at or near the isocenter. In each case, the dose was calculated and recorded to this point. For each patient - volume and dose (PTV, PTV mean, median and modal) information was extracted from the planned dose-volume histogram. Results: The ICRU reference dose vs PTV mean dose relationship in IMRT exhibited a weak positive association (Pearson correlation coefficient 0.63). In approximately 65% of the cases studied, dose at the ICRU reference point was greater than the corresponding PTV mean dose. The dose difference between ICRU reference and PTV mean doses was ≤2% in approximately 79% of the cases studied (average 1.21% (±1.55), range -4% to +4%). Paired t-test analyses showed that the ICRU reference doses and PTV median doses were statistically similar (p = 0.42). The magnitude of PTV did not influence the difference between ICRU reference and PTV mean doses. Conclusions: The general relationship between ICRU reference and PTV mean doses in IMRT is similar to that

  11. [Computer-assisted operational planning for pediatric abdominal surgery. 3D-visualized MRI with volume rendering].

    Science.gov (United States)

    Günther, P; Tröger, J; Holland-Cunz, S; Waag, K L; Schenk, J P

    2006-08-01

    Exact surgical planning is necessary for complex operations of pathological changes in anatomical structures of the pediatric abdomen. 3D visualization and computer-assisted operational planning based on CT data are being increasingly used for difficult operations in adults. To minimize radiation exposure and for better soft tissue contrast, sonography and MRI are the preferred diagnostic methods in pediatric patients. Because of manifold difficulties 3D visualization of these MRI data has not been realized so far, even though the field of embryonal malformations and tumors could benefit from this.A newly developed and modified raycasting-based powerful 3D volume rendering software (VG Studio Max 1.2) for the planning of pediatric abdominal surgery is presented. With the help of specifically developed algorithms, a useful surgical planning system is demonstrated. Thanks to the easy handling and high-quality visualization with enormous gain of information, the presented system is now an established part of routine surgical planning.

  12. Computer-assisted operational planning for pediatric abdominal surgery. 3D-visualized MRI with volume rendering

    International Nuclear Information System (INIS)

    Guenther, P.; Holland-Cunz, S.; Waag, K.L.

    2006-01-01

    Exact surgical planning is necessary for complex operations of pathological changes in anatomical structures of the pediatric abdomen. 3D visualization and computer-assisted operational planning based on CT data are being increasingly used for difficult operations in adults. To minimize radiation exposure and for better soft tissue contrast, sonography and MRI are the preferred diagnostic methods in pediatric patients. Because of manifold difficulties 3D visualization of these MRI data has not been realized so far, even though the field of embryonal malformations and tumors could benefit from this. A newly developed and modified raycasting-based powerful 3D volume rendering software (VG Studio Max 1.2) for the planning of pediatric abdominal surgery is presented. With the help of specifically developed algorithms, a useful surgical planning system is demonstrated. Thanks to the easy handling and high-quality visualization with enormous gain of information, the presented system is now an established part of routine surgical planning. (orig.) [de

  13. Gamma histograms for radiotherapy plan evaluation

    International Nuclear Information System (INIS)

    Spezi, Emiliano; Lewis, D. Geraint

    2006-01-01

    Background and purpose: The technique known as the 'γ evaluation method' incorporates pass-fail criteria for both distance-to-agreement and dose difference analysis of 3D dose distributions and provides a numerical index (γ) as a measure of the agreement between two datasets. As the γ evaluation index is being adopted in more centres as part of treatment plan verification procedures for 2D and 3D dose maps, the development of methods capable of encapsulating the information provided by this technique is recommended. Patients and methods: In this work the concept of γ index was extended to create gamma histograms (GH) in order to provide a measure of the agreement between two datasets in two or three dimensions. Gamma area histogram (GAH) and gamma volume histogram (GVH) graphs were produced using one or more 2D γ maps generated for each slice of the irradiated volume. GHs were calculated for IMRT plans, evaluating the 3D dose distribution from a commercial treatment planning system (TPS) compared to a Monte Carlo (MC) calculation used as reference dataset. Results: The extent of local anatomical inhomogenities in the plans under consideration was strongly correlated with the level of difference between reference and evaluated calculations. GHs provided an immediate visual representation of the proportion of the treated volume that fulfilled the γ criterion and offered a concise method for comparative numerical evaluation of dose distributions. Conclusions: We have introduced the concept of GHs and investigated its applications to the evaluation and verification of IMRT plans. The gamma histogram concept set out in this paper can provide a valuable technique for quantitative comparison of dose distributions and could be applied as a tool for the quality assurance of treatment planning systems

  14. Planning magnetic resonance imaging for prostate cancer intensity-modulated radiation therapy: Impact on target volumes, radiotherapy dose and androgen deprivation administration.

    Science.gov (United States)

    Horsley, Patrick J; Aherne, Noel J; Edwards, Grace V; Benjamin, Linus C; Wilcox, Shea W; McLachlan, Craig S; Assareh, Hassan; Welshman, Richard; McKay, Michael J; Shakespeare, Thomas P

    2015-03-01

    Magnetic resonance imaging (MRI) scans are increasingly utilized for radiotherapy planning to contour the primary tumors of patients undergoing intensity-modulated radiation therapy (IMRT). These scans may also demonstrate cancer extent and may affect the treatment plan. We assessed the impact of planning MRI detection of extracapsular extension, seminal vesicle invasion, or adjacent organ invasion on the staging, target volume delineation, doses, and hormonal therapy of patients with prostate cancer undergoing IMRT. The records of 509 consecutive patients with planning MRI scans being treated with IMRT for prostate cancer between January 2010 and July 2012 were retrospectively reviewed. Tumor staging and treatment plans before and after MRI were compared. Of the 509 patients, 103 (20%) were upstaged and 44 (9%) were migrated to a higher risk category as a result of findings at MRI. In 94 of 509 patients (18%), the MRI findings altered management. Ninety-four of 509 patients (18%) had a change to their clinical target volume (CTV) or treatment technique, and in 41 of 509 patients (8%) the duration of hormone therapy was changed because of MRI findings. The use of radiotherapy planning MRI altered CTV design, dose and/or duration of androgen deprivation in 18% of patients in this large, single institution series of men planned for dose-escalated prostate IMRT. This has substantial implications for radiotherapy target volumes and doses, as well as duration of androgen deprivation. Further research is required to investigate whether newer MRI techniques can simultaneously fulfill staging and radiotherapy contouring roles. © 2014 Wiley Publishing Asia Pty Ltd.

  15. Use of wall-less 18F-doped gelatin phantoms for improved volume delineation and quantification in PET/CT

    International Nuclear Information System (INIS)

    Sydoff, Marie; Andersson, Martin; Mattsson, Sören; Leide-Svegborn, Sigrid

    2014-01-01

    Positron emission tomography (PET) with 18 F-FDG is a valuable tool for staging, planning treatment, and evaluating the treatment response for many different types of tumours. The correct volume estimation is of utmost importance in these situations. To date, the most common types of phantoms used in volume quantification in PET utilize fillable, hollow spheres placed in a circular or elliptical cylinder made of polymethyl methacrylate. However, the presence of a non-radioactive sphere wall between the hotspot and the background activity in images of this type of phantom could cause inaccuracies. To investigate the influence of the non-active walls, we developed a phantom without non-active sphere walls for volume delineation and quantification in PET. Three sizes of gelatin hotspots were moulded and placed in a Jaszczak phantom together with hollow plastic spheres of the same sizes containing the same activity concentration. 18 F PET measurements were made with zero background activity and with tumour-to-background ratios of 12.5, 10, 7.5, and 5. The background-corrected volume reproducing threshold, T vol , was calculated for both the gelatin and the plastic spheres. It was experimentally verified that the apparent background dependence of T vol , i.e., a decreasing T vol  with increasing background fraction, was not present for wall-less spheres; the opposite results were seen in plastic, hollow spheres in commercially-available phantoms. For the types of phantoms commonly used in activity quantification, the estimation of T vol  using fillable, hollow, plastic spheres with non-active walls would lead to an overestimate of the tumour volume, especially for small volumes in a high activity background. (paper)

  16. Use of wall-less 18F-doped gelatin phantoms for improved volume delineation and quantification in PET/CT

    Science.gov (United States)

    Sydoff, Marie; Andersson, Martin; Mattsson, Sören; Leide-Svegborn, Sigrid

    2014-03-01

    Positron emission tomography (PET) with 18F-FDG is a valuable tool for staging, planning treatment, and evaluating the treatment response for many different types of tumours. The correct volume estimation is of utmost importance in these situations. To date, the most common types of phantoms used in volume quantification in PET utilize fillable, hollow spheres placed in a circular or elliptical cylinder made of polymethyl methacrylate. However, the presence of a non-radioactive sphere wall between the hotspot and the background activity in images of this type of phantom could cause inaccuracies. To investigate the influence of the non-active walls, we developed a phantom without non-active sphere walls for volume delineation and quantification in PET. Three sizes of gelatin hotspots were moulded and placed in a Jaszczak phantom together with hollow plastic spheres of the same sizes containing the same activity concentration. 18F PET measurements were made with zero background activity and with tumour-to-background ratios of 12.5, 10, 7.5, and 5. The background-corrected volume reproducing threshold, Tvol, was calculated for both the gelatin and the plastic spheres. It was experimentally verified that the apparent background dependence of Tvol, i.e., a decreasing Tvol with increasing background fraction, was not present for wall-less spheres; the opposite results were seen in plastic, hollow spheres in commercially-available phantoms. For the types of phantoms commonly used in activity quantification, the estimation of Tvol using fillable, hollow, plastic spheres with non-active walls would lead to an overestimate of the tumour volume, especially for small volumes in a high activity background.

  17. Procedures for treating common cause failures in safety and reliability studies: Volume 2, Analytic background and techniques: Final report

    International Nuclear Information System (INIS)

    Mosleh, A.; Fleming, K.N.; Parry, G.W.; Paula, H.M.; Worledge, D.H.; Rasmuson, D.M.

    1988-12-01

    This report presents a framework for the inclusion of the impact of common cause failures in risk and reliability evaluations. Common cause failures are defined as that subset of dependent failures for which causes are not explicitly included in the logic model as basic events. The emphasis here is on providing procedures for a practical, systematic approach that can be used to perform and clearly document the analysis. The framework and the methods discussed for performing the different stages of the analysis integrate insights obtained from engineering assessments of the system and the historical evidence from multiple failure events into a systematic, reproducible, and defensible analysis. This document, Volume 2, contains a series of appendices that provide additional background and methodological detail on several important topics discussed in Volume 1

  18. Automated planning target volume generation: an evaluation pitting a computer-based tool against human experts

    International Nuclear Information System (INIS)

    Ketting, Case H.; Austin-Seymour, Mary; Kalet, Ira; Jacky, Jon; Kromhout-Schiro, Sharon; Hummel, Sharon; Unger, Jonathan; Fagan, Lawrence M.; Griffin, Tom

    1997-01-01

    Purpose: Software tools are seeing increased use in three-dimensional treatment planning. However, the development of these tools frequently omits careful evaluation before placing them in clinical use. This study demonstrates the application of a rigorous evaluation methodology using blinded peer review to an automated software tool that produces ICRU-50 planning target volumes (PTVs). Methods and Materials: Seven physicians from three different institutions involved in three-dimensional treatment planning participated in the evaluation. Four physicians drew partial PTVs on nine test cases, consisting of four nasopharynx and five lung primaries. Using the same information provided to the human experts, the computer tool generated PTVs for comparison. The remaining three physicians, designated evaluators, individually reviewed the PTVs for acceptability. To exclude bias, the evaluators were blinded to the source (human or computer) of the PTVs they reviewed. Their scorings of the PTVs were statistically examined to determine if the computer tool performed as well as the human experts. Results: The computer tool was as successful as the human experts in generating PTVs. Failures were primarily attributable to insufficient margins around the clinical target volume and to encroachment upon critical structures. In a qualitative analysis, the human and computer experts displayed similar types and distributions of errors. Conclusions: Rigorous evaluation of computer-based radiotherapy tools requires comparison to current practice and can reveal areas for improvement before the tool enters clinical practice

  19. Feasibility of using intensity-modulated radiotherapy to improve lung sparing in treatment planning for distal esophageal cancer

    International Nuclear Information System (INIS)

    Chandra, Anurag; Guerrero, Thomas M.; Liu, H. Helen; Tucker, Susan L.; Liao Zhongxing; Wang Xiaochun; Murshed, Hasan; Bonnen, Mark D.; Garg, Amit K.; Stevens, Craig W.; Chang, Joe Y.; Jeter, Melinda D.; Mohan, Radhe; Cox, James D.; Komaki, Ritsuko

    2005-01-01

    Background and purpose: To evaluate the feasibility whether intensity-modulated radiotherapy (IMRT) can be used to reduce doses to normal lung than three-dimensional conformal radiotherapy (3DCRT) in treating distal esophageal malignancies. Patients and methods: Ten patient cases with cancer of the distal esophagus were selected for a retrospective treatment-planning study. IMRT plans using four, seven, and nine beams (4B, 7B, and 9B) were developed for each patient and compared with the 3DCRT plan used clinically. IMRT and 3DCRT plans were evaluated with respect to PTV coverage and dose-volumes to irradiated normal structures, with statistical comparison made between the two types of plans using the Wilcoxon matched-pair signed-rank test. Results: IMRT plans (4B, 7B, 9B) reduced total lung volume treated above 10 Gy (V 1 ), 20 Gy (V 2 ), mean lung dose (MLD), biological effective volume (V eff ), and lung integral dose (P 1 , 5% for V 2 , and 2.5 Gy for MLD. IMRT improved the PTV heterogeneity (P<0.05), yet conformity was better with 7B-9B IMRT plans. No clinically meaningful differences were observed with respect to the irradiated volumes of spinal cord, heart, liver, or total body integral doses. Conclusions: Dose-volume of exposed normal lung can be reduced with IMRT, though clinical investigations are warranted to assess IMRT treatment outcome of esophagus cancers

  20. Management response plan for the Chemical Safety Vulnerability Working Group report. Volume 2

    International Nuclear Information System (INIS)

    1994-09-01

    The Chemical Safety Vulnerability (CSV) Working Group was established to identify adverse conditions involving hazardous chemicals at DOE facilities that might result in fires or explosions, release of hazardous chemicals to the environment, or exposure of workers or the public to chemicals. A CSV Review was conducted in 146 facilities at 29 sites. Eight generic vulnerabilities were documented related to: abandoned chemicals and chemical residuals; past chemical spills and ground releases; characterization of legacy chemicals and wastes; disposition of legacy chemicals; storage facilities and conditions; condition of facilities and support systems; unanalyzed and unaddressed hazards; and inventory control and tracking. Weaknesses in five programmatic areas were also identified related to: management commitment and planning; chemical safety management programs; aging facilities that continue to operate; nonoperating facilities awaiting deactivation; and resource allocations. To address the facility-specific and site-specific vulnerabilities, responsible DOE and site-contractor line organizations have developed initial site response plans. These plans, presented as Volume 2 of this Management Response Plan, describe the actions needed to mitigate or eliminate the facility- and site-specific vulnerabilities identified by the CSV Working Group field verification teams. Initial site response plans are described for: Brookhaven National Lab., Hanford Site, Idaho National Engineering Lab., Lawrence Livermore National Lab., Los Alamos National Lab., Oak Ridge Reservation, Rocky Flats Plant, Sandia National Laboratories, and Savannah River Site

  1. Utilize target motion to cover clinical target volume (ctv) - a novel and practical treatment planning approach to manage respiratory motion

    International Nuclear Information System (INIS)

    Jin Jianyue; Ajlouni, Munther; Kong Fengming; Ryu, Samuel; Chetty, Indrin J.; Movsas, Benjamin

    2008-01-01

    Purpose: To use probability density function (PDF) to model motion effects and incorporate this information into treatment planning for lung cancers. Material and methods: PDFs were calculated from the respiratory motion traces of 10 patients. Motion effects were evaluated by convolving static dose distributions with various PDFs. Based on a differential dose prescription with relatively lower dose to the clinical target volume (CTV) than to the gross tumor volume (GTV), two approaches were proposed to incorporate PDFs into treatment planning. The first approach uses the GTV-based internal target volume (ITV) as the planning target volume (PTV) to ensure full dose to the GTV, and utilizes the motion-induced dose gradient to cover the CTV. The second approach employs an inhomogeneous static dose distribution within a minimized PTV to best match the prescription dose gradient. Results: Motion effects on dose distributions were minimal in the anterior-posterior (AP) and lateral directions: a 10-mm motion only induced about 3% of dose reduction in the peripheral target region. The motion effect was remarkable in the cranial-caudal direction. It varied with the motion amplitude, but tended to be similar for various respiratory patterns. For the first approach, a 10-15 mm motion would adequately cover the CTV (presumed to be 60-70% of the GTV dose) without employing the CTV in planning. For motions 15-mm. An example of inhomogeneous static dose distribution in a reduced PTV was given, and it showed significant dose reduction in the normal tissue without compromising target coverage. Conclusions: Respiratory motion-induced dose gradient can be utilized to cover the CTV and minimize the lung dose without the need for more sophisticated technologies

  2. Utility of Quantitative 99mTc-MAA SPECT/CT for 90yttrium-Labelled Microsphere Treatment Planning: Calculating Vascularized Hepatic Volume and Dosimetric Approach

    Science.gov (United States)

    Garin, Etienne; Rolland, Yan; Lenoir, Laurence; Pracht, Marc; Mesbah, Habiba; Porée, Philippe; Laffont, Sophie; Clement, Bruno; Raoul, Jean-Luc; Boucher, Eveline

    2011-01-01

    Objectives. The aim of this study was to assess the effectiveness of SPECT/CT for volume measurements and to report a case illustrating the major impact of SPECT/CT in calculating the vascularized liver volume and dosimetry prior to injecting radiolabelled yttrium-90 microspheres (Therasphere). Materials and Methods. This was a phantom study, involving volume measurements carried out by two operators using SPECT and SPECT/CT images. The percentage of error for each method was calculated, and interobserver reproducibility was evaluated. A treatment using Therasphere was planned in a patient with three hepatic arteries, and the quantitative analysis of SPECT/CT for this patient is provided. Results. SPECT/CT volume measurements proved to be accurate (mean error Therasphere used. Conclusions. MAA SPECT/CT is accurate for vascularized liver volume measurements, providing a valuable contribution to the therapeutic planning of patients with complex hepatic vascularization. PMID:21822489

  3. Comparison of CT-based 3D treatment planning with simulator planning of pelvic irradiation of primary cervical carcinoma

    International Nuclear Information System (INIS)

    Knocke, T.H.; Pokrajac, B.; Fellner, C.; Poetter, R.

    1999-01-01

    In a prospective study on 20 subsequent patients with primary cervical carcinoma in Stages I to III simulator planning of a 4-field box-technique was performed. After defining the planning target volume (PTV) in the 3D planning system the field configuration of the simulator planning was transmitted. The resulting plan was compared to a second one based on the defined PTV and evaluated regarding a possible geographical miss and encompassment of the PTV by the treated volume (ICRU). Volumes of open and shaped portals were calculated for both techniques. Planning by simulation resulted in 1 geographical miss and in 10 more cases the encompassment of the PTV by the treated volume was inadequate. For a PTV of mean 1 729 cm 3 the mean volume defined by simulation was 3 120 cm 3 for the open portals and 2 702 cm 3 for the shaped portals. The volume reduction by blocks was 13,4% (mean). With CT-based 3D treatment planning the volume of the open portals was 3,3% (mean) enlarged to 3 224 cm 3 . The resulting mean volume of the shaped portals was 2 458 ccm. The reduction compared to the open portals was 23,8% (mean). The treated volumes were 244 cm 3 or 9% (mean) smaller compared to simulator planning. The 'treated volume/planning target volume ratio' was decreased from 1.59 to 1.42. (orig.) [de

  4. A Phase II Comparative Study of Gross Tumor Volume Definition With or Without PET/CT Fusion in Dosimetric Planning for Non–Small-Cell Lung Cancer (NSCLC): Primary Analysis of Radiation Therapy Oncology Group (RTOG) 0515

    International Nuclear Information System (INIS)

    Bradley, Jeffrey; Bae, Kyounghwa; Choi, Noah; Forster, Ken; Siegel, Barry A.; Brunetti, Jacqueline; Purdy, James; Faria, Sergio; Vu, Toni; Thorstad, Wade; Choy, Hak

    2012-01-01

    Background: Radiation Therapy Oncology Group (RTOG) 0515 is a Phase II prospective trial designed to quantify the impact of positron emission tomography (PET)/computed tomography (CT) compared with CT alone on radiation treatment plans (RTPs) and to determine the rate of elective nodal failure for PET/CT-derived volumes. Methods: Each enrolled patient underwent definitive radiation therapy for non–small-cell lung cancer (≥60 Gy) and had two RTP datasets generated: gross tumor volume (GTV) derived with CT alone and with PET/CT. Patients received treatment using the PET/CT-derived plan. The primary end point, the impact of PET/CT fusion on treatment plans was measured by differences of the following variables for each patient: GTV, number of involved nodes, nodal station, mean lung dose (MLD), volume of lung exceeding 20 Gy (V20), and mean esophageal dose (MED). Regional failure rate was a secondary end point. The nonparametric Wilcoxon matched-pairs signed-ranks test was used with Bonferroni adjustment for an overall significance level of 0.05. Results: RTOG 0515 accrued 52 patients, 47 of whom are evaluable. The follow-up time for all patients is 12.9 months (2.7–22.2). Tumor staging was as follows: II = 6%; IIIA = 40%; and IIIB = 54%. The GTV was statistically significantly smaller for PET/CT-derived volumes (98.7 vs. 86.2 mL; p < 0.0001). MLDs for PET/CT plans were slightly lower (19 vs. 17.8 Gy; p = 0.06). There was no significant difference in the number of involved nodes (2.1 vs. 2.4), V20 (32% vs. 30.8%), or MED (28.7 vs. 27.1 Gy). Nodal contours were altered by PET/CT for 51% of patients. One patient (2%) has developed an elective nodal failure. Conclusions: PET/CT-derived tumor volumes were smaller than those derived by CT alone. PET/CT changed nodal GTV contours in 51% of patients. The elective nodal failure rate for GTVs derived by PET/CT is quite low, supporting the RTOG standard of limiting the target volume to the primary tumor and involved nodes.

  5. National Waste Terminal Storage Program: planning and control plan. Volume II. Plan description

    International Nuclear Information System (INIS)

    1977-05-01

    Objective of the NWTS program planning and control plan is to provide the information necessary for timely and effective OWI management decisions. Purpose is to describe the concepts and techniques that will be utilized by OWI to establish structured, completely planned and controlled technical, cost, and schedule NWTS baselines from which performance or progress can be accurately measured

  6. Adaptive brachytherapy of cervical cancer, comparison of conventional point A and CT based individual treatment planning

    International Nuclear Information System (INIS)

    Wanderaas, Anne D.; Langdal, Ingrid; Danielsen, Signe; Frykholm, Gunilla; Marthinsen, Anne B. L; Sundset, Marit

    2012-01-01

    Background. Locally advanced cervical cancer is commonly treated with external radiation therapy combined with local brachytherapy. The brachytherapy is traditionally given based on standard dose planning with prescription of dose to point A. Dosimetric aspects when changing from former standard treatment to individualized treatment plans based on computed tomography (CT) images are here investigated. Material and methods. Brachytherapy data from 19 patients with a total of 72 individual treatment fractions were retrospectively reviewed. Standard library plans were analyzed with respect to doses to organs at risk (OARs), and the result was compared to corresponding delivered individualized plans. The theoretical potential of further optimization based on prescription to target volumes was investigated. The treatments were performed with a Fletcher applicator. Results. For standard treatment planning, the tolerance dose limits were exceeded in the bladder, rectum and sigmoid in 26%, 4% and 15% of the plans, respectively. This was observed most often for the smallest target volumes. The individualized planning of the delivered treatment gave the possibility of controlling the dose to critical organs to below certain limits. The dose was still prescribed to point A. An increase in target dose coverage was achieved when additional individual optimization was performed, while still keeping the dose to the OARs below predefined limits. Relatively low average target coverage, especially for the largest volumes was however seen. Conclusion. The individualized delivered treatment plans ensured that doses to OARs were within acceptable limits. This was not the case in 42% of the corresponding standard plans. Further optimized treatment plans were found to give an overall better dose coverage. In lack of MR capacity, it may be favorable to use CT for planning due to possible protection of OARs. The CT based target volumes were, however, not equivalent to the volumes described

  7. The incidence of inclusion of the sigmoid colon and small bowel in the planning target volume in radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Meerleer, G.O. de; Vakaet, L.; Neve, W.J. de; Villeirs, G.M.; Delrue, L.J.

    2004-01-01

    Background and purpose: in radiotherapy for prostate cancer, the rectum is considered the dose-limiting organ. The incidence of overlap between the sigmoid colon and/or small bowel and the planning target volume (PTV) as well as the dose to sigmoid colon and small bowel were investigated. Patients and methods: the CT data of 75 prostate cancer patients were analyzed. The clinical target volume (CTV) consisted of prostate and seminal vesicles. The PTV was defined as a three-dimensional expansion of the CTV with a 10-mm margin in craniocaudal and a 7-mm margin in the other directions. All patients were planned to a mean CTV dose of at least 76 Gy. Minimum CTV dose was set at 70 Gy. Dose inhomogeneity within the CTV was kept between 12% and 17%. Sigmoid colon was defined upward from the level where the rectum turned in a transverse plane. Contrast-filled small bowel was contoured on all slices where it was visible. The presence of sigmoid colon and/or small bowel in close vicinity to or overlapping with the PTV was recorded. For each case, the dose to the sigmoid colon and small bowel was calculated. Results: the PTV was found to overlap with the sigmoid colon in 60% and with the small bowel in 19% of the cases. In these patients, mean maximum dose to the sigmoid colon was 76.2 Gy (5th-95th percentile: 70.0-80.7 Gy). Mean maximum dose to the small bowel was 74.9 Gy (5th-95th percentile: 68.0-80.0 Gy). Conclusion: when systematically investigating the anatomic position of sigmoid colon and small bowel in patients accepted for prostate irradiation, parts of both organs were often observed in close vicinity to the PTV. Apart from the rectum, these organs may be dose-limiting in prostate radiotherapy. (orig.)

  8. The incidence of inclusion of the sigmoid colon and small bowel in the planning target volume in radiotherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Meerleer, G.O. de; Vakaet, L.; Neve, W.J. de [Dept. of Radiation Oncology, Gent Univ. Hospital, Gent (Belgium); Villeirs, G.M.; Delrue, L.J. [Dept. of Radiology, Gent Univ. Hospital, Gent (Belgium)

    2004-09-01

    Background and purpose: in radiotherapy for prostate cancer, the rectum is considered the dose-limiting organ. The incidence of overlap between the sigmoid colon and/or small bowel and the planning target volume (PTV) as well as the dose to sigmoid colon and small bowel were investigated. Patients and methods: the CT data of 75 prostate cancer patients were analyzed. The clinical target volume (CTV) consisted of prostate and seminal vesicles. The PTV was defined as a three-dimensional expansion of the CTV with a 10-mm margin in craniocaudal and a 7-mm margin in the other directions. All patients were planned to a mean CTV dose of at least 76 Gy. Minimum CTV dose was set at 70 Gy. Dose inhomogeneity within the CTV was kept between 12% and 17%. Sigmoid colon was defined upward from the level where the rectum turned in a transverse plane. Contrast-filled small bowel was contoured on all slices where it was visible. The presence of sigmoid colon and/or small bowel in close vicinity to or overlapping with the PTV was recorded. For each case, the dose to the sigmoid colon and small bowel was calculated. Results: the PTV was found to overlap with the sigmoid colon in 60% and with the small bowel in 19% of the cases. In these patients, mean maximum dose to the sigmoid colon was 76.2 Gy (5th-95th percentile: 70.0-80.7 Gy). Mean maximum dose to the small bowel was 74.9 Gy (5th-95th percentile: 68.0-80.0 Gy). Conclusion: when systematically investigating the anatomic position of sigmoid colon and small bowel in patients accepted for prostate irradiation, parts of both organs were often observed in close vicinity to the PTV. Apart from the rectum, these organs may be dose-limiting in prostate radiotherapy. (orig.)

  9. Towards the elimination of Monte Carlo statistical fluctuation from dose volume histograms for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Sempau, J.; Bielajew, A.F.

    2000-01-01

    The Monte Carlo calculation of dose for radiotherapy treatment planning purposes introduces unavoidable statistical noise into the prediction of dose in a given volume element (voxel). When the doses in these voxels are summed to produce dose volume histograms (DVHs), this noise translates into a broadening of differential DVHs and correspondingly flatter DVHs. A brute force approach would entail calculating dose for long periods of time - enough to ensure that the DVHs had converged. In this paper we introduce an approach for deconvolving the statistical noise from DVHs, thereby obtaining estimates for converged DVHs obtained about 100 times faster than the brute force approach described above. There are two important implications of this work: (a) decisions based upon DVHs may be made much more economically using the new approach and (b) inverse treatment planning or optimization methods may employ Monte Carlo dose calculations at all stages of the iterative procedure since the prohibitive cost of Monte Carlo calculations at the intermediate calculation steps can be practically eliminated. (author)

  10. Comparison of planning target volumes based on three-dimensional and four-dimensional CT imaging of thoracic esophageal cancer

    Directory of Open Access Journals (Sweden)

    Wang W

    2016-08-01

    Full Text Available Wei Wang, Jianbin Li, Yingjie Zhang, Qian Shao, Min Xu, Tingyong Fan, Jinzhi Wang Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong Academy of Medical Sciences, Shandong, People’s Republic of China Background and purpose: To investigate the definition of planning target volumes (PTVs based on four-dimensional computed tomography (4DCT compared with conventional PTV definition and PTV definition using asymmetrical margins for thoracic primary esophageal cancer. Materials and methods: Forty-three patients with esophageal cancer underwent 3DCT and 4DCT simulation scans during free breathing. The motions of primary tumors located in the proximal (group A, middle (group B, and distal (group C thoracic esophagus were obtained from the 4DCT scans. PTV3D was defined on 3DCT using the tumor motion measured based on 4DCT, PTV conventional (PTVconv was defined on 3DCT by adding a 1.0 cm margin to the clinical target volume, and PTV4D was defined as the union of the target volumes contoured on the ten phases of the 4DCT images. The centroid positions, volumetric differences, and dice similarity coefficients were evaluated for all PTVs. Results: The median centroid shifts between PTV3D and PTV4D and between PTVconv and PTV4D in all three dimensions were <0.3 cm for the three groups. The median size ratios of PTV4D to PTV3D were 0.80, 0.88, and 0.71, and PTV4D to PTVconv were 0.67, 0.73, and 0.76 (χ2=–3.18, –2.98, and –3.06; P=0.001, 0.003, and 0.002 for groups A, B, and C, respectively. The dice similarity coefficients were 0.87, 0.90, and 0.81 between PTV4D and PTV3D and 0.80, 0.84, and 0.83 between PTV4D and PTVconv (χ2=–3.18, –2.98, and –3.06; P=0.001, 0.003, and 0.002 for groups A, B, and C, respectively. The difference between the degree of inclusion of PTV4D in PTV3D and that of PTV4D in PTVconv was <2% for all groups. Compared with PTVconv, the amount of irradiated normal tissue

  11. Proton therapy of uveal melanomas. Intercomparison of MRI-based and conventional treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Marnitz, S.; Hinkelbein, W. [Dept. of Radiooncology, Charite Univ. Medicine, Berlin (Germany); Cordini, D.; Heufelder, J.; Simiantonakis, I.; Kluge, H. [Eye Tumor Therapy, Hahn-Meitner Inst., Berlin (Germany); Bendl, R. [Dept. of Medical Physics, German Cancer Research Center (DKFZ), Heidelberg (Germany); Lemke, A.J. [Dept. of Diagnostic Radiology, Charite Univ. Medicine, Berlin (Germany); Bechrakis, N.E.; Foerster, M.H. [Dept. of Ophthalmology, Charite Univ. Medicine, Berlin (Germany)

    2006-07-15

    Background and purpose: proton therapy for uveal melanoma provides high-conformal dose application to the target volume and, thus, an optimal saving of the organs at risk nearby. Treatment planning is done with the model-based treatment-planning system eyeplan. Tumor reconstruction is based only on a fundus composite, which often leads to an overestimation of the clinical target volume (CTV). The purpose was to exploit MRI on trial in a proton therapy-planning system by using the novel image-based treatment-planning system octopus. Patients and methods: ten patients with uveal melanomas received both a high-resolution planning CT and MRI of the eye. MR examinations were made with an eye coil. Eyeplan requires eye geometry data for modeling, and tantalum marker clips for submillimeter positioning and additional information from ultrasound and 3-D imaging. By contrast, octopus provides the full integration of 3-D imaging (e.g., CT, MRI). CTVs were delineated in each slice. For all patients, CTVs (eyeplan vs. octopus) were compared intraindividually. Results: octopus planning led to a mean reduction of the target volume by a factor of 1.7 (T1-weighted [T1w]) and 2.2 (T2w) without compromising safety. The corresponding field size could be scaled down on average by a factor of 1.2 (T1w) and 1.4 (T2w), respectively. Conclusion: compared with the conventional eyeplan, MRI-based treatment planning of ocular tumors with octopus could be a powerful tool for reducing the CTV and, consequently, the treatment volume and the field size. This might be translated into a better patient compliance during treatment and a decreased late toxicity. (orig.)

  12. Proton therapy of uveal melanomas. Intercomparison of MRI-based and conventional treatment planning

    International Nuclear Information System (INIS)

    Marnitz, S.; Hinkelbein, W.; Cordini, D.; Heufelder, J.; Simiantonakis, I.; Kluge, H.; Bendl, R.; Lemke, A.J.; Bechrakis, N.E.; Foerster, M.H.

    2006-01-01

    Background and purpose: proton therapy for uveal melanoma provides high-conformal dose application to the target volume and, thus, an optimal saving of the organs at risk nearby. Treatment planning is done with the model-based treatment-planning system eyeplan. Tumor reconstruction is based only on a fundus composite, which often leads to an overestimation of the clinical target volume (CTV). The purpose was to exploit MRI on trial in a proton therapy-planning system by using the novel image-based treatment-planning system octopus. Patients and methods: ten patients with uveal melanomas received both a high-resolution planning CT and MRI of the eye. MR examinations were made with an eye coil. Eyeplan requires eye geometry data for modeling, and tantalum marker clips for submillimeter positioning and additional information from ultrasound and 3-D imaging. By contrast, octopus provides the full integration of 3-D imaging (e.g., CT, MRI). CTVs were delineated in each slice. For all patients, CTVs (eyeplan vs. octopus) were compared intraindividually. Results: octopus planning led to a mean reduction of the target volume by a factor of 1.7 (T1-weighted [T1w]) and 2.2 (T2w) without compromising safety. The corresponding field size could be scaled down on average by a factor of 1.2 (T1w) and 1.4 (T2w), respectively. Conclusion: compared with the conventional eyeplan, MRI-based treatment planning of ocular tumors with octopus could be a powerful tool for reducing the CTV and, consequently, the treatment volume and the field size. This might be translated into a better patient compliance during treatment and a decreased late toxicity. (orig.)

  13. ICPP calcined solids storage facility closure study. Volume II: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

    International Nuclear Information System (INIS)

    1998-02-01

    This document contains Volume II of the Closure Study for the Idaho Chemical Processing Plant Calcined Solids Storage Facility. This volume contains draft information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the four options described in Volume I: (1) Risk-Based Clean Closure; NRC Class C fill, (2) Risk-Based Clean Closure; Clean fill, (3) Closure to landfill Standards; NRC Class C fill, and (4) Closure to Landfill Standards; Clean fill

  14. ICPP calcined solids storage facility closure study. Volume II: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This document contains Volume II of the Closure Study for the Idaho Chemical Processing Plant Calcined Solids Storage Facility. This volume contains draft information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the four options described in Volume I: (1) Risk-Based Clean Closure; NRC Class C fill, (2) Risk-Based Clean Closure; Clean fill, (3) Closure to landfill Standards; NRC Class C fill, and (4) Closure to Landfill Standards; Clean fill.

  15. Comparison of CT based-CTV plan and CT based-ICRU38 plan in brachytherapy planning of uterine cervix cancer

    International Nuclear Information System (INIS)

    Shim, Jin Sup; Jo, Jung Kun; Si, Chang Keun; Lee, Ki Ho; Lee, Du Hyun; Choi, Kye Suk

    2004-01-01

    Although Improve of CT, MRI Radio-diagnosis and Radiation Therapy Planing, but we still use ICRU38 Planning system(2D film-based) broadly. 3-Dimensional ICR plan(CT image based) is not only offer tumor and normal tissue dose but also support DVH information. On this study, we plan irradiation-goal dose on CTV(CTV plan) and irradiation-goal dose on ICRU 38 point(ICRU38 plan) by use CT image. And compare with tumor-dose, rectal-dose, bladder-dose on both planning, and analysis DVH Sample 11 patients who treated by Ir-192 HDR. After 40 Gy external radiation therapy, ICR plan established. All the patients carry out CT-image scanned by CT-simulator. And we use PLATO(Nucletron) v.14.2 planing system. We draw CTV, rectum, bladder on the CT image. And establish plan irradiation- dose on CTV(CTV plan) and irradiation- dose on A-point(ICRU38 plan) CTV volume(average±SD) is 21.8±26.6 cm 3 , rectum volume(average±SD) is 60.9±25.0 cm 3 , bladder volume(average±SD) is 116.1±40.1cm 3 sampled 11 patients. The volume including 100% dose is 126.7±18.9 cm 3 on ICRU plan and 98.2±74.5 cm 3 on CTV plan. On ICRU planning, the other one's 22.0 cm 3 CTV volume who residual tumor size excess 4cm is not including 100% isodose. 8 patient's 12.9±5.9 cm 3 tumor volume who residual tumor size below 4 cm irradiated 100% dose. Bladder dose(recommended by ICRU 38) is 90.1±21.3 % on ICRU plan, 68.7±26.6% on CTV plan, and rectal dose is 86.4±18.3%, 76.9±15.6%. Bladder and Rectum maximum dose is 137.2±5.9%, 101.1±41.8% on ICRU plan, 107.6±47.9%, 86.9±30.8% on CTV plan. Therefore CTV plan more less normal issue-irradiated dose than ICRU plan. But one patient case who residual tumor size excess 4 cm, Normal tissue dose more higher than critical dose remarkably on CTV plan. 80% over-Irradiated rectal dose(V80rec) is 1.8±2.4 cm 3 on ICRU plan, 0.7±1.0 cm 3 on CTV plan. 80% over-Irradiated bladder dose(V80bla) is 12.2%±8.9 cm 3 on ICRU plan, 3.5±4.1 cm 3 on CTV plan. Likewise, CTV

  16. Effect of 3D radiotherapy planning compared to 2D planning within a conventional treatment schedule of advanced lung cancer

    International Nuclear Information System (INIS)

    Schraube, P.; Spahn, U.; Oetzel, D.; Wannenmacher, M.

    2000-01-01

    Background: The effect of 3D radiotherapy planning (3D RTP) in comparison to 2D radiotherapy planning (2D RTP) was evaluated in a usually practiced treatment schedule (starting by v./d. opposing portals, continued with computer-planned portals) for non-small-cell lung cancer. Patients and Methods: In 20 patients with locally advanced non-small-cell lung cancer the computer-planned part of the treatment schedule was calculated 2- and 3-dimensionally. Target volume were the primary tumor, the involved and the electively irradiated mediastinal lymph nodes. The results of the 2D RTP were recalculated 3-dimensionally and the mean doses to target volume and organs at risk were defined. Further, the normal tissue complications were calculated. Results: Under the prerequisite of 44 Gy maximally allowed to the spinal cord and a dose to the reference point of 50 Gy a small, but significant advantage with 2.1 Gy to the target (p=0.004) and a reduction of 3.6 Gy to the heart (p=0.05) was achievable for 3D RTP. The dose to the lungs did not differ significantly (19.7 Gy for 2D RTP, 20.3 Gy for 3D RTP). The dose to the heart was not estimated critical by NTCP (normal tissue complication probability). The NTCP for the ipsilateral lung was 16.1 and 18.7% for 2D RTP and 3D RTP, respectively. Regarding the simulator-planned ap/pa fields at the start of the radiotherapy the advantage of 3D RTP was further reduced but remained significant. Favorable with respect to the mean lung dose and the NTCP (18.7% NTCP ipsilateral lung for early onset of 3D planned radiotherapy vs 31.7% for late onset of 3D planned radiotherapy) but not significantly measurable is the early start of the treatment by computerized RTP. Conclusion: The main advantage of 3D RTP in treatment of advanced lung cancer is the better coverage of the target volume. A reduction of the mean lung dose cannot be expected. A dose escalation by 3D RTP to target volumes as described here seems not to be possible because of

  17. SU-F-T-150: Comparing Normal Tissue Irradiated Volumes for Proton Vs. Photon Treatment Plans On Lung Patients

    Energy Technology Data Exchange (ETDEWEB)

    Liu, A; Mohan, R; Liao, Z [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: The aim of this work is to compare the “irradiated volume” (IRV) of normal tissues receiving 5, 20, 50, 80 and 90% or higher of the prescription dose with passively scattered proton therapy (PSPT) vs. IMRT of lung cancer patients. The overall goal of this research is to understand the factors affecting outcomes of a randomized PSPT vs. IMRT lung trial. Methods: Thirteen lung cancer patients, selected randomly, were analyzed. Each patient had PSPT and IMRT 74 Gy (RBE) plans meeting the same normal tissue constraints generated. IRVs were created for pairs of IMRT and PSPT plans on each patient. The volume of iGTV, (respiratory motion-incorporated GTV) was subtracted from each IRV to create normal tissue irradiated volume IRVNT. The average of IRVNT DVHs over all patients was also calculated for both modalities and inter-compared as were the selected dose-volume indices. Probability (p value) curves were calculated based on the Wilcoxon matched-paired signed-rank test to determine the dose regions where the statistically significant differences existed. Results: As expected, the average 5, 20 and 50% IRVNT’s for PSPT was found to be significantly smaller than for IMRT (p < 0.001, 0.01, and 0.001 respectively). However, the average 90% IRVNT for PSPT was greater than for IMRT (p = 0.003) presumably due to larger penumbra of protons and the long range of protons in lower density media. The 80% IRVNT for PSPT was also larger but not statistically distinguishable (p = .224). Conclusion: PSPT modality has smaller irradiated volume at lower doses, but larger volume at high doses. A larger cohort of lung patients will be analyzed in the future and IRVNT of patients treated with PSPT and IMRT will be compared to determine if the irradiated volumes (the magnitude of “dose bath”) correlate with outcomes.

  18. Influence of increment of gantry angle and number of arcs on esophageal volumetric modulated arc therapy planning in Monaco planning system: A planning study

    Directory of Open Access Journals (Sweden)

    L Nithya

    2014-01-01

    Full Text Available The objective of this study was to analyze the influence of the increment of gantry angle and the number of arcs on esophageal volumetric modulated arc therapy plan. All plans were done in Monaco planning system for Elekta Synergy linear accelerator with 80 multileaf collimator (MLC. Volumetric modulated arc therapy (VMAT plans were done with different increment of gantry angle like 15 o , 20 o , 30 o and 40 o . The remaining parameters were similar for all the plans. The results were compared. To compare the plan quality with number of arcs, VMAT plans were done with single and dual arc with increment of gantry angle of 20 o . The dose to gross tumor volume (GTV for 60 Gy and planning target volume (PTV for 48 Gy was compared. The dosimetric parameters D 98% , D 95% , D 50% and D max of GTV were analyzed. The homogeneity index (HI and conformity index (CI of GTV were studied and the dose to 98% and 95% of PTV was analyzed. Maximum dose to spinal cord and planning risk volume of cord (PRV cord was compared. The Volume of lung receiving 10 Gy, 20 Gy and mean dose was analyzed. The volume of heart receiving 30 Gy and 45 Gy was compared. The volume of normal tissue receiving greater than 2 Gy and 5 Gy was compared. The number of monitor units (MU required to deliver the plans were compared. The plan with larger increment of gantry angle proved to be superior to smaller increment of gantry angle plans in terms of dose coverage, HI, CI and normal tissue sparing. The number of arcs did not make any difference in the quality of the plan.

  19. Adaptive radiotherapy in muscle invasive urinary bladder cancer - An effective method to reduce the irradiated bowel volume

    International Nuclear Information System (INIS)

    Tuomikoski, Laura; Collan, Juhani; Keyrilaeinen, Jani; Visapaeae, Harri; Saarilahti, Kauko; Tenhunen, Mikko

    2011-01-01

    Background and purpose: To evaluate the benefits of adaptive radiotherapy for bladder cancer in decreasing irradiation of small bowel. Material and methods: Five patients with muscle invasive bladder cancer received adaptive radiotherapy to a total dose of 55.8-65 Gy with daily cone-beam computed tomography scanning. The whole bladder was treated to 45-50.4 Gy, followed by a partial bladder boost. The plan of the day was chosen from 3 to 4 pre-planned treatment plans according to the visible extent of bladder wall in cone-beam computed tomography images. Dose volume histograms for intestinal cavity volumes were constructed and compared with corresponding histograms calculated for conventional non-adaptive radiotherapy with single treatment plan of 2 cm CTV-PTV margins. CTV dose coverage in adaptive treatment technique was compared with CTV dose coverage in conventional radiotherapy. Results: The average volume of intestinal cavity receiving ≥45 Gy was reduced from 335 ± 106 cm 3 to 180 ± 113 cm 3 (1SD). The maximum volume of intestinal cavity spared at 45 Gy on a single patient was 240 cm 3 , while the minimum volume was 65 cm 3 . The corresponding reduction in average intestinal cavity volume receiving ≥45 Gy calculated for the whole bladder treatment only was 66 ± 36 cm 3 . CTV dose coverage was improved on two out of five patients and decreased on three patients. Conclusions: Adaptive radiotherapy considerably reduces dose to the small bowel, while maintaining the dose coverage of CTV at similar level when compared to the conventional treatment technique.

  20. The incorporation of SPECT functional lung imaging into inverse radiotherapy planning for non-small cell lung cancer

    International Nuclear Information System (INIS)

    Christian, Judith A.; Partridge, Mike; Nioutsikou, Elena; Cook, Gary; McNair, Helen A.; Cronin, Bernadette; Courbon, Frederic; Bedford, James L.; Brada, Michael

    2005-01-01

    Background and purpose: Patients with non-small cell lung cancer (NSCLC) often have inhomogeneous lung perfusion. Radiotherapy planning computed tomography (CT) scans have been accurately co-registered with lung perfusion single photon emission computed tomography (SPECT) scans to design radiotherapy treatments which limit dose to healthy 'perfused' lung. Patients and methods: Patients with localised NSCLC had CT and SPECT scans accurately co-registered in the planning system. The SPECT images were used to define a volume of perfused 'functioning' lung (FL). Inverse planning software was used to create 3D-conformal plans, the planning objective being either to minimise the dose to whole lungs (WL) or to minimise the dose to FL. Results: Four plans were created for each of six patients. The mean difference in volume between WL and FL was 1011.7 cm 3 (range 596.2-1581.1 cm 3 ). One patient with bilateral upper lobe perfusion deficits had a 16% reduction in FLV 2 (the percentage volume of functioning lung receiving ≥20 Gy). The remaining patients had inhomogeneous perfusion deficits such that inverse planning was not able to sufficiently optimise beam angles to avoid functioning lung. Conclusion: SPECT perfusion images can be accurately co-registered with radiotherapy planning CT scans and may be helpful in creating treatment plans for patients with large perfusion deficits

  1. Development of whole-building energy design targets for commercial buildings: Phase 1, Planning: Volume 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crawley, D.B.; Briggs, R.S.; Jones, J.W.; Seaton, W.W.; Kaufman, J.E.; Deringer, J.J.; Kennett, E.W.

    1987-04-01

    This report describes background research for preparation of a plan for development of whole-building energy targets for new commercial buildings. The lead laboratory for this program is the Pacific Northwest Laboratory. A wide variety of expertise and resources from industry, academia, other government entities, and other DOE laboratories are used in planning, reviewing and conducting research activities. Cooperative and complementary research development, and technology transfer activities with other interested organizations are actively pursued.

  2. A method to combine target volume data from 3D and 4D planned thoracic radiotherapy patient cohorts for machine learning applications

    NARCIS (Netherlands)

    Johnson, Corinne; Price, Gareth; Khalifa, Jonathan; Faivre-Finn, Corinne; Dekker, Andre; Moore, Christopher; van Herk, Marcel

    2017-01-01

    The gross tumour volume (GTV) is predictive of clinical outcome and consequently features in many machine-learned models. 4D-planning, however, has prompted substitution of the GTV with the internal gross target volume (iGTV). We present and validate a method to synthesise GTV data from the iGTV,

  3. Acute small bowel toxicity and preoperative chemoradiotherapy for rectal cancer: Investigating dose-volume relationships and role for inverse planning

    International Nuclear Information System (INIS)

    Tho, Lye Mun; Glegg, Martin; Paterson, Jennifer; Yap, Christina; MacLeod, Alice; McCabe, Marie; McDonald, Alexander C.

    2006-01-01

    Purpose: The relationship between volume of irradiated small bowel (VSB) and acute toxicity in rectal cancer radiotherapy is poorly quantified, particularly in patients receiving concurrent preoperative chemoradiotherapy. Using treatment planning data, we studied a series of such patients. Methods and Materials: Details of 41 patients with locally advanced rectal cancer were reviewed. All received 45 Gy in 25 fractions over 5 weeks, 3-4 fields three-dimensional conformal radiotherapy with daily 5-fluorouracil and folinic acid during Weeks 1 and 5. Toxicity was assessed prospectively in a weekly clinic. Using computed tomography planning software, the VSB was determined at 5 Gy dose intervals (V 5 , V 1 , etc.). Eight patients with maximal VSB had dosimetry and radiobiological modeling outcomes compared between inverse and conformal three-dimensional planning. Results: VSB correlated strongly with diarrheal severity at every dose level (p 5 and V 15 . Conclusions: A strong dose-volume relationship exists between VSB and acute diarrhea at all dose levels during preoperative chemoradiotherapy. Our constructed model may be useful in predicting toxicity, and this has been derived without the confounding influence of surgical excision on bowel function. Inverse planning can reduce calculated dose to small bowel and late NTCP, and its clinical role warrants further investigation

  4. An interactive tool for CT volume rendering and sagittal plane-picking of the prostate for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Jani, Ashesh B.; Pelizzari, Charles A.; Chen, George T.Y.; Grzezcszuk, Robert P.; Vijayakumar, Srinivasan

    1997-01-01

    Objective: Accurate and precise target volume and critical structure definition is a basic necessity in radiotherapy. The prostate, particularly the apex (an important potential site of recurrence in prostate cancer patients), is a challenging structure to define using any modality, including conventional axial CT. Invasive or expensive techniques, such as retrograde urethrography or MRI, could be avoided if localization of the prostate were possible using information already available on the planning CT. Our primary objective was to build a software tool to determine whether volume rendering and sagittal plane-picking, which are CT-based, noninvasive visualization techniques, were of utility in radiotherapy treatment planning for the prostate. Methods: Using AVS (Application Visualization System) on a Silicon Graphics Indigo 2 High Impact workstation, we have developed a tool that enables the clinician to efficiently navigate a CT volume and to use volume rendering and sagittal plane-picking to better define structures at any anatomic site. We applied the tool to the specific example of the prostate to compare the two visualization techniques with the current standard of axial CT. The prostate was defined on 80-slice CT scans (scanning thickness 4mm, pixel size 2mm x 2mm) of prostate cancer patients using axial CT images, volume-rendered CT images, and sagittal plane-picked images. Results: The navigation of the prostate using the different visualization techniques qualitatively demonstrated that the sagittal plane-picked images, and even more so the volume-rendered images, revealed the prostate (particularly the lower border) better in relationship to the surrounding regional anatomy (bladder, rectum, pelvis, and penile structures) than did the axial images. A quantitative comparison of the target volumes obtained by navigating using the different visualization techniques demonstrated that, when compared to the prostate volume defined on axial CT, a larger volume

  5. 3D-segmentation of the 18F-choline PET signal for target volume definition in radiation therapy of the prostate.

    Science.gov (United States)

    Ciernik, I Frank; Brown, Derek W; Schmid, Daniel; Hany, Thomas; Egli, Peter; Davis, J Bernard

    2007-02-01

    Volumetric assessment of PET signals becomes increasingly relevant for radiotherapy (RT) planning. Here, we investigate the utility of 18F-choline PET signals to serve as a structure for semi-automatic segmentation for forward treatment planning of prostate cancer. 18F-choline PET and CT scans of ten patients with histologically proven prostate cancer without extracapsular growth were acquired using a combined PET/CT scanner. Target volumes were manually delineated on CT images using standard software. Volumes were also obtained from 18F-choline PET images using an asymmetrical segmentation algorithm. PTVs were derived from CT 18F-choline PET based clinical target volumes (CTVs) by automatic expansion and comparative planning was performed. As a read-out for dose given to non-target structures, dose to the rectal wall was assessed. Planning target volumes (PTVs) derived from CT and 18F-choline PET yielded comparable results. Optimal matching of CT and 18F-choline PET derived volumes in the lateral and cranial-caudal directions was obtained using a background-subtracted signal thresholds of 23.0+/-2.6%. In antero-posterior direction, where adaptation compensating for rectal signal overflow was required, optimal matching was achieved with a threshold of 49.5+/-4.6%. 3D-conformal planning with CT or 18F-choline PET resulted in comparable doses to the rectal wall. Choline PET signals of the prostate provide adequate spatial information amendable to standardized asymmetrical region growing algorithms for PET-based target volume definition for external beam RT.

  6. Comparison between dose values specified at the ICRU reference point and the mean dose to the planning target volume

    International Nuclear Information System (INIS)

    Kukoowicz, Pawel F.; Mijnheer, Bernard J.

    1997-01-01

    Background and purpose: To compare dose values specified at the reference point, as recommended by the International Commission on Radiation Units and Measurements, ICRU, and the mean dose to the planning target volume, PTV. Material and methods: CT-based dose calculations were performed with a 3-D treatment planning system for 6 series of patients treated for bladder, brain, breast, lung, oropharynx and parotid gland tumour. All patients were arbitrarily chosen from a set of previously treated patients irradiated with a two- or three-field technique using customised blocks. Appropriate wedge angles and beam weights were chosen to make the dose distribution as homogeneous as possible. Results: The dose at the ICRU reference point was generally higher than the mean dose to the PTV. The difference between the ICRU reference dose and the mean dose to the PTV for an individual patient was less than 3% in 88% of cases and less than 2% in 72% of the cases. The differences were larger in those patients where the dose distribution is significantly influenced by the presence of lungs or air gaps. For each series of patients the mean difference between the ICRU reference dose and the mean dose to the PTV was calculated. The difference between these two values never exceeded 2%. Because not all planning systems are able to calculate the mean dose to the PTV, the concept of the mean central dose, the mean of the dose values at the centre of the PTV in each CT slice, has been introduced. The mean central dose was also calculated for the same patients and was closer to the mean dose to the PTV than the ICRU reference dose. Conclusion: The mean dose to the PTV is well estimated by either the ICRU reference dose or the mean central dose for a variety of treatment techniques for common types of cancer

  7. Sequentially delivered boost plans are superior to simultaneously delivered plans in head and neck cancer when the boost volume is located further away from the parotid glands

    International Nuclear Information System (INIS)

    Lamers-Kuijper, Emmy; Heemsbergen, Wilma; Mourik, Anke van; Rasch, Coen

    2011-01-01

    Purpose: To find parameters that predict which head and neck patients benefit from a sequentially delivered boost treatment plan compared to a simultaneously delivered plan, with the aim to spare the salivary glands. Methods and materials: We evaluated 50 recently treated head and neck cancer patients. Apart from the clinical plan with a sequentially (SEQ) given boost using an Intensity Modulated Radiotherapy Technique (IMRT), a simultaneous integrated boost (SIB) technique plan was constructed with the same beam set-up. The mean dose to the parotid glands was calculated and compared. The elective nodal areas were bilateral in all cases, with a boost on either one side or both sides of the neck. Results: When the parotid gland volume and the Planning Target Volume (PTV) for the boost overlap there is on average a lower dose to the parotid gland with a SIB technique (-1.2 Gy), which is, however, not significant (p = 0.08). For all parotid glands with no boost PTV overlap, there is a benefit from a SEQ technique compared to a SIB technique for the gland evaluated (on average a 2.5 Gy lower dose to the parotid gland, p < 0.001). When the distance between gland and PTV is 0-1 cm, this difference is on average 0.8 Gy, for 1-2 cm distance 2.9 Gy and for glands with a distance greater than 2 cm, 3.3 Gy. When the lymph nodes on the evaluated side are also included in the boost PTV, however, this relationship between the distance and the gain of a SEQ seems less clear. Conclusions: A sequentially delivered boost technique results in a better treatment plan for most cases, compared to a simultaneous integrated boost IMRT technique, if the boost PTV is more than 1 cm away from at least one parotid gland.

  8. Methods for Reducing Normal Tissue Complication Probabilities in Oropharyngeal Cancer: Dose Reduction or Planning Target Volume Elimination

    Energy Technology Data Exchange (ETDEWEB)

    Samuels, Stuart E.; Eisbruch, Avraham; Vineberg, Karen; Lee, Jae; Lee, Choonik; Matuszak, Martha M.; Ten Haken, Randall K.; Brock, Kristy K., E-mail: kbrock@med.umich.edu

    2016-11-01

    Purpose: Strategies to reduce the toxicities of head and neck radiation (ie, dysphagia [difficulty swallowing] and xerostomia [dry mouth]) are currently underway. However, the predicted benefit of dose and planning target volume (PTV) reduction strategies is unknown. The purpose of the present study was to compare the normal tissue complication probabilities (NTCP) for swallowing and salivary structures in standard plans (70 Gy [P70]), dose-reduced plans (60 Gy [P60]), and plans eliminating the PTV margin. Methods and Materials: A total of 38 oropharyngeal cancer (OPC) plans were analyzed. Standard organ-sparing volumetric modulated arc therapy plans (P70) were created and then modified by eliminating the PTVs and treating the clinical tumor volumes (CTVs) only (C70) or maintaining the PTV but reducing the dose to 60 Gy (P60). NTCP dose models for the pharyngeal constrictors, glottis/supraglottic larynx, parotid glands (PGs), and submandibular glands (SMGs) were analyzed. The minimal clinically important benefit was defined as a mean change in NTCP of >5%. The P70 NTCP thresholds and overlap percentages of the organs at risk with the PTVs (56-59 Gy, vPTV{sub 56}) were evaluated to identify the predictors for NTCP improvement. Results: With the P60 plans, only the ipsilateral PG (iPG) benefited (23.9% vs 16.2%; P<.01). With the C70 plans, only the iPG (23.9% vs 17.5%; P<.01) and contralateral SMG (cSMG) (NTCP 32.1% vs 22.9%; P<.01) benefited. An iPG NTCP threshold of 20% and 30% predicted NTCP benefits for the P60 and C70 plans, respectively (P<.001). A cSMG NTCP threshold of 30% predicted for an NTCP benefit with the C70 plans (P<.001). Furthermore, for the iPG, a vPTV{sub 56} >13% predicted benefit with P60 (P<.001) and C70 (P=.002). For the cSMG, a vPTV{sub 56} >22% predicted benefit with C70 (P<.01). Conclusions: PTV elimination and dose-reduction lowered the NTCP of the iPG, and PTV elimination lowered the NTCP of the cSMG. NTCP thresholds and the

  9. Impact of 18-fluorodeoxyglucose positron emission tomography on computed tomography defined target volumes in radiation treatment planning of esophageal cancer : reduction in geographic misses with equal inter-observer variability

    NARCIS (Netherlands)

    Schreurs, Liesbeth; Busz, D. M.; Paardekooper, G. M. R. M.; Beukema, J. C.; Jager, P. L.; Van der Jagt, E. J.; van Dam, G. M.; Groen, H.; Plukker, J. Th. M.; Langendijk, J. A.

    P>Target volume definition in modern radiotherapy is based on planning computed tomography (CT). So far, 18-fluorodeoxyglucose positron emission tomography (FDG-PET) has not been included in planning modality in volume definition of esophageal cancer. This study evaluates fusion of FDG-PET and CT in

  10. Standardization of prostate brachytherapy treatment plans

    International Nuclear Information System (INIS)

    Ove, Roger; Wallner, Kent; Badiozamani, Kas; Korjsseon, Tammy; Sutlief, Steven

    2001-01-01

    Purpose: Whereas custom-designed plans are the norm for prostate brachytherapy, the relationship between linear prostate dimensions and volume calls into question the routine need for customized treatment planning. With the goal of streamlining the treatment-planning process, we have compared the treatment margins (TMs) achieved with one standard plan applied to patients with a wide range of prostate volumes. Methods and Materials: Preimplant transrectal ultrasound (TRUS) images of 50 unselected University of Washington patients with T1-T2 cancer and a prostate volume between 20 cc and 50 cc were studied. Patients were arbitrarily grouped into categories of 20-30 cc, 30-40 cc, and 40-50 cc. A standard 19-needle plan was devised for patients in the 30- to 40-cc range, using an arbitrary minimum margin of 5 mm around the gross tumor volume (GTV), making use of inverse planning technology to achieve 100% coverage of the target volume with accentuation of dose at the periphery and sparing of the central region. The idealized plan was applied to each patient's TRUS study. The distances (TMs) between the prostatic edge (GTV) and treated volume (TV) were determined perpendicular to the prostatic margin. Results: Averaged over the entire patient group, the ratio of thickness to width was 1.4, whereas the ratio of length to width was 1.3. These values were fairly constant over the range of volumes, emphasizing that the prostate retains its general shape as volume increases. The idealized standard plan was overlaid on the ultrasound images of the 17 patients in the 30- to 40-cc group and the V100, the percentage of target volume receiving 100% or more of the prescription dose, was 98% or greater for 15 of the 17 patients. The lateral and posterior TMs fell within a narrow range, most being within 2 mm of the idealized 5-mm TM. To estimate whether a 10-cc volume-interval stratification was reasonable, the standard plan generated from the 30- to 40-cc prostate model was

  11. The need for rotational margins in intensity-modulated radiotherapy and a new method for planning target volume design

    International Nuclear Information System (INIS)

    Langer, Mark Peter; Papiez, Lech; Spirydovich, Siarhei; Thai, Van

    2005-01-01

    Purpose: The effect of rotational errors on the coverage of clinical target volumes (CTVs) is examined. A new planning target volume (PTV) construction that considers the individual paths traced by movements of the target boundary points is developed. Methods and Materials: A standard uniform margin expansion was compared with a PTV constructed from the space swept out by a concave moving target. A new method formed the PTV by aggregating the separate convex hulls taken of the positions of the individual target boundary points in a sampling of CTV displacements. Results: A 0.5-cm uniform margin adequate for translations was inadequate given CTV rotation about a fixed off-center axis. A PTV formed of the target's swept-out area was 22% smaller than needed for coverage by a uniform margin, but computationally is not readily extended to translations combined with rotations about a shifting axis. Forming instead the union of convex hulls of the boundary points in a sampling of CTV displacements represented these movements in the PTV design and retained the target's concave shape. Conclusions: Planning target volumes should accommodate target rotation. The union of convex hulls of the boundary point positions in a sampling of displacements can effectively represent multiple sources of deviations while preserving target concavities

  12. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy

    2014-05-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  13. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2014-01-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  14. Reliability of dose volume constraint inference from clinical data

    DEFF Research Database (Denmark)

    Lutz, C M; Møller, D S; Hoffmann, L

    2017-01-01

    Dose volume histogram points (DVHPs) frequently serve as dose constraints in radiotherapy treatment planning. An experiment was designed to investigate the reliability of DVHP inference from clinical data for multiple cohort sizes and complication incidence rates. The experimental background...... was radiation pneumonitis in non-small cell lung cancer and the DVHP inference method was based on logistic regression. From 102 NSCLC real-life dose distributions and a postulated DVHP model, an 'ideal' cohort was generated where the most predictive model was equal to the postulated model. A bootstrap...

  15. Routine Radiological Environmental Monitoring Plan, Volume 2 Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel Nevada

    1998-12-31

    Supporting material for the plan includes: QUALITY ASSURANCE, ANALYSIS, AND SAMPLING PLAN FOR NTS AIR; QUALITY ASSURANCE, ANALYSIS, AND SAMPLING PLAN FOR WATER ON AND OFF THE NEVADA TEST SITE; QUALITY ASSURANCE, ANALYSIS, AND SAMPLING PLAN FOR NTS BIOTA; QUALITY ASSURANCE, ANALYSIS, AND SAMPLING PLAN FOR DIRECT RADIATION MONITORING; DATA QUALITY OBJECTIVES PROCESS; VADOSE ZONE MONITORING PLAN CHECKLIST.

  16. An Analysis of Plan Robustness for Esophageal Tumors: Comparing Volumetric Modulated Arc Therapy Plans and Spot Scanning Proton Planning

    International Nuclear Information System (INIS)

    Warren, Samantha; Partridge, Mike; Bolsi, Alessandra; Lomax, Anthony J.; Hurt, Chris; Crosby, Thomas; Hawkins, Maria A.

    2016-01-01

    Purpose: Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. Methods and Materials: For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV)_5_0_G_y or PTV_6_2_._5_G_y (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose–volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. Results: SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D_9_8 was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D_9_8 was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D_9_8 was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D_9_8 was lower by 0.3% to 2.2% of the prescribed GTV dose. Conclusions: The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup errors and might be

  17. An Analysis of Plan Robustness for Esophageal Tumors: Comparing Volumetric Modulated Arc Therapy Plans and Spot Scanning Proton Planning

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Samantha, E-mail: samantha.warren@oncology.ox.ac.uk [Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford (United Kingdom); Partridge, Mike [Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford (United Kingdom); Bolsi, Alessandra; Lomax, Anthony J. [Centre for Proton Therapy, Paul Scherrer Institute, Villigen (Switzerland); Hurt, Chris [Wales Cancer Trials Unit, School of Medicine, Heath Park, Cardiff (United Kingdom); Crosby, Thomas [Velindre Cancer Centre, Velindre Hospital, Cardiff (United Kingdom); Hawkins, Maria A. [Cancer Research UK/Medical Research Council Oxford Institute for Radiation Oncology, Gray Laboratories, University of Oxford, Oxford (United Kingdom)

    2016-05-01

    Purpose: Planning studies to compare x-ray and proton techniques and to select the most suitable technique for each patient have been hampered by the nonequivalence of several aspects of treatment planning and delivery. A fair comparison should compare similarly advanced delivery techniques from current clinical practice and also assess the robustness of each technique. The present study therefore compared volumetric modulated arc therapy (VMAT) and single-field optimization (SFO) spot scanning proton therapy plans created using a simultaneous integrated boost (SIB) for dose escalation in midesophageal cancer and analyzed the effect of setup and range uncertainties on these plans. Methods and Materials: For 21 patients, SIB plans with a physical dose prescription of 2 Gy or 2.5 Gy/fraction in 25 fractions to planning target volume (PTV){sub 50Gy} or PTV{sub 62.5Gy} (primary tumor with 0.5 cm margins) were created and evaluated for robustness to random setup errors and proton range errors. Dose–volume metrics were compared for the optimal and uncertainty plans, with P<.05 (Wilcoxon) considered significant. Results: SFO reduced the mean lung dose by 51.4% (range 35.1%-76.1%) and the mean heart dose by 40.9% (range 15.0%-57.4%) compared with VMAT. Proton plan robustness to a 3.5% range error was acceptable. For all patients, the clinical target volume D{sub 98} was 95.0% to 100.4% of the prescribed dose and gross tumor volume (GTV) D{sub 98} was 98.8% to 101%. Setup error robustness was patient anatomy dependent, and the potential minimum dose per fraction was always lower with SFO than with VMAT. The clinical target volume D{sub 98} was lower by 0.6% to 7.8% of the prescribed dose, and the GTV D{sub 98} was lower by 0.3% to 2.2% of the prescribed GTV dose. Conclusions: The SFO plans achieved significant sparing of normal tissue compared with the VMAT plans for midesophageal cancer. The target dose coverage in the SIB proton plans was less robust to random setup

  18. Image-guided radiotherapy of bladder cancer: bladder volume variation and its relation to margins

    DEFF Research Database (Denmark)

    Muren, Ludvig; Redpath, Anthony Thomas; Lord, Hannah

    2007-01-01

    : The correlation between the relative bladder volume (RBV, defined as repeat scan volume/planning scan volume) and the margins required to account for internal motion was first studied using a series of 20 bladder cancer patients with weekly repeat CT scanning during treatment. Both conformal RT (CRT) and IGRT......BACKGROUND AND PURPOSE: To control and account for bladder motion is a major challenge in radiotherapy (RT) of bladder cancer. This study investigates the relation between bladder volume variation and margins in conformal and image-guided RT (IGRT) for this disease. MATERIALS AND METHODS...... these patients were given fluid intake restrictions on alternating weeks during treatment. RESULTS: IGRT gave the strongest correlation between the RBV and margin size (R(2)=0.75; p10mm were required in only 1% of the situations when the RBV1, whereas isotropic margins >10...

  19. The application of positron emission tomography/computed tomography in radiation treatment planning: effect on gross target volume definition and treatment management.

    Science.gov (United States)

    Iğdem, S; Alço, G; Ercan, T; Unalan, B; Kara, B; Geceer, G; Akman, C; Zengin, F O; Atilla, S; Okkan, S

    2010-04-01

    To analyse the effect of the use of molecular imaging on gross target volume (GTV) definition and treatment management. Fifty patients with various solid tumours who underwent positron emission tomography (PET)/computed tomography (CT) simulation for radiotherapy planning from 2006 to 2008 were enrolled in this study. First, F-18 fluorodeoxyglucose (FDG)-PET and CT scans of the treatment site in the treatment position and then a whole body scan were carried out with a dedicated PET/CT scanner and fused thereafter. FDG-avid primary tumour and lymph nodes were included into the GTV. A multidisciplinary team defined the target volume, and contouring was carried out by a radiation oncologist using visual methods. To compare the PET/CT-based volumes with CT-based volumes, contours were drawn on CT-only data with the help of site-specific radiologists who were blind to the PET/CT results after a median time of 7 months. In general, our PET/CT volumes were larger than our CT-based volumes. This difference was significant in patients with head and neck cancers. Major changes (> or =25%) in GTV delineation were observed in 44% of patients. In 16% of cases, PET/CT detected incidental second primaries and metastatic disease, changing the treatment strategy from curative to palliative. Integrating functional imaging with FDG-PET/CT into the radiotherapy planning process resulted in major changes in a significant proportion of our patients. An interdisciplinary approach between imaging and radiation oncology departments is essential in defining the target volumes. Copyright 2010 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  20. CT planning of boost irradiation in radiotherapy of breast cancer after conservative surgery

    International Nuclear Information System (INIS)

    Messer, Peter M.; Kirikuta, Ion C.; Bratengeier, Klaus; Flentje, Michael

    1997-01-01

    Background and purpose: A study was performed to compare the accuracy of clinical treatment set-up and CT planning of boost irradiation in radiotherapy of breast cancer. Material and methods: Between September 1993 and October 1994, 45 women who underwent breast conserving surgery and irradiation containing a boost to the tumour bed were investigated. Prospective evaluation of CT planning of the boost was carried out. The target volume/boost field, electron energy and treatment set-up had been defined on the basis of clinical examination, initial and postsurgical mammograms by one radiotherapist. Next, a planning CT was performed in treatment position and a CT-based treatment plan was calculated according to a target volume defined by another radiotherapist. The clinical treatment set-up was imported into our computer planning system and the resulting isodose plots were compared with those from CT planning and reviewed critically. Results: The clinically defined treatment set-up had to be modified in 80% of the patients. Most discrepancies observed were related to the size of the boost field itself and the chosen electron energy. Minor changes had to be made with respect to angle of table and gantry. Conclusions: Critical review of the isodose plots from both methods showed clear advantages for CT planning. Guidelines for target definition in CT planning of boost irradiation and subgroups of patients benefiting from this technique are described

  1. Management of low-level radioactive waste in the Southeast Compact Region: Volume 2, Management plan: Final report

    International Nuclear Information System (INIS)

    1985-07-01

    The Southeast Compact Commission for Low-Level Radioactive Waste Management has begun the development of a regional low-level radioactive waste management plan. They have reviewed and analyzed existing data on current low-level radioactive waste volumes shipped for disposal by generators in the Southeast region and have supplemented existing data by direct contact with State regulatory personnel, disposal site operators, and individual generators. The Commission has also projected the amounts and types of waste expected to require offsite disposal. This characterized data base and the projections of waste volumes and types through 1996 are included in this volume. Alternative disposal and treatment technologies were evaluated for management of the waste in the region. This evaluation consisted of a review of the literature concerning the several technologies in low level radioactive waste management. This information is summarized in Appendix A. 72 refs., 28 figs., 30 tabs

  2. Explicit optimization of plan quality measures in intensity-modulated radiation therapy treatment planning.

    Science.gov (United States)

    Engberg, Lovisa; Forsgren, Anders; Eriksson, Kjell; Hårdemark, Björn

    2017-06-01

    To formulate convex planning objectives of treatment plan multicriteria optimization with explicit relationships to the dose-volume histogram (DVH) statistics used in plan quality evaluation. Conventional planning objectives are designed to minimize the violation of DVH statistics thresholds using penalty functions. Although successful in guiding the DVH curve towards these thresholds, conventional planning objectives offer limited control of the individual points on the DVH curve (doses-at-volume) used to evaluate plan quality. In this study, we abandon the usual penalty-function framework and propose planning objectives that more closely relate to DVH statistics. The proposed planning objectives are based on mean-tail-dose, resulting in convex optimization. We also demonstrate how to adapt a standard optimization method to the proposed formulation in order to obtain a substantial reduction in computational cost. We investigated the potential of the proposed planning objectives as tools for optimizing DVH statistics through juxtaposition with the conventional planning objectives on two patient cases. Sets of treatment plans with differently balanced planning objectives were generated using either the proposed or the conventional approach. Dominance in the sense of better distributed doses-at-volume was observed in plans optimized within the proposed framework. The initial computational study indicates that the DVH statistics are better optimized and more efficiently balanced using the proposed planning objectives than using the conventional approach. © 2017 American Association of Physicists in Medicine.

  3. A methodology for incorporating functional bone marrow sparing in IMRT planning for pelvic radiation therapy

    International Nuclear Information System (INIS)

    McGuire, Sarah M.; Menda, Yusuf; Boles Ponto, Laura L.; Gross, Brandie; Juweid, Malik; Bayouth, John E.

    2011-01-01

    Background and purpose: The purpose of this study was to design a radiation therapy treatment planning approach that would spare hematopoietically active bone marrow using [ 18 F]FLT PET imaging. Materials and methods: We have developed an IMRT planning methodology to incorporate functional PET imaging using [ 18 F]FLT scans. Plans were generated for two simulated cervical cancer patients, where pelvic active bone marrow regions were incorporated as avoidance regions based on the ranges: SUV4 ≥ 4; 4 > SUV3 ≥ 3; and 3 > SUV2 ≥ 2. Dose objectives were set to reduce bone marrow volume that received 10 (V 10 ) and 20 (V 20 ) Gy. Results: Active bone marrow regions identified by [ 18 F]FLT with an SUV ≥ 2, SUV ≥ 3, and SUV ≥ 4 represented an average of 43.0%, 15.3%, and 5.8%, respectively of the total osseous pelvis for the two cases studied. Improved dose-volume histograms for all identified bone marrow SUV volumes and decreases in V 10 , and V 20 were achieved without clinically significant changes to PTV or OAR doses. Conclusions: Incorporation of [ 18 F]FLT PET in IMRT planning provides a methodology to reduce radiation dose to active bone marrow without compromising PTV or OAR dose objectives in pelvic malignancies.

  4. Hierarchical production planning for consumer goods

    NARCIS (Netherlands)

    Kok, de A.G.

    1990-01-01

    Abstract In this paper the mathematical logic behind a hierarchical planning procedure is discussed. The planning procedure is used to derive production volumes of consumer products. The essence of the planning procedure is that first a commitment is made concerning the production volume for a

  5. National Waste Terminal Storage Program: information management plan. Volume II. Plan description

    International Nuclear Information System (INIS)

    1977-05-01

    A comprehensive information management plan to provide for the systematic processing of large amounts of internally prepared and externally acquired documentation that will accrue to the Office of Waste Isolation (OWI) during the next decade is outlined. The Information Management Plan of the National Waste Terminal Storage (NWTS) Program is based on time proven procedures developed by government and industry for the requirements determination, acquisition, and the administration of documentation. The NWTS Information Management Plan is designed to establish the basis for the planning, development, implemenation, operation and maintenance of the NWTS Information Management System. This plan will help assure that documentation meets required quality standards and that each organization's needs are reflected when soliciting documentation from subcontractors. An example would be the Quality Assurance documentation requirement necessary to comply with eventual NRC licensing regulations. The provisions of the NWTS Information Management Plan will apply to all documentation from OWI contractors, subcontractors, and suppliers, and to OWI organizations for documentation prepared periodically for external dissemination

  6. Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation

    Science.gov (United States)

    Unkelbach, Jan; Menze, Bjoern H.; Konukoglu, Ender; Dittmann, Florian; Le, Matthieu; Ayache, Nicholas; Shih, Helen A.

    2014-02-01

    Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher-Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most

  7. Radiotherapy planning for glioblastoma based on a tumor growth model: improving target volume delineation

    International Nuclear Information System (INIS)

    Unkelbach, Jan; Dittmann, Florian; Le, Matthieu; Shih, Helen A; Menze, Bjoern H; Ayache, Nicholas; Konukoglu, Ender

    2014-01-01

    Glioblastoma differ from many other tumors in the sense that they grow infiltratively into the brain tissue instead of forming a solid tumor mass with a defined boundary. Only the part of the tumor with high tumor cell density can be localized through imaging directly. In contrast, brain tissue infiltrated by tumor cells at low density appears normal on current imaging modalities. In current clinical practice, a uniform margin, typically two centimeters, is applied to account for microscopic spread of disease that is not directly assessable through imaging. The current treatment planning procedure can potentially be improved by accounting for the anisotropy of tumor growth, which arises from different factors: anatomical barriers such as the falx cerebri represent boundaries for migrating tumor cells. In addition, tumor cells primarily spread in white matter and infiltrate gray matter at lower rate. We investigate the use of a phenomenological tumor growth model for treatment planning. The model is based on the Fisher–Kolmogorov equation, which formalizes these growth characteristics and estimates the spatial distribution of tumor cells in normal appearing regions of the brain. The target volume for radiotherapy planning can be defined as an isoline of the simulated tumor cell density. This paper analyzes the model with respect to implications for target volume definition and identifies its most critical components. A retrospective study involving ten glioblastoma patients treated at our institution has been performed. To illustrate the main findings of the study, a detailed case study is presented for a glioblastoma located close to the falx. In this situation, the falx represents a boundary for migrating tumor cells, whereas the corpus callosum provides a route for the tumor to spread to the contralateral hemisphere. We further discuss the sensitivity of the model with respect to the input parameters. Correct segmentation of the brain appears to be the most

  8. [Target volume margins for lung cancer: internal target volume/clinical target volume].

    Science.gov (United States)

    Jouin, A; Pourel, N

    2013-10-01

    The aim of this study was to carry out a review of margins that should be used for the delineation of target volumes in lung cancer, with a focus on margins from gross tumour volume (GTV) to clinical target volume (CTV) and internal target volume (ITV) delineation. Our review was based on a PubMed literature search with, as a cornerstone, the 2010 European Organisation for Research and Treatment of Cancer (EORTC) recommandations by De Ruysscher et al. The keywords used for the search were: radiotherapy, lung cancer, clinical target volume, internal target volume. The relevant information was categorized under the following headings: gross tumour volume definition (GTV), CTV-GTV margin (first tumoural CTV then nodal CTV definition), in field versus elective nodal irradiation, metabolic imaging role through the input of the PET scanner for tumour target volume and limitations of PET-CT imaging for nodal target volume definition, postoperative radiotherapy target volume definition, delineation of target volumes after induction chemotherapy; then the internal target volume is specified as well as tumoural mobility for lung cancer and respiratory gating techniques. Finally, a chapter is dedicated to planning target volume definition and another to small cell lung cancer. For each heading, the most relevant and recent clinical trials and publications are mentioned. Copyright © 2013. Published by Elsevier SAS.

  9. Nr 257 - Opinion presented on the behalf of the Commission of sustainable development and land planning on the finance bill for 2013 (nr 235), Volumes 1-10, ecology, sustainable development and planning, regional policies, research and higher education

    International Nuclear Information System (INIS)

    Krabal, Jacques; Sermier, Jean-Marie; Gaillard, Genevieve; Baupin, Denis; Pauvros, Remi; Benisti, Jacques Alain; Fromantin, Jean-Christophe; Calmette, Alain; Plisson, Philippe; Ginesy, Charles-Ange

    2012-01-01

    This huge document comprises ten volumes which present and discuss public programs (objectives, strategies, plans, and actions), public finances, economic activity data and evolutions, debates by commissions, and amendments on different issues. A first set of issues deals with ecology, sustainable development and planning: protection of the environment and risk prevention (volume 1), and then with sustainable development policies (vol. 2), landscapes, water, biodiversity, and geographic and cartographic information (vol. 3), ecological transition (vol. 4), road, railway and water transports (vol. 5), air transports (vol. 6), maritime affairs (vol. 7). The next volume addresses regional policies (vol. 8). The last parts concern research and higher education: research in the field of sustainable development (vol. 9) and in the fields of environments and resources (vol. 10)

  10. Risk factors for radiation pneumonitis after stereotactic radiation therapy for lung tumours: clinical usefulness of the planning target volume to total lung volume ratio.

    Science.gov (United States)

    Ueyama, Tomoko; Arimura, Takeshi; Takumi, Koji; Nakamura, Fumihiko; Higashi, Ryutaro; Ito, Soichiro; Fukukura, Yoshihiko; Umanodan, Tomokazu; Nakajo, Masanori; Koriyama, Chihaya; Yoshiura, Takashi

    2018-06-01

    To identify risk factors for symptomatic radiation pneumonitis (RP) after stereotactic radiation therapy (SRT) for lung tumours. We retrospectively evaluated 68 lung tumours in 63 patients treated with SRT between 2011 and 2015. RP was graded according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4.0. SRT was delivered at 7.0-12.0 Gy per each fraction, once daily, to a total of 48-64 Gy (median, 50 Gy). Univariate analysis was performed to assess patient- and treatment-related factors, including age, sex, smoking index (SI), pulmonary function, tumour location, serum Krebs von den Lungen-6 value (KL-6), dose-volume metrics (V5, V10, V20, V30, V40 and VS5), homogeneity index of the planning target volume (PTV), PTV dose, mean lung dose (MLD), contralateral MLD and V2, PTV volume, lung volume and the PTV/lung volume ratio (PTV/Lung). Performance of PTV/Lung in predicting symptomatic RP was also analysed using receiver operating characteristic (ROC) analysis. The median follow-up period was 21 months. 10 of 63 patients (15.9%) developed symptomatic RP after SRT. On univariate analysis, V10, V20, PTV volume and PTV/Lung were significantly associated with occurrence of RP  ≥Grade 2. ROC curves indicated that symptomatic RP could be predicted using PTV/Lung [area under curve (AUC): 0.88, confidence interval (CI: 0.78-0.95), cut-off value: 1.09, sensitivity: 90.0% and specificity: 72.4%]. PTV/Lung is a good predictor of symptomatic RP after SRT. Advances in knowledge: The cases with high PTV/Lung should be carefully monitored with caution for the occurrence of RP after SRT.

  11. Dosimetric accuracy of a treatment planning system for actively scanned proton beams and small target volumes: Monte Carlo and experimental validation

    Science.gov (United States)

    Magro, G.; Molinelli, S.; Mairani, A.; Mirandola, A.; Panizza, D.; Russo, S.; Ferrari, A.; Valvo, F.; Fossati, P.; Ciocca, M.

    2015-09-01

    This study was performed to evaluate the accuracy of a commercial treatment planning system (TPS), in optimising proton pencil beam dose distributions for small targets of different sizes (5-30 mm side) located at increasing depths in water. The TPS analytical algorithm was benchmarked against experimental data and the FLUKA Monte Carlo (MC) code, previously validated for the selected beam-line. We tested the Siemens syngo® TPS plan optimisation module for water cubes fixing the configurable parameters at clinical standards, with homogeneous target coverage to a 2 Gy (RBE) dose prescription as unique goal. Plans were delivered and the dose at each volume centre was measured in water with a calibrated PTW Advanced Markus® chamber. An EBT3® film was also positioned at the phantom entrance window for the acquisition of 2D dose maps. Discrepancies between TPS calculated and MC simulated values were mainly due to the different lateral spread modeling and resulted in being related to the field-to-spot size ratio. The accuracy of the TPS was proved to be clinically acceptable in all cases but very small and shallow volumes. In this contest, the use of MC to validate TPS results proved to be a reliable procedure for pre-treatment plan verification.

  12. Dosimetric accuracy of a treatment planning system for actively scanned proton beams and small target volumes: Monte Carlo and experimental validation

    International Nuclear Information System (INIS)

    Magro, G; Molinelli, S; Mairani, A; Mirandola, A; Panizza, D; Russo, S; Valvo, F; Fossati, P; Ciocca, M; Ferrari, A

    2015-01-01

    This study was performed to evaluate the accuracy of a commercial treatment planning system (TPS), in optimising proton pencil beam dose distributions for small targets of different sizes (5–30 mm side) located at increasing depths in water. The TPS analytical algorithm was benchmarked against experimental data and the FLUKA Monte Carlo (MC) code, previously validated for the selected beam-line. We tested the Siemens syngo ® TPS plan optimisation module for water cubes fixing the configurable parameters at clinical standards, with homogeneous target coverage to a 2 Gy (RBE) dose prescription as unique goal. Plans were delivered and the dose at each volume centre was measured in water with a calibrated PTW Advanced Markus ® chamber. An EBT3 ® film was also positioned at the phantom entrance window for the acquisition of 2D dose maps. Discrepancies between TPS calculated and MC simulated values were mainly due to the different lateral spread modeling and resulted in being related to the field-to-spot size ratio. The accuracy of the TPS was proved to be clinically acceptable in all cases but very small and shallow volumes. In this contest, the use of MC to validate TPS results proved to be a reliable procedure for pre-treatment plan verification. (paper)

  13. Comparison of CT based-CTV plan and CT based-ICRU38 plan in brachytherapy planning of uterine cervix cancer

    International Nuclear Information System (INIS)

    Cho, Jung Keun; Han, Tae Jong

    2007-01-01

    Purpose : In spite of recent remarkable improvement of diagnostic imaging modalities such as CT, MRI, and PET and radiation therapy planing systems, ICR plan of uterine cervix cancer, based on recommendation of ICRU38(2D film-based) such as point A, is still used widely. A 3-dimensional ICR plan based on CT image provides Dose-Volume Histogram(DVH) information of the tumor and normal tissue. In this study, we compared tumor-dose, rectal-dose and bladder-dose through an analysis of DVH between CTV plan and ICRU38 plan based on CT image. Method and Material : We analyzed 11 patients with a cervix cancer who received the ICR of Ir-192 HDR. After 40Gy of external beam radiation therapy, ICR plan was established using PLATO(Nucletron) v.14.2 planning system. CT scan was done to all the patients using CT-simulator(Ultra Z, Philips). We contoured CTV, rectum and bladder on the CT image and established CTV plan which delivers the 100% dose to CTV and ICRU plan which delivers the 100% dose to the point A. Result : The volume(average±SD) of CTV, rectum and bladder in all of 11 patients is 21.8±6.6cm 3 , 60.9±25.0cm 3 , 111.6±40.1cm 3 respectively. The volume covered by 100% isodose curve is 126.7±18.9cm 3 in ICRU plan and 98.2±74.5cm 3 in CTV plan(p=0.0001), respectively. In (On) ICRU planning 22.0cm 3 of CTV volume was not covered by 100% isodose curve in one patient whose residual tumor size is greater than 4cm, while more than 100% dose was irradiated unnecessarily to the normal organ of 62.2±4.8cm 3 other than the tumor in the remaining 10 patients with a residual tumor less than 4cm in size. Bladder dose recommended by ICRU 38 was 90.1±21.3% and 68.7±26.6% in ICRU plan and in CTV plan respectively(p=0.001) while rectal dose recommended by ICRU 38 was 86.4±18.3% and 76.9±15.6% in ICRU plan and in CTV plan, respectively(p=0.08). Bladder and rectum maximum dose was 137.2±50.1%, 101.1±41.8% in ICRU plan and 107.6±47.9%, 86.9±30.8% in CTV plan, respectively

  14. Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System

    Science.gov (United States)

    Court, Laurence E.; Kisling, Kelly; McCarroll, Rachel; Zhang, Lifei; Yang, Jinzhong; Simonds, Hannah; du Toit, Monique; Trauernicht, Chris; Burger, Hester; Parkes, Jeannette; Mejia, Mike; Bojador, Maureen; Balter, Peter; Branco, Daniela; Steinmann, Angela; Baltz, Garrett; Gay, Skylar; Anderson, Brian; Cardenas, Carlos; Jhingran, Anuja; Shaitelman, Simona; Bogler, Oliver; Schmeller, Kathleen; Followill, David; Howell, Rebecca; Nelson, Christopher; Peterson, Christine; Beadle, Beth

    2018-01-01

    The Radiation Planning Assistant (RPA) is a system developed for the fully automated creation of radiotherapy treatment plans, including volume-modulated arc therapy (VMAT) plans for patients with head/neck cancer and 4-field box plans for patients with cervical cancer. It is a combination of specially developed in-house software that uses an application programming interface to communicate with a commercial radiotherapy treatment planning system. It also interfaces with a commercial secondary dose verification software. The necessary inputs to the system are a Treatment Plan Order, approved by the radiation oncologist, and a simulation computed tomography (CT) image, approved by the radiographer. The RPA then generates a complete radiotherapy treatment plan. For the cervical cancer treatment plans, no additional user intervention is necessary until the plan is complete. For head/neck treatment plans, after the normal tissue and some of the target structures are automatically delineated on the CT image, the radiation oncologist must review the contours, making edits if necessary. They also delineate the gross tumor volume. The RPA then completes the treatment planning process, creating a VMAT plan. Finally, the completed plan must be reviewed by qualified clinical staff. PMID:29708544

  15. Balanced program plan. Volume 10. Fusion: analysis for biomedical and environmental research

    International Nuclear Information System (INIS)

    Hungate, F.P.

    1976-06-01

    Development of the Balanced Program Plan for analysis for biomedical and environmental research was initiated in the spring of 1975. The goal was a redefinition of research efforts and priorities to meet ERDA's requirements for a program of health and environmental research to support the development and commercialization of energy technologies. As part of the Balanced Program planning effort the major ERDA-supported multidisciplinary laboratories were assigned responsibility for analyzing the research needs of each of nine energy technologies and describing a research program to meet these needs. The staff of the Division of Biomedical and Environmental Research was assigned the task of defining a research program addressed to each of five biomedical and environmental research categories (characterization, measurement and monitoring; physical and chemical processes and effects; health effects; ecological effects; and integrated assessment and socioeconomic processes and effects) applicable to all energy technologies. The first drafts of these documents were available for a work-shop in June 1975 at which the DBER staff and scientists from the laboratories developed a comprehensive set of program recommendations. Pacific Northwest Laboratory was assigned responsibility for defining research needs and a recommended research program for fusion and fission technologies. This report, Volume 10, presents the input for fusion

  16. Routine Radiological Environmental Monitoring Plan. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel Nevada

    1999-12-31

    The U.S. Department of Energy manages the Nevada Test Site in a manner that meets evolving DOE Missions and responds to the concerns of affected and interested individuals and agencies. This Routine Radiological Monitoring Plan addressess complicance with DOE Orders 5400.1 and 5400.5 and other drivers requiring routine effluent monitoring and environmental surveillance on the Nevada Test Site. This monitoring plan, prepared in 1998, addresses the activities conducted onsite NTS under the Final Environmental Impact Statement and Record of Decision. This radiological monitoring plan, prepared on behalf of the Nevada Test Site Landlord, brings together sitewide environmental surveillance; site-specific effluent monitoring; and operational monitoring conducted by various missions, programs, and projects on the NTS. The plan provides an approach to identifying and conducting routine radiological monitoring at the NTS, based on integrated technical, scientific, and regulatory complicance data needs.

  17. A local contrast based approach to threshold segmentation for PET target volume delineation

    International Nuclear Information System (INIS)

    Drever, Laura; Robinson, Don M.; McEwan, Alexander; Roa, Wilson

    2006-01-01

    Current radiation therapy techniques, such as intensity modulated radiation therapy and three-dimensional conformal radiotherapy rely on the precise delivery of high doses of radiation to well-defined volumes. CT, the imaging modality that is most commonly used to determine treatment volumes cannot, however, easily distinguish between cancerous and normal tissue. The ability of positron emission tomography (PET) to more readily differentiate between malignant and healthy tissues has generated great interest in using PET images to delineate target volumes for radiation treatment planning. At present the accurate geometric delineation of tumor volumes is a subject open to considerable interpretation. The possibility of using a local contrast based approach to threshold segmentation to accurately delineate PET target cross sections is investigated using well-defined cylindrical and spherical volumes. Contrast levels which yield correct volumetric quantification are found to be a function of the activity concentration ratio between target and background, target size, and slice location. Possibilities for clinical implementation are explored along with the limits posed by this form of segmentation

  18. Persistently better treatment planning results of intensity-modulated (IMRT) over conformal radiotherapy (3D-CRT) in prostate cancer patients with significant variation of clinical target volume and/or organs-at-risk

    International Nuclear Information System (INIS)

    Fenoglietto, Pascal; Laliberte, Benoit; Allaw, Ali; Ailleres, Norbert; Idri, Katia; Hay, Meng Huor; Moscardo, Carmen Llacer; Gourgou, Sophie; Dubois, Jean-Bernard; Azria, David

    2008-01-01

    Purpose: To compare the dose coverage of planning and clinical target volume (PTV, CTV), and organs-at-risk (OAR) between intensity-modulated (3D-IMRT) and conventional conformal radiotherapy (3D-CRT) before and after internal organ variation in prostate cancer. Methods and materials: We selected 10 patients with clinically significant interfraction volume changes. Patients were treated with 3D-IMRT to 80 Gy (minimum PTV dose of 76 Gy, excluding rectum). Fictitious, equivalent 3D-CRT plans (80 Gy at isocenter, with 95% isodose (76 Gy) coverage of PTV, with rectal blocking above 76 Gy) were generated using the same planning CT data set ('CT planning'). The plans were then also applied to a verification CT scan ('CT verify') obtained at a different moment. PTV, CTV, and OAR dose coverage were compared using non-parametric tests statistics for V95, V90 (% of the volume receiving ≥95 or 90% of the dose) and D50 (dose to 50% of the volume). Results: Mean V95 of the PTV for 'CT planning' was 94.3% (range, 88-99) vs 89.1% (range, 84-94.5) for 3D-IMRT and 3D-CRT (p = 0.005), respectively. Mean V95 of the CTV for 'CT verify' was 97% for both 3D-IMRT and 3D-CRT. Mean D50 of the rectum for 'CT planning' was 26.8 Gy (range, 22-35) vs 43.5 Gy (range, 33.5-50.5) for 3D-IMRT and 3D-CRT (p = 0.0002), respectively. For 'CT verify', this D50 was 31.1 Gy (range, 16.5-44) vs 44.2 Gy (range, 34-55) for 3D-IMRT and 3D-CRT (p = 0.006), respectively. V95 of the rectum was 0% for both plans for 'CT planning', and 2.3% (3D-IMRT) vs 2.1% (3D-CRT) for 'CT verify' (p = non-sig.). Conclusion: Dose coverage of the PTV and OAR was better with 3D-IMRT for each patient and remained so after internal volume changes

  19. Management response plan for the Chemical Safety Vulnerability Working Group report. Volume 1

    International Nuclear Information System (INIS)

    1994-09-01

    The Chemical Safety Vulnerability (CSV) Working Group was established to identify adverse conditions involving hazardous chemicals at DOE facilities that might result in fires or explosions, release of hazardous chemicals to the environment, or exposure of workers or the public to chemicals. A CSV Review was conducted in 146 facilities at 29 sites. Eight generic vulnerabilities were documented related to: abandoned chemicals and chemical residuals; past chemical spills and ground releases; characterization of legacy chemicals and wastes; disposition of legacy chemicals; storage facilities and conditions; condition of facilities and support systems; unanalyzed and unaddressed hazards; and inventory control and tracking. Weaknesses in five programmatic areas were also identified related to: management commitment and planning; chemical safety management programs; aging facilities that continue to operate; nonoperating facilities awaiting deactivation; and resource allocations. Volume 1 contains a discussion of the chemical safety improvements planned or already underway at DOE sites to correct facility or site-specific vulnerabilities. The main part of the report is a discussion of each of the programmatic deficiencies; a description of the tasks to be accomplished; the specific actions to be taken; and the organizational responsibilities for implementation

  20. Evaluation of dose-volume histograms after prostate seed implantation. 4-year experience

    International Nuclear Information System (INIS)

    Hoinkis, C.; Lehmann, D.; Winkler, C.; Herrmann, T.; Hakenberg, O.W.; Wirth, M.P.

    2004-01-01

    Background and purpose: permanent interstitial brachytherapy by seed implantation is a treatment alternative for low-volume low-risk prostate cancer and a complex interdisciplinary treatment with a learning curve. Dose-volume histograms are used to assess postimplant quality. The authors evaluated their learning curve based on dose-volume histograms and analyzed factors influencing implantation quality. Patients and methods: since 1999, 38 patients with a minimum follow-up of 6 months were treated at the authors' institution with seed implantation using palladium-103 or iodine-125, initially using the preplan method and later real-time planning. Postimplant CT was performed after 4 weeks. The dose-volume indices D90, V100, V150, the D max of pre- and postplans, and the size and position of the volume receiving the prescribed dose (high-dose volume) of the postplans were evaluated. In six patients, postplan imaging both by CT and MRI was used and prostate volumes were compared with preimplant transrectal ultrasound volumes. The first five patients were treated under external supervision. Results: patients were divided into three consecutive groups for analysis of the learning curve (group 1: n = 5 patients treated under external supervision; group 2: n = 13 patients; group 3: n = 20 patients). D90 post for the three groups were 79.3%, 74.2%, and 99.9%, the V100 post were 78.6%, 73.5%, and 88.2%, respectively. The relationship between high-dose volume and prostate volume showed a similar increase as the D90, while the relationship between high-dose volume lying outside the prostate and prostate volume remained constant. The ratio between prostate volumes from transrectal ultrasound and CT imaging decreased with increasing D90 post , while the preplanning D90 and V100 remained constant. The different isotopes used, the method of planning, and the implanted activity per prostate volume did not influence results. Conclusion: a learning curve characterized by an increase

  1. Licensing an assured isolation facility for low-level radioactive waste. Volume 1: Licensing strategy and issues

    International Nuclear Information System (INIS)

    Silverman, D.J.; Bauser, M.A.; Baird, R.D.

    1998-07-01

    This report provides a detailed set of proposed criteria and guidance for the preparation of a license application for an assured isolation facility (AIF). The report is intended to provide a detailed planning basis upon which a prospective applicant may begin pre-licensing discussions with the Nuclear Regulatory Commission and initiate development of a license application. The report may also be useful to the NRC or to state regulatory agencies that may be asked to review such an application. Volume 1 of this report provides background information, and describes the licensing approach and methodology. Volume 2 identifies specific information that is recommended for inclusion in a license application

  2. Background characterization in a liquid scintillation spectrometer

    International Nuclear Information System (INIS)

    Rodriguez Barquero, L.; Los Arcos, J.M.; Jimenez de Mingo, A.

    1995-01-01

    An alternate procedure for background count rate estimation in a liquid scintillation spectrometer is presented, which does not require to measure a blank with similar composition, volume and quench, to the problem sample. The procedure is based on a double linear parameterization which was obtained from a systematic study of the background observed with glass vials, in three different windows, 0 - 20 KeV, 0 - 800 KeV and 0 - 2 MeV, for volume between 2 and 20 mi of three commercial scintillators, Hisafe II, Ultima-Gold and Instagel, and quenching degree in the interval equivalent to 50% - 3% tritium efficiency. This procedure was tested with standard samples of 3H, and led to average discrepancies less than 10% for activity ≥0,6 Bq, against conventional methods for which the discrepancies are twice on average. (Author) 10 refs

  3. Background characterization in a liquid scintillation spectrometer

    International Nuclear Information System (INIS)

    Rodriguez Barquero, L.; Los arcos, J.M.; Jimenez de Mingo, A.

    1995-01-01

    An alternate procedure for background count rate estimation in a liquid scintillation spectrometer is presented, which does not require to measure a blank with similar composition, volume and quench, to the problem sample. The procedure is based on a double linear parameterization which was obtained from a systematic study of the background observed with glass vials, in three different windows, 0-20 KeV, 0-800 KeV and 0-2 MeV, for volume between 2 and 20 ml of three commercial scintillators, Hisafe II, Ultima-gold and Instagel, and quenching degree in the interval equivalent to 50%-3% tritium efficiency. This procedure was tested with standard samples of ''3 H, and led to average discrepancies less than 10% for activity => 0,6 Bq, against conventional methods for which the discrepancies are twice on average

  4. Interactively exploring optimized treatment plans

    International Nuclear Information System (INIS)

    Rosen, Isaac; Liu, H. Helen; Childress, Nathan; Liao Zhongxing

    2005-01-01

    Purpose: A new paradigm for treatment planning is proposed that embodies the concept of interactively exploring the space of optimized plans. In this approach, treatment planning ignores the details of individual plans and instead presents the physician with clinical summaries of sets of solutions to well-defined clinical goals in which every solution has been optimized in advance by computer algorithms. Methods and materials: Before interactive planning, sets of optimized plans are created for a variety of treatment delivery options and critical structure dose-volume constraints. Then, the dose-volume parameters of the optimized plans are fit to linear functions. These linear functions are used to show in real time how the target dose-volume histogram (DVH) changes as the DVHs of the critical structures are changed interactively. A bitmap of the space of optimized plans is used to restrict the feasible solutions. The physician selects the critical structure dose-volume constraints that give the desired dose to the planning target volume (PTV) and then those constraints are used to create the corresponding optimized plan. Results: The method is demonstrated using prototype software, Treatment Plan Explorer (TPEx), and a clinical example of a patient with a tumor in the right lung. For this example, the delivery options included 4 open beams, 12 open beams, 4 wedged beams, and 12 wedged beams. Beam directions and relative weights were optimized for a range of critical structure dose-volume constraints for the lungs and esophagus. Cord dose was restricted to 45 Gy. Using the interactive interface, the physician explored how the tumor dose changed as critical structure dose-volume constraints were tightened or relaxed and selected the best compromise for each delivery option. The corresponding treatment plans were calculated and compared with the linear parameterization presented to the physician in TPEx. The linear fits were best for the maximum PTV dose and worst

  5. Eleventh annual Department of Energy low-level waste management conference. Volume 2: Low-level waste strategy and planning, decontamination and decommissioning, compliance monitoring

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1989-11-01

    Nineteen papers are presented in volume 2. The 11 papers in the LLW Strategy and Planning section discuss plans for disposal facilities in Texas, Pennsylvania, Hanford, the Southwest and Southeast Compacts, and others. Three papers discuss decontamination technology and activities. Environmental monitoring requirements and recommendations at LLW facilities are discussed in 5 papers. Papers have been processed separately for inclusion on the data base.

  6. Automatic liver contouring for radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Li, Dengwang; Kapp, Daniel S; Xing, Lei; Liu, Li

    2015-01-01

    To develop automatic and efficient liver contouring software for planning 3D-CT and four-dimensional computed tomography (4D-CT) for application in clinical radiation therapy treatment planning systems.The algorithm comprises three steps for overcoming the challenge of similar intensities between the liver region and its surrounding tissues. First, the total variation model with the L1 norm (TV-L1), which has the characteristic of multi-scale decomposition and an edge-preserving property, is used for removing the surrounding muscles and tissues. Second, an improved level set model that contains both global and local energy functions is utilized to extract liver contour information sequentially. In the global energy function, the local correlation coefficient (LCC) is constructed based on the gray level co-occurrence matrix both of the initial liver region and the background region. The LCC can calculate the correlation of a pixel with the foreground and background regions, respectively. The LCC is combined with intensity distribution models to classify pixels during the evolutionary process of the level set based method. The obtained liver contour is used as the candidate liver region for the following step. In the third step, voxel-based texture characterization is employed for refining the liver region and obtaining the final liver contours.The proposed method was validated based on the planning CT images of a group of 25 patients undergoing radiation therapy treatment planning. These included ten lung cancer patients with normal appearing livers and ten patients with hepatocellular carcinoma or liver metastases. The method was also tested on abdominal 4D-CT images of a group of five patients with hepatocellular carcinoma or liver metastases. The false positive volume percentage, the false negative volume percentage, and the dice similarity coefficient between liver contours obtained by a developed algorithm and a current standard delineated by the expert group

  7. Sandia software guidelines: Software quality planning

    Energy Technology Data Exchange (ETDEWEB)

    1987-08-01

    This volume is one in a series of Sandia Software Guidelines intended for use in producing quality software within Sandia National Laboratories. In consonance with the IEEE Standard for Software Quality Assurance Plans, this volume identifies procedures to follow in producing a Software Quality Assurance Plan for an organization or a project, and provides an example project SQA plan. 2 figs., 4 tabs.

  8. A Treatment Planning Analysis of Inverse-Planned and Forward-Planned Intensity-Modulated Radiation Therapy in Nasopharyngeal Carcinoma

    International Nuclear Information System (INIS)

    Poon, Ian M; Xia Ping; Weinberg, Vivien; Sultanem, Khalil; Akazawa, Clayton C.; Akazawa, Pamela C.; Verhey, Lynn; Quivey, Jeanne Marie; Lee, Nancy

    2007-01-01

    Purpose: To compare dose-volume histograms of target volumes and organs at risk in 57 patients with nasopharyngeal carcinoma (NPC) with inverse- (IP) or forward-planned (FP) intensity-modulated radiation treatment (IMRT). Methods and Materials: The DVHs of 57 patients with NPC with IMRT with or without chemotherapy were reviewed. Thirty-one patients underwent IP IMRT, and 26 patients underwent FP IMRT. Treatment goals were to prescribe a minimum dose of 66-70 Gy for gross tumor volume and 59.4 Gy for planning target volume to greater than 95% of the volume. Multiple selected end points were used to compare dose-volume histograms of the targets, including minimum, mean, and maximum doses; percentage of target volume receiving less than 90% (1-V90%), less than 95% (1-V95%), and greater than 105% (1-V105%). Dose-volume histograms of organs at risk were evaluated with characteristic end points. Results: Both planning methods provided excellent target coverage with no statistically significant differences found, although a trend was suggested in favor of improved target coverage with IP IMRT in patients with T3/T4 NPC (p = 0.10). Overall, IP IMRT statistically decreased the dose to the parotid gland, temporomandibular joint, brain stem, and spinal cord overall, whereas IP led to a dose decrease to the middle/inner ear in only the T1/T2 subgroup. Conclusions: Use of IP and FP IMRT can lead to good target coverage while maintaining critical structures within tolerance. The IP IMRT selectively spared these critical organs to a greater degree and should be considered the standard of treatment in patients with NPC, particularly those with T3/T4. The FP IMRT is an effective second option in centers with limited IP IMRT capacity. As a modification of conformal techniques, the human/departmental resources to incorporate FP-IMRT should be nominal

  9. Task Analysis and Descriptions of Required Job Competencies for Robotics/Automated Systems Technicians. Final Report. Volume 2. Curriculum Planning Guide.

    Science.gov (United States)

    Hull, Daniel M.; Lovett, James E.

    This volume of the final report for the Robotics/Automated Systems Technician (RAST) curriculum project is a curriculum planning guide intended for school administrators, faculty, and student counselors/advisors. It includes step-by-step procedures to help institutions evaluate their community's needs and their capabilities to meet these needs in…

  10. Change in Seroma Volume During Whole-Breast Radiation Therapy

    International Nuclear Information System (INIS)

    Sharma, Rajiv; Spierer, Marnee; Mutyala, Subhakar; Thawani, Nitika; Cohen, Hillel W.; Hong, Linda; Garg, Madhur K.; Kalnicki, Shalom

    2009-01-01

    Purpose: After breast-conserving surgery, a seroma often forms in the surgical cavity. If not drained, it may affect the volume of tumor bed requiring a boost after whole-breast radiation therapy (WBRT). Our objective was to evaluate the change in seroma volume that occurs during WBRT, before boost planning. Methods and Materials: A retrospective review was performed of women receiving breast-conserving therapy with evidence of seroma at the time of WBRT planning. Computed tomography (CT) simulation was performed before WBRT and before the tumor bed boost. All patients received either a hypofractionated (42.4 Gy/16 fraction + 9.6 Gy/4 fraction boost) or standard fractionated (50.4 Gy/28 fraction + 10 Gy/5 fraction boost) regimen. Seroma volumes were contoured and compared on CT at the time of WBRT simulation and tumor bed boost planning. Results: Twenty-four patients with evidence of seroma were identified and all patients received WBRT without drainage of the seroma. Mean seroma volume before WBRT and at boost planning were significantly different at 65.7 cm 3 (SD, 50.5 cm 3 ) and 35.6 cm 3 (SD, 24.8 cm 3 ), respectively (p < 0.001). Mean and median reduction in seroma volume during radiation were 39.6% (SD, 23.8%) and 46.2% (range, 10.7-76.7%), respectively. Fractionation schedule was not correlated with change in seroma volume. Length of time from surgery to start of radiation therapy showed an inverse correlation with change in seroma volume (Pearson correlation r = -0.53, p < 0.01). Conclusions: The volume of seroma changes significantly during WBRT. Consequently, the accuracy of breast boost planning is likely affected, as is the volume of normal breast tissue irradiated. CT-based boost planning before boost irradiation is suggested to ensure appropriate coverage.

  11. Treatment planning for multicatheter interstitial brachytherapy of breast cancer – from Paris system to anatomy-based inverse planning

    Directory of Open Access Journals (Sweden)

    Tibor Major

    2017-02-01

    Full Text Available In the last decades, treatment planning for multicatheter interstitial breast brachytherapy has evolved considerably from fluoroscopy-based 2D to anatomy-based 3D planning. To plan the right positions of the catheters, ultrasound or computed tomography (CT imaging can be used, but the treatment plan is always based on postimplant CT images. With CT imaging, the 3D target volume can be defined more precisely and delineation of the organs at risk volumes is also possible. Consequently, parameters calculated from dose-volume histogram can be used for quantitative plan evaluation. The catheter reconstruction is also easier and faster on CT images compared to X-ray films. In high dose rate brachytherapy, using a stepping source, a number of forward dose optimization methods (manual, geometrical, on dose points, graphical are available to shape the dose distribution to the target volume, and these influence dose homogeneities to different extent. Currently, inverse optimization algorithms offer new possibilities to improve dose distributions further considering the requirements for dose coverage, dose homogeneity, and dose to organs at risk simultaneously and automatically. In this article, the evolvement of treatment planning for interstitial breast implants is reviewed, different forward optimization methods are discussed, and dose-volume parameters used for quantitative plan evaluation are described. Finally, some questions of the inverse optimization method are investigated and initial experiences of the authors are presented.

  12. What margins should be added to the clinical target volume in radiotherapy treatment planning of lung cancer?

    International Nuclear Information System (INIS)

    Ekberg, L.; Wittgren, L.; Holmberg, O.

    1995-01-01

    When defining the planning target volume (PTV) in radiotherapy treatment planning, it is vital to add geometrical margins of normal tissue around the clinical target volume (CTV). This is to ensure that the whole CTV will receive the planned absorbed dose taking into account both set-up deviations and target movements as well as other geometrical variations in the treatment chain. The problem is our limited knowledge of how large these margins should be. To assess the size of needed margins around the CTV in conformal radiotherapy of lung cancer, electronic portal imaging was employed in 232 irradiation field set-ups of 14 patients. This was done in order to quantify the uncertainty in the execution of treatment considering patient movement and set-up displacements. For an estimation of the added geometrical variation from target movement during irradiation, fluoroscopy was used at the simulation of the irradiation fields. The set-up study showed an average systematic deviation for all individual fields of 3.1 mm and an average maximal systematic deviation (in either transversal or craniocaudal direction) of 4.8 mm. The random errors can be described by an average standard deviation of 2.8 mm for all fields in either direction. Major gradual displacements as a function of time was also detected in one of the patients. CTV-movements of several millimetres during respiration could be observed. It was also seen that heartbeats could add to CTV-movements during irradiation with an equal magnitude. The combined effect of these factors are considered when making an overall estimation of margins that should be added to the CTV

  13. Ribbons on the Cosmic Background Radiation Sky: A Powerful Test of a Baryon Symmetric Universe

    International Nuclear Information System (INIS)

    Kinney, W.H.; Kolb, E.W.; Turner, M.S.; Kolb, E.W.; Turner, M.S.; Turner, M.S.

    1997-01-01

    If the Universe consists of domains of matter and antimatter, annihilations at domain interfaces leave a distinctive imprint on the cosmic background radiation (CBR) sky. The signature is anisotropies in the form of long, thin ribbons of width θ W ∼0.1 circ , separated by angle θ L ≅1 circ (L/100h -1 Mpc) (L is the characteristic domain size) and with distortion parameter y∼10 -6 . Such a pattern could potentially be detected by the high-resolution CBR anisotropy experiments planned for the next decade, and such experiments may finally settle the question of whether or not our Hubble volume is baryon symmetric. copyright 1997 The American Physical Society

  14. WE-AB-209-07: Explicit and Convex Optimization of Plan Quality Metrics in Intensity-Modulated Radiation Therapy Treatment Planning

    International Nuclear Information System (INIS)

    Engberg, L; Eriksson, K; Hardemark, B; Forsgren, A

    2016-01-01

    Purpose: To formulate objective functions of a multicriteria fluence map optimization model that correlate well with plan quality metrics, and to solve this multicriteria model by convex approximation. Methods: In this study, objectives of a multicriteria model are formulated to explicitly either minimize or maximize a dose-at-volume measure. Given the widespread agreement that dose-at-volume levels play important roles in plan quality assessment, these objectives correlate well with plan quality metrics. This is in contrast to the conventional objectives, which are to maximize clinical goal achievement by relating to deviations from given dose-at-volume thresholds: while balancing the new objectives means explicitly balancing dose-at-volume levels, balancing the conventional objectives effectively means balancing deviations. Constituted by the inherently non-convex dose-at-volume measure, the new objectives are approximated by the convex mean-tail-dose measure (CVaR measure), yielding a convex approximation of the multicriteria model. Results: Advantages of using the convex approximation are investigated through juxtaposition with the conventional objectives in a computational study of two patient cases. Clinical goals of each case respectively point out three ROI dose-at-volume measures to be considered for plan quality assessment. This is translated in the convex approximation into minimizing three mean-tail-dose measures. Evaluations of the three ROI dose-at-volume measures on Pareto optimal plans are used to represent plan quality of the Pareto sets. Besides providing increased accuracy in terms of feasibility of solutions, the convex approximation generates Pareto sets with overall improved plan quality. In one case, the Pareto set generated by the convex approximation entirely dominates that generated with the conventional objectives. Conclusion: The initial computational study indicates that the convex approximation outperforms the conventional objectives

  15. Adaptive Radiotherapy Planning on Decreasing Gross Tumor Volumes as Seen on Megavoltage Computed Tomography Images

    International Nuclear Information System (INIS)

    Woodford, Curtis; Yartsev, Slav; Dar, A. Rashid; Bauman, Glenn; Van Dyk, Jake

    2007-01-01

    Purpose: To evaluate gross tumor volume (GTV) changes for patients with non-small-cell lung cancer by using daily megavoltage (MV) computed tomography (CT) studies acquired before each treatment fraction on helical tomotherapy and to relate the potential benefit of adaptive image-guided radiotherapy to changes in GTV. Methods and Materials: Seventeen patients were prescribed 30 fractions of radiotherapy on helical tomotherapy for non-small-cell lung cancer at London Regional Cancer Program from Dec 2005 to March 2007. The GTV was contoured on the daily MVCT studies of each patient. Adapted plans were created using merged MVCT-kilovoltage CT image sets to investigate the advantages of replanning for patients with differing GTV regression characteristics. Results: Average GTV change observed over 30 fractions was -38%, ranging from -12 to -87%. No significant correlation was observed between GTV change and patient's physical or tumor features. Patterns of GTV changes in the 17 patients could be divided broadly into three groups with distinctive potential for benefit from adaptive planning. Conclusions: Changes in GTV are difficult to predict quantitatively based on patient or tumor characteristics. If changes occur, there are points in time during the treatment course when it may be appropriate to adapt the plan to improve sparing of normal tissues. If GTV decreases by greater than 30% at any point in the first 20 fractions of treatment, adaptive planning is appropriate to further improve the therapeutic ratio

  16. Treatment planning comparison of electron arc therapy and photon intensity modulated radiotherapy for Askin's tumor of chest wall

    International Nuclear Information System (INIS)

    Jamema, Swamidas V.; Sharma, Pramod K.; Laskar, Siddhartha; Deshpande, Deepak D.; Shrivastava, Shyam K.

    2007-01-01

    Background and Purpose: A dosimetric study to quantitatively compare radiotherapy treatment plans for Askin's tumor using Electron Arc (EA) vs. photon Intensity Modulated Radiotherapy (IMRT). Materials and methods: Five patients treated with EA were included in this study. Treatment plans were generated for each patient using EA and IMRT. Plans were compared using dose volume histograms (DVH) of the Planning Target Volume (PTV) and Organs at Risk (OAR). Results: IMRT resulted in superior PTV coverage, and homogeneous dose distribution compared to EA. For EA, 92% of the PTV was covered to 85% of the dose compared to IMRT in which 96% was covered to 95% of the dose. V 107 that represents the hot spot within the PTV was more in IMRT compared to EA: 7.4(±2)% vs. 3(±0.5)%, respectively. With PTVs located close to the spinal cord (SC), the dose to SC was more with EA, whereas for PTVs located away from the SC, the dose to SC was more with IMRT. The cardiac dose profile was similar to that of SC. Ipsilateral lung received lower doses with IMRT while contralateral lung received higher dose with IMRT compared to EA. For non-OAR normal tissues, IMRT resulted in large volumes of low dose regions. Conclusions: IMRT resulted in superior PTV coverage and sparing of OAR compared to EA plans. Although IMRT seems to be superior to EA, one needs to keep in mind the volume of low dose regions associated with IMRT, especially while treating young children

  17. Atomic Energy Control Board 1991-92 estimates part III expenditure plan

    International Nuclear Information System (INIS)

    1991-01-01

    This Expenditure Plan is designed to be used as a reference document. As such, it contains several levels of detail to respond to the various needs of its audience. This Plan is divided into two sections. Section 1 presents an overview of the Program including a description, information on its background, objectives and planning perspective as well as performance information that forms the basis for the resources requested. Section 2 provides further information on costs and resources as well as special analyses that the reader may require to understand the Program more fully. Section 1 is preceded by details of Spending Authorities from Part 2 of the Estimates and Volume 2 of the Public Accounts. This is to provide continuity with other Estimates documents and to help in assessing the Program's financial performance over the past year. 22 figs

  18. Atomic Energy Control Board 1991-92 estimates part III expenditure plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    This Expenditure Plan is designed to be used as a reference document. As such, it contains several levels of detail to respond to the various needs of its audience. This Plan is divided into two sections. Section 1 presents an overview of the Program including a description, information on its background, objectives and planning perspective as well as performance information that forms the basis for the resources requested. Section 2 provides further information on costs and resources as well as special analyses that the reader may require to understand the Program more fully. Section 1 is preceded by details of Spending Authorities from Part 2 of the Estimates and Volume 2 of the Public Accounts. This is to provide continuity with other Estimates documents and to help in assessing the Program`s financial performance over the past year. 22 figs.

  19. Atomic Energy Control Board 1992-93 estimates part III expenditure plan

    International Nuclear Information System (INIS)

    1992-01-01

    This Expenditure Plan is designed to be used as a reference document. As such, it contains several levels of detail to respond to the various needs of its audience. This Plan is divided into two sections. Section 1 presents an overview of the Program including a description, information on its background, objectives and planning perspective as well as performance information that forms the basis for the resources requested. Section 2 provides further information on costs and resources as well as special analyses that the reader may require to understand the Program more fully. Section 1 is preceded by details of Spending Authorities from Part 2 of the Estimates and Volume 2 of the Public Accounts. This is to provide continuity with other Estimates documents and to help in assessing the Program's financial performance over the past year. 7 refs., 21 figs

  20. Atomic Energy Control Board 1992-93 estimates part III expenditure plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    This Expenditure Plan is designed to be used as a reference document. As such, it contains several levels of detail to respond to the various needs of its audience. This Plan is divided into two sections. Section 1 presents an overview of the Program including a description, information on its background, objectives and planning perspective as well as performance information that forms the basis for the resources requested. Section 2 provides further information on costs and resources as well as special analyses that the reader may require to understand the Program more fully. Section 1 is preceded by details of Spending Authorities from Part 2 of the Estimates and Volume 2 of the Public Accounts. This is to provide continuity with other Estimates documents and to help in assessing the Program`s financial performance over the past year. 7 refs., 21 figs.

  1. Effects of placement point of background music on shopping website.

    Science.gov (United States)

    Lai, Chien-Jung; Chiang, Chia-Chi

    2012-01-01

    Consumer on-line behaviors are more important than ever due to highly growth of on-line shopping. The purposes of this study were to design placement methods of background music for shopping website and examine the effect on browsers' emotional and cognitive response. Three placement points of background music during the browsing, i.e. 2 min., 4 min., and 6 min. from the start of browsing were considered for entry points. Both browsing without music (no music) and browsing with constant music volume (full music) were treated as control groups. Participants' emotional state, approach-avoidance behavior intention, and action to adjust music volume were collected. Results showed that participants had a higher level of pleasure, arousal and approach behavior intention for the three placement points than for no music and full music. Most of the participants for full music (5/6) adjusted the background music. Only 16.7% (3/18) participants for other levels turn off the background music. The results indicate that playing background music after the start of browsing is benefit for on-line shopping atmosphere. It is inappropriate to place background music at the start of browsing shopping website. The marketer must manipulated placement methods of background music for a web store carefully.

  2. Inverse planning and class solutions for brachytherapy treatment planning

    International Nuclear Information System (INIS)

    Trnkova, P.

    2010-01-01

    Brachytherapy or interventional radiooncology is a method of radiation therapy. It is a method, where a small encapsulated radioactive source is placed near to / in the tumour and therefore delivers high doses directly to the target volume. Organs at risk (OARs) are spared due to the inverse square dose fall-off. In the past years there was a slight stagnation in the development of techniques for brachytherapy treatment. While external beam radiotherapy became more and more sophisticated, in brachytherapy traditional methods have been still used. Recently, 3D imaging was considered also as the modality for brachytherapy and more precise brachytherapy could expand. Nowadays, an image guided brachytherapy is state-of-art in many centres. Integration of imaging methods lead to the dose distribution individually tailored for each patient. Treatment plan optimization is mostly performed manually as an adaptation of a standard loading pattern. Recently, inverse planning approaches have been introduced into brachytherapy. The aim of this doctoral thesis was to analyze inverse planning and to develop concepts how to integrate inverse planning into cervical cancer brachytherapy. First part of the thesis analyzes the Hybrid Inverse treatment Planning and Optimization (HIPO) algorithm and proposes a workflow how to safely work with this algorithm. The problem of inverse planning generally is that only the dose and volume parameters are taken into account and spatial dose distribution is neglected. This fact can lead to unwanted high dose regions in a normal tissue. A unique implementation of HIPO into the treatment planning system using additional features enabled to create treatment plans similar to the plans resulting from manual optimization and to shape the high dose regions inside the CTV. In the second part the HIPO algorithm is compared to the Inverse Planning Simulated Annealing (IPSA) algorithm. IPSA is implemented into the commercial treatment planning system. It

  3. Open-source software for demand forecasting of clinical laboratory test volumes using time-series analysis

    Directory of Open Access Journals (Sweden)

    Emad A Mohammed

    2017-01-01

    Full Text Available Background: Demand forecasting is the area of predictive analytics devoted to predicting future volumes of services or consumables. Fair understanding and estimation of how demand will vary facilitates the optimal utilization of resources. In a medical laboratory, accurate forecasting of future demand, that is, test volumes, can increase efficiency and facilitate long-term laboratory planning. Importantly, in an era of utilization management initiatives, accurately predicted volumes compared to the realized test volumes can form a precise way to evaluate utilization management initiatives. Laboratory test volumes are often highly amenable to forecasting by time-series models; however, the statistical software needed to do this is generally either expensive or highly technical. Method: In this paper, we describe an open-source web-based software tool for time-series forecasting and explain how to use it as a demand forecasting tool in clinical laboratories to estimate test volumes. Results: This tool has three different models, that is, Holt-Winters multiplicative, Holt-Winters additive, and simple linear regression. Moreover, these models are ranked and the best one is highlighted. Conclusion: This tool will allow anyone with historic test volume data to model future demand.

  4. Advantages of three-dimensional treatment planning in radiation therapy

    International Nuclear Information System (INIS)

    Attalla, E.M.; ELSAyed, A.A.; ElGantiry, M.; ElTahher, Z.

    2003-01-01

    This study was designed to demonstrate the feasibility of three-dimensional (3-D) treatment planning in-patients maxilla, breast, bladder, and lung tumors to explore its potential therapeutic advantage over the traditional dimensional (2-D) approach in these diseases. Conventional two-dimensional (2-D) treatment planning was compared to three-dimensional (3-D) treatment planning. In five selected disease sites, plans calculated with both types of treatment planning were compared. The (3-D) treatment planning system used in this work TMS version 5.1 B from helax AB is based on a monte Carlo-based pencil beam model. The other treatment planning system (2-D 0, introduced in this study was the multi data treatment planning system version 2.35. For the volumes of interest; quality of dose distribution concerning homogeneity in the target volume and the isodose distribution in organs at risk, was discussed. Qualitative and quantitative comparisons between the two planning systems were made using dose volume histograms (DVH's) . For comparisons of dose distributions in real-patient cases, differences ranged from 0.8% to 6.4% for 6 MV, while in case of 18 MV photon, it ranged from 1,8% to 6.5% and was within -+3 standard deviations for the dose between the two planning systems.Dose volume histogram (DVH) shows volume reduction of the radiation-related organs at risk 3-D planning

  5. Dose distribution assessment (comparison) in the target volume treated with VMAT given by the planning system and evaluated by TL dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Bravim, A.; Sakuraba, R.K.; Campos, L.L., E-mail: ambravim@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2015-07-01

    Volumetric-modulated arc therapy (VMAT) is a relatively new therapy technique in which treatment is delivered using a cone beam that rotates around the patient. The radiation is delivered in a continuous gantry rotation while the cone beam is modulated by the intertwining of dynamic multileaf collimators (MLCs). Studies of VMAT plans have shown reduction in the treatment delivery time and monitor units (MU) comparable to IMRT plans improving major comfort to the patient and reducing uncertainties associated with patient movement during treatment. The treatment using VMAT minimizes the biological effects of radiation to critical structures near to the target volumes and produces excellent dose distributions. The dosimetry of ionizing radiation is essential for the radiological protection programs for quality assurance and licensing of equipment. For radiation oncology a quality assurance program is essentially to maintain the quality of patient care. As the VMAT is a new technique of radiation therapy it is important to optimize quality assurance mechanisms to ensure that tests are performed in order to preserve the patient and the equipment. This paper aims to determinate the dose distribution in the target volume (tumor to be treated) and the scattered dose distribution in the risk organs for VMAT technique comparing data given by the planning system and thermoluminescent (TL) response. (author)

  6. The Magic Background of Pearl Harbor. Volume 3. Appendix

    Science.gov (United States)

    1977-01-01

    activities in the Americas to confer with our Minister there, in order to realize our plans in a concrete fashion based on would like to bring to your...Nanking, Shanghai, Tientsin October 2, 1941 Circular # 2110. (Part 2 of 3.) Message to Peking # 564. States: 1. Early in August when the Heian Maru left...America are, as I have given them above. Both the incidents concerning the passengers boarding the Heian Maru and the Asama Maru occurred immediately

  7. A comparison of arc-based and static mini-multileaf collimator-based radiosurgery treatment plans

    International Nuclear Information System (INIS)

    Kubo, Hideo Dale; Pappas, Conrad T.E.; Wilder, Richard B.

    1997-01-01

    Background: The purpose of this study is to compare arc-based and mini-multileaf collimator (mMLC)-based radiosurgery treatment plans using isodose distributions and dose-volume histograms. Methods: Of 11 patients who underwent conventional arc-based radiosurgery for intracranial malignancies, four were treated with one isocenter, four were treated with two isocenters and three were treated with three isocenters. The same cases were re-planned using a test version of mMLC-based radiosurgery software for multiple static non-coplanar fields. Results and conclusion: For non-spherical targets, treatment planning is relatively intuitive with mMLC-based radiosurgery, reducing the amount of time required for planning. Moreover, a lower dose of radiation is delivered to normal tissue with mMLC-based radiosurgery than with arc-based radiosurgery, which theoretically should lead to a reduced risk of complications

  8. Consequences of additional use of PET information for target volume delineation and radiotherapy dose distribution for esophageal cancer

    International Nuclear Information System (INIS)

    Muijs, Christina T.; Schreurs, Liesbeth M.; Busz, Dianne M.; Beukema, Jannet C.; Borden, Arnout J. van der; Pruim, Jan; Van der Jagt, Eric J.; Plukker, John Th.; Langendijk, Johannes A.

    2009-01-01

    Background and purpose: To determine the consequences of target volume (TV) modifications, based on the additional use of PET information, on radiation planning, assuming PET/CT-imaging represents the true extent of the tumour. Materials and methods: For 21 patients with esophageal cancer, two separate TV's were retrospectively defined based on CT (CT-TV) and co-registered PET/CT images (PET/CT-TV). Two 3D-CRT plans (prescribed dose 50.4 Gy) were constructed to cover the corresponding TV's. Subsequently, these plans were compared for target coverage, normal tissue dose-volume histograms and the corresponding normal tissue complication probability (NTCP) values. Results: The addition of PET led to the modification of CT-TV with at least 10% in 12 of 21 patients (57%) (reduction in 9, enlargement in 3). PET/CT-TV was inadequately covered by the CT-based treatment plan in 8 patients (36%). Treatment plan modifications resulted in significant changes (p < 0.05) in dose distributions to heart and lungs. Corresponding changes in NTCP values ranged from -3% to +2% for radiation pneumonitis and from -0.2% to +1.2% for cardiac mortality. Conclusions: This study demonstrated that TV's based on CT might exclude PET-avid disease. Consequences are under dosing and thereby possibly ineffective treatment. Moreover, the addition of PET in radiation planning might result in clinical important changes in NTCP.

  9. Is ad-hoc plan adaptation based on 2-Step IMRT feasible?

    International Nuclear Information System (INIS)

    Bratengeier, Klaus; Polat, Buelent; Gainey, Mark; Grewenig, Patricia; Meyer, Juergen; Flentje, Michael

    2009-01-01

    Background: The ability of a geometry-based method to expeditiously adapt a '2-Step' step and shoot IMRT plan was explored. Both changes of the geometry of target and organ at risk have to be balanced. A retrospective prostate planning study was performed to investigate the relative benefits of beam segment adaptation to the changes in target and organ at risk coverage. Methods: Four patients with six planning cases with extraordinarily large deformations of rectum and prostate were chosen for the study. A 9-field IMRT plan (A) using 2-Step IMRT segments was planned on an initial CT study. The plan had to fulfil all the requirements of a conventional high-quality step and shoot IMRT plan. To adapt to changes of the anatomy in a further CT data set, three approaches were considered: the original plan with optimized isocentre position (B), a newly optimized plan (C) and the original plan, adapted using the 2-Step IMRT optimization rules (D). DVH parameters were utilized for quantification of plan quality: D 99 for the CTV and the central planning target volume (PTV), D 95 for an outer PTV, V 95 , V 80 and V 50 for rectum and bladder. Results: The adapted plan (D) achieved almost the same target coverage as the newly optimized plan (C). Target coverage for plan B was poor and for the organs at risk, the rectum V 80 was slightly increased. The volume with more than 95% of the target dose (V 95 ) was 1.5 ± 1.5 cm 3 for the newly optimized plan (C), compared to 2.2 ± 1.3 cm 3 for the original plan (A) and 7.2 ± 4.8 cm 3 (B) on the first and the second CT, respectively. The adapted plan resulted in 4.3 ± 2.1 cm 3 (D), an intermediate dose load to the rectum. All other parameters were comparable for the newly optimized and the adapted plan. Conclusions: The first results for adaptation of interfractional changes using the 2-Step IMRT algorithm are encouraging. The plans were superior to plans with optimized isocentre position and only marginally inferior to a newly

  10. Functional avoidance of lung in plan optimization with an aperture-based inverse planning system

    International Nuclear Information System (INIS)

    St-Hilaire, Jason; Lavoie, Caroline; Dagnault, Anne; Beaulieu, Frederic; Morin, Francis; Beaulieu, Luc; Tremblay, Daniel

    2011-01-01

    Purpose: To implement SPECT-based optimization in an anatomy-based aperture inverse planning system for the functional avoidance of lung in thoracic irradiation. Material and methods: SPECT information has been introduced as a voxel-by-voxel modulation of lung importance factors proportionally to the local perfusion count. Fifteen cases of lung cancer have been retrospectively analyzed by generating angle-optimized non-coplanar plans, comparing a purely anatomical approach and our functional approach. Planning target volume coverage and lung sparing have been compared. Statistical significance was assessed by a Wilcoxon matched pairs test. Results: For similar target coverage, perfusion-weighted volume receiving 10 Gy was reduced by a median of 2.2% (p = 0.022) and mean perfusion-weighted lung dose, by a median of 0.9 Gy (p = 0.001). A separate analysis of patients with localized or non-uniform hypoperfusion could not show which would benefit more from SPECT-based treatment planning. Redirection of dose sometimes created overdosage regions in the target volume. Plans consisted of a similar number of segments and monitor units. Conclusions: Angle optimization and SPECT-based modulation of importance factors allowed for functional avoidance of the lung while preserving target coverage. The technique could be also applied to implement PET-based modulation inside the target volume, leading to a safer dose escalation.

  11. Transcranial sonography: integration into target volume definition for glioblastoma multiforme

    International Nuclear Information System (INIS)

    Vordermark, Dirk; Becker, Georg; Flentje, Michael; Richter, Susanne; Goerttler-Krauspe, Irene; Koelbl, Oliver

    2000-01-01

    Purpose: Recent studies indicate that transcranial sonography (TCS) reliably displays the extension of malignant brain tumors. The effect of integrating TCS into radiotherapy planning for glioblastoma multiforme (GBM) was investigated herein. Methods and Materials: Thirteen patients subtotally resected for GBM underwent TCS during radiotherapy planning and were conventionally treated (54 to 60 Gy). Gross tumor volumes (GTVs) and stereotactic boost planning target volumes (PTVs, 3-mm margin) were created, based on contrast enhancement on computed tomography (CT) only (PTV CT ) or the combined CT and TCS information (PTV CT+TCS ). Noncoplonar conformal treatment plans for both PTVs were compared. Tumor progression patterns and preoperative magnetic resonance imaging (MRI) were related to both PTVs. Results: A sufficient temporal bone window for TCS was present in 11 of 13 patients. GTVs as defined by TCS were considerably larger than the respective CT volumes: Of the composite GTV CT+TCS (median volume 42 ml), 23%, 13%, and 66% (medians) were covered by the overlap of both methods, CT only and TCS only, respectively. Median sizes of PTV CT and PTV CT+TCS were 34 and 74 ml, respectively. Addition of TCS to CT information led to a median increase of the volume irradiated within the 80% isodose by 32 ml (median factor 1.51). PTV CT+TCS volume was at median 24% of a 'conventional' MRI(T2)-based PTV. Of eight progressions analyzed, three and six occurred inside the 80% isodose of the plans for PTV CT and for PTV CT+TCS , respectively. Conclusion: Addition of TCS tumor volume to the contrast-enhancing CT volume in postoperative radiotherapy planning for GBM increases the treated volume by a median factor of 1.5. Since a high frequency of marginal recurrences is reported from dose-escalation trials of this disease, TCS may complement established methods in PTV definition

  12. MRI-assisted versus conventional treatment planning in brachytherapy of cervical and endometrial carcinoma: The impact of individual anatomy on dose distribution in target volume and organs at risk

    International Nuclear Information System (INIS)

    Wulf, Joern; Sauer, Otto A.; Herbolsheimer, Michael; Oppitz, Ulrich; Flentje, Michael

    1996-01-01

    Objective: Dose prescription and definition of target volume in brachytherapy of cervical and endometrial cancer are calculated to standard points as Manchester point A or point My(ometrium) in most centers. Calculation of doses to organs at risk mainly relies on ICRU-report 38. But standard dose prescription neglects individual patient anatomy. While MRI and CT had widespread impact on individual planning in external beam radiotherapy, there is still a minor influence on brachytherapy. The impact of individual anatomy on dose distribution in target volume and organs at risk demonstrates the objective of individual brachytherapy planning. Materials and Methods: 8 patients with cervical and 4 patients with endometrial carcinoma underwent MRI of the pelvis with in-situ applicators (ring-tandem applicators for cervical carcinoma and modified Heyman-capsules for endometrial carcinoma). T1w slices were angulated coronal and sagittal to get rectangular reproductions to applicator axis. Orthogonal or isocentric X-ray films for conventional treatment planning were done. MRI-information on target and organs at risk was transformed into coordinates relative to applicator axis and dose calculation on the database of conventional treatment planning was performed by Nucletron Planning System PLATO. Isodoses were projected into MRI slices. Prescribed dose to patients with cervical cancer was 8.5 Gy to point A resp. 10 Gy to point My (2cm below fundal myometrium and 2cm lateral applicator axis) in endometrial cancer. Results: Dose prescription to Manchester point A or point My represented in only 50% of cases uterine serosa. Instead of 2cm lateral of applicator axis, uterine surface ranged from 1.0 cm to 3.9 cm at the level of point A (mean 2.25 cm coronal and 1.77 cm sagittal) and from 1.5 cm to 4.4 cm at the level of point My (mean 2.7 cm coronal and 2.1 cm sagittal). Uterine volume ranged from 69 cc to 277 cc, mean volume was 150cc. Dose-volume histograms of patients with

  13. Inverse planning for interstitial gynecologic template brachytherapy: truly anatomy-based planning

    International Nuclear Information System (INIS)

    Lessard, Etienne; Hsu, I-Chou; Pouliot, Jean

    2002-01-01

    Purpose: Commercially available optimization schemes generally result in an undesirable dose distribution, because of the particular shapes of tumors extending laterally from the tandem. Dose distribution is therefore manually obtained by adjusting relative dwell time values until an acceptable solution is found. The objective of this work is to present the clinical application of an inverse planning dose optimization tool for the automatic determination of source dwell time values in the treatment of interstitial gynecologic templates. Methods and Materials: In cases where the tumor extends beyond the range of the tandem-ovoid applicator, catheters as well as the tandem are inserted into the paravaginal and parametrial region in an attempt to cover the tumor volume. CT scans of these patients are then used for CT-based dose planning. Dose distribution is obtained manually by varying the relative dwell times until adequate dose coverage is achieved. This manual planning is performed by an experienced physician. In parallel, our in-house inverse planning based on simulated annealing is used to automatically determine which of all possible dwell positions will become active and to calculate the dwell time values needed to fulfill dose constraints applied to the tumor volume and to each organ at risk. To compare the results of these planning methods, dose-volume histograms and isodose distributions were generated for the target and each organ at risk. Results: This procedure has been applied for the dose planning of 12 consecutive interstitial gynecologic templates cases. For all cases, once the anatomy was contoured, the routine of inverse planning based on simulated annealing found the solution to the dose constraints within 1 min of CPU time. In comparison, manual planning took more than 45 min. The inverse planning-generated plans showed improved protection to organs at risk for the same coverage compared to manual planning. Conclusion: This inverse planning tool

  14. Intensity modulated radiation therapy (IMRT: differences in target volumes and improvement in clinically relevant doses to small bowel in rectal carcinoma

    Directory of Open Access Journals (Sweden)

    Delclos Marc E

    2011-06-01

    Full Text Available Abstract Background A strong dose-volume relationship exists between the amount of small bowel receiving low- to intermediate-doses of radiation and the rates of acute, severe gastrointestinal toxicity, principally diarrhea. There is considerable interest in the application of highly conformal treatment approaches, such as intensity-modulated radiation therapy (IMRT, to reduce dose to adjacent organs-at-risk in the treatment of carcinoma of the rectum. Therefore, we performed a comprehensive dosimetric evaluation of IMRT compared to 3-dimensional conformal radiation therapy (3DCRT in standard, preoperative treatment for rectal cancer. Methods Using RTOG consensus anorectal contouring guidelines, treatment volumes were generated for ten patients treated preoperatively at our institution for rectal carcinoma, with IMRT plans compared to plans derived from classic anatomic landmarks, as well as 3DCRT plans treating the RTOG consensus volume. The patients were all T3, were node-negative (N = 1 or node-positive (N = 9, and were planned to a total dose of 45-Gy. Pairwise comparisons were made between IMRT and 3DCRT plans with respect to dose-volume histogram parameters. Results IMRT plans had superior PTV coverage, dose homogeneity, and conformality in treatment of the gross disease and at-risk nodal volume, in comparison to 3DCRT. Additionally, in comparison to the 3DCRT plans, IMRT achieved a concomitant reduction in doses to the bowel (small bowel mean dose: 18.6-Gy IMRT versus 25.2-Gy 3DCRT; p = 0.005, bladder (V40Gy: 56.8% IMRT versus 75.4% 3DCRT; p = 0.005, pelvic bones (V40Gy: 47.0% IMRT versus 56.9% 3DCRT; p = 0.005, and femoral heads (V40Gy: 3.4% IMRT versus 9.1% 3DCRT; p = 0.005, with an improvement in absolute volumes of small bowel receiving dose levels known to induce clinically-relevant acute toxicity (small bowel V15Gy: 138-cc IMRT versus 157-cc 3DCRT; p = 0.005. We found that the IMRT treatment volumes were typically larger than that

  15. Dosimetric improvements following 3D planning of tangential breast irradiation

    International Nuclear Information System (INIS)

    Aref, Amr; Thornton, Dale; Youssef, Emad; He, Tony; Tekyi-Mensah, Samuel; Denton, Lori; Ezzell, Gary

    2000-01-01

    Purpose: To evaluate the dosimetric difference between a simple radiation therapy plan utilizing a single contour and a more complex three-dimensional (3D) plan utilizing multiple contours, lung inhomogeneity correction, and dose-based compensators. Methods and Materials: This is a study of the radiation therapy (RT) plans of 85 patients with early breast cancer. All patients were considered for breast-conserving management and treated by conventional tangential fields technique. Two plans were generated for each patient. The first RT plan was based on a single contour taken at the central axis and utilized two wedges. The second RT plan was generated by using the 3D planning system to design dose-based compensators after lung inhomogeneity correction had been made. The endpoints of the study were the comparison between the volumes receiving greater than 105% and greater than 110% of the reference dose, as well as the magnitude of the treated volume maximum dose. Dosimetric improvement was defined to be of significant value if the volume receiving > 105% of one plan was reduced by at least 50% with the absolute difference between the volumes being 5% or greater. The dosimetric improvements in 49 3D plans (58%) were considered of significant value. Patients' field separation and breast size did not predict the magnitude of improvement in dosimetry. Conclusion: Dose-based compensator plans significantly reduced the volumes receiving > 105%, >110%, and volume maximum dose.

  16. F-18-FDG-PET Confined Radiotherapy of Locally Advanced NSCLC With Concomitant Chemotherapy: Results of the PET-PLAN Pilot Trial

    Energy Technology Data Exchange (ETDEWEB)

    Fleckenstein, Jochen [Department of Radiotherapy and Radiation Oncology, Saarland University Medical School, Homburg (Germany); Hellwig, Dirk [Department of Nuclear Medicine, Saarland University Medical School, Homburg (Germany); Kremp, Stephanie [Department of Radiotherapy and Radiation Oncology, Saarland University Medical School, Homburg (Germany); Grgic, Aleksandar [Department of Nuclear Medicine, Saarland University Medical School, Homburg (Germany); Groeschel, Andreas [Department of Internal Medicine V, Saarland University Medical School, Homburg (Germany); Kirsch, Carl-Martin [Department of Nuclear Medicine, Saarland University Medical School, Homburg (Germany); Nestle, Ursula [Department of Nuclear Medicine, Saarland University Medical School, Homburg (Germany); Clinic for Radiotherapy, University Hospital, Freiburg (Germany); Ruebe, Christian, E-mail: christian.ruebe@uks.eu [Department of Radiotherapy and Radiation Oncology, Saarland University Medical School, Homburg (Germany)

    2011-11-15

    Purpose: The integration of fluoro-deoxy-D-glucose positron emission tomography (FDG-PET) in the process of radiotherapy (RT) planning of locally advanced non-small-cell lung cancer (NSCLC) may improve diagnostic accuracy and minimize interobserver variability compared with target volume definition solely based on computed tomography. Furthermore, irradiating only FDG-PET-positive findings and omitting elective nodal regions may allow dose escalation by treating smaller volumes. The aim of this prospective pilot trial was to evaluate the therapeutic safety of FDG-PET-based RT treatment planning with an autocontour-derived delineation of the primary tumor. Methods and Materials: Eligible patients had Stages II-III inoperable NSCLC, and simultaneous, platinum-based radiochemotherapy was indicated. FDG-PET and computed tomography acquisitions in RT treatment planning position were coregistered. The clinical target volume (CTV) included the FDG-PET-defined primary tumor, which was autodelineated with a source-to-background algorithm, plus FDG-PET-positive lymph node stations. Limited by dose restrictions for normal tissues, prescribed total doses were in the range of 66.6 to 73.8 Gy. The primary endpoint was the rate of out-of-field isolated nodal recurrences (INR). Results: As per intent to treat, 32 patients received radiochemotherapy. In 15 of these patients, dose escalation above 66.6 Gy was achieved. No Grade 4 toxicities occurred. After a median follow-up time of 27.2 months, the estimated median survival time was 19.3 months. During the observation period, one INR was observed in 23 evaluable patients. Conclusions: FDG-PET-confined target volume definition in radiochemotherapy of NSCLC, based on a contrast-oriented source-to-background algorithm, was associated with a low risk of INR. It might provide improved tumor control because of dose escalation.

  17. Radioactive waste management plan. Plan 82

    International Nuclear Information System (INIS)

    1982-06-01

    The report is the first account of the nuclear power utilities of Sweden about the plans for the final disposal of the radioactive waste products of the nuclear power. Part 1 describes the general background, the plans for research and development, including the necessary facilities. The time schedule and the calculated costs of the operations are presented. (G.B.)

  18. Evaluation of IMRT plans of prostate carcinoma from four treatment planning systems based on Monte Carlo

    International Nuclear Information System (INIS)

    Chi Zifeng; Han Chun; Liu Dan; Cao Yankun; Li Runxiao

    2011-01-01

    Objective: With the Monte Carlo method to recalculate the IMRT dose distributions from four TPS to provide a platform for independent comparison and evaluation of the plan quality.These results will help make a clinical decision as which TPS will be used for prostate IMRT planning. Methods: Eleven prostate cancer cases were planned with the Corvus, Xio, Pinnacle and Eclipse TPS. The plans were recalculated by Monte Carlo using leaf sequences and MUs for individual plans. Dose-volume-histograms and isodose distributions were compared. Other quantities such as D min (the minimum dose received by 99% of CTV/PTV), D max (the maximum dose received by 1% of CTV/PTV), V 110% , V 105% , V 95% (the volume of CTV/PTV receiving 110%, 105%, 95% of the prescription dose), the volume of rectum and bladder receiving >65 Gy and >40 Gy, and the volume of femur receiving >50 Gy were evaluated. Total segments and MUs were also compared. Results: The Monte Carlo results agreed with the dose distributions from the TPS to within 3%/3 mm. The Xio, Pinnacle and Eclipse plans show less target dose heterogeneity and lower V 65 and V 40 for the rectum and bladder compared to the Corvus plans. The PTV D min is about 2 Gy lower for Xio plans than others while the Corvus plans have slightly lower female head V 50 (0.03% and 0.58%) than others. The Corvus plans require significantly most segments (187.8) and MUs (1264.7) to deliver and the Pinnacle plans require fewest segments (82.4) and MUs (703.6). Conclusions: We have tested an independent Monte Carlo dose calculation system for dose reconstruction and plan evaluation. This system provides a platform for the fair comparison and evaluation of treatment plans to facilitate clinical decision making in selecting a TPS and beam delivery system for particular treatment sites. (authors)

  19. Berkeley Low Background Facility

    International Nuclear Information System (INIS)

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-01-01

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

  20. Significance of breast boost volume changes during radiotherapy in relation to current clinical interobserver variations

    International Nuclear Information System (INIS)

    Hurkmans, Coen; Admiraal, Marjan; Sangen, Maurice van der; Dijkmans, Ingrid

    2009-01-01

    Background and purpose: Nowadays, many departments introduce CT images for breast irradiation techniques, aiming to obtain a better accuracy in the definition of the relevant target volumes. However, the definition of the breast boost volume based on CT images requires further investigation, because it may not only vary between observers, but it may also change during the course of treatment. This study aims to quantify the variability of the CT based visible boost volume (VBV) during the course of treatment in relation to the variability between observers. Materials and methods: Ten patients with stage T1-2 invasive breast cancer treated with breast conservative surgery and post surgical radiotherapy were included in this study. In addition to the regular planning CT which is obtained several days prior to radiotherapy, three additional CT scans were acquired 3, 5 and 7 weeks after the planning CT scan. Four radiation oncologists delineated the VBV in all scans. Conformity of the delineations was analysed both between observers, and between scans taken at different periods of the radiotherapy treatment. Results: The VBV averaged over all patients decreased during the course of the treatment from an initial 40 cm 3 to 28 cm 3 , 27 cm 3 and 25 cm 3 after 3, 5 and 7 weeks, respectively. Assuming the VBV to be spherical, this corresponds to a reduction in diameter of 5-6 mm. More detailed analysis revealed that this reduction was more pronounced when radiotherapy started within 30 days after surgery. These boost volume changes over time were found to be significant (p = 0.02) even in the presence of interobserver variations. Moreover, the conformity index (CI) for the volume changes was of the same magnitude as the conformity index for the interobserver variation (0.25 and 0.31, respectively). Conclusions: Breast boost volume variations during a course of radiotherapy are significant in relation to current clinical interobserver variations. This is an important

  1. Hazardous air pollutant emissions from process units in the synthetic organic chemical manufacturing industry: Background information for proposed standards. Volume 1B. Control technologies. Draft report

    International Nuclear Information System (INIS)

    1992-11-01

    A draft rule for the regulation of emissions of organic hazardous air pollutants (HAP's) from chemical processes of the synthetic organic chemical manufacturing industry (SOCMI) is being proposed under the authority of Sections 112, 114, 116, and 301 of the Clean Air Act, as amended in 1990. The volume of the Background Information Document presents discussions of control technologies used in the industry and the costs of those technologies

  2. Method and apparatus for imaging volume data

    International Nuclear Information System (INIS)

    Drebin, R.; Carpenter, L.C.

    1987-01-01

    An imaging system projects a two dimensional representation of three dimensional volumes where surface boundaries and objects internal to the volumes are readily shown, and hidden surfaces and the surface boundaries themselves are accurately rendered by determining volume elements or voxels. An image volume representing a volume object or data structure is written into memory. A color and opacity is assigned to each voxel within the volume and stored as a red (R), green (G), blue (B), and opacity (A) component, three dimensional data volume. The RGBA assignment for each voxel is determined based on the percentage component composition of the materials represented in the volume, and thus, the percentage of color and transparency associated with those materials. The voxels in the RGBA volume are used as mathematical filters such that each successive voxel filter is overlayed over a prior background voxel filter. Through a linear interpolation, a new background filter is determined and generated. The interpolation is successively performed for all voxels up to the front most voxel for the plane of view. The method is repeated until all display voxels are determined for the plane of view. (author)

  3. Waste Feed Delivery Planning at Hanford - 13232

    International Nuclear Information System (INIS)

    Certa, Paul J.; Hohl, Ted M.; Kelly, James W.; Larsen, Douglas C.; West, Elizha B.; Ritari, Jaakob S.; Rodriguez, Juissepp S.

    2013-01-01

    The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades. (authors)

  4. Waste Feed Delivery Planning at Hanford - 13232

    Energy Technology Data Exchange (ETDEWEB)

    Certa, Paul J.; Hohl, Ted M.; Kelly, James W.; Larsen, Douglas C.; West, Elizha B.; Ritari, Jaakob S.; Rodriguez, Juissepp S. [Washington River Protection Solutions, LLC, P.O. 850, Richland, WA 99352 (United States)

    2013-07-01

    The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades. (authors)

  5. Waste feed delivery planning at Hanford-13232

    International Nuclear Information System (INIS)

    Certa, Paul J.; West, Elizha B.; Rodriguez, Juissepp S.; Hohl, Ted M.; Larsen, Douglas C.; Ritari, Jaakob S.; Kelly, James W.

    2013-01-01

    The Integrated Waste Feed Delivery Plan (IWFDP) describes how waste feed will be delivered to the Waste Treatment and Immobilization Plant (WTP) to safely and efficiently accomplish the River Protection Project (RPP) mission. The IWFDP, which is integrated with the Baseline Case operating scenario, is comprised of three volumes. Volume 1 - Process Strategy provides an overview of waste feed delivery (WFD) and describes how the WFD system will be used to prepare and deliver feed to the WTP based on the equipment configuration and functional capabilities of the WFD system. Volume 2 - Campaign Plan describes the plans for the first eight campaigns for delivery to the WTP, evaluates projected feed for systematic issues, projects 242-A Evaporator campaigns, and evaluates double-shell tank (DST) space and availability of contingency feed. Volume 3 - Project Plan identifies the scope and timing of the DST and infrastructure upgrade projects necessary to feed the WTP, and coordinates over 30 projectized projects and operational activities that comprise the needed WFD upgrades

  6. Viability Assessment Volume 1

    International Nuclear Information System (INIS)

    1998-01-01

    Since May 1996, under its draft Civilian Radioactive Waste Management Program Plan (DOE 1996), DOE has been carrying out a 5-year program of work to support the decision in 2001 by the Secretary of Energy on whether or not to recommend the site to the President. Part of this program was to address major unresolved technical issues and to complete an assessment of the viability of the Yucca Mountain site by 1998. Affirming the DOE plans, Congress directed DOE in the 1997 Energy and Water Development Appropriations Act to provide a viability assessment of the Yucca Mountain site to Congress and the President. This Viability Assessment (VA) document is the DOE report to Congress and the President. They are expected to use the VA to make an informed decision about program direction and funding. Drawing on 15 years of scientific investigation and design work at Yucca Mountain, the VA summarizes a large technical basis of field investigations, laboratory tests, models, analyses, and engineering, described in cited references. The VA identifies the major uncertainties relevant to the technical defensibility of DOE analyses and designs, the DOE approach to managing these uncertainties, and the status of work toward the site recommendation and LA. The VA also identifies DOE plans for the remaining work, and the estimated costs of completing an LA and constructing and operating a repository. The attention to uncertainties is important because DOE must evaluate how the repository will perform during the next 10,000 years or longer. Uncertainties exist because of variability in the natural (geologic and hydrologic) systems at Yucca Mountain and because of imperfect scientific understanding of the natural processes that might affect the repository system. This is Volume 1 and it covers, Introduction and Site Characteristics, includes a high-level summary of the results of the VA and some additional background information. (The overview is bound separately.) Section 1 of Volume

  7. Impact of database quality in knowledge-based treatment planning for prostate cancer.

    Science.gov (United States)

    Wall, Phillip D H; Carver, Robert L; Fontenot, Jonas D

    2018-03-13

    This article investigates dose-volume prediction improvements in a common knowledge-based planning (KBP) method using a Pareto plan database compared with using a conventional, clinical plan database. Two plan databases were created using retrospective, anonymized data of 124 volumetric modulated arc therapy (VMAT) prostate cancer patients. The clinical plan database (CPD) contained planning data from each patient's clinically treated VMAT plan, which were manually optimized by various planners. The multicriteria optimization database (MCOD) contained Pareto-optimal plan data from VMAT plans created using a standardized multicriteria optimization protocol. Overlap volume histograms, incorporating fractional organ at risk volumes only within the treatment fields, were computed for each patient and used to match new patient anatomy to similar database patients. For each database patient, CPD and MCOD KBP predictions were generated for D 10 , D 30 , D 50 , D 65 , and D 80 of the bladder and rectum in a leave-one-out manner. Prediction achievability was evaluated through a replanning study on a subset of 31 randomly selected database patients using the best KBP predictions, regardless of plan database origin, as planning goals. MCOD predictions were significantly lower than CPD predictions for all 5 bladder dose-volumes and rectum D 50 (P = .004) and D 65 (P databases affects the performance and achievability of dose-volume predictions from a common knowledge-based planning approach for prostate cancer. Bladder and rectum dose-volume predictions derived from a database of standardized Pareto-optimal plans were compared with those derived from clinical plans manually designed by various planners. Dose-volume predictions from the Pareto plan database were significantly lower overall than those from the clinical plan database, without compromising achievability. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. PlanJury: probabilistic plan evaluation revisited

    Science.gov (United States)

    Witte, M.; Sonke, J.-J.; van Herk, M.

    2014-03-01

    Purpose: Over a decade ago, the 'Van Herk margin recipe paper' introduced plan evaluation through DVH statistics based on population distributions of systematic and random errors. We extended this work for structures with correlated uncertainties (e.g. lymph nodes or parotid glands), and considered treatment plans containing multiple (overlapping) dose distributions (e.g. conventional lymph node and hypo-fractionated tumor doses) for which different image guidance protocols may lead to correlated errors. Methods: A command-line software tool 'PlanJury' was developed which reads 3D dose and structure data exported from a treatment planning system. Uncertainties are specified by standard deviations and correlation coefficients. Parameters control the DVH statistics to be computed: e.g. the probability of reaching a DVH constraint, or the dose absorbed at given confidence in a (combined) volume. Code was written in C++ and parallelized using OpenMP. Testing geometries were constructed using idealized spherical volumes and dose distributions. Results: Negligible stochastic noise could be attained within two minutes computation time for a single target. The confidence to properly cover both of two targets was 90% for two synchronously moving targets, but decreased by 7% if the targets moved independently. For two partially covered organs at risk the confidence of at least one organ below the mean dose threshold was 40% for synchronous motion, 36% for uncorrelated motion, but only 20% for either of the organs separately. Two abutting dose distributions ensuring 91% confidence of proper target dose for correlated motions led to 28% lower confidence for uncorrelated motions as relative displacements between the doses resulted in cold spots near the target. Conclusions: Probabilistic plan evaluation can efficiently be performed for complicated treatment planning situations, thus providing important plan quality information unavailable in conventional PTV based evaluations.

  9. A Gaussian mixture model for definition of lung tumor volumes in positron emission tomography

    International Nuclear Information System (INIS)

    Aristophanous, Michalis; Penney, Bill C.; Martel, Mary K.; Pelizzari, Charles A.

    2007-01-01

    The increased interest in 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in radiation treatment planning in the past five years necessitated the independent and accurate segmentation of gross tumor volume (GTV) from FDG-PET scans. In some studies the radiation oncologist contours the GTV based on a computed tomography scan, while incorporating pertinent data from the PET images. Alternatively, a simple threshold, typically 40% of the maximum intensity, has been employed to differentiate tumor from normal tissue, while other researchers have developed algorithms to aid the PET based GTV definition. None of these methods, however, results in reliable PET tumor segmentation that can be used for more sophisticated treatment plans. For this reason, we developed a Gaussian mixture model (GMM) based segmentation technique on selected PET tumor regions from non-small cell lung cancer patients. The purpose of this study was to investigate the feasibility of using a GMM-based tumor volume definition in a robust, reliable and reproducible way. A GMM relies on the idea that any distribution, in our case a distribution of image intensities, can be expressed as a mixture of Gaussian densities representing different classes. According to our implementation, each class belongs to one of three regions in the image; the background (B), the uncertain (U) and the target (T), and from these regions we can obtain the tumor volume. User interaction in the implementation is required, but is limited to the initialization of the model parameters and the selection of an ''analysis region'' to which the modeling is restricted. The segmentation was developed on three and tested on another four clinical cases to ensure robustness against differences observed in the clinic. It also compared favorably with thresholding at 40% of the maximum intensity and a threshold determination function based on tumor to background image intensities proposed in a recent paper. The parts of the

  10. The effect of acetazolamide on cerebral blood volume and intracranial pressure in patients with hydrocephalus. Theoretical background of the acetazolamide challenge test

    International Nuclear Information System (INIS)

    Ogawa, Daiji

    2000-01-01

    The acetazolamide challenge test is one of the useful tests for diagnosing normal pressure hydrocephalus (NPH). It has the advantage of being less invasive than other tests. However, the manner of increment in cerebral blood volume (CBV) has not been well clarified. Therefore, the theoretical background of the test is also unclear. The aims of this study were to evaluate the effect of acetazolamide on CBV and intracranial pressure (ICP) and elucidate the theoretical background of the test. Thirteen patients with NPH were studied. CBV and ICP were measured before and after the intravenous injection of acetazolamide (1000 mg). CBV was evaluated by means of cerebral pool SPECT; ICP was evaluated by OSAKA telesensor or a pressure transducer via ventricular catheter. Immediately after the injection, CBV increased rapidly, reaching its maximum (15% increase) at 6 minutes. Then CBV gradually decreased. ICP also elevated rapidly, reaching its maximum (12.6 mmHg elevation) at 4 minutes. A gradual decrement ICP was observed, and 26 minutes after injection, the ICP became lower than the pre-injection level. The rapid increase in CBV caused the ICP elevation, and the increment ratio reflected the cerebral compliance. Therefore, we concluded that the acetazolamide challenge test is based on the alteration of cerebral compliance seen in NPH patients. The decrement ratio of ICP is affected not only by the resistance cerebrospinal fluid (CSF) absorption but also by decrease in the CBV and CSF production induced by acetazolamide. Consequently, it is difficult to evaluate the resistance of CSF absorption by this test. Because CBV increased in all cases, it is assumed that acetazolamide administration can be used to reliably load the volume. (author)

  11. Hazardous air pollutant emissions from process units in the synthetic organic chemical manufacturing industry: Background information for proposed standards. Volume 1A. National impacts assessment. Draft report

    International Nuclear Information System (INIS)

    1992-11-01

    A draft rule for the regulation of emissions of organic hazardous air pollutants (HAP's) from chemical processes of the synthetic organic chemical manufacturing industry (SOCMI) is being proposed under the authority of Sections 112, 114, 116, and 301 of the Clean Air Act, as amended in 1990. The volume of the Background Information Document presents the results of the national impacts assessment for the proposed rule

  12. Volume arc therapy of gynaecological tumours: target volume coverage improvement without dose increase for critical organs; Arctherapie volumique des tumeurs gynecologiques: amelioration de la couverture du volume cible sans augmentation de la dose aux organes critiques

    Energy Technology Data Exchange (ETDEWEB)

    Ducteil, A.; Kerr, C.; Idri, K.; Fenoglietto, P.; Vieillot, S.; Ailleres, N.; Dubois, J.B.; Azria, D. [CRLC Val-d' Aurelle, Montpellier (France)

    2011-10-15

    The authors report the assessment of the application of conventional intensity-modulated conformational radiotherapy (IMRT) and volume arc-therapy (RapidArc) for the treatment of cervical cancers, with respect to conventional radiotherapy. Dosimetric plans associated with each of these techniques have been compared. Dose-volume histograms of these three plans have also been compared for the previsional target volume (PTV), organs at risk, and sane tissue. IMCT techniques are equivalent in terms of sparing of organs at risk, and improve target volume coverage with respect to conventional radiotherapy. Arc-therapy reduces significantly treatment duration. Short communication

  13. Mechanical homeostasis regulating adipose tissue volume

    Directory of Open Access Journals (Sweden)

    Svedman Paul

    2007-09-01

    Full Text Available Abstract Background The total body adipose tissue volume is regulated by hormonal, nutritional, paracrine, neuronal and genetic control signals, as well as components of cell-cell or cell-matrix interactions. There are no known locally acting homeostatic mechanisms by which growing adipose tissue might adapt its volume. Presentation of the hypothesis Mechanosensitivity has been demonstrated by mesenchymal cells in tissue culture. Adipocyte differentiation has been shown to be inhibited by stretching in vitro, and a pathway for the response has been elucidated. In humans, intermittent stretching of skin for reconstructional purposes leads to thinning of adipose tissue and thickening of epidermis – findings matching those observed in vitro in response to mechanical stimuli. Furthermore, protracted suspension of one leg increases the intermuscular adipose tissue volume of the limb. These findings may indicate a local homeostatic adipose tissue volume-regulating mechanism based on movement-induced reduction of adipocyte differentiation. This function might, during evolution, have been of importance in confined spaces, where overgrowth of adipose tissue could lead to functional disturbance, as for instance in the turtle. In humans, adipose tissue near muscle might in particular be affected, for instance intermuscularly, extraperitoneally and epicardially. Mechanical homeostasis might also contribute to protracted maintainment of soft tissue shape in the face and neck region. Testing of the hypothesis Assessment of messenger RNA-expression of human adipocytes following activity in adjacent muscle is planned, and study of biochemical and volumetric adipose tissue changes in man are proposed. Implications of the hypothesis The interpretation of metabolic disturbances by means of adipose tissue might be influenced. Possible applications in the head and neck were discussed.

  14. Wilderness fire management planning guide

    Science.gov (United States)

    William C. Fischer

    1984-01-01

    Outlines a procedure for fire management planning for parks; wilderness areas; and other wild, natural, or essentially undeveloped areas. Discusses background and philosophy of wilderness fire management, planning concepts, planning elements, and planning methods.

  15. SU-F-T-359: Incorporating Dose Volume Histogram Prediction Into Auto-Planning for Volumetric-Modulated Arc Therapy in Rectal Cancer

    International Nuclear Information System (INIS)

    Li, K; Chen, X; Wang, J; Lu, S; Chen, Y; Hu, W

    2016-01-01

    Purpose: To incorporate dose volume histogram (DVH) prediction into Auto-Planning for volumetric-modulated arc therapy (VMAT) treatment planning and investigate the benefit of this new technique for rectal cancer. Methods: Ninety clinically accepted VMAT plans for patients with rectal cancer were selected and trained in the RapidPlan for DVH prediction. Both internal and external validations were performed before implementing the prediction model. A new VMAT planning method (hybrid-VMAT) was created with combining the DVH prediction and Auto-Planning. For each new patient, the DVH will be predicted and individual DVH constrains will be obtained and were exported as the original optimization parameters to the Auto-Planning (Pinnacle3 treatment planning system, v9.10) for planning. A total of 20 rectal cancer patients previously treated with manual VMAT (manual-VMAT) plans were replanned using this new method. Dosimetric comparisons were performed between manual VMAT and new method plans. Results: Hybrid-VMAT shows similar PTV coverage to manual-VMAT in D2%, D98% and HI (p>0.05) and superior coverage in CI (p=0.000). For the bladder, the means of V40 and mean dose are 36.0% and 35.6Gy for hybrid-VMAT and 42% and 38.0Gy for the manual-VMAT. For the left (right) femur, the means of V30 and mean dose are 10.6% (11.6%) and 17.9Gy (19.2Gy) for the hybrid-VMAT and 25.6% (24.1%) and 27.3Gy (26.2Gy) for the manual-VMAT. The hybrid-VMAT has significantly improved the organs at risk sparing. Conclusion: The integration of DVH prediction and Auto-Planning significantly improve the VMAT plan quality in the rectal cancer radiotherapy. Our results show the benefit of the new method and will be further investigated in other tumor sites.

  16. SU-F-T-359: Incorporating Dose Volume Histogram Prediction Into Auto-Planning for Volumetric-Modulated Arc Therapy in Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Li, K; Chen, X; Wang, J; Lu, S; Chen, Y; Hu, W [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China)

    2016-06-15

    Purpose: To incorporate dose volume histogram (DVH) prediction into Auto-Planning for volumetric-modulated arc therapy (VMAT) treatment planning and investigate the benefit of this new technique for rectal cancer. Methods: Ninety clinically accepted VMAT plans for patients with rectal cancer were selected and trained in the RapidPlan for DVH prediction. Both internal and external validations were performed before implementing the prediction model. A new VMAT planning method (hybrid-VMAT) was created with combining the DVH prediction and Auto-Planning. For each new patient, the DVH will be predicted and individual DVH constrains will be obtained and were exported as the original optimization parameters to the Auto-Planning (Pinnacle3 treatment planning system, v9.10) for planning. A total of 20 rectal cancer patients previously treated with manual VMAT (manual-VMAT) plans were replanned using this new method. Dosimetric comparisons were performed between manual VMAT and new method plans. Results: Hybrid-VMAT shows similar PTV coverage to manual-VMAT in D2%, D98% and HI (p>0.05) and superior coverage in CI (p=0.000). For the bladder, the means of V40 and mean dose are 36.0% and 35.6Gy for hybrid-VMAT and 42% and 38.0Gy for the manual-VMAT. For the left (right) femur, the means of V30 and mean dose are 10.6% (11.6%) and 17.9Gy (19.2Gy) for the hybrid-VMAT and 25.6% (24.1%) and 27.3Gy (26.2Gy) for the manual-VMAT. The hybrid-VMAT has significantly improved the organs at risk sparing. Conclusion: The integration of DVH prediction and Auto-Planning significantly improve the VMAT plan quality in the rectal cancer radiotherapy. Our results show the benefit of the new method and will be further investigated in other tumor sites.

  17. Strategy for Alternative Occupant Volume Testing

    Science.gov (United States)

    2009-10-20

    This paper describes plans for a series of quasi-static : compression tests of rail passenger equipment. These tests are : designed to evaluate the strength of the occupant volume under : static loading conditions. The research plan includes a detail...

  18. Comparison of two dimensional and three dimensional radiotherapy treatment planning in locally advanced non-small cell lung cancer treated with continuous hyperfractionated accelerated radiotherapy weekend less

    International Nuclear Information System (INIS)

    Wilson, Elena M.; Joy Williams, Frances; Ethan Lyn, Basil; Aird, Edwin G.A.

    2005-01-01

    Background and purpose: Patients with inoperable non-small cell lung cancer being treated with continuous hyperfractionated accelerated radiotherapy weekend less (CHARTWEL) were planned and treated with a three dimensional (3D) conformal protocol and comparison made with two dimensional (2D) planning, as used previously, to compare past practice and methods. Patients and methods: Twenty-four patients were planned initially using 3D and then replanned using a 2D system. The 2D plans were transferred onto the 3D system and recalculated. Dose volume histograms could then be constructed of planning target volumes for phases 1 and 2 (PTV 1 and 2, respectively), lung and spinal cord for the 2D plans and compared with the 3D plans. Results: There was a significantly lower absolute dose to the isocentre with 2D compared to 3D planning with dose reductions of 3.9% for phase 1, 4.4% for phase 2 and 4.7% for those treated with a single phase. Maximum dose to spinal cord was greater in 17 of the 24 2D plans with a median dose reduction of 0.82 Gy for 3D (P=0.04). The percentage volume of whole lung receiving ≥20 Gy (V 20 ) was greater in 16 of the 24 2D plans with a median reduction in V 20 of 2.4% for 3D (P=0.03). Conclusions: A lower dose to tumour was obtained using 2D planning due to the method of dose calculation and spinal cord and lung doses were significantly higher

  19. "Planned" Teenage Pregnancy: Perspectives of Young Women from Disadvantaged Backgrounds in England

    Science.gov (United States)

    Coleman, Lester; Cater, Suzanne

    2006-01-01

    The reduction of teenage pregnancy has attracted much interest in research, practice and social policy. Little is known about teenagers who report their pregnancies as "planned." Forty-one in-depth interviews were undertaken, in six different parts of England, among young women who reported their pregnancy as "planned". The…

  20. Definition of internal target volume and domestric study for hepatocellular carcinoma using four-dimensional CT

    International Nuclear Information System (INIS)

    Xi Mian; Liu Mengzhong; Deng Xiaowu; Zhang Li; Huang Xiaoyan; Cai Ling

    2009-01-01

    Objective: To define individualized internal target volume (ITV) for hepatocellular carcinoma using four-dimensional (4D) CT, and to compare the differences in target volume definition and dose distribution among 3D, 4D and respiratory-gated plans. Methods: 4DCT scanning was obtained for 12 patients with hepatocellular. Gross tumor volume (GTV), clinical target volume (CTV) and normal tissues were contoured on all 10 respiratory phases of 4DCT images. The 3D, 4D and gated treatment plans were prepared for each patient using three different planning target volumes (PTVs): 1) PTV 3D was derived from a single CTV plus conventional margins; 2) PTV 4D was derived from ITV 4D , which encompassed all 10 CTVs plus setup margins (SMs); 3) PT Gating was derived from ITV Gating , which encompassed 3 CTVs within gating-window at end-expiration plus SMs. The PTV volume and dose distribution were compared among different plans. Results: The PTV3D was the largest in all 12 patients, but still missed partial target volume in 5 patients when comparing with PTV4D. Both the 4D plans and the gated plans spared more normal tissues than the 3D plans, especially the liver. Without increasing normal tissue dose, the 4D plans allowed for increasing the calculated dose from (50.8 ± 2.0) Gy (3D plans) to (54.7 ± 3.3) Gy, and the gated plans could further increase the dose to (58.0 ± 3.9) Gy. Conclusions: The 4DCT-based plans can ensure optimal target coverage with less irradiation of normal tissues and allow dose escalation when compared with 3D plans. Respiratory gated radiotherapy can further reduce the target volumes to spare more surrounding tissues, especially for patients with large extent of respiratory mobility. (authors)

  1. Phantom study of PET/CT guided delineation of radiation therapy volume

    International Nuclear Information System (INIS)

    Lin Lin; Zheng Rong; Wang Yibin; Geng Jianhua; Wu Ning; Zhao Ping

    2012-01-01

    Objective: To propose a model-based method for calculating the threshold in GTV determination by 18 F-FDG PET in a phantom study. Methods: A phantom was constructed of a 9 L cylindrical tank.Glass spheres with volumes ranging from 0.5 to 16 ml (0.5, 1, 2, 4, 8 and 16 ml) were suspended within the tank. The six spheres were filled with an identical concentration of FDG (203.5 MBq/L) and suspended within 3 different background baths of FDG (6.179, 16.021, 0 MBq/L) solutions, creating 3 target-to-background ratios of 32.96 : 1, 12.69 : 1 and target to zero background. A linear regressive function was constructed which represented the relationship between the threshold and the average activity concentration of the target. A 40% of maximum intensity threshold and the linear regressive function method were applied to define the spheres filled with 18 F-FDG. The volume differences between the two methods and the true volumes of the spheres were compared with t-test. Results: The linear regressive function model was derived as:threshold =(mean target concentration + 2.6227)/1.9752. The results indicated that a smaller deviation occurred when the function was utilized to estimate the volumes of the phantoms as compared to the 40% of maximum intensity threshold method, but there were no significant differences between them (t=0.306, P>0.05). The effect of the linear regressive function on volume was such that when the phantom sphere volumes were ≥ 1 ml, the average deviation between the defined volumes and the true volumes of phantoms was 1.01%; but when the phantom sphere volume was 0.5 ml, the average deviation was 9.53%. When the 40% of maximum intensity threshold method was applied to define the phantom spheres of volume ≥2 ml, the average deviation between the defined volumes and the true volumes of phantoms was -4.62%; but, the average deviation of that was 19.9% when the volumes of spheres were 0.5 and 1 ml. When the linear regressive function was applied to

  2. Logistics and Planning of Output Volume

    Directory of Open Access Journals (Sweden)

    V. I. Pokhabov

    2005-01-01

    Full Text Available On the basis of logistics conception the paper considers an adaptation of an enterprise to environmental changes with due account of its emergement properties. Taking into account emergement properties of an enterprise a logistics method for planning an optimum movement of the material flow is proposed in the paper.

  3. IMRT for adjuvant radiation in gastric cancer: A preferred plan?

    International Nuclear Information System (INIS)

    Ringash, Jolie; Perkins, Greg; Brierley, James; Lockwood, Gina; Islam, Mohammad; Catton, Pamela; Cummings, Bernard; Kim, John; Wong, Rebecca; Dawson, Laura

    2005-01-01

    Purpose: To assess the potential advantage of intensity-modulated radiotherapy (IMRT) over conformal planning for postoperative adjuvant radiotherapy in patients with gastric carcinoma. Methods and Materials: Twenty patients who had undergone treatment planning with conformal beam arrangements for 4500 cGy adjuvant radiotherapy between 2000 and 2001 underwent repeat planning using IMRT techniques. Conformal five-field plans were compared with seven- to nine-field coplanar sliding-window IMRT plans. For each patient, the cumulative dose-volume histograms and organ-dose summaries (without distributions or digitally reconstructed radiographs) were provided to two independent, 'blinded' GI radiation oncologists. The oncologists indicated which plan provided better planning target volume coverage and critical organ sparing, any safety concerns with either plan, and which plan they would choose to treat the patient. Results: In 18 (90%) of 20 cases, both oncologists chose the same plan. Cases with disagreement were given to a third 'blinded' reviewer. A 'preferred plan' could be determined in 19 (95%) of 20 cases. IMRT was preferred in 17 (89%) of 19 cases. In 4 (20%) of 20 IMRT plans at least one radiation oncologist had safety concerns because of the spinal cord dose (3 cases) or small bowel dose (2 cases). Of 42 ratings, IMRT was thought to provide better planning target volume coverage in 36 (86%) and better sparing of the spinal cord in 31 (74%) of 42, kidneys in 29 (69%), liver in 30 (71%), and heart in 29 (69%) of 42 ratings. The median underdose volume (1.7 vs. 4.1 cm 3 ), maximal dose to the spinal cord (36.85 vs. 45.65 Gy), and dose to 50% of the liver (17.29 vs. 27.97), heart (12.89 vs. 15.50 Gy), and left kidney (15.50 vs. 16.06 Gy) were lower with IMRT than with the conformal plans. Conclusion: Compared with the conformal plans, oncologists frequently preferred IMRT plans when using dose-volume histogram data. The advantages of IMRT plans include both

  4. Low contrast medium-volume third-generation dual-source computed tomography angiography for transcatheter aortic valve replacement planning

    Energy Technology Data Exchange (ETDEWEB)

    Felmly, Lloyd M. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiothoracic Surgery, Department of Surgery, Charleston, SC (United States); De Cecco, Carlo N.; Varga-Szemes, Akos; McQuiston, Andrew D. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Schoepf, U.J.; Litwin, Sheldon E.; Bayer, Richard R. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States); Mangold, Stefanie [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Vogl, Thomas J. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Wichmann, Julian L. [Medical University of South Carolina, Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Charleston, SC (United States); University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

    2017-05-15

    To investigate feasibility, image quality and safety of low-tube-voltage, low-contrast-volume comprehensive cardiac and aortoiliac CT angiography (CTA) for planning transcatheter aortic valve replacement (TAVR). Forty consecutive TAVR candidates prospectively underwent combined CTA of the aortic root and vascular access route (270 mgI/ml iodixanol). Patients were assigned to group A (second-generation dual-source CT [DSCT], 100 kV, 60 ml contrast, 4.0 ml/s flow rate) or group B (third-generation DSCT, 70 kV, 40 ml contrast, 2.5 ml/s flow rate). Vascular attenuation, noise, signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were compared. Subjective image quality was assessed by two observers. Estimated glomerular filtration (eGFR) at CTA and follow-up were measured. Besides a higher body-mass-index in group B (24.8±3.8 kg/m{sup 2} vs. 28.1±5.4 kg/m{sup 2}, P=0.0339), patient characteristics between groups were similar (P≥0.0922). Aortoiliac SNR (P=0.0003) was higher in group B. Cardiac SNR (P=0.0003) and CNR (P=0.0181) were higher in group A. Subjective image quality was similar (P≥0.213) except for aortoiliac image noise (4.42 vs. 4.12, P=0.0374). TAVR-planning measurements were successfully obtained in all patients. There were no significant changes in eGFR among and between groups during follow-up (P≥0.302). TAVR candidates can be safely and effectively evaluated by a comprehensive CTA protocol with low contrast volume using low-tube-voltage acquisition. (orig.)

  5. Low contrast medium-volume third-generation dual-source computed tomography angiography for transcatheter aortic valve replacement planning

    International Nuclear Information System (INIS)

    Felmly, Lloyd M.; De Cecco, Carlo N.; Varga-Szemes, Akos; McQuiston, Andrew D.; Schoepf, U.J.; Litwin, Sheldon E.; Bayer, Richard R.; Mangold, Stefanie; Vogl, Thomas J.; Wichmann, Julian L.

    2017-01-01

    To investigate feasibility, image quality and safety of low-tube-voltage, low-contrast-volume comprehensive cardiac and aortoiliac CT angiography (CTA) for planning transcatheter aortic valve replacement (TAVR). Forty consecutive TAVR candidates prospectively underwent combined CTA of the aortic root and vascular access route (270 mgI/ml iodixanol). Patients were assigned to group A (second-generation dual-source CT [DSCT], 100 kV, 60 ml contrast, 4.0 ml/s flow rate) or group B (third-generation DSCT, 70 kV, 40 ml contrast, 2.5 ml/s flow rate). Vascular attenuation, noise, signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were compared. Subjective image quality was assessed by two observers. Estimated glomerular filtration (eGFR) at CTA and follow-up were measured. Besides a higher body-mass-index in group B (24.8±3.8 kg/m 2 vs. 28.1±5.4 kg/m 2 , P=0.0339), patient characteristics between groups were similar (P≥0.0922). Aortoiliac SNR (P=0.0003) was higher in group B. Cardiac SNR (P=0.0003) and CNR (P=0.0181) were higher in group A. Subjective image quality was similar (P≥0.213) except for aortoiliac image noise (4.42 vs. 4.12, P=0.0374). TAVR-planning measurements were successfully obtained in all patients. There were no significant changes in eGFR among and between groups during follow-up (P≥0.302). TAVR candidates can be safely and effectively evaluated by a comprehensive CTA protocol with low contrast volume using low-tube-voltage acquisition. (orig.)

  6. Simultaneous optimization of sequential IMRT plans

    International Nuclear Information System (INIS)

    Popple, Richard A.; Prellop, Perri B.; Spencer, Sharon A.; Santos, Jennifer F. de los; Duan, Jun; Fiveash, John B.; Brezovich, Ivan A.

    2005-01-01

    Radiotherapy often comprises two phases, in which irradiation of a volume at risk for microscopic disease is followed by a sequential dose escalation to a smaller volume either at a higher risk for microscopic disease or containing only gross disease. This technique is difficult to implement with intensity modulated radiotherapy, as the tolerance doses of critical structures must be respected over the sum of the two plans. Techniques that include an integrated boost have been proposed to address this problem. However, clinical experience with such techniques is limited, and many clinicians are uncomfortable prescribing nonconventional fractionation schemes. To solve this problem, we developed an optimization technique that simultaneously generates sequential initial and boost IMRT plans. We have developed an optimization tool that uses a commercial treatment planning system (TPS) and a high level programming language for technical computing. The tool uses the TPS to calculate the dose deposition coefficients (DDCs) for optimization. The DDCs were imported into external software and the treatment ports duplicated to create the boost plan. The initial, boost, and tolerance doses were specified and used to construct cost functions. The initial and boost plans were optimized simultaneously using a gradient search technique. Following optimization, the fluence maps were exported to the TPS for dose calculation. Seven patients treated using sequential techniques were selected from our clinical database. The initial and boost plans used to treat these patients were developed independently of each other by dividing the tolerance doses proportionally between the initial and boost plans and then iteratively optimizing the plans until a summation that met the treatment goals was obtained. We used the simultaneous optimization technique to generate plans that met the original planning goals. The coverage of the initial and boost target volumes in the simultaneously optimized

  7. Computerised tomography in radiotherapy planning

    International Nuclear Information System (INIS)

    Badcock, P.C.

    1983-01-01

    This study evaluates the effectiveness of computed tomography as an adjunct to radiotherapy planning. Until recently, acquisition of accurate data concerning tumour anatomy lagged behind other developments in radiotherapy. With the advent of computer-tomography (CT), these data can be displayed and transmitted to a treatment planning computer. It is concluded that the greatest inaccuracies in the radiation treatment of patients are to be found in both the inadequate delineation of the target volume within the patient and changes in body outline relative to the target volume over the length of the irradiated volume. The technique was useful in various subgroups (pelvic, intra-thoracic and chest-wall tumours) and for those patients being treated palliatively. With an estimated improvement in cure rate of 4.5% and cost-effective factors of between 3.3 and 5, CT-assisted radiotherapy planning appears to be a worthwhile procedure. (orig.)

  8. 3D Conformal radiotherapy for gastric cancer-results of a comparative planning study

    International Nuclear Information System (INIS)

    Leong, Trevor; Willis, David; Joon, Daryl Lim; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.

    2005-01-01

    Background and purpose: Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Materials and methods: Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. Results: The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. Conclusions: 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity

  9. Systemic Planning: Dealing with Complexity by a Wider Approach to Planning

    DEFF Research Database (Denmark)

    Leleur, Steen

    2005-01-01

    and methodology that can be helpful for planning under circumstances characterised by complexity and uncertainty. It is argued that compared to conventional, planning – referred to as systematic planning - there is a need for a wider, more systemic approach to planning that is better suited to current real......On the basis of a new book Systemic Planning this paper addresses systems thinking and complexity in a context of planning. Specifically, renewal of planning thinking on this background is set out as so-called systemic planning (SP). The principal concern of SP is to provide principles...

  10. Licensing an assured isolation facility for low-level radioactive waste. Volume 2: Recommendations on the content and review of an application

    International Nuclear Information System (INIS)

    Silverman, D.J.; Bauser, M.A.; Baird, R.D.

    1998-07-01

    This report provides a detailed set of proposed criteria and guidance for the preparation of a license application for an assured isolation facility (AIF). The report is intended to provide a detailed planning basis upon which a prospective applicant may begin pre-licensing discussions with the Nuclear Regulatory Commission and initiate development of a license application. The report may also be useful to the NRC or to state regulatory agencies that may be asked to review such an application. Volume 1 of this report provides background information, and describes the licensing approach and methodology. Volume 2 identifies specific information that is recommended for inclusion in a license application

  11. Licensing an assured isolation facility for low-level radioactive waste. Volume 2: Recommendations on the content and review of an application

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, D.J.; Bauser, M.A. [Morgan, Lewis and Bockius, Washington, DC (United States); Baird, R.D. [Rogers and Associates Engineering Corp., Salt Lake City, UT (United States)

    1998-07-01

    This report provides a detailed set of proposed criteria and guidance for the preparation of a license application for an assured isolation facility (AIF). The report is intended to provide a detailed planning basis upon which a prospective applicant may begin pre-licensing discussions with the Nuclear Regulatory Commission and initiate development of a license application. The report may also be useful to the NRC or to state regulatory agencies that may be asked to review such an application. Volume 1 of this report provides background information, and describes the licensing approach and methodology. Volume 2 identifies specific information that is recommended for inclusion in a license application.

  12. Hybrid IMRT plans-concurrently treating conventional and IMRT beams for improved breast irradiation and reduced planning time

    International Nuclear Information System (INIS)

    Mayo, Charles S.; Urie, Marcia M.; Fitzgerald, Thomas J.

    2005-01-01

    Purpose: To evaluate a hybrid intensity modulated radiation therapy (IMRT) technique as a class solution for treatment of the intact breast. Methods and materials: The following five plan techniques were compared for 10 breast patients using dose-volume histogram analysis: conventional wedged-field tangents (Tangents), forward-planned field-within-a-field tangents (FIF), IMRT-only tangents (IMRT tangents), conventional open plus IMRT tangents (4-field hybrid), and conventional open plus IMRT tangents with 2 anterior oblique IMRT beams (6-field hybrid). Results: The 4-field hybrid and FIF achieved dose distributions better than Tangents and IMRT tangents. The volume of tissue outside the planning target volume receiving ≥110% of prescribed dose was largest for IMRT tangents (average 158 cc) and least for 6-field hybrid (average 1 cc); the FIF and 4-field hybrid were comparable (average 15 cc). Heart volume ≥30 Gy averaged 13 cc for all techniques, except Tangents, for which it was 32 cc. Average total lung volume ≥20 Gy was 7% for all. Contralateral breast doses were < 3% for all. Planning time for hybrid techniques was significantly less than for conventional FIF technique. Conclusions: The 4-field hybrid technique is a viable class solution. The 6-field hybrid technique creates the most conformal dose distribution at the expense of more normal tissue receiving low dose

  13. Green4sure. The Green Energy Plan. Background report; Green4sure. Het Groene Energieplan. Achtergrondrapport

    Energy Technology Data Exchange (ETDEWEB)

    Rooijers, F.J. (ed.) (and others)

    2007-05-15

    The Green Energy Plan indicates how the ambitious climate targets of the cabinet can be achieved at the lowest cost. Main issue is that all energy consumers individually (industry, electricity production, aviation) or collectively (built environment, transport) are placed in an emission credits system with climate budget. The effort and costs are differentiated in order to ensure a largest possible acceptance. Moreover, new standards will be introduced for vehicles, buildings (existing and new) and appliances. The effects of the plan have been calculated and will lead to the desired halving of greenhouse gas emissions, an annual efficiency improvement of 2.1%. In 2030 the annual cost will amount to over 4 billion euro, but there are also substantial social benefits. This background report focuses on households, utilities and SME, greenhouse farming, traffic, industry, electricity, renewable energy, biomass and biodiversity, CO2 storage, external costs and benefits of Green4Sure, employment and socio-economic effects as well as the climate act. [mk]. [Dutch] Het Groene Energieplan geeft aan hoe de ambitieuze klimaatdoelen van het kabinet gehaald kunnen worden tegen de laagste kosten. Belangrijkste punten zijn dat alle energiegebruikers individueel (industrie, elektriciteitsproductie, luchtvaart) of collectief (gebouwde omgeving, transport) onder een emissierechtensysteem met klimaatbudget komen te vallen. De inspanningen, en daarmee de kosten zijn gedifferentieerd om de acceptatie zo groot mogelijk te laten zijn. Daarnaast komen er normen voor voertuigen, gebouwen (nieuw en bestaand) en apparaten. De effecten van het plan zijn doorgerekend en leiden tot de gewenste halvering van de broeikasgassen, een jaarlijkse efficiencyverbetering van 2,1%. De kosten bedragen in 2030 jaarlijks ruim 4 miljard euro, maar er zijn ook forse maatschappelijke baten. In dit achtergrondrapport wordt aandacht besteed aan huishoudens, utiliteiten en MKB, glastuinbouw, verkeer, industrie

  14. Volume reduction philosophy and techniques in use or planned

    Energy Technology Data Exchange (ETDEWEB)

    Row, T.H.

    1984-01-01

    Siting and development of nuclear waste disposal facilities is an expensive task. In the private sector, such developments face siting and licensing issues, public intervention, and technology challenges. The United States Department of Energy (DOE) faces similar challenges in the management of waste generated by the research and production facilities. Volume reduction can be used to lengthen the service life of existing facilities. A wide variety of volume reduction techniques are applied to different waste forms. Compressible waste is compacted into drums, cardboard and metal boxes, and the loaded drums are supercompacted into smaller units. Large metallic items are size-reduced and melted for recycle or sent to shallow land burial. Anaerobic digestion is a process that can reduce cellulosic and animal wastes by 80%. Incinerators of all types have been investigated for application to nuclear wastes and a number of installations operate or are constructing units for low-level and transuranic solid and liquid combustibles. Technology may help solve many of the problems in volume reduction, but the human element also has an important part in solving the puzzle. Aggressive educational campaigns at two sites have proved very successful in reducing waste generation. This overview of volume reduction is intended to transfer the current information from many DOE facilities. 44 references, 85 figures, 5 tables.

  15. Volume reduction philosophy and techniques in use or planned

    International Nuclear Information System (INIS)

    Row, T.H.

    1984-01-01

    Siting and development of nuclear waste disposal facilities is an expensive task. In the private sector, such developments face siting and licensing issues, public intervention, and technology challenges. The United States Department of Energy (DOE) faces similar challenges in the management of waste generated by the research and production facilities. Volume reduction can be used to lengthen the service life of existing facilities. A wide variety of volume reduction techniques are applied to different waste forms. Compressible waste is compacted into drums, cardboard and metal boxes, and the loaded drums are supercompacted into smaller units. Large metallic items are size-reduced and melted for recycle or sent to shallow land burial. Anaerobic digestion is a process that can reduce cellulosic and animal wastes by 80%. Incinerators of all types have been investigated for application to nuclear wastes and a number of installations operate or are constructing units for low-level and transuranic solid and liquid combustibles. Technology may help solve many of the problems in volume reduction, but the human element also has an important part in solving the puzzle. Aggressive educational campaigns at two sites have proved very successful in reducing waste generation. This overview of volume reduction is intended to transfer the current information from many DOE facilities. 44 references, 85 figures, 5 tables

  16. Customized Computed Tomography-Based Boost Volumes in Breast-Conserving Therapy: Use of Three-Dimensional Histologic Information for Clinical Target Volume Margins

    International Nuclear Information System (INIS)

    Hanbeukers, Bianca; Borger, Jacques; Ende, Piet van den; Ent, Fred van der; Houben, Ruud; Jager, Jos; Keymeulen, Kristien; Murrer, Lars; Sastrowijoto, Suprapto; Vijver, Koen van de; Boersma, Liesbeth

    2009-01-01

    Purpose: To determine the difference in size between computed tomography (CT)-based irradiated boost volumes and simulator-based irradiated volumes in patients treated with breast-conserving therapy and to analyze whether the use of anisotropic three-dimensional clinical target volume (CTV) margins using the histologically determined free resection margins allows for a significant reduction of the CT-based boost volumes. Patients and Methods: The CT data from 49 patients were used to delineate a planning target volume (PTV) with isotropic CTV margins and to delineate a PTV sim that mimicked the PTV as delineated in the era of conventional simulation. For 17 patients, a PTV with anisotropic CTV margins was defined by applying customized three-dimensional CTV margins, according to the free excision margins in six directions. Boost treatment plans consisted of conformal portals for the CT-based PTVs and rectangular fields for the PTV sim . Results: The irradiated volume (volume receiving ≥95% of the prescribed dose [V 95 ]) for the PTV with isotropic CTV margins was 1.6 times greater than that for the PTV sim : 228 cm 3 vs. 147 cm 3 (p 95 was similar to the V 95 for the PTV sim (190 cm 3 vs. 162 cm 3 ; p = NS). The main determinant for the irradiated volume was the size of the excision cavity (p < .001), which was mainly related to the interval between surgery and the planning CT scan (p = .029). Conclusion: CT-based PTVs with isotropic margins for the CTV yield much greater irradiated volumes than fluoroscopically based PTVs. Applying individualized anisotropic CTV margins allowed for a significant reduction of the irradiated boost volume.

  17. Effect of volume expansion on systemic hemodynamics and central and arterial blood volume in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

    1995-01-01

    , and arterial pressure were determined before and during a volume expansion induced by infusion of a hyperosmotic galactose solution. RESULTS: During volume expansion, the central and arterial blood volume increased significantly in patients with class A and controls, whereas no significant change was found...... in patients with either class B or class C. Conversely, the noncentral blood volume increased in patients with class B and C. In both patients and controls, the cardiac output increased and the systemic vascular resistance decreased, whereas the mean arterial blood pressure did not change significantly......BACKGROUND & AIMS: Systemic vasodilatation in cirrhosis may lead to hemodynamic alterations with reduced effective blood volume and decreased arterial blood pressure. This study investigates the response of acute volume expansion on hemodynamics and regional blood volumes in patients with cirrhosis...

  18. Comparative evaluation of respiratory-gated and ungated FDG-PET for target volume definition in radiotherapy treatment planning for pancreatic cancer.

    Science.gov (United States)

    Kishi, Takahiro; Matsuo, Yukinori; Nakamura, Akira; Nakamoto, Yuji; Itasaka, Satoshi; Mizowaki, Takashi; Togashi, Kaori; Hiraoka, Masahiro

    2016-08-01

    The purpose of this study was to evaluate the usefulness of respiratory-gated positron emission tomography (4D-PET) in pancreatic cancer radiotherapy treatment planning (RTTP). Fourteen patients with 18F-fluorodeoxyglucose (FDG)-avid pancreatic tumours were evaluated between December 2013 and March 2015. Two sets of volumes were contoured for the pancreatic tumour of each patient. The biological target volume in three-dimensional RTTP (BTV3D) was contoured using conventional respiratory un-gated PET. The BTV3D was then expanded using population-based margins to generate a series of internal target volume 3D (ITV3D) values. The ITV 4D (ITV4D) was contoured using 4D-PET. Each of the five phases of 4D-PET was used for 4D contouring, and the ITV4D was constructed by summing the volumes defined on the five individual 4D-PET images. The relative volumes and normalized volumetric overlap were computed between ITV3D and ITV4D. On average, the FDG-avid tumour volumes were 1.6 (range: 0.8-2.3) fold greater in the ITV4D than in the BTV3D. On average, the ITV3D values were 2.0 (range: 1.1-3.4) fold larger than the corresponding ITV4D values. The ITV generated from 4D-PET can be used to improve the accuracy or reduce normal tissue irradiation compared with conventional un-gated PET-based ITV. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. ABC/2 Method Does not Accurately Predict Cerebral Arteriovenous Malformation Volume.

    Science.gov (United States)

    Roark, Christopher; Vadlamudi, Venu; Chaudhary, Neeraj; Gemmete, Joseph J; Seinfeld, Joshua; Thompson, B Gregory; Pandey, Aditya S

    2018-02-01

    Stereotactic radiosurgery (SRS) is a treatment option for cerebral arteriovenous malformations (AVMs) to prevent intracranial hemorrhage. The decision to proceed with SRS is usually based on calculated nidal volume. Physicians commonly use the ABC/2 formula, based on digital subtraction angiography (DSA), when counseling patients for SRS. To determine whether AVM volume calculated using the ABC/2 method on DSA is accurate when compared to the exact volume calculated from thin-cut axial sections used for SRS planning. Retrospective search of neurovascular database to identify AVMs treated with SRS from 1995 to 2015. Maximum nidal diameters in orthogonal planes on DSA images were recorded to determine volume using ABC/2 formula. Nidal target volume was extracted from operative reports of SRS. Volumes were then compared using descriptive statistics and paired t-tests. Ninety intracranial AVMs were identified. Median volume was 4.96 cm3 [interquartile range (IQR) 1.79-8.85] with SRS planning methods and 6.07 cm3 (IQR 1.3-13.6) with ABC/2 methodology. Moderate correlation was seen between SRS and ABC/2 (r = 0.662; P ABC/2 (t = -3.2; P = .002). When AVMs were dichotomized based on ABC/2 volume, significant differences remained (t = 3.1, P = .003 for ABC/2 volume ABC/2 volume > 7 cm3). The ABC/2 method overestimates cerebral AVM volume when compared to volumetric analysis from SRS planning software. For AVMs > 7 cm3, the overestimation is even greater. SRS planning techniques were also significantly different than values derived from equations for cones and cylinders. Copyright © 2017 by the Congress of Neurological Surgeons

  20. The background and theory of integrated risk management

    Science.gov (United States)

    Hunsucker, John L.

    1995-01-01

    While all good managers have always considered risk in their decision making, only recently have formal programs to do so been introduced. This report covers the logical structure behind the formulation of an integrated risk management plan (IRM). Included in the report are factors forcing the development of a formal plan to consider risk, the basic objective or purpose of an IRM, and desirable traits of such a plan. The report moves on to a discussion of background issues, seeks to formalize some definitions, and then discusses required information on threats. The report concludes with the steps for an IRM.

  1. On the validity of density overrides for VMAT lung SBRT planning

    International Nuclear Information System (INIS)

    Wiant, David; Vanderstraeten, Caroline; Maurer, Jacqueline; Pursley, Jan; Terrell, Jonathon; Sintay, Benjamin J.

    2014-01-01

    Purpose: Modeling dose to a moving target in lung is a very difficult task. Current approaches to planning lung stereotactic body radiotherapy (SBRT) generally calculate dose on either free breathing or average computed tomography (CT) scans, which do not always accurately predict dose to parts of the target volume not occupied by tumor on the planning scan. In this work, the authors look at using density overrides of the target volumes to more accurately predict dose for lung SBRT using the analytic anisotropic algorithm (AAA). Methods: Volumetric modulated arc therapy plans were created on free breathing scans (FBP), time average scans (AVGP), free breathing scans with the internal target volume overridden to tumor density (ITVP), free breathing scans with the planning target volume overridden to tumor density (PTVP), and free breathing scan using a hybrid scheme with the internal target volume set to tumor density and the planning target volume minus the internal target volume set to a density intermediate between lung and tumor (HP) for the case of a 4D motion phantom and five patient cases. Radiochromic film measurements were made for the phantom plans, with gamma analysis used to compare the planned to delivered dose. The patient plans were recalculated on each of the phases of a 4DCT to evaluate tumor coverage and conformity index (CI). A modified modulation complexity score (MCSv) and average open area per control point (AA) metrics were used to evaluate multileaf collimator (MLC) modulation for each of the plans. Results: The HP plans showed significantly higher gamma passing rates (p < 0.05) than the FBP, AVGP, and ITVP for criteria of 2 mm/2% and 1 mm/1%. No significant correlation was observed between gamma values and AA or MCSv. The tumor volume was covered by the prescription dose on all phases of the 4DCT for all patient plans. The PTVP and HP yielded lower mean CI than the other plans for all five patients, with three of the cases showing

  2. On the validity of density overrides for VMAT lung SBRT planning

    Energy Technology Data Exchange (ETDEWEB)

    Wiant, David, E-mail: david.wiant@conehealth.com; Vanderstraeten, Caroline; Maurer, Jacqueline; Pursley, Jan; Terrell, Jonathon; Sintay, Benjamin J. [Cone Health Cancer Center, Greensboro, North Carolina 27403 (United States)

    2014-08-15

    Purpose: Modeling dose to a moving target in lung is a very difficult task. Current approaches to planning lung stereotactic body radiotherapy (SBRT) generally calculate dose on either free breathing or average computed tomography (CT) scans, which do not always accurately predict dose to parts of the target volume not occupied by tumor on the planning scan. In this work, the authors look at using density overrides of the target volumes to more accurately predict dose for lung SBRT using the analytic anisotropic algorithm (AAA). Methods: Volumetric modulated arc therapy plans were created on free breathing scans (FBP), time average scans (AVGP), free breathing scans with the internal target volume overridden to tumor density (ITVP), free breathing scans with the planning target volume overridden to tumor density (PTVP), and free breathing scan using a hybrid scheme with the internal target volume set to tumor density and the planning target volume minus the internal target volume set to a density intermediate between lung and tumor (HP) for the case of a 4D motion phantom and five patient cases. Radiochromic film measurements were made for the phantom plans, with gamma analysis used to compare the planned to delivered dose. The patient plans were recalculated on each of the phases of a 4DCT to evaluate tumor coverage and conformity index (CI). A modified modulation complexity score (MCSv) and average open area per control point (AA) metrics were used to evaluate multileaf collimator (MLC) modulation for each of the plans. Results: The HP plans showed significantly higher gamma passing rates (p < 0.05) than the FBP, AVGP, and ITVP for criteria of 2 mm/2% and 1 mm/1%. No significant correlation was observed between gamma values and AA or MCSv. The tumor volume was covered by the prescription dose on all phases of the 4DCT for all patient plans. The PTVP and HP yielded lower mean CI than the other plans for all five patients, with three of the cases showing

  3. National Energy Board 1992-93 estimates part III expenditure plan

    International Nuclear Information System (INIS)

    1992-01-01

    This Expenditure Plan is designed to be used as a reference document. As such, it contains several levels of detail to respond to the various needs of its audience. This Plan is divided into two sections. Section 1 presents an overview of the Program including a description, information on its background, objectives and planning perspective as well as performance information that forms the basis for the resources requested. Section 2 provides further information on costs and resources as well as special analyses that the reader may require to understand the Program more fully. Section 1 is preceded by details of Spending Authorities from Part 2 of the Estimates and Volume 2 of the Public Accounts. This is to provide continuity with other Estimates documents and to help in assessing the Program's financial performance over the past year. The format and organization of the document should be regarded as transitional. For the most part the document is organized to be consistent with the program structure approved for the National Energy Board. 16 figs

  4. National Energy Board 1992-93 estimates part III expenditure plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    This Expenditure Plan is designed to be used as a reference document. As such, it contains several levels of detail to respond to the various needs of its audience. This Plan is divided into two sections. Section 1 presents an overview of the Program including a description, information on its background, objectives and planning perspective as well as performance information that forms the basis for the resources requested. Section 2 provides further information on costs and resources as well as special analyses that the reader may require to understand the Program more fully. Section 1 is preceded by details of Spending Authorities from Part 2 of the Estimates and Volume 2 of the Public Accounts. This is to provide continuity with other Estimates documents and to help in assessing the Program`s financial performance over the past year. The format and organization of the document should be regarded as transitional. For the most part the document is organized to be consistent with the program structure approved for the National Energy Board. 16 figs.

  5. Status and habitat requirements of the white sturgeon populations in the Columbia River downstream from McNary Dam. Volume 2: Supplemental papers and data documentation; Final report

    International Nuclear Information System (INIS)

    Beamesderfer, R.C.; Nigro, A.A.

    1995-01-01

    This is the final report for research on white sturgeon Acipenser transmontanus from 1986--92 and conducted by the National Marine Fisheries Service (NMFS), Oregon Department of Fish and Wildlife (ODFW), US Fish and Wildlife Service (USFWS), and Washington Department of Fisheries (WDF). Findings are presented as a series of papers, each detailing objectives, methods, results, and conclusions for a portion of this research. This volume includes supplemental papers which provide background information needed to support results of the primary investigations addressed in Volume 1. This study addresses measure 903(e)(1) of the Northwest Power Planning Council's 1987 Fish and Wildlife Program that calls for ''research to determine the impact of development and operation of the hydropower system on sturgeon in the Columbia River Basin.'' Study objectives correspond to those of the ''White Sturgeon Research Program Implementation Plan'' developed by BPA and approved by the Northwest Power Planning Council in 1985. Work was conducted on the Columbia River from McNary Dam to the estuary

  6. Developing and assessing accident management plans for nuclear power plants

    International Nuclear Information System (INIS)

    Hanson, D.J.; Johnson, S.P.; Blackman, H.S.; Stewart, M.A.

    1992-07-01

    This document is the second of a two-volume NUREG/CR that discusses development of accident management plans for nuclear power plants. The first volume (a) describes a four-phase approach for developing criteria that could be used for assessing the adequacy of accident management plans, (b) identifies the general attributes of accident management plans (Phase 1), (c) presents a prototype process for developing and implementing severe accident management plans (Phase 2), and (d) presents criteria that can be used to assess the adequacy of accident management plans. This volume (a) describes results from an evaluation of the capabilities of the prototype process to produce an accident management plan (Phase 3) and (b), based on these results and preliminary criteria included in NUREG/CR-5543, presents modifications to the criteria where appropriate

  7. Relative blood volume changes underestimate total blood volume changes during hemodialysis

    NARCIS (Netherlands)

    Dasselaar, Judith J.; Lub-de Hooge, Marjolijn N.; Pruim, Jan; Nijnuis, Hugo; Wiersum, Anneke; de Jong, Paul E.; Huisman, Roel M.; Franssen, Casper F. M.

    Background: Measurements of relative blood volume changes (ARBV) during hemodialysis (HD) are based on hemoconcentration and assume uniform mixing of erythrocytes and plasma throughout the circulation. However, whole-body hematocrit (Ht) is lower than systemic Ht. During HD, a change in the ratio

  8. The dependence of prostate postimplant dosimetric quality on CT volume determination

    International Nuclear Information System (INIS)

    Merrick, Gregory S.; Butler, Wayne M.; Dorsey, Anthony T.; Lief, Jonathan H.

    1999-01-01

    Purpose: The postoperative evaluation of permanent prostate brachytherapy requires a subjective determination of the implant volume. This work investigates the magnitude of the effect that various methods of treatment volume delineation have on dosimetric quality parameters for a treatment planning philosophy that defines a target volume as the prostate with a periprostatic margin. Methods and Materials: Eight consecutive prostate brachytherapy patients with a prescribed dose of 145 Gy from 125 I as monotherapy comprised the study population. The prostate ultrasound volume was enlarged to a planning volume by an average factor of 1.8 to encompass probable extracapsular extension in the periprostatic region. For this cohort, the mean pretreatment parameters were 30.3 cm 3 ultrasound volume, 51.8 cm 3 planning volume, 131 seeds per patient, and 42.9 mCi total activity. On CT study sets obtained less than 2 hours postoperatively, target volumes were drawn using three methods: prostate plus a periprostatic margin, prostate only which excluded the puborectalis muscles, the periprostatic fat and the periprostatic venous plexus, and the preplanning ultrasound magnified to conform to the magnification factor of the postimplant CT scan. Three sets of 5 dosimetric quality parameters corresponding to the different volumetric approaches were calculated: V100, V150, and V200 which are the fractions of the target volume covered by 100, 150, and 200% of the prescribed dose, and D90 and D100, which are the minimal doses covering 90 and 100% of the target volume. Results: The postoperative CT volume utilizing the prostate plus margin technique was comparable to the initial planning volume (mean 55.5 cm 3 vs. 51.8 cm 3 , respectively) whereas those determined via superimposing the preplan ultrasound resulted in volumes nearly identical to the initial ultrasound evaluation (mean 32.4 cm 3 vs. 30.3 cm 3 ). The prostate only approach resulted in volumes approximately 25% larger than

  9. The planning target volume margins detected by cone-beam CT in head and neck cancer patients treated by image-guided intensity modulated radiotherapy

    International Nuclear Information System (INIS)

    Liu Jun; Chen Hong; Zhang Guoqiao; Chen Fei; Zhang Li

    2011-01-01

    Objective: To determine the planning target volume margins of head and neck cancers treated by image guided radiotherapy (IGRT). Methods: 464 sets cone beam computed tomography (CBCT) images before setup correction and 126 sets CBCT images after correction were obtained from 51 head and neck cancer patients treated by IGRT in our department. The systematic and random errors were evaluated by either online or offline correction through registering the CBCT images to the planning CT. The data was divided into 3 groups according to the online correction times. Results: The isocenter shift were 0.37 mm ± 2.37 mm, -0.43 mm ± 2.30 mm and 0.47 mm ± 2.65 mm in right-left (RL), anterior-posterior (AP) and superior-inferior (SI) directions respectively before correction, and it reduced to 0.08 mm ± 0.68 mm, -0.03 mm ± 0.74 mm and 0.03 mm ± 0.80 mm when evaluated by 126 sets corrected CBCT images. The planning target volume (PTV) margin from clinical target volume (CTV) before correction were: 6.41 mm, 6.15 mm and 7.10 mm based on two parameter model, and it reduced to 1.78 mm, 1.80 mm and 1.97 mm after correction. The PTV margins were 3.8 mm, 3.8 mm, 4.0 mm; 4.0 mm, 4.0 mm, 5.0 mm and 5.4 mm, 5.2 mm, 6.1 mm in RL, AP and SI respectively when online-correction times were more than 15 times, 11-15 times, 5-10 times. Conclusions: CBCT-based on online correction reduce the PTV margin for head and neck cancers treated by IGRT and ensure more precise dose delivery and less normal tissue complications. (authors)

  10. Systems Engineering Management Plan

    International Nuclear Information System (INIS)

    1994-01-01

    The purpose of this Monitored Retrievable Storage (MRS) Project Systems Engineering Management Plan (SEMP) is to define and establish the MRS Project Systems Engineering process that implements the approved policy and requirements of the Office of Civilian Radioactive Waste Management (OCRWM) for the US Department of Energy (DOE). This plan is Volume 5 of the MRS Project Management Plan (PMP). This plan provides the framework for implementation of systems engineering on the MRS Project consistent with DOE Order 4700.1, the OCRWM Program Management System Manual (PMSM), and the OCRWM Systems Engineering Management Plan (SEMP)

  11. [Preoperative imaging/operation planning for liver surgery].

    Science.gov (United States)

    Schoening, W N; Denecke, T; Neumann, U P

    2015-12-01

    The currently established standard for planning liver surgery is multistage contrast media-enhanced multidetector computed tomography (CM-CT), which as a rule enables an appropriate resection planning, e.g. a precise identification and localization of primary and secondary liver tumors as well as the anatomical relation to extrahepatic and/or intrahepatic vascular and biliary structures. Furthermore, CM-CT enables the measurement of tumor volume, total liver volume and residual liver volume after resection. Under the condition of normal liver function a residual liver volume of 25 % is nowadays considered sufficient and safe. Recent studies in patients with liver metastases of colorectal cancer showed a clear staging advantage of contrast media-enhanced magnetic resonance imaging (CM-MRI) versus CM-CT. In addition, most recent data showed that the use of liver-specific MRI contrast media further increases the sensitivity and specificity of detection of liver metastases. This imaging technology seems to lead closer to the ideal "one stop shopping" diagnostic tool in preoperative planning of liver resection.

  12. Progress on stochastic background search codes for LIGO

    International Nuclear Information System (INIS)

    Whelan, John T; Anderson, Warren G; Casquette, Martha; Diaz, Mario C; Heng, Ik Siong; McHugh, Martin; Romano, Joseph D; Jr, Charlie W Torres; Trejo, Rosa M; Vecchio, Alberto

    2002-01-01

    One of the types of signals for which the LIGO interferometric gravitational wave detectors will search is a stochastic background of gravitational radiation. We review the technique of searching for a background using the optimally filtered cross-correlation statistic, and describe the state of plans to perform such cross-correlations between the two LIGO interferometers as well as between LIGO and other gravitational-wave detectors, in particular the preparation of software to perform such data analysis

  13. AUA Program Master Plan. Volume 1: Overview

    Science.gov (United States)

    1997-03-01

    The Office of Air Traffic Systems Development (AUA) Program Master Plan : summarizes the management, development approach, and status of products and : services provided by the AUA organization to fulfill its role in supporting : National Airspace Sy...

  14. Computer-assisted operational planning for pediatric abdominal surgery. 3D-visualized MRI with volume rendering; Die computerassistierte Operationsplanung in der Abdominalchirurgie des Kindes. 3D-Visualisierung mittels ''volume rendering'' in der MRT

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, P.; Holland-Cunz, S.; Waag, K.L. [Universitaetsklinikum Heidelberg (Germany). Kinderchirurgie; Troeger, J. [Universitaetsklinikum Heidelberg, (Germany). Paediatrische Radiologie; Schenk, J.P. [Universitaetsklinikum Heidelberg, (Germany). Paediatrische Radiologie; Universitaetsklinikum, Paediatrische Radiologie, Heidelberg (Germany)

    2006-08-15

    Exact surgical planning is necessary for complex operations of pathological changes in anatomical structures of the pediatric abdomen. 3D visualization and computer-assisted operational planning based on CT data are being increasingly used for difficult operations in adults. To minimize radiation exposure and for better soft tissue contrast, sonography and MRI are the preferred diagnostic methods in pediatric patients. Because of manifold difficulties 3D visualization of these MRI data has not been realized so far, even though the field of embryonal malformations and tumors could benefit from this. A newly developed and modified raycasting-based powerful 3D volume rendering software (VG Studio Max 1.2) for the planning of pediatric abdominal surgery is presented. With the help of specifically developed algorithms, a useful surgical planning system is demonstrated. Thanks to the easy handling and high-quality visualization with enormous gain of information, the presented system is now an established part of routine surgical planning. (orig.) [German] Komplexe Operationen bei ausgepraegten pathologischen Veraenderungen anatomischer Strukturen des kindlichen Abdomens benoetigen eine exakte Operationsvorbereitung. 3D-Visualisierung und computerassistierte Operationsplanung anhand von CT-Daten finden fuer schwierige chirurgische Eingriffe bei Erwachsenen in zunehmendem Masse Anwendung. Aus strahlenhygienischen Gruenden und bei besserer Weichteildifferenzierung ist jedoch neben der Sonographie die Magnetresonanztomographie (MRT) bei Kindern das Diagnostikum der Wahl. Die 3D-Visualisierung dieser MRT-Daten ist dabei jedoch aufgrund vielfaeltiger Schwierigkeiten bisher nicht durchgefuehrt worden, obwohl sich das Gebiet embryonaler Fehlbildungen und Tumoren geradezu anbietet. Vorgestellt wird eine weiterentwickelte und an die Fragestellungen der abdominellen Kinderchirurgie angepasste, sehr leistungsstarke raycastingbasierte 3D-volume-rendering-Software (VG Studio Max 1

  15. Improvement of internal tumor volumes of non-small cell lung cancer patients for radiation treatment planning using interpolated average CT in PET/CT.

    Directory of Open Access Journals (Sweden)

    Yao-Ching Wang

    Full Text Available Respiratory motion causes uncertainties in tumor edges on either computed tomography (CT or positron emission tomography (PET images and causes misalignment when registering PET and CT images. This phenomenon may cause radiation oncologists to delineate tumor volume inaccurately in radiotherapy treatment planning. The purpose of this study was to analyze radiology applications using interpolated average CT (IACT as attenuation correction (AC to diminish the occurrence of this scenario. Thirteen non-small cell lung cancer patients were recruited for the present comparison study. Each patient had full-inspiration, full-expiration CT images and free breathing PET images by an integrated PET/CT scan. IACT for AC in PET(IACT was used to reduce the PET/CT misalignment. The standardized uptake value (SUV correction with a low radiation dose was applied, and its tumor volume delineation was compared to those from HCT/PET(HCT. The misalignment between the PET(IACT and IACT was reduced when compared to the difference between PET(HCT and HCT. The range of tumor motion was from 4 to 17 mm in the patient cohort. For HCT and PET(HCT, correction was from 72% to 91%, while for IACT and PET(IACT, correction was from 73% to 93% (*p<0.0001. The maximum and minimum differences in SUVmax were 0.18% and 27.27% for PET(HCT and PET(IACT, respectively. The largest percentage differences in the tumor volumes between HCT/PET and IACT/PET were observed in tumors located in the lowest lobe of the lung. Internal tumor volume defined by functional information using IACT/PET(IACT fusion images for lung cancer would reduce the inaccuracy of tumor delineation in radiation therapy planning.

  16. The rationale and technique of staged-volume arteriovenous malformation radiosurgery

    International Nuclear Information System (INIS)

    Pollock, Bruce E.; Kline, Robert W.; Stafford, Scott L.; Foote, Robert L.; Schomberg, Paula J.

    2000-01-01

    Purpose: Stereotactic radiosurgery is an effective management strategy for properly selected arteriovenous malformation (AVM) patients. However, the risk of postradiosurgical radiation-related injury generally limits this procedure to patients with AVMs of an average diameter of 3 cm or less. Radiosurgery of large AVMs in a planned staged fashion was undertaken to limit the radiation exposure to the surrounding normal brain. Methods and Materials: Between April 1997 and December 1999, 10 patients with a median AVM volume of 17.4 cm 3 (range, 7.4-53.3 cm 3 ) underwent staged-volume radiosurgery (23 procedures). At the first radiosurgical procedure, the total volume of the AVM is estimated and a dose plan calculated that covers 10 cm 3 -15 cm 3 , or one-half the nidus volume if the AVM is critically located (brainstem, thalamus, or basal ganglia). At 6-month intervals thereafter, radiosurgery was repeated to different portions of the AVM with the previous dose plan(s) being re-created utilizing intracranial landmarks to minimize radiation overlap. Radiosurgical procedures were continued until the entire malformation has been irradiated. Results: The radiation dosimetry of staged-volume AVM radiosurgery was compared to hypothetical single-session procedures for the 10 patients. Staged-volume radiosurgery decreased the 12-Gy volume by an average of 11.1% (range, 4.9-21%) (p < 0.001). The non-AVM 12-Gy volume was reduced by an average of 27.2% (range, 12.5-51.3%) (p < 0.001). Discussion: Staged-volume radiosurgery of large AVMs results in less radiation exposure to the adjacent brain. Further follow-up is needed to determine whether this technique provides a high rate of AVM obliteration while maintaining an acceptable rate of radiation-related complications

  17. X-ray volume imaging in bladder radiotherapy verification

    International Nuclear Information System (INIS)

    Henry, Ann M.; Stratford, Julia; McCarthy, Claire; Davies, Julie; Sykes, Jonathan R.; Amer, Ali; Marchant, Tom; Cowan, Richard; Wylie, James; Logue, John; Livsey, Jacqueline; Khoo, Vincent S.; Moore, Chris; Price, Pat

    2006-01-01

    Purpose: To assess the clinical utility of X-ray volume imaging (XVI) for verification of bladder radiotherapy and to quantify geometric error in bladder radiotherapy delivery. Methods and Materials: Twenty subjects undergoing conformal bladder radiotherapy were recruited. X-ray volume images and electronic portal images (EPIs) were acquired for the first 5 fractions and then once weekly. X-ray volume images were co-registered with the planning computed tomography scan and clinical target volume coverage assessed in three dimensions (3D). Interfraction bladder volume change was described by quantifying changes in bladder volume with time. Bony setup errors were compared from both XVI and EPI. Results: The bladder boundary was clearly visible on coronal XVI views in nearly all images, allowing accurate 3D treatment verification. In 93.5% of imaged fractions, the clinical target volume was within the planning target volume. Most subjects displayed consistent bladder volumes, but 25% displayed changes that could be predicted from the first three XVIs. Bony setup errors were similar whether calculated from XVI or EPI. Conclusions: Coronal XVI can be used to verify 3D bladder radiotherapy delivery. Image-guided interventions to reduce geographic miss and normal tissue toxicity are feasible with this technology

  18. Strategic plan for geriatrics and extended care in the veterans health administration: background, plan, and progress to date.

    Science.gov (United States)

    Shay, Kenneth; Hyduke, Barbara; Burris, James F

    2013-04-01

    The leaders of Geriatrics and Extended Care (GEC) in the Veterans Health Administration (VHA) undertook a strategic planning process that led to approval in 2009 of a multidisciplinary, evidence-guided strategic plan. This article reviews the four goals contained in that plan and describes VHA's progress in addressing them. The goals included transforming the healthcare system to a veteran-centric approach, achieving universal access to a panel of services, ensuring that the Veterans Affair's (VA) healthcare workforce was adequately prepared to manage the needs of the growing elderly veteran population, and integrating continuous improvement into all care enhancements. There has been substantial progress in addressing all four goals. All VHA health care has undergone an extensive transformation to patient-centered care, has enriched the services it can offer caregivers of dependent veterans, and has instituted models to better integrate VA and non-VA cares and services. A range of successful models of geriatric care described in the professional literature has been adapted to VA environments to gauge suitability for broader implementation. An executive-level task force developed a three-pronged approach for enhancing the VA's geriatric workforce. The VHA's performance measurement approaches increasingly include incentives to enhance the quality of management of vulnerable elderly adults in primary care. The GEC strategic plan was intended to serve as a road map for keeping VHA aligned with an ambitious but important long-term vision for GEC services. Although no discrete set of resources was appropriated for fulfillment of the plan's recommendations, this initial report reflects substantial progress in addressing most of its goals. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

  19. Implementation Plan. Environmental Restoration and Waste Management Programmatic Environmental Impact Statement

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    In accordance with the Department of Energy`s National Environmental Policy Act implementing procedures in Volume 10 of the Code of Federal Regulations, Section 1021,312, the Environmental Restoration and Waste Management Programmatic Environmental Impact Statement Implementation Plan has two primary purposes: to provide guidance for the preparation of the Programmatic Environmental Impact Statement and to record the issues resulting from the scoping and the extended public participation process. The Implementation Plan identifies and discusses the following: background of Environmental Restoration and Waste Management activities, the purpose of the Programmatic Environmental Impact Statement, and the relationship of the Programmatic Environmental Impact Statement to other Departmental initiatives (Chapter 1); need and purposes for action (Chapter 2); scoping process and results of the public participation program in defining the scope of the Programmatic Environmental Impact Statement, including a summary of the comments received and their disposition (Chapter 3); planned scope and content of the Programmatic Environmental Impact Statement (Chapter 4); consultations with other agencies and the role of cooperating agencies (Chapter 5); planned schedule of major Programmatic Environmental Impact Statement milestones (Chapter 6); and responsibilities for preparation of the Programmatic Environmental Impact Statement (Chapter 7).

  20. Long-term research plan for human factors affecting safeguards at nuclear power plants. Volume 1. Summary and users' guide. Vol. 1

    International Nuclear Information System (INIS)

    O'Brien, J.N.; Fainberg, A.

    1984-04-01

    This report presents a long-term research plan for addressing human factors which can adversely affect safeguards at nuclear power plants. It was developed in order to prioritize and propose research for NRC in regulating power plant safeguards. Research efforts addressing human factors in safeguards were developed and prioritized according to the importance of human factors areas. Research was also grouped to take advantage of common research approaches and data sources where appropriate. Four main program elements emerged from the analysis, namely (1) Training and Performance Evaluation, (2) Organizational Factors, (3) Man-Machine Interface, and (4) Trustworthiness and Reliability. Within each program element, projects are proposed with results and information flowing between program elements where useful. An overall research plan was developed for a 4-year period and it would lead ultimately to regulatory activities including rulemaking, regulatory guides, and technical bases for regulatory action. The entire plan is summarized in Volume 1 of this report

  1. Some aspects of the relation between the volume of prostate carcinoma and its interstitial BT volume

    International Nuclear Information System (INIS)

    Zivanovic, A; Babic, J; Erak, M.; Dabic, K.; Donat, D.; Kuzmanovic, Z.; Savic, D.

    1996-01-01

    It is a fact that the volume achieved by the interstitial procedure during the brachy treatment of prostate carcinoma is several times smaller than the one we get in, so called, external beam therapy. Furthermore, interstitial brachytherapy offers the possibility to apply large dose into the small volume. However, both dose and volume are at the same time the factors that limit the therapy and the main technical offenders in case of therapy failure. We tried, through a strong individual approach, to compare the volume obtained mathematically and the volume obtained by planning (TPS). By means of clinical examinations and CT scans we conceived a prostate as half of the volume of ellipsoid under one condition only: the magnification of the prostate has to be a symmetrical one. Finally, we applied the following formula: V prostate=(1(2)) ellipsoid=2.09·a/2·e/2·b where a=(1(2)) of sagittal diameter b=prostate height (from apex to base) c=(1(2)) of transversal diameter Each volume obtained in the this way has been taken into account during the application of interstitial needles which in their own way and in accordance to a routine planning, form an active therapeutic interstitial volume. The obtained data showed differences between these two types of volumes. From the statistical point of view, mathematically obtained volume of CV was 16.6% while interstitial volume was 14.9%. T-test was 3.9. On average, mathematical volume is lower and this balance is a desirable one because it means a smaller possibility for potential positive biopsy as a result of a 'rest' tumour. If on the other hand, positive biopsy is a result of the 'rest' tumour and our interpretation has been a contradictory one, precious time with disappointing results will be lost. At the end we achieved: a) double checked control of the embraced volumes, b) stronger fulcrum for the next step: dose-fraction balance

  2. Current situation and future plans in radioactive waste management in Mexico

    International Nuclear Information System (INIS)

    Lopez, H.; Jimenez, M.

    1992-01-01

    A brief introduction is offered in this document in order to explain the importance which is given in Mexico to the safe management of radioactive wastes. The Secretaria de Energia, Minas e Industria Paraestatal is the organization responsible for this issue. Also, a brief historical background is offered so as to understand the evolution of these activities since they were originated. This background allows us to describe the present situation, which consists in a substantial change in the volume of produced radioactive wastes; in other words, before the present situation only the, nuclear wastes from the application of radioisotopes were generated whereas currently, with the starting of commercial operation of the first unit of Laguna Verde Nuclear Power Plant (LVNPP), large volumes of industrial radioactive wastes are being generated. A mention is given as well of the acquired experience during more than 20 years of waste management and of the technologies which have been applied or practiced in the use and disposal of such wastes. Finally, some general trends in relation to the future planning are indicated, which essentially consist in the siting and characterization of a site so as to, design and construct a permanent disposal facility in order to dispose the operational radioactive wastes from LVNPP

  3. Integrated operations plan for the MFTF-B Mirror Fusion Test Facility. Volume II. Integrated operations plan

    Energy Technology Data Exchange (ETDEWEB)

    1981-12-01

    This document defines an integrated plan for the operation of the Lawrence Livermore National Laboratory (LLNL) Mirror Fusion Test Facility (MFTF-B). The plan fulfills and further delineates LLNL policies and provides for accomplishing the functions required by the program. This plan specifies the management, operations, maintenance, and engineering support responsibilities. It covers phasing into sustained operations as well as the sustained operations themselves. Administrative and Plant Engineering support, which are now being performed satisfactorily, are not part of this plan unless there are unique needs.

  4. Integrated operations plan for the MFTF-B Mirror Fusion Test Facility. Volume II. Integrated operations plan

    International Nuclear Information System (INIS)

    1981-12-01

    This document defines an integrated plan for the operation of the Lawrence Livermore National Laboratory (LLNL) Mirror Fusion Test Facility (MFTF-B). The plan fulfills and further delineates LLNL policies and provides for accomplishing the functions required by the program. This plan specifies the management, operations, maintenance, and engineering support responsibilities. It covers phasing into sustained operations as well as the sustained operations themselves. Administrative and Plant Engineering support, which are now being performed satisfactorily, are not part of this plan unless there are unique needs

  5. SU-F-T-340: Direct Editing of Dose Volume Histograms: Algorithms and a Unified Convex Formulation for Treatment Planning with Dose Constraints

    Energy Technology Data Exchange (ETDEWEB)

    Ungun, B [Stanford University, Stanford, CA (United States); Stanford University School of Medicine, Stanford, CA (United States); Fu, A; Xing, L [Stanford University School of Medicine, Stanford, CA (United States); Boyd, S [Stanford University, Stanford, CA (United States)

    2016-06-15

    Purpose: To develop a procedure for including dose constraints in convex programming-based approaches to treatment planning, and to support dynamic modification of such constraints during planning. Methods: We present a mathematical approach that allows mean dose, maximum dose, minimum dose and dose volume (i.e., percentile) constraints to be appended to any convex formulation of an inverse planning problem. The first three constraint types are convex and readily incorporated. Dose volume constraints are not convex, however, so we introduce a convex restriction that is related to CVaR-based approaches previously proposed in the literature. To compensate for the conservatism of this restriction, we propose a new two-pass algorithm that solves the restricted problem on a first pass and uses this solution to form exact constraints on a second pass. In another variant, we introduce slack variables for each dose constraint to prevent the problem from becoming infeasible when the user specifies an incompatible set of constraints. We implement the proposed methods in Python using the convex programming package cvxpy in conjunction with the open source convex solvers SCS and ECOS. Results: We show, for several cases taken from the clinic, that our proposed method meets specified constraints (often with margin) when they are feasible. Constraints are met exactly when we use the two-pass method, and infeasible constraints are replaced with the nearest feasible constraint when slacks are used. Finally, we introduce ConRad, a Python-embedded free software package for convex radiation therapy planning. ConRad implements the methods described above and offers a simple interface for specifying prescriptions and dose constraints. Conclusion: This work demonstrates the feasibility of using modifiable dose constraints in a convex formulation, making it practical to guide the treatment planning process with interactively specified dose constraints. This work was supported by the

  6. SU-F-T-340: Direct Editing of Dose Volume Histograms: Algorithms and a Unified Convex Formulation for Treatment Planning with Dose Constraints

    International Nuclear Information System (INIS)

    Ungun, B; Fu, A; Xing, L; Boyd, S

    2016-01-01

    Purpose: To develop a procedure for including dose constraints in convex programming-based approaches to treatment planning, and to support dynamic modification of such constraints during planning. Methods: We present a mathematical approach that allows mean dose, maximum dose, minimum dose and dose volume (i.e., percentile) constraints to be appended to any convex formulation of an inverse planning problem. The first three constraint types are convex and readily incorporated. Dose volume constraints are not convex, however, so we introduce a convex restriction that is related to CVaR-based approaches previously proposed in the literature. To compensate for the conservatism of this restriction, we propose a new two-pass algorithm that solves the restricted problem on a first pass and uses this solution to form exact constraints on a second pass. In another variant, we introduce slack variables for each dose constraint to prevent the problem from becoming infeasible when the user specifies an incompatible set of constraints. We implement the proposed methods in Python using the convex programming package cvxpy in conjunction with the open source convex solvers SCS and ECOS. Results: We show, for several cases taken from the clinic, that our proposed method meets specified constraints (often with margin) when they are feasible. Constraints are met exactly when we use the two-pass method, and infeasible constraints are replaced with the nearest feasible constraint when slacks are used. Finally, we introduce ConRad, a Python-embedded free software package for convex radiation therapy planning. ConRad implements the methods described above and offers a simple interface for specifying prescriptions and dose constraints. Conclusion: This work demonstrates the feasibility of using modifiable dose constraints in a convex formulation, making it practical to guide the treatment planning process with interactively specified dose constraints. This work was supported by the

  7. Radiogenic and muon-induced backgrounds in the LUX dark matter detector

    Science.gov (United States)

    Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Bernard, E.; Bernstein, A.; Bradley, A.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chapman, J. J.; Chiller, A. A.; Chiller, C.; Coffey, T.; Currie, A.; de Viveiros, L.; Dobi, A.; Dobson, J.; Druszkiewicz, E.; Edwards, B.; Faham, C. H.; Fiorucci, S.; Flores, C.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C.; Hertel, S. A.; Horn, M.; Huang, D. Q.; Ihm, M.; Jacobsen, R. G.; Kazkaz, K.; Knoche, R.; Larsen, N. A.; Lee, C.; Lindote, A.; Lopes, M. I.; Malling, D. C.; Mannino, R.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H.; Neves, F.; Ott, R. A.; Pangilinan, M.; Parker, P. D.; Pease, E. K.; Pech, K.; Phelps, P.; Reichhart, L.; Shutt, T.; Silva, C.; Solovov, V. N.; Sorensen, P.; O'Sullivan, K.; Sumner, T. J.; Szydagis, M.; Taylor, D.; Tennyson, B.; Tiedt, D. R.; Tripathi, M.; Uvarov, S.; Verbus, J. R.; Walsh, N.; Webb, R.; White, J. T.; Witherell, M. S.; Wolfs, F. L. H.; Woods, M.; Zhang, C.

    2015-03-01

    The Large Underground Xenon (LUX) dark matter experiment aims to detect rare low-energy interactions from Weakly Interacting Massive Particles (WIMPs). The radiogenic backgrounds in the LUX detector have been measured and compared with Monte Carlo simulation. Measurements of LUX high-energy data have provided direct constraints on all background sources contributing to the background model. The expected background rate from the background model for the 85.3 day WIMP search run is (2.6 ±0.2stat ±0.4sys) ×10-3 events keVee-1 kg-1day-1 in a 118 kg fiducial volume. The observed background rate is (3.6 ±0.4stat) ×10-3 events keVee-1 kg-1day-1 , consistent with model projections. The expectation for the radiogenic background in a subsequent one-year run is presented.

  8. Definition of gross tumor volume in lung cancer: inter-observer variability

    International Nuclear Information System (INIS)

    Van de Steene, Jan; Linthout, Nadine; Mey, Johan de; Vinh-Hung, Vincent; Claassens, Cornelia; Noppen, Marc; Bel, Arjan; Storme, Guy

    2002-01-01

    Background and purpose: To determine the inter-observer variation in gross tumor volume (GTV) definition in lung cancer, and its clinical relevance. Material and methods: Five clinicians involved in lung cancer were asked to define GTV on the planning CT scan of eight patients. Resulting GTVs were compared on the base of geometric volume, dimensions and extensions. Judgement of invasion of lymph node (LN) regions was evaluated using the ATS/LCSG classification of LN. Clinical relevance of the variation was studied through 3D-dosimetry of standard conformal plans: volume of critical organs (heart, lungs, esophagus, spinal cord) irradiated at toxic doses, 95% isodose volumes of GTVs, normal tissue complication probabilities (NTCP) and tumor control probabilities (TCP) were compared for evaluation of observer variability. Results: Before evaluation of observer variability, critical review of planning CT scan led to up- (two cases) and downstaging (one case) of patients as compared to the respective diagnostic scans. The defined GTVs showed an inter-observer variation with a ratio up to more than 7 between maximum and minimum geometric content. The dimensions of the primary tumor had inter-observer ranges of 4.2 (transversal), 7.9 (cranio-caudal) and 5.4 (antero-posterior) cm. Extreme extensions of the GTVs (left, right, cranial, caudal, anterior and posterior) varied with ranges of 2.8-7.3 cm due to inter-observer variation. After common review, only 63% of involved lymph node regions were delineated by the clinicians (i.e. 37% are false negative). Twenty-two percent of drawn in lymph node regions were accepted to be false positive after review. In the conformal plans, inter-observer ranges of irradiated normal tissue volume were on average 12%, with a maximum of 66%. The probability (in the population of all conformal plans) of irradiating at least 95% of the GTV with at least 95% of the nominal treatment dose decreased from 96 to 88% when swapping the matched GTV

  9. Reachable volume RRT

    KAUST Repository

    McMahon, Troy

    2015-05-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  10. Reachable volume RRT

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2015-01-01

    © 2015 IEEE. Reachable volumes are a new technique that allows one to efficiently restrict sampling to feasible/reachable regions of the planning space even for high degree of freedom and highly constrained problems. However, they have so far only been applied to graph-based sampling-based planners. In this paper we develop the methodology to apply reachable volumes to tree-based planners such as Rapidly-Exploring Random Trees (RRTs). In particular, we propose a reachable volume RRT called RVRRT that can solve high degree of freedom problems and problems with constraints. To do so, we develop a reachable volume stepping function, a reachable volume expand function, and a distance metric based on these operations. We also present a reachable volume local planner to ensure that local paths satisfy constraints for methods such as PRMs. We show experimentally that RVRRTs can solve constrained problems with as many as 64 degrees of freedom and unconstrained problems with as many as 134 degrees of freedom. RVRRTs can solve problems more efficiently than existing methods, requiring fewer nodes and collision detection calls. We also show that it is capable of solving difficult problems that existing methods cannot.

  11. Reduction of heart volume during neoadjuvant chemoradiation in patients with resectable esophageal cancer

    International Nuclear Information System (INIS)

    Haj Mohammad, Nadia; Kamphuis, Martijn; Hulshof, Maarten C.C.M.; Lutkenhaus, Lotte J.; Gisbertz, Suzanne S.; Bergman, Jacques J.G.H.M.; Bruin-Bon, H.A.C.M. Rianne de; Geijsen, Elisabeth D.; Bel, Arjan; Boekholdt, S. Mathijs; Laarhoven, Hanneke W.M. van

    2015-01-01

    Background and purpose: Neoadjuvant chemoradiation (nCRT) followed by surgery is considered curative intent treatment for patients with resectable esophageal cancer. The aim was to establish hemodynamic aspects of changes in heart volume and to explore whether changes in heart volume resulted in clinically relevant changes in the dose distribution of radiotherapy. Methods: A prospective study was conducted in patients who were treated with nCRT consisting of carboplatin and paclitaxel concomitant with radiotherapy (41.4 Gy/1.8 Gy per fraction). Physical parameters, cardiac volume on CT and Cone beam CT, cardiac blood markers and cardiac ultrasound were obtained. Results: In 23 patients a significant decrease of 55.3 ml in heart volume was detected (95% CI 36.7–73.8 ml, p < 0.001). There was a decrease in both systolic (mean decrease 18 mmHg, 95% CI 11–26 mmHg, p < 0.001) and diastolic blood pressure (mean decrease 8 mmHg, 95% CI 2–14 mmHg, p = 0.008) and an increase in heart rate with 6 beats/min (95% CI 1–11 beats/min, p = 0.021). Except for Troponin T, no change in other cardiac markers and echocardiography parameters were observed. The change in heart volume did not result in a clinically relevant change in radiation dose distribution. Conclusion: Heart volume was significantly reduced, but was not accompanied by overt cardiac dysfunction. All observed changes in hemodynamic parameters are consistent with volume depletion. Adaptation of the treatment plan during the course of radiotherapy is not advocated

  12. INDOT Technical Training Plan

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations : for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and E...

  13. Very Low Cerebral Blood Volume Predicts Parenchymal Hematoma in Acute Ischemic Stroke

    DEFF Research Database (Denmark)

    Hermitte, Laure; Cho, Tae-Hee; Ozenne, Brice

    2013-01-01

    BACKGROUND AND PURPOSE: Parenchymal hematoma (PH) may worsen the outcome of patients with stroke. The aim of our study was to confirm the relationship between the volume of very low cerebral blood volume (CBV) and PH using a European multicenter database (I-KNOW). A secondary objective was to exp......BACKGROUND AND PURPOSE: Parenchymal hematoma (PH) may worsen the outcome of patients with stroke. The aim of our study was to confirm the relationship between the volume of very low cerebral blood volume (CBV) and PH using a European multicenter database (I-KNOW). A secondary objective...

  14. Change in volume of lumpectomy cavity during external-beam irradiation of the intact breast

    International Nuclear Information System (INIS)

    Jacobson, Geraldine; Betts, Vicki; Smith, Brian

    2006-01-01

    Purpose: Definition of the lumpectomy cavity is an important component of irradiation of the breast. We use computed tomography (CT)-based planning and contour the lumpectomy volume on the planning CT. We obtained a second CT in the 4th or 5th week of treatment for boost planning and compared the volume change with the first planning-CT scan. Methods and Materials: This retrospective study reviewed the planning-CT data for 20 patients. In the first CT, images were obtained from the mandible to 2 cm below the breast in 3-mm slices. In the second CT, for the boost, images were obtained from the top to the bottom of the clinically defined breast, in 3-mm slices. Lumpectomy cavities were contoured on both CT scans and volumes compared. Results: Sixteen of the 20 patients (80%) had more than a 20% decrease from the first to the second volume, with a corresponding 95% confidence interval. The mean decrease was 16.13 cc, with a standard deviation of 14.05. The Spearman correlation coefficient of 0.18 did not show a significant correlation between the initial volume and the percent change. Conclusions: During external breast irradiation, many patients will have significant volume reduction in the lumpectomy cavity. Because CT-based definition of the lumpectomy cavity can influence the planning of a boost technique, further study appears warranted

  15. WE-B-304-03: Biological Treatment Planning

    International Nuclear Information System (INIS)

    Orton, C.

    2015-01-01

    The ultimate goal of radiotherapy treatment planning is to find a treatment that will yield a high tumor control probability (TCP) with an acceptable normal tissue complication probability (NTCP). Yet most treatment planning today is not based upon optimization of TCPs and NTCPs, but rather upon meeting physical dose and volume constraints defined by the planner. It has been suggested that treatment planning evaluation and optimization would be more effective if they were biologically and not dose/volume based, and this is the claim debated in this month’s Point/Counterpoint. After a brief overview of biologically and DVH based treatment planning by the Moderator Colin Orton, Joseph Deasy (for biological planning) and Charles Mayo (against biological planning) will begin the debate. Some of the arguments in support of biological planning include: this will result in more effective dose distributions for many patients DVH-based measures of plan quality are known to have little predictive value there is little evidence that either D95 or D98 of the PTV is a good predictor of tumor control sufficient validated outcome prediction models are now becoming available and should be used to drive planning and optimization Some of the arguments against biological planning include: several decades of experience with DVH-based planning should not be discarded we do not know enough about the reliability and errors associated with biological models the radiotherapy community in general has little direct experience with side by side comparisons of DVH vs biological metrics and outcomes it is unlikely that a clinician would accept extremely cold regions in a CTV or hot regions in a PTV, despite having acceptable TCP values Learning Objectives: To understand dose/volume based treatment planning and its potential limitations To understand biological metrics such as EUD, TCP, and NTCP To understand biologically based treatment planning and its potential limitations

  16. Effect of background music on maximum acceptable weight of manual lifting tasks.

    Science.gov (United States)

    Yu, Ruifeng

    2014-01-01

    This study used the psychophysical approach to investigate the impact of tempo and volume of background music on the maximum acceptable weight of lift (MAWL), heart rate (HR) and rating of perceived exertion (RPE) of participants engaged in lifting. Ten male college students participated in this study. They lifted a box from the floor, walked 1-2 steps as required, placed the box on a table and walked back twice per minute. The results showed that the tempo of music had a significant effect on both MAWL and HR. Fast tempo background music resulted in higher MAWL and HR values than those resulting from slow tempo music. The effects of both the tempo and volume on the RPE were insignificant. The results of this study suggest fast tempo background music may be used in manual materials handling tasks to increase performance without increasing perceived exertion because of its ergogenic effect on human psychology and physiology.

  17. The effect of planning algorithms in oesophageal radiotherapy in the context of the SCOPE 1 trial

    International Nuclear Information System (INIS)

    Wills, Lucy; Millin, Anthony; Paterson, Jennifer; Crosby, Tom; Staffurth, John

    2009-01-01

    Background and purpose: In radiotherapy clinical trials multiple centres contribute to patient recruitment. Depending on the calculation algorithm used, the reported dose distributions may differ significantly: broadly, the results for algorithms which do not model lateral electron transport (type a) give less accurate results than the more recently available algorithms that do (type b) when compared to Monte Carlo simulations and measurements. Clinical implementation studies for type b algorithms have yet to be reported for oesophageal radiotherapy. Furthermore, clinical trials must ensure an equivalent effect of the treatment regardless of calculation method. This retrospective planning study aims to define guidance for type b planning in a UK oesophageal clinical trial, to enable acceptable consistency of dose distributions regardless of algorithm, and allow for the improved calculation accuracy of type b to be incorporated into the optimization. Materials and methods: Fifteen patient data sets were planned using a single type a algorithm. Plans were recalculated using a single type b algorithm and subsequently re-optimized with the type b in accordance with optimization rules. The changes in absolute dose at the point of prescription for type a were compared to the recalculated type b. Dose-volume data for organs at risk (OARs), and target volumes were compared, and the volume of the planning target volume (PTV) receiving 95% of the prescribed dose (V95%) was compared to the percentage of PTV overlapping with lung. Results: Dose at the prescription point decreased by 0.69% on average (SD = 0.71), p = 0.0021, for type b compared to that for type a. For the re-optimized type b, the OAR doses corresponding to the trial dose-volume constraints were maintained within 1.0% of the type a levels on average. Reductions in the mean PTV V95% of 9.3% and 3.8% were observed for the recalculated and re-optimized type b plans, respectively, when compared to the mean PTV V95

  18. Turnaround Operations Analysis for OTV. Volume 3: Technology Development Plan

    Science.gov (United States)

    1988-01-01

    An integrated technology development plan for the technologies required to process both GBOTVs and SBOTVs are described. The plan includes definition of the tests and experiments to be accomplished on the ground, in a Space Shuttle Sortie Mission, on an Expendable Launch Vehicle, or at the Space Station as a Technology Development Mission (TDM). The plan reflects and accommodates current and projected research and technology programs where appropriate.

  19. Recommendations for energy conservation standards for new residential buildings - volume 3: Introduction and Background to the Standard Development Effort

    Energy Technology Data Exchange (ETDEWEB)

    1989-05-01

    The Energy Conservation for New Buildings Act of 1976, as amended, 42 U.S.C Section 6831 et. seq. requires the US Department of Energy to issue energy conservation standards for the design of new residential and commercial buildings. The standards will be mandatory only for the design of new federal buildings, and will serve as voluntary guidelines for the design of new non-federal buildings. This report documents the development and testing of a set of recommendations, from the American Society of Heating, Refrigeration and Air Conditioning Engineers, Inc. (ASHRAE) Special Projects Committee No. 53, designed to provide the technical foundation for the Congressionally-mandated energy standard for new residential buildings. The recommendations have been developed over the past 25 months by a multidisciplinary project team, under the management of the US Department of Energy and its prime contractor, Pacific Northwest Laboratory. Volume III -- Introduction and Background to the Standard Development Effort is a description of the Standard development process and contains the rationale for the general approach and specific criteria contained within the recommendations.

  20. Development of natural radiation model for evaluation of background radiation in radiation portal monitor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Bum; Lee, Jin Hyung; Moon, Myung Kook [Radioisotope Research and Development Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-11-15

    In ports and airports, radiation portal monitors (RPM) are deployed to detect illicit radioactive materials. Detected gamma rays in a RPM include background radiation and radiation from a freight. As a vehicle moves through the RPM, the vehicle causes the fluctuations in the natural background radiation signal, which ranges of up to 30%. The fluctuation increases the uncertainty of detection signal and can be a cause of RPM false alarm. Therefore, it is important to evaluate background radiation as well as radiation from a container. In this paper, a natural background radiation model was developed to evaluate RPM. To develop natural background radiation model, a Monte Carlo simulation was performed and compared with experimental measurements from a RPM for {sup 40}K, {sup 232}Th series, and {sup 235}U series, which are major sources of natural background radiation. For a natural radiation source, we considered a cylindrical soil volume with 300 m radius and 1 m depth, which was estimated as the maximum range affecting the RPM by MCNP6 simulation. The volume source model was converted to surface source by using MCNP SSW card for computational efficiency. The computational efficiency of the surface source model was improved to approximately 200 times better than that of the volume source model. The surface source model is composed of a hemisphere with 20 m radius in which the RPM and container are modelled. The natural radiation spectrum from the simulation was best fitted to the experimental measurement when portions of {sup 40}K, {sup 232}Th series, and {sup 235}U series were 0.75, 0.0636, and 0.0552 Bq·g{sup -1}, respectively. For gross counting results, the difference between simulation and experiment was around 5%. The background radiation model was used to evaluate background suppression from a 40 ft container with 7.2 m·s{sup -1} speed. In further study, background models and freight models for RPM in real container ports will be developed and applied to

  1. A comparison of different three-dimensional treatment planning techniques for localized radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Koswig, S.; Dinges, S.; Buchali, A.; Boehmer, D.; Salk, J.; Rosenthal, P.; Harder, C.; Schlenger, L.; Budach, V.

    1999-01-01

    Purpose: Four different three-dimensional planning techniques for localized radiotherapy of prostate cancer were compared with regard to dose homogeneity within the target volume and dose to organs at risk, dependent upon tumor stage. Patients and Methods: Six patients with stage T1, 7 patients with stage T2 and 4 patients with stage T3 were included in this study. Four different 3D treatment plans (rotation, 4-field, 5-field and 6-field technique) were calculated for each patient. Dose was calculated with the reference point at the isocenter (100%). The planning target volume was encompassed within the 95% isodose surface. All the techniques used different shaped portal for each beam. Dose volume histograms were created and compared for the planning target volume and the organs at risk (33%, 50%, 66% volume level) in all techniques. Results: The 4 different three-dimensional planning techniques revealed no differences concerning dose homogeneity within the planning target volume. The dose volume distribution at organs at risk show differences between the calculated techniques. In our study the best protection for bladder and rectum in stage T1 and T2 was achieved by the 6-field technique. A significant difference was achieved between 6-field and 4-field technique only in the 50% volume of the bladder (p=0.034), between the 6-field and rotation technique (all volume levels) and between 5-field and rotation technique (all volume levels). In stage T1, T2 6-field and 4-field technique in 50% (p-0.033) and 66% (p=0.011) of the rectum volume. In stage T3 a significant difference was not observed between the 4 techniques. The best protection of head of the femur was achieved by the rotation technique. Conclusion: In the localized radiotherapy of prostate cancer in stage T1 or T2 the best protection for bladder and rectum was achieved by a 3D-planned conformal 6-field technique. If the seminal vesicles have been included in the target volume and in the case of large

  2. Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

    International Nuclear Information System (INIS)

    Thompson, S.A.; Fung, A.Y.C.; Zaider, M.

    2002-01-01

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. (author)

  3. Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, S.A. [Department of Medical Physics, North Shore-Long Island Jewish Health System, Manhassett, NY (United States); Fung, A.Y.C.; Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2002-08-21

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. (author)

  4. A prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer

    International Nuclear Information System (INIS)

    Leong, Trevor; Everitt, Craig; Yuen, Kally; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.; Pitman, Alexander; Lau, Eddie W.F.; MacManus, Michael; Binns, David; Ackerly, Trevor; Hicks, Rodney J.

    2006-01-01

    Background and purpose: This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatment planning of oesophageal cancer would alter the delineation of tumour volumes compared to CT alone if PET/CT is assumed to more accurately represent true disease extent. Patients and methods: All patients underwent FDG-PET/CT scanning in the radiotherapy treatment position. For each patient, two separate gross tumour volumes (GTV) were defined, one based on CT images alone (GTV-CT) and another based on combined PET/CT data (GTV-PET). Corresponding planning target volumes (PTV) were generated, and separate treatment plans were then produced. For each patient, volumetric analysis of GTV-CT, PTV-CT and GTV-PET was performed to quantify the proportion of PET-avid disease that was not included in the GTV and PTV (geographic miss) if CT data alone were used for radiotherapy planning. Assessment of the cranial and caudal extent of the primary oesophageal tumour as defined by CT alone vs PET/CT was also compared. Results: The addition of PET information altered the clinical stage in 8 of 21 eligible patients enrolled on the study (38%); 4 patients had distant metastatic disease and 4 had unsuspected regional nodal disease. Sixteen patients proceeded to the radiotherapy planning phase of the study and received definitive chemoradiation planned with the PET/CT data set. The GTV based on CT information alone excluded PET-avid disease in 11 patients (69%), and in five patients (31%) this would have resulted in a geographic miss of gross tumour. The discordance between CT and PET/CT was due mainly to differences in defining the longitudinal extent of disease in the oesophagus. The cranial extent of the primary tumour as defined by CT vs PET/CT differed in 75% of cases, while the caudal extent differed in 81%. Conclusions: This study demonstrates that if combined PET/CT is used for radiotherapy treatment planning, there may be alterations to the delineation

  5. 2000 Physical Acoustics Summer School (PASS 00). Volume II: Transparencies

    National Research Council Canada - National Science Library

    Bass, Henry

    2001-01-01

    .... Volume II of these proceedings contains copies of the transparencies used by the lecturers and Volume III contains background materials that were sent to student and discussion leader participants...

  6. Analysis of nodal coverage utilizing image guided radiation therapy for primary gynecologic tumor volumes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Faisal [University of Utah School of Medicine, Salt Lake City, UT (United States); Loma Linda University Medical Center, Department of Radiation Oncology, Loma Linda, CA (United States); Sarkar, Vikren; Gaffney, David K.; Salter, Bill [Department of Radiation Oncology, University of Utah, Salt Lake City, UT (United States); Poppe, Matthew M., E-mail: matthew.poppe@hci.utah.edu [Department of Radiation Oncology, University of Utah, Salt Lake City, UT (United States)

    2016-10-01

    Purpose: To evaluate radiation dose delivered to pelvic lymph nodes, if daily Image Guided Radiation Therapy (IGRT) was implemented with treatment shifts based on the primary site (primary clinical target volume [CTV]). Our secondary goal was to compare dosimetric coverage with patient outcomes. Materials and methods: A total of 10 female patients with gynecologic malignancies were evaluated retrospectively after completion of definitive intensity-modulated radiation therapy (IMRT) to their pelvic lymph nodes and primary tumor site. IGRT consisted of daily kilovoltage computed tomography (CT)-on-rails imaging fused with initial planning scans for position verification. The initial plan was created using Varian's Eclipse treatment planning software. Patients were treated with a median radiation dose of 45 Gy (range: 37.5 to 50 Gy) to the primary volume and 45 Gy (range: 45 to 64.8 Gy) to nodal structures. One IGRT scan per week was randomly selected from each patient's treatment course and re-planned on the Eclipse treatment planning station. CTVs were recreated by fusion on the IGRT image series, and the patient's treatment plan was applied to the new image set to calculate delivered dose. We evaluated the minimum, maximum, and 95% dose coverage for primary and nodal structures. Reconstructed primary tumor volumes were recreated within 4.7% of initial planning volume (0.9% to 8.6%), and reconstructed nodal volumes were recreated to within 2.9% of initial planning volume (0.01% to 5.5%). Results: Dosimetric parameters averaged less than 10% (range: 1% to 9%) of the original planned dose (45 Gy) for primary and nodal volumes on all patients (n = 10). For all patients, ≥99.3% of the primary tumor volume received ≥ 95% the prescribed dose (V95%) and the average minimum dose was 96.1% of the prescribed dose. In evaluating nodal CTV coverage, ≥ 99.8% of the volume received ≥ 95% the prescribed dose and the average minimum dose was 93%. In

  7. How precise is manual CT-MRI registration for cranial radiotherapy planning?

    International Nuclear Information System (INIS)

    Mosleh-Shirazi, M. A.; South, P. C.

    2005-01-01

    Manual fusion is a readily available image registration technique that does not require matching algorithms. The operator performs rigid-body transformations interactively. The precision of Manual fusion (as implemented on the Philips Pinnacle treatment planning system) was required for cranial CT-MR images used in radiotherapy planning for typical centrally located planning target volumes . Materials and Methods: A multi-stage Manual fusion procedure was developed which 11 observers followed to match the head contour, bones, soft tissues and contoured structures for 5 patient image-sets. Registration parameters were calculated by solving the transformation matrix following a consistent order of translations (T) and rotations (R). The mean position of centre of each planning target volumes averaged over all observers was used as the reference. The effect of mis registration on the planning target volumes co-ordinates and the volume increase resulting from application of a margin for registration uncertainty were calculated. Results: Mean intra- and inter-observer T/R SDs were 0.5 mm/ 0.4 d ig a nd 1.1 mm/ 1.0 d ig , respectively. Mean intra- and inter-observer registration error (3D distance of each planning target volumes centre from the mean position for all observers) was 0.7 ±0.3 mm (1 SD) and 1.6±0.7 mm respectively, the latter reducing to 1.4±0.6 mm excluding the 3 least experienced operators. A subsequent 2 mm margin for mis registration on average increased the planning target volume by 27%. Conclusion: Moderately trained operators produced clinically acceptable results while experienced operators improved the precision. Manual fusion still has an important role in the registration of cranial CT and MR images for radiotherapy planning especially for under-resourced centers

  8. A comparison of volume control and pressure-regulated volume control ventilation in acute respiratory failure

    OpenAIRE

    Guldager, Henrik; Nielsen, Soeren L; Carl, Peder; Soerensen, Mogens B

    1997-01-01

    Background: The aim of this study was to test the hypothesis that a new mode of ventilation (pressure-regulated volume control; PRVC) is associated with improvements in respiratory mechanics and outcome when compared with conventional volume control (VC) ventilation in patients with acute respiratory failure. We conducted a randomised, prospective, open, cross over trial on 44 patients with acute respiratory failure in the general intensive care unit of a university hospital. After a stabiliz...

  9. Twelve Middle-School Teachers' Planning.

    Science.gov (United States)

    Brown, Deborah Sardo

    1988-01-01

    Case studies described 12 middle-school teachers' instructional yearly, unit, weekly, and daily planning on the basis of a background questionnaire, interview protocols, an analysis of written plans, think-aloud typescripts, and a questionnaire. A process model best characterized teachers long-term planning, while an agenda-formulation model fit…

  10. Wien Automatic System Planning (WASP) Package. A computer code for power generating system expansion planning. Version WASP-III Plus. User's manual. Volume 1: Chapters 1-11

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    (FIXSYS plants); user control of the distribution of capital cost expenditures during the construction period (if required to be different from the general 'S' curve distribution used as default). The present document has been produced to support use of the WASP-Ill Plus computer code and to illustrate the capabilities of the program. This Manual is organized in two separate volumes. This first one includes 11 main chapters describing how to use the WASP-Ill Plus computer program. Chapter 1 gives a summary description and some background information about the program. Chapter 2 introduces some concepts, mainly related to the computer requirements imposed by the program, that are used throughout the Manual. Chapters 3 to 9 describe how to execute each of the various programs (or modules) of the WASP-Ill Plus package. (abstract truncated)

  11. 3-D conformal radiation therapy - Part I: Treatment planning

    International Nuclear Information System (INIS)

    Burman, Chandra M.; Mageras, Gikas S.

    1997-01-01

    Objective: In this presentation we will look into the basic components of 3-dimensional conformal treatment planning, and will discuss planning for some selected sites. We will also review some current and future trends in 3-D treatment planning. External beam radiation therapy is one of the arms of cancer treatment. In the recent years 3-D conformal therapy had significant impact on the practice of external beam radiation therapy. Conformal radiation therapy shapes the high-dose volume so as to conform to the target volume while minimizing the dose to the surrounding normal tissues. The advances that have been achieved in conformal therapy are in part due to the development of 3-D treatment planning, which in turn has capitalized on 3-D imaging for tumor and normal tissue localization, as well as on available computational power for the calculation of 3-D dose distributions, visualization of anatomical and dose volumes, and numerical evaluation of treatment plans. In this course we will give an overview of how 3-D conformal treatments are designed and transferred to the patient. Topics will include: 1) description of the major components of a 3-D treatment planning system, 2) techniques for designing treatments, 3) evaluation of treatment plans using dose distribution displays, dose-volume histograms and normal tissue complication probabilities, 4) implementation of treatments using shaped blocks and multileaf collimators, 5) verification of treatment delivery using portal films and electronic portal imaging devices. We will also discuss some current and future trends in 3-D treatment planning, such as field shaping with multileaf collimation, computerized treatment plan optimization, including the use of nonuniform beam profiles (intensity modulation), and incorporating treatment uncertainties due to patient positioning errors and organ motion into treatment planning process

  12. Long-range research plan. FY 1987-FY 1991. Volume 3

    International Nuclear Information System (INIS)

    1986-08-01

    The Long-Range Research Plan (LRRP) was prepared by the Office of Nuclear Regulatory Research (RES) to assist the NRC in coordinating its long-range research planning with the short-range budget cycles. The LRRP lays out programmatic approaches for research to help resolve regulatory issues. The plan will be updated annually. It covers: operating reactor inspection, maintenance, and repair; equipment qualification; seismic research; reactor operations and risk; thermal-hydraulic transients; severe accidents; radiation protection and health effects; and waste management

  13. Long-Range Research Plan, FY 1986-FY 1990. Volume 2

    International Nuclear Information System (INIS)

    1985-08-01

    The Long-Range Research Plan (LRRP) was prepared by the Office of Nuclear Regulatory Research (RES) to assist the NRC in coordinating its long-range research planning with the short-range budget cycles. The LRRP lays out programmatic approaches for research to help resolve regulatory issues. The plan will be updated annually. It covers: operating reactor inspection, maintenance, and repair; equipment qualification; seismic research; reactor operations and risk; thermal-hydraulic transients; severe accidents; radiation protection and health effects; and waste management

  14. Gravitational-Wave Stochastic Background from Cosmic Strings

    International Nuclear Information System (INIS)

    Siemens, Xavier; Creighton, Jolien; Mandic, Vuk

    2007-01-01

    We consider the stochastic background of gravitational waves produced by a network of cosmic strings and assess their accessibility to current and planned gravitational wave detectors, as well as to big bang nucleosynthesis (BBN), cosmic microwave background (CMB), and pulsar timing constraints. We find that current data from interferometric gravitational wave detectors, such as Laser Interferometer Gravitational Wave Observatory (LIGO), are sensitive to areas of parameter space of cosmic string models complementary to those accessible to pulsar, BBN, and CMB bounds. Future more sensitive LIGO runs and interferometers such as Advanced LIGO and Laser Interferometer Space Antenna (LISA) will be able to explore substantial parts of the parameter space

  15. Annual plan, December 1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This annual plan is being provided as required under Section 'D' of the Alberta Energy and Utilities Board Information Letter IL 90-8. The objective is to provide the Board, NOVA Gas Transmission (NGTL) customers and other interested parties with a comprehensive overview of NOVA Gas Transmission's pipeline system expansion plans for the gas year 2000/ 2001, and the winter season of the 2001/2002 gas year. The plan includes descriptions of NGTL's design assumptions and criteria, as well as long term outlook for field deliverability, productive capability, gas deliveries, proposed facility additions, capital expenditures, revenue requirements and firm service demand rates. Major factors affecting the facility requirements for the period under consideration are a decrease in the maximum day delivery volume at the Empress border point, an increase in intra-Alberta maximum day delivery volumes and associated decline in productive capability. Chapter One of the Plan describes the the Annual Plan process itself; Chapter Two is devoted to a discussion of facilities design methodology; Chapter Three deals with economic assumptions; Chapter Four describes design flow, while Chapters Five and Six outline the mainline , meter stations, laterals, and lateral loops facility requirements. Chapter Seven provides and overview of the capital and financial forecasts. tabs., figs.

  16. Strategies for automatic online treatment plan reoptimization using clinical treatment planning system: A planning parameters study

    International Nuclear Information System (INIS)

    Li, Taoran; Wu, Qiuwen; Zhang, You; Vergalasova, Irina; Lee, W. Robert; Yin, Fang-Fang; Wu, Q. Jackie

    2013-01-01

    Purpose: Adaptive radiation therapy for prostate cancer using online reoptimization provides an improved control of interfractional anatomy variations. However, the clinical implementation of online reoptimization is currently limited by the low efficiency of current strategies and the difficulties associated with integration into the current treatment planning system. This study investigates the strategies for performing fast (∼2 min) automatic online reoptimization with a clinical fluence-map-based treatment planning system; and explores the performance with different input parameters settings: dose-volume histogram (DVH) objective settings, starting stage, and iteration number (in the context of real time planning).Methods: Simulated treatments of 10 patients were reoptimized daily for the first week of treatment (5 fractions) using 12 different combinations of optimization strategies. Options for objective settings included guideline-based RTOG objectives, patient-specific objectives based on anatomy on the planning CT, and daily-CBCT anatomy-based objectives adapted from planning CT objectives. Options for starting stages involved starting reoptimization with and without the original plan's fluence map. Options for iteration numbers were 50 and 100. The adapted plans were then analyzed by statistical modeling, and compared both in terms of dosimetry and delivery efficiency.Results: All online reoptimized plans were finished within ∼2 min with excellent coverage and conformity to the daily target. The three input parameters, i.e., DVH objectives, starting stage, and iteration number, contributed to the outcome of optimization nearly independently. Patient-specific objectives generally provided better OAR sparing compared to guideline-based objectives. The benefit in high-dose sparing from incorporating daily anatomy into objective settings was positively correlated with the relative change in OAR volumes from planning CT to daily CBCT. The use of the

  17. Dosimetric accuracy of a treatment planning system for actively scanned proton beams and small target volumes: Monte Carlo and experimental validation

    CERN Document Server

    Magro, G; Mairani, A; Mirandola, A; Panizza, D; Russo, S; Ferrari, A; Valvo, F; Fossati, P; Ciocca, M

    2015-01-01

    This study was performed to evaluate the accuracy of a commercial treatment planning system (TPS), in optimising proton pencil beam dose distributions for small targets of different sizes (5–30 mm side) located at increasing depths in water. The TPS analytical algorithm was benchmarked against experimental data and the FLUKA Monte Carlo (MC) code, previously validated for the selected beam-line. We tested the Siemens syngo® TPS plan optimisation module for water cubes fixing the configurable parameters at clinical standards, with homogeneous target coverage to a 2 Gy (RBE) dose prescription as unique goal. Plans were delivered and the dose at each volume centre was measured in water with a calibrated PTW Advanced Markus® chamber. An EBT3® film was also positioned at the phantom entrance window for the acquisition of 2D dose maps. Discrepancies between TPS calculated and MC simulated values were mainly due to the different lateral spread modeling and resulted in being related to the field-to-spot size r...

  18. Knowledge-based radiation therapy (KBRT) treatment planning versus planning by experts: validation of a KBRT algorithm for prostate cancer treatment planning

    International Nuclear Information System (INIS)

    Nwankwo, Obioma; Mekdash, Hana; Sihono, Dwi Seno Kuncoro; Wenz, Frederik; Glatting, Gerhard

    2015-01-01

    A knowledge-based radiation therapy (KBRT) treatment planning algorithm was recently developed. The purpose of this work is to investigate how plans that are generated with the objective KBRT approach compare to those that rely on the judgment of the experienced planner. Thirty volumetric modulated arc therapy plans were randomly selected from a database of prostate plans that were generated by experienced planners (expert plans). The anatomical data (CT scan and delineation of organs) of these patients and the KBRT algorithm were given to a novice with no prior treatment planning experience. The inexperienced planner used the knowledge-based algorithm to predict the dose that the OARs receive based on their proximity to the treated volume. The population-based OAR constraints were changed to the predicted doses. A KBRT plan was subsequently generated. The KBRT and expert plans were compared for the achieved target coverage and OAR sparing. The target coverages were compared using the Uniformity Index (UI), while 5 dose-volume points (D 10 , D 30, D 50 , D 70 and D 90 ) were used to compare the OARs (bladder and rectum) doses. Wilcoxon matched-pairs signed rank test was used to check for significant differences (p < 0.05) between both datasets. The KBRT and expert plans achieved mean UI values of 1.10 ± 0.03 and 1.10 ± 0.04, respectively. The Wilcoxon test showed no statistically significant difference between both results. The D 90 , D 70, D 50 , D 30 and D 10 values of the two planning strategies, and the Wilcoxon test results suggests that the KBRT plans achieved a statistically significant lower bladder dose (at D 30 ), while the expert plans achieved a statistically significant lower rectal dose (at D 10 and D 30 ). The results of this study show that the KBRT treatment planning approach is a promising method to objectively incorporate patient anatomical variations in radiotherapy treatment planning

  19. Volumetric-modulated arc therapy in postprostatectomy radiotherapy patients: A planning comparison study

    International Nuclear Information System (INIS)

    Forde, Elizabeth; Kneebone, Andrew; Bromley, Regina; Guo, Linxin; Hunt, Peter; Eade, Thomas

    2013-01-01

    The purpose of this study was to compare postprostatectomy planning for volumetric-modulated arc therapy (VMAT) with both single arc (SA) and double arcs (DA) against dynamic sliding window intensity-modulated radiotherapy (IMRT). Ten cases were planned with IMRT, SA VMAT, and DA VMAT. All cases were planned to achieve a minimum dose of 68 Gy to 95% of the planning target volume (PTV) and goals to limit rectal volume >40 Gy to 35% and >65 Gy to 17%, and bladder volumes >40 Gy to 50% and >65 Gy to 25%. Plans were averaged across the 10 patients and compared for mean dose, conformity, homogeneity, rectal and bladder doses, and monitor units. The mean dose to the clinical target volume and PTV was significantly higher (p<0.05) for SA compared with DA or IMRT. The homogeneity index was not significantly different: SA = 0.09; DA = 0.08; and IMRT = 0.07. The rectal V40 was lowest for the DA plan. The rectal V20 was significantly lower (p<0.05) for both the VMAT plans compared with IMRT. There were no significant differences for bladder V40 or rectal and bladder V65. The IMRT plans required 1400 MU compared with 745 for DA and 708 for SA. This study shows that for equivalent dose coverage, SA and DA VMAT plans result in higher mean doses to the clinical target volume and PTV. This greater dose heterogeneity is balanced by improved low-range rectal doses and halving of the monitor units

  20. Volumetric-modulated arc therapy in postprostatectomy radiotherapy patients: A planning comparison study

    Energy Technology Data Exchange (ETDEWEB)

    Forde, Elizabeth, E-mail: eforde@tcd.ie [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Kneebone, Andrew [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia); Bromley, Regina [Institute of Medical Physics, School of Physics, University of Sydney, New South Wales (Australia); Guo, Linxin; Hunt, Peter [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Eade, Thomas [Radiation Oncology Department, Northern Sydney Cancer Centre, St Leonards, New South Wales (Australia); Northern Clinical School, University of Sydney, New South Wales (Australia)

    2013-10-01

    The purpose of this study was to compare postprostatectomy planning for volumetric-modulated arc therapy (VMAT) with both single arc (SA) and double arcs (DA) against dynamic sliding window intensity-modulated radiotherapy (IMRT). Ten cases were planned with IMRT, SA VMAT, and DA VMAT. All cases were planned to achieve a minimum dose of 68 Gy to 95% of the planning target volume (PTV) and goals to limit rectal volume >40 Gy to 35% and >65 Gy to 17%, and bladder volumes >40 Gy to 50% and >65 Gy to 25%. Plans were averaged across the 10 patients and compared for mean dose, conformity, homogeneity, rectal and bladder doses, and monitor units. The mean dose to the clinical target volume and PTV was significantly higher (p<0.05) for SA compared with DA or IMRT. The homogeneity index was not significantly different: SA = 0.09; DA = 0.08; and IMRT = 0.07. The rectal V40 was lowest for the DA plan. The rectal V20 was significantly lower (p<0.05) for both the VMAT plans compared with IMRT. There were no significant differences for bladder V40 or rectal and bladder V65. The IMRT plans required 1400 MU compared with 745 for DA and 708 for SA. This study shows that for equivalent dose coverage, SA and DA VMAT plans result in higher mean doses to the clinical target volume and PTV. This greater dose heterogeneity is balanced by improved low-range rectal doses and halving of the monitor units.

  1. Evaluation of a commercial biologically based IMRT treatment planning system

    International Nuclear Information System (INIS)

    Semenenko, Vladimir A.; Reitz, Bodo; Day, Ellen; Qi, X. Sharon; Miften, Moyed; Li, X. Allen

    2008-01-01

    A new inverse treatment planning system (TPS) for external beam radiation therapy with high energy photons is commercially available that utilizes both dose-volume-based cost functions and a selection of cost functions which are based on biological models. The purpose of this work is to evaluate quality of intensity-modulated radiation therapy (IMRT) plans resulting from the use of biological cost functions in comparison to plans designed using a traditional TPS employing dose-volume-based optimization. Treatment planning was performed independently at two institutions. For six cancer patients, including head and neck (one case from each institution), prostate, brain, liver, and rectal cases, segmental multileaf collimator IMRT plans were designed using biological cost functions and compared with clinically used dose-based plans for the same patients. Dose-volume histograms and dosimetric indices, such as minimum, maximum, and mean dose, were extracted and compared between the two types of treatment plans. Comparisons of the generalized equivalent uniform dose (EUD), a previously proposed plan quality index (fEUD), target conformity and heterogeneity indices, and the number of segments and monitor units were also performed. The most prominent feature of the biologically based plans was better sparing of organs at risk (OARs). When all plans from both institutions were combined, the biologically based plans resulted in smaller EUD values for 26 out of 33 OARs by an average of 5.6 Gy (range 0.24 to 15 Gy). Owing to more efficient beam segmentation and leaf sequencing tools implemented in the biologically based TPS compared to the dose-based TPS, an estimated treatment delivery time was shorter in most (five out of six) cases with some plans showing up to 50% reduction. The biologically based plans were generally characterized by a smaller conformity index, but greater heterogeneity index compared to the dose-based plans. Overall, compared to plans based on dose-volume

  2. Stochastic background of gravitational waves from hybrid preheating.

    Science.gov (United States)

    García-Bellido, Juan; Figueroa, Daniel G

    2007-02-09

    The process of reheating the Universe after hybrid inflation is extremely violent. It proceeds through the nucleation and subsequent collision of large concentrations of energy density in bubblelike structures, which generate a significant fraction of energy in the form of gravitational waves. We study the power spectrum of the stochastic background of gravitational waves produced at reheating after hybrid inflation. We find that the amplitude could be significant for high-scale models, although the typical frequencies are well beyond what could be reached by planned gravitational wave observatories. On the other hand, low-scale models could still produce a detectable stochastic background at frequencies accessible to those detectors. The discovery of such a background would open a new window into the very early Universe.

  3. WECC Variable Generation Planning Reference Book: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, Yuri V.; Du, Pengwei; Etingov, Pavel V.; Ma, Jian; Vyakaranam, Bharat

    2013-05-13

    The document titled “WECC Variable Generation Planning Reference Book”. This book is divided into two volumes; one is the main document (volume 1)and the other is appendices (volume 2). The main document is a collection of the best practices and the information regarding the application and impact of variables generation on power system planning. This volume (appendices) has additional information on the following topics: Probabilistic load flow problems. 2. Additional useful indices. 3. high-impact low-frequency (HILF) events. 4. Examples of wide-area nomograms. 5. Transmission line ratings, types of dynamic rating methods. 6. Relative costs per MW-km of different electric power transmission technologies. 7. Ultra-high voltage (UHV) transmission. 8.High voltage direct current (VSC-HVDC). 9. HVDC. 10. Rewiring of existing transmission lines. 11. High-temperature low sag (HTLS) conductors. 12. The direct method and energy functions for transient stability analysis in power systems. 13.Blackouts caused by voltage instability. 14. Algorithm for parameter continuation predictor-corrector methods. 15. Approximation techniques available for security regions. 16. Impacts of wind power on power system small signals stability. 17. FIDVR. 18. FACTS. 19. European planning standard and practices. 20. International experience in wind and solar energy sources. 21. Western Renewable Energy Zones (WREZ). 22. various energy storage technologies. 23. demand response. 24. BA consolidation and cooperation options. 25. generator power management requirements and 26. European planning guidelines.

  4. Clinically significant change in stroke volume in pulmonary hypertension

    NARCIS (Netherlands)

    van Wolferen, S.A.; van de Veerdonk, M.C.; Mauritz, G.J.; Jacobs, W.; Marcus, J.T.; Marques, K.M.J.; Bronzwaer, J.G.F.; Heijmans, M.W.; Boonstra, A.; Postmus, P.E.; Westerhof, N.; Noordegraaf, A.V.

    2011-01-01

    Background: Stroke volume is probably the best hemodynamic parameter because it reflects therapeutic changes and contains prognostic information in pulmonary hypertension (PH). Stroke volume directly reflects right ventricular function in response to its load, without the correction of compensatory

  5. Illinois statewide gas utility plan, 1993-2002. Volume 1. Executive summary

    International Nuclear Information System (INIS)

    1992-12-01

    The second Illinois Statewide Natural Gas Utility Plan is a continuation of the Least-Cost Planning effort introduced by the Public Utilities Act of 1986. The purpose of the Plan, like its predecessor, is to provide a framework and a set of policies which will allow and encourage local distribution companies to develop least-cost plans consistent with the goals of the Act: to provide efficient, environmentally sound, reliable, and equitable public utility service at the least possible cost. The Plan assesses natural gas demand and supply under five scenarios for the period 1993-2002. Key issues related to the development of least-cost natural gas plans are identified, and policies for addressing the issues are developed. The rationale and potential for natural gas demand side management (DSM) programs and policies are explored, and recommendations made with respect to utility DSM capability-building and DSM cost-recovery

  6. National Energy Plan II

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    This volume contains the Administration's second National Energy Plan, as required by section 801 of the Department of Energy Organization Act (Public Law 95-91). A second volume will contain an assessment of the environmental trends associated with the energy futures reported here. Detailed appendices to the Plan will be published separately. The eight chapters and their subtitles are: Crisis and Uncertainty in the World Energy Future (The Immediate Crisis and the Continuing Problem, The Emergence of the Energy Problem, The Uncertainties of the World Energy Future, World Oil Prices, Consequences for the U.S.); The U.S. Energy Future: The Implications for Policy (The Near-, Mid-, and Long-Term, The Strategy in Perspective); Conservation (Historical Changes in Energy Use, Post-Embargo Changes - In Detail, Conservation Policies and Programs, The Role of Conservation); Oil and Gas (Oil, Natural Gas); Coal and Nuclear (Coal, Nuclear, Policy for Coal and Nuclear Power); Solar and Other Inexhaustible Energy Sources (Solar Energy, Geothermal, Fusion, A Strategy for Inexhaustible Resources); Making Decisions Promptly and Fairly (Managing Future Energy Crises: Emergency Planning, Managing the Current Shortfall: The Iranian Response Plan, Managing the Long-Term Energy Problem: The Institutional Framework, Fairness in Energy Policy, Public Participation in the Development of Energy Policy); and NEP-II and the Future (The Second National Energy Plan and the Nation's Energy Future, The Second National Energy Plan and the Economy, Employment and Energy Policy, The Second National Energy Plan and Individuals, The Second National Energy Plan and Capital Markets, and The Second National Energy Plan and the Environment). (ERA citation 04:041097)

  7. Changes in Upper Airway Volume Following Orthognathic Surgery.

    Science.gov (United States)

    Marcussen, Lillian; Stokbro, Kasper; Aagaard, Esben; Torkov, Peter; Thygesen, Torben

    2017-01-01

    Reduced volume of the internal skeletal dimensions of the face is 1 of the main causes of obstructive sleep apnea, and attention to patients' airways is necessary when planning orthognathic treatment. This study aims to describe changes in upper airway volume following virtually planned orthognathic surgery.A retrospective pilot study was designed with 30 randomly selected patients (10 men and 20 women, aged 23.1 ± 6.8 years, molar-relations: 15 neutral, 8 distal, and 7 mesial). Cone-beam computed tomography scans were performed before surgery and 1 week following surgery. The authors did total upper airway volume measurements and obtained 1-mm slices at vertical levels in the velo-, oro-, and hypopharynx and at the smallest visible cross-section.Measurements before and after surgery were compared using Student t test.After orthognathic surgery, the minimum cross-sectional area at the vertical level increased from 83 mm ± 33 before surgery to 102 mm ± 36 after surgery (P = 0.019). In patients with neutral and distal occlusions, the minimum cross-sectional slice volume increased in 87% but in only 57% with mesial occlusion.The present findings suggest that orthognathic surgery increases upper airway volume parameters, but a few patients have continued impairment of the airways following orthognathic surgery. Further studies are needed to confirm an individual surgical planning approach that potentially could bring the minimum cross sectional area out of the risk zone.

  8. Radiosurgical treatment planning for intracranial AVM based on images generated by principal component analysis. A simulation study

    International Nuclear Information System (INIS)

    Kawaguchi, Osamu; Kunieda, Etsuo; Nyui, Yoshiyuki

    2009-01-01

    One of the most important factors in stereotactic radiosurgery (SRS) for intracranial arteriovenous malformation (AVM) is to determine accurate target delineation of the nidus. However, since intracranial AVMs are complicated in structure, it is often difficult to clearly determine the target delineation. The purpose of this study was to investigate the usefulness of principal component analysis (PCA) on intra-arterial contrast enhanced dynamic CT (IADCT) images as a tool for delineating accurate target volumes for stereotactic radiosurgery of AVMs. IADCT and intravenous contrast-enhanced CT (IVCT) were used to examine 4 randomly selected cases of AVM. PCA images were generated from the IADCT data. The first component images were considered feeding artery predominant, the second component images were considered draining vein predominant, and the third component images were considered background. Target delineations were first carried out from IVCT, and then again while referring to the first and second components of the PCA images. Dose calculation simulations for radiosurgical treatment plans with IVCT and PCA images were performed. Dose volume histograms of the vein areas as well as the target volumes were compared. In all cases, the calculated target volumes based on IVCT images were larger than those based on PCA images, and the irradiation doses for the vein areas were reduced. In this study, we simulated radiosurgical treatment planning for intracranial AVM based on PCA images. By using PCA images, the irradiation doses for the vein areas were substantially reduced. (author)

  9. Dosimetric consequences of the shift towards computed tomography guided target definition and planning for breast conserving radiotherapy

    International Nuclear Information System (INIS)

    Laan, Hans Paul van der; Dolsma, Wil V; Maduro, John H; Korevaar, Erik W; Langendijk, Johannes A

    2008-01-01

    The shift from conventional two-dimensional (2D) to three-dimensional (3D)-conformal target definition and dose-planning seems to have introduced volumetric as well as geometric changes. The purpose of this study was to compare coverage of computed tomography (CT)-based breast and boost planning target volumes (PTV), absolute volumes irradiated, and dose delivered to the organs at risk with conventional 2D and 3D-conformal breast conserving radiotherapy. Twenty-five patients with left-sided breast cancer were subject of CT-guided target definition and 3D-conformal dose-planning, and conventionally defined target volumes and treatment plans were reconstructed on the planning CT. Accumulated dose-distributions were calculated for the conventional and 3D-conformal dose-plans, taking into account a prescribed dose of 50 Gy for the breast plans and 16 Gy for the boost plans. With conventional treatment plans, CT-based breast and boost PTVs received the intended dose in 78% and 32% of the patients, respectively, and smaller volumes received the prescribed breast and boost doses compared with 3D-conformal dose-planning. The mean lung dose, the volume of the lungs receiving > 20 Gy, the mean heart dose, and volume of the heart receiving > 30 Gy were significantly less with conventional treatment plans. Specific areas within the breast and boost PTVs systematically received a lower than intended dose with conventional treatment plans. The shift towards CT-guided target definition and planning as the golden standard for breast conserving radiotherapy has resulted in improved target coverage at the cost of larger irradiated volumes and an increased dose delivered to organs at risk. Tissue is now included into the breast and boost target volumes that was never explicitly defined or included with conventional treatment. Therefore, a coherent definition of the breast and boost target volumes is needed, based on clinical data confirming tumour control probability and normal

  10. Waste isolation in the U.S., technical programs and public education. Volume 2 - low level waste, volume reduction methodologies and economics. Vol. 2

    International Nuclear Information System (INIS)

    Post, R.G.

    1984-01-01

    This volume presents information regarding low-level waste, volume reduction methodologies and economics. Topics include: public education on nuclear waste; economics of low-level waste management systems; operating experience with advanced volume reduction techniques; solidification of waste; operating experience with advanced volume reduction techniques--incineration; regional plans for the disposal of low-level waste; radwaste system modifications at nuclear power plants; operating experience with advanced volume reduction techniques--operations and on-site storage issues; and economic impact of 10CFR61

  11. Procedural issues in the development of a production plan in the petroleum transport computerized system of plan projects

    Energy Technology Data Exchange (ETDEWEB)

    German, V T; Karlikov, Y P; Papeev, V M; Samorodkin, V D; Vasil' ev, Y I

    1980-01-01

    The process of planning petroleum transportation must be described by a model that may be used to vary the distribution of the volumes of oil transported and to organize the oil flows so as to satisfy users requiring a particular volume of unprocessed petroleum. By means of the studies performed here, a number of conclusions may be drawn: 1. Available algorithms make it possible to compute the detailed network-wide indicators for petroleum transportation in the annual planning model; determine the capacities needed for individual members of the network; and create the necessary list of output documents for compliation of the tenative plan of production for oil transport; 2. An implementation of the oil transport plan using the specified route method should be based on an heuristic approach (a route is specified by a specialist or the routes of the current year are used), thereby allowing us to obtain the necessary production plans.

  12. National Waste Terminal Storage Program: configuration management plan. Volume II. Plan description

    International Nuclear Information System (INIS)

    1977-05-01

    Purpose of the Configuration Management Plan is to provide the management discipline through which the integrity and continuity of program cost and schedule trade-off decisions which are made concerning the site selections and facilities performance, producibility, operability and supportability are recorded, communicated, and controlled by the Office of Waste Isolation

  13. NOTE: Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

    Science.gov (United States)

    Thompson, S. A.; Fung, A. Y. C.; Zaider, M.

    2002-08-01

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results.

  14. Dosimetric impact of prostate volume change between CT-based HDR brachytherapy fractions

    International Nuclear Information System (INIS)

    Kim, Yongbok; Hsu, I-C.; Lessard, Etienne; Vujic, Jasmina; Pouliot, Jean

    2004-01-01

    Purpose: The objective is to evaluate the prostate volume change and its dosimetric consequences after the insertion of catheters for high-dose-rate brachytherapy. Methods and Materials: For 13 consecutive patients, a spiral CT scan was acquired before each of the 2 fractions, separated on average by 20 hours. The coordinates of the catheters were obtained on 3 axial CT slices corresponding to apex, mid portion, and base portion of the prostate. A mathematical expansion model was used to evaluate the change of prostate volumes between the 2 fractions. It is based on the difference in the cube of the average distance between the centroid and catheter positions. The variation of implant dose-volume histograms between fractions was computed for plans produced by either inverse planning based on simulated annealing or geometric optimization. Results: The average magnitude of either increase or reduction in prostate volume was 7.8% (range, 2-17%). This volume change corresponds to an average prostate radius change of only 2.5% (range, 0.7-5.4%). For 5 patients, the prostate volume increased on average by 9% (range, 2-17%), whereas a reduction was observed for 8 patients by an average of 7% (range, 2-13%). More variation was observed at the prostate base than at mid or apex gland. The comparison of implant dose-volume histograms showed a small reduction of V100 receiving the prescription dose, with an average of 3.5% (range, 0.5-12%) and 2.2% (range, 1-6%) for inverse planning based on our simulated annealing and geometric optimization plans, respectively. Conclusion: Small volume change was observed between treatment fractions. This translates into small changes in dose delivered to the prostate volume

  15. Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

    Science.gov (United States)

    Madau, Piero; Fragos, Tassos

    2017-05-01

    We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior to and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z ≲ 4. Together with an updated empirical determination of the cosmic history of star formation, recent modeling of the stellar mass-metallicity relation, and a scheme for absorption by the IGM that accounts for the presence of ionized H II bubbles during the epoch of reionization, our detailed calculations provide refined predictions of the X-ray volume emissivity and filtered radiation background from “normal” galaxies at z ≳ 6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. Because of the energy dependence of photoabsorption, soft X-ray photons are produced by local sources, while more energetic radiation arrives unattenuated from larger cosmological volumes. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct He I photoionizations are the main source of IGM heating, and the temperature of the largely neutral medium in between H II cavities increases above the temperature of the cosmic microwave background (CMB) only at z ≲ 10, when the volume filling factor of H II bubbles is already ≳0.1. Therefore, in this scenario, it is only at relatively late epochs that neutral intergalactic hydrogen

  16. Radiation Backgrounds at Cosmic Dawn: X-Rays from Compact Binaries

    Energy Technology Data Exchange (ETDEWEB)

    Madau, Piero [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Fragos, Tassos [Geneva Observatory, University of Geneva, Chemin des Maillettes 51, 1290 Sauverny (Switzerland)

    2017-05-01

    We compute the expected X-ray diffuse background and radiative feedback on the intergalactic medium (IGM) from X-ray binaries prior to and during the epoch of reionization. The cosmic evolution of compact binaries is followed using a population synthesis technique that treats separately neutron stars and black hole binaries in different spectral states and is calibrated to reproduce the observed X-ray properties of galaxies at z ≲ 4. Together with an updated empirical determination of the cosmic history of star formation, recent modeling of the stellar mass–metallicity relation, and a scheme for absorption by the IGM that accounts for the presence of ionized H ii bubbles during the epoch of reionization, our detailed calculations provide refined predictions of the X-ray volume emissivity and filtered radiation background from “normal” galaxies at z ≳ 6. Radiative transfer effects modulate the background spectrum, which shows a characteristic peak between 1 and 2 keV. Because of the energy dependence of photoabsorption, soft X-ray photons are produced by local sources, while more energetic radiation arrives unattenuated from larger cosmological volumes. While the filtering of X-ray radiation through the IGM slightly increases the mean excess energy per photoionization, it also weakens the radiation intensity below 1 keV, lowering the mean photoionization and heating rates. Numerical integration of the rate and energy equations shows that the contribution of X-ray binaries to the ionization of the bulk IGM is negligible, with the electron fraction never exceeding 1%. Direct He i photoionizations are the main source of IGM heating, and the temperature of the largely neutral medium in between H ii cavities increases above the temperature of the cosmic microwave background (CMB) only at z ≲ 10, when the volume filling factor of H ii bubbles is already ≳0.1. Therefore, in this scenario, it is only at relatively late epochs that neutral intergalactic

  17. A knowledge-based approach to improving and homogenizing intensity modulated radiation therapy planning quality among treatment centers: an example application to prostate cancer planning.

    Science.gov (United States)

    Good, David; Lo, Joseph; Lee, W Robert; Wu, Q Jackie; Yin, Fang-Fang; Das, Shiva K

    2013-09-01

    Intensity modulated radiation therapy (IMRT) treatment planning can have wide variation among different treatment centers. We propose a system to leverage the IMRT planning experience of larger institutions to automatically create high-quality plans for outside clinics. We explore feasibility by generating plans for patient datasets from an outside institution by adapting plans from our institution. A knowledge database was created from 132 IMRT treatment plans for prostate cancer at our institution. The outside institution, a community hospital, provided the datasets for 55 prostate cancer cases, including their original treatment plans. For each "query" case from the outside institution, a similar "match" case was identified in the knowledge database, and the match case's plan parameters were then adapted and optimized to the query case by use of a semiautomated approach that required no expert planning knowledge. The plans generated with this knowledge-based approach were compared with the original treatment plans at several dose cutpoints. Compared with the original plan, the knowledge-based plan had a significantly more homogeneous dose to the planning target volume and a significantly lower maximum dose. The volumes of the rectum, bladder, and femoral heads above all cutpoints were nominally lower for the knowledge-based plan; the reductions were significantly lower for the rectum. In 40% of cases, the knowledge-based plan had overall superior (lower) dose-volume histograms for rectum and bladder; in 54% of cases, the comparison was equivocal; in 6% of cases, the knowledge-based plan was inferior for both bladder and rectum. Knowledge-based planning was superior or equivalent to the original plan in 95% of cases. The knowledge-based approach shows promise for homogenizing plan quality by transferring planning expertise from more experienced to less experienced institutions. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. A comparison of optic nerve dosimetry in craniospinal radiotherapy planned and treated with conventional and intensity modulated techniques

    International Nuclear Information System (INIS)

    Rene, Nicholas J.; Brodeur, Marylene; Parker, William; Roberge, David; Freeman, Carolyn

    2010-01-01

    Background and purpose: Some CNS tumours present leptomeningeal dissemination. Craniospinal radiotherapy is complex and recurrences may occur at sites of target volume underdosage. IMRT, being highly conformal to the target, could theoretically underdose the optic nerves if they are not specifically targeted leading to optic nerve recurrences. We analyzed optic nerve dosimetry when they are not specifically targeted. Materials and methods: We designed 3D-conformal and tomotherapy plans for our last five patients treated to the craniospinal axis, not including the optic nerves in the target volume. We analyzed the dose delivered to the optic nerves, to the anterior and posterior half of the optic nerves, and to a theoretical optic nerve-PTV. Results: The dose delivered to the optic nerves was similar for both plans in all patients (V95% close to 100%) except one in whom tomotherapy considerably underdosed the anterior optic nerves. The dose to the optic nerve-PTV was lower with tomotherapy in all patients. Conclusion: Despite not intentionally targeting the optic nerves, the dose to the optic nerves with IMRT was similar to 3D-conformal plans in most cases but left no margin for setup error. In individual cases the anterior half of the optic nerves could be significantly underdosed.

  19. Business plan: Supplemental draft environmental impact statement. Volume 2. Appendices

    International Nuclear Information System (INIS)

    1995-02-01

    This document contains the appendices for the Bonneville Power Administration (BPA) Business Plan: Supplemental Draft Environmental Impact Statement. Included are: BPA products and services; Rate design; Methodology and assumptions for numerical analysis; Retail utility operations; Comments and responses to the draft business plan EIS

  20. Business Plan : Supplemental Draft Environmental Impact Statement, Volume 2, Appendices.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1995-02-01

    This document contains the appendices for the Bonneville Power Administration (BPA) Business Plan: Supplemental Draft Environmental Impact Statement. Included are: BPA products and services; Rate design; Methodology and assumptions for numerical analysis; Retail utility operations; Comments and responses to the draft business plan EIS.

  1. Assessment of liver volume with spiral computerized tomography scanning: predicting liver volume by age and height

    OpenAIRE

    Madhu Sharma; Abhishek Singh; Shewtank Goel; Setu Satani; Kavita Mudgil

    2016-01-01

    Background: Estimation of liver size has critical clinical implication. Precise knowledge of liver dimensions and volume is prerequisite for clinical assessment of liver disorders. Liver span as measured by palpation and USG is prone to inter-observer variability and poor repeatability. The aim was to assess the normal liver volume of healthy adults using spiral computed tomography scans and to observe its relationship with various body indices. Methods: In this prospective study, all the...

  2. Environmental monitoring plan

    International Nuclear Information System (INIS)

    Holland, R.C.

    1997-02-01

    This Environmental Monitoring Plan was written to fulfill the requirements of Department of Energy (DOE) Order 5400.1 and DOE Environmental Regulatory Guide DOE/EH 0173T. This Plan documents the background, organizational structure, and methods used for effluent monitoring and environmental surveillance at Sandia National Laboratories/California. The design, rationale, and historical results of the environmental monitoring system are discussed in detail. Throughout the Plan, recommendations for improvements to the monitoring system are made. 52 refs., 10 figs., 12 tabs

  3. Background reduction in the SNO+ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Segui, L. [University of Oxford, Denys Wilkinson Building, Keble Road, OX1 Oxford (United Kingdom)

    2015-08-17

    SNO+ is a large multi-purpose liquid scintillator experiment, which first aim is to detect the neutrinoless double beta decay of {sup 130}Te. It is placed at SNOLAB, at 6000 m.w.e. and it is based on the SNO infrastructure. SNO+ will contain approximately 780 tonnes of liquid scintillator, loaded with {sup 130}Te inside an acrylic vessel (AV) with an external volume of ultra pure water to reduce the external backgrounds. Light produced in the scintillator by the interaction of particles will be detected with about 9,000 photomultiplier’s. For the neutrinoless double beta decay phase, due to its the extremely low rate expected, the control, knowledge and reduction of the background is essential. Moreover, it will also benefit other phases of the experiment focused on the study of solar neutrinos, nucleon decay, geoneutrinos and supernovae. In order to reduce the internal background level, a novel purification technique for tellurium loaded scintillators has been developed by the collaboration that reduces the U/Th concentration and several cosmic-activated isotopes by at least a factor 10{sup 2} -10{sup 3} in a single pass. In addition, different rejection techniques have been developed for the remaining internal backgrounds based on Monte-Carlo simulations. In this work, the scintillator purification technique and the levels obtained with it will be discussed. Furthermore, an overview of the different backgrounds for the double-beta phase will be presented, highlighting some of the techniques developed to reject the remained decays based on their expected timing differences.

  4. Volume-Dependent Overestimation of Spontaneous Intracerebral Hematoma Volume by the ABC/2 Formula

    International Nuclear Information System (INIS)

    Chih-Wei Wang; Chun-Jung Juan; Hsian-He Hsu; Hua-Shan Liu; Cheng-Yu Chen; Chun-Jen Hsueh; Hung-Wen Kao; Guo-Shu Huang; Yi-Jui Liu; Chung-Ping Lo

    2009-01-01

    Background: Although the ABC/2 formula has been widely used to estimate the volume of intracerebral hematoma (ICH), the formula tends to overestimate hematoma volume. The volume-related imprecision of the ABC/2 formula has not been documented quantitatively. Purpose: To investigate the volume-dependent overestimation of the ABC/2 formula by comparing it with computer-assisted volumetric analysis (CAVA). Material and Methods: Forty patients who had suffered spontaneous ICH and who had undergone non-enhanced brain computed tomography scans were enrolled in this study. The ICH volume was estimated based on the ABC/2 formula and also calculated by CAVA. Based on the ICH volume calculated by the CAVA method, the patients were divided into three groups: group 1 consisted of 17 patients with an ICH volume of less than 20 ml; group 2 comprised 13 patients with an ICH volume of 20 to 40 ml; and group 3 was composed of 10 patients with an ICH volume larger than 40 ml. Results: The mean estimated hematoma volume was 43.6 ml when using the ABC/2 formula, compared with 33.8 ml when using the CAVA method. The mean estimated difference was 1.3 ml, 4.4 ml, and 31.4 ml for groups 1, 2, and 3, respectively, corresponding to an estimation error of 9.9%, 16.7%, and 37.1% by the ABC/2 formula (P<0.05). Conclusion: The ABC/2 formula significantly overestimates the volume of ICH. A positive association between the estimation error and the volume of ICH is demonstrated

  5. Status and Habitat Requirements of the White Sturgeon Populations in the Columbia River Downstream from McNary Dam Volume II; Supplemental Papers and Data Documentation, 1986-1992 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Beamesderfer, Raymond C.; Nigro, Anthony A. [Oregon Dept. of Fish and Wildlife, Clackamas, OR (US)

    1995-01-01

    This is the final report for research on white sturgeon Acipenser transmontanus from 1986--92 and conducted by the National Marine Fisheries Service (NMFS), Oregon Department of Fish and Wildlife (ODFW), US Fish and Wildlife Service (USFWS), and Washington Department of Fisheries (WDF). Findings are presented as a series of papers, each detailing objectives, methods, results, and conclusions for a portion of this research. This volume includes supplemental papers which provide background information needed to support results of the primary investigations addressed in Volume 1. This study addresses measure 903(e)(1) of the Northwest Power Planning Council's 1987 Fish and Wildlife Program that calls for ''research to determine the impact of development and operation of the hydropower system on sturgeon in the Columbia River Basin.'' Study objectives correspond to those of the ''White Sturgeon Research Program Implementation Plan'' developed by BPA and approved by the Northwest Power Planning Council in 1985. Work was conducted on the Columbia River from McNary Dam to the estuary.

  6. SU-E-T-357: Semi-Automated Knowledge-Based Radiation Therapy (KBRT) Planning for Head-And-Neck Cancer (HNC): Can KBRT Plans Achieve Better Results Than Manual Planning?

    International Nuclear Information System (INIS)

    Lutzky, C; Grzetic, S; Lo, J; Das, S

    2014-01-01

    Purpose: Knowledge Based Radiation Therapy Treatment (KBRT) planning can be used to semi-automatically generate IMRT plans for new patients using constraints derived from previously manually-planned, geometrically similar patients. We investigate whether KBRT plans can achieve greater dose sparing than manual plans using optimized, organspecific constraint weighting factors. Methods: KBRT planning of HNC radiotherapy cases geometrically matched each new (query) case to one of the 105 clinically approved plans in our database. The dose distribution of the planned match was morphed to fit the querys geometry. Dose-volume constraints extracted from the morphed dose distribution were used to run the IMRT optimization with no user input. In the first version, all constraints were multiplied by a weighting factor of 0.7. The weighting factors were then systematically optimized (in order of OARs with increasing separation from the target) to maximize sparing to each OAR without compromising other OARs. The optimized, second version plans were compared against the first version plans and the clinically approved plans for 45 unilateral/bilateral target cases using the dose metrics: mean, median and maximum (brainstem and cord) doses. Results: Compared to the first version, the second version significantly reduced mean/median contralateral parotid doses (>2Gy) for bilateral cases. Other changes between the two versions were not clinically meaningful. Compared to the original clinical plans, both bilateral and unilateral plans in the second version had lower average dose metrics for 5 of the 6 OARs. Compared to the original plans, the second version achieved dose sparing that was at least as good for all OARs and better for the ipsilateral parotid (bilateral) and oral cavity (bilateral/unilateral). Differences in planning target volume coverage metrics were not clinically significant. Conclusion: HNC-KBRT planning generated IMRT plans with at least equivalent dose sparing to

  7. SU-E-T-357: Semi-Automated Knowledge-Based Radiation Therapy (KBRT) Planning for Head-And-Neck Cancer (HNC): Can KBRT Plans Achieve Better Results Than Manual Planning?

    Energy Technology Data Exchange (ETDEWEB)

    Lutzky, C; Grzetic, S; Lo, J; Das, S [Duke University Medical Center, Durham, NC (United States)

    2014-06-01

    Purpose: Knowledge Based Radiation Therapy Treatment (KBRT) planning can be used to semi-automatically generate IMRT plans for new patients using constraints derived from previously manually-planned, geometrically similar patients. We investigate whether KBRT plans can achieve greater dose sparing than manual plans using optimized, organspecific constraint weighting factors. Methods: KBRT planning of HNC radiotherapy cases geometrically matched each new (query) case to one of the 105 clinically approved plans in our database. The dose distribution of the planned match was morphed to fit the querys geometry. Dose-volume constraints extracted from the morphed dose distribution were used to run the IMRT optimization with no user input. In the first version, all constraints were multiplied by a weighting factor of 0.7. The weighting factors were then systematically optimized (in order of OARs with increasing separation from the target) to maximize sparing to each OAR without compromising other OARs. The optimized, second version plans were compared against the first version plans and the clinically approved plans for 45 unilateral/bilateral target cases using the dose metrics: mean, median and maximum (brainstem and cord) doses. Results: Compared to the first version, the second version significantly reduced mean/median contralateral parotid doses (>2Gy) for bilateral cases. Other changes between the two versions were not clinically meaningful. Compared to the original clinical plans, both bilateral and unilateral plans in the second version had lower average dose metrics for 5 of the 6 OARs. Compared to the original plans, the second version achieved dose sparing that was at least as good for all OARs and better for the ipsilateral parotid (bilateral) and oral cavity (bilateral/unilateral). Differences in planning target volume coverage metrics were not clinically significant. Conclusion: HNC-KBRT planning generated IMRT plans with at least equivalent dose sparing to

  8. Multi-institutional Comparison of Intensity Modulated Radiation Therapy (IMRT) Planning Strategies and Planning Results for Nasopharyngeal Cancer

    Science.gov (United States)

    Park, Sung Ho; Park, Suk Won; Oh, Do Hoon; Choi, Youngmin; Kim, Jeung Kee; Ahn, Yong Chan; Park, Won; Suh, Hyun Sook; Lee, Rena; Bae, Hoonsik

    2009-01-01

    The intensity-modulated radiation therapy (IMRT) planning strategies for nasopharyngeal cancer among Korean radiation oncology facilities were investigated. Five institutions with IMRT planning capacity using the same planning system were invited to participate in this study. The institutions were requested to produce the best plan possible for 2 cases that would deliver 70 Gy to the planning target volume of gross tumor (PTV1), 59.4 Gy to the PTV2, and 51.5 Gy to the PTV3 in which elective irradiation was required. The advised fractionation number was 33. The planning parameters, resultant dose distributions, and biological indices were compared. We found 2-3-fold variations in the volume of treatment targets. Similar degree of variation was found in the delineation of normal tissue. The physician-related factors in IMRT planning had more influence on the plan quality. The inhomogeneity index of PTV dose ranged from 4 to 49% in Case 1, and from 5 to 46% in Case 2. Variation in tumor control probabilities for the primary lesion and involved LNs was less marked. Normal tissue complication probabilities for parotid glands and skin showed marked variation. Results from this study suggest that greater efforts in providing training and continuing education in terms of IMRT planning parameters usually set by physician are necessary for the successful implementation of IMRT. PMID:19399266

  9. Cone Beam CT Imaging Analysis of Interfractional Variations in Bladder Volume and Position During Radiotherapy for Bladder Cancer

    International Nuclear Information System (INIS)

    Yee, Don; Parliament, Matthew; Rathee, Satyapal; Ghosh, Sunita; Ko, Lawrence; Murray, Brad

    2010-01-01

    Purpose: To quantify daily bladder size and position variations during bladder cancer radiotherapy. Methods and Materials: Ten bladder cancer patients underwent daily cone beam CT (CBCT) imaging of the bladder during radiotherapy. Bladder and planning target volumes (bladder/PTV) from CBCT and planning CT scans were compared with respect to bladder center-of-mass shifts in the x (lateral), y (anterior-posterior), and z (superior-inferior) coordinates, bladder/PTV size, bladder/PTV margin positions, overlapping areas, and mutually exclusive regions. Results: A total of 262 CBCT images were obtained from 10 bladder cancer patients. Bladder center of mass shifted most in the y coordinate (mean, -0.32 cm). The anterior bladder wall shifted the most (mean, -0.58 cm). Mean ratios of CBCT-derived bladder and PTV volumes to planning CT-derived counterparts were 0.83 and 0.88. The mean CBCT-derived bladder volume (± standard deviation [SD]) outside the planning CT counterpart was 29.24 cm 3 (SD, 29.71 cm 3 ). The mean planning CT-derived bladder volume outside the CBCT counterpart was 47.74 cm 3 (SD, 21.64 cm 3 ). The mean CBCT PTV outside the planning CT-derived PTV was 47.35 cm 3 (SD, 36.51 cm 3 ). The mean planning CT-derived PTV outside the CBCT-derived PTV was 93.16 cm 3 (SD, 50.21). The mean CBCT-derived bladder volume outside the planning PTV was 2.41 cm 3 (SD, 3.97 cm 3 ). CBCT bladder/ PTV volumes significantly differed from planning CT counterparts (p = 0.047). Conclusions: Significant variations in bladder and PTV volume and position occurred in patients in this trial.

  10. Observational aspects of the microwave cosmic background spectrum

    International Nuclear Information System (INIS)

    Martin, D.H.

    1982-01-01

    The discovery of the isotropic microwave background, in 1964, was followed by a decade of careful measurements of the background flux throughout the centimetric and millimetric ranges of wavelength. The results of these measurements are not inconsistent with a Planckian spectrum but the absolute precision of the measurements is not as high as is frequently assumed. More recently attention has turned to searches for variations in the flux density with direction in the sky, while preparations are made in laboratories around the world for a second wave of measurements of the spectrum which are to have a much higher absolute precision. The author points out the limitations in present knowledge of the microwave background, identifies the observational difficulties in improving that knowledge and reports on some of the plans for future measurements. (Auth.)

  11. Geometrical Comparison Measures for Tumor Delineation, what do they mean for the Actual Dosis Plan?

    DEFF Research Database (Denmark)

    Hollensen, Christian; Persson, G.; Højgaard, L.

    2012-01-01

    Purpose/Objective: Gross tumour volume (GTV) delineation is central for radiotherapy planning. It provides the basis of the clinical target volume and finally the planning target volume (PTV) which is used for dose optimization. GTV delineations are prone to intermethod and inter......observer variation. In clinical studies this variation is commonly represented by geometrical volume comparison measures (GVCMs) as volume assessment, centre of mass and overlap. The correlation between these measures and the radiotherapy plan are however unclear. The aim of the present study is to investigate...... the correlation between GVCMs and the radiotherapy plans of patients with peripheral lung tumours. Materials and Methods: Peripheral lung tumours of 10 patients referred for stereotactic body radiotherapy in 2008 were delineated by 3 radiologists and 3 oncologists. From these GTV delineations 6 different...

  12. A spreadsheet to determine the volume ratio for target and breast in partial breast irradiation

    International Nuclear Information System (INIS)

    Kron, T.; Willis, D.; Miller, J.; Hubbard, P.; Oliver, M.; Chua, B.

    2009-01-01

    Full text: The technical feasibility of Partial Breast Irradiation (PBI) using external beam radiotherapy depends on the ratio between the evaluation planning target volume (PTV e val) and the whole breast volume (PBI volume ratio = PVR). We aimed to develop a simple method to determine PVR using measurements performed at the time of the planning CT scan. A PVR calculation tool was developed using a Microsoft Excel spreadsheet to determine the PTV from three orthogonal dimensions of the seroma cavity and a given margin on the CT scans. The breast volume is estimated from the separation and breast height in five equally spaced CT slices. The PTV e val and whole breast volume were determined for 29 patients from two centres using the spreadsheet calculation tool and compared to volumes delineated on computerised treatment planning systems. Both the PTV e val and whole breast volumes were underestimated by approximately 25% using the spreadsheet. The resulting PVRs were 1.05 +/- 0.35 (mean +/- 1 S D) times larger than the ones determined from planning. Estimations of the PVR using the calculation tool were achievable in around 5 minutes at the time of CT scanning and allow a prompt decision on the suitability of the patients for PBI.

  13. White Rose development plan amendment production volume increase

    International Nuclear Information System (INIS)

    2006-09-01

    In January 2001, Husky Oil Operations Limited (Husky), in joint-venture with Petro-Canada, submitted a Benefits Plan for the White Rose Development to the Canada- Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB). This revised document provided the case for requesting an increase in the facility maximum daily production rate and the average annual production rate for the White Rose field from 100,000 barrels per day (bpd) as stated in the approved White Rose Development Plan to 140,000 bpd. In order to determine the potential for increasing oil production through the Floating Production, Storage and Offloading (FPSO) vessel, two things were considered, namely the proper reservoir management of the White Rose field to ensure optimum resource recovery, and the capacity of the FPSO topsides processing system and supporting utilities to accommodate increased production. This document presented a detailed review of all the implications of increased production on the South White Rose Reservoir. In addition, the results from FPSO performance testing were reviewed, including a study of options for de-bottlenecking the process plant on the topsides and capacity testing of selected process streams and support systems. Vibration analysis was conducted before and during performance testing in July 2006 and a small number of areas addressed. The document also addressed flow metering, resource management, certifying authority review, safety plan revisions, environmental effects, as well as benefits to Canada and Newfoundland. 21 tabs., 60 refs

  14. Sandia software guidelines, Volume 4: Configuration management

    Energy Technology Data Exchange (ETDEWEB)

    1992-06-01

    This volume is one in a series of Sandia Software Guidelines for use in producing quality software within Sandia National Laboratories. This volume is based on the IEEE standard and guide for software configuration management. The basic concepts and detailed guidance on implementation of these concepts are discussed for several software project types. Example planning documents for both projects and organizations are included.

  15. Prostate HDR brachytherapy catheter displacement between planning and treatment delivery

    International Nuclear Information System (INIS)

    Whitaker, May; Hruby, George; Lovett, Aimee; Patanjali, Nitya

    2011-01-01

    Background and purpose: HDR brachytherapy is used as a conformal boost for treating prostate cancer. Given the large doses delivered, it is critical that the volume treated matches that planned. Our outpatient protocol comprises two 9 Gy fractions, two weeks apart. We prospectively assessed catheter displacement between CT planning and treatment delivery. Materials and methods: Three fiducial markers and the catheters were implanted under transrectal ultrasound guidance. Metal marker wires were inserted into 4 reference catheters before CT; marker positions relative to each other and to the marker wires were measured from the CT scout. Measurements were repeated immediately prior to treatment delivery using pelvic X-ray with marker wires in the same reference catheters. Measurements from CT scout and film were compared. For displacements of 5 mm or more, indexer positions were adjusted prior to treatment delivery. Results: Results are based on 48 implants, in 25 patients. Median time from planning CT to treatment delivery was 254 min (range 81–367 min). Median catheter displacement was 7.5 mm (range −2.9–23.9 mm), 67% of implants had displacement of 5 mm or greater. Displacements were predominantly caudal. Conclusions: Catheter displacement can occur in the 1–3 h between the planning CT scan and treatment. It is recommended that departments performing HDR prostate brachytherapy verify catheter positions immediately prior to treatment delivery.

  16. Fully automatic guidance and control for rotorcraft nap-of-the-Earth flight following planned profiles. Volume 1: Real-time piloted simulation

    Science.gov (United States)

    Clement, Warren F.; Gorder, Peter J.; Jewell, Wayne F.

    1991-01-01

    Developing a single-pilot, all-weather nap-of-the-earth (NOE) capability requires fully automatic NOE (ANOE) navigation and flight control. Innovative guidance and control concepts are investigated in a four-fold research effort that: (1) organizes the on-board computer-based storage and real-time updating of NOE terrain profiles and obstacles in course-oriented coordinates indexed to the mission flight plan; (2) defines a class of automatic anticipative pursuit guidance algorithms and necessary data preview requirements to follow the vertical, lateral, and longitudinal guidance commands dictated by the updated flight profiles; (3) automates a decision-making process for unexpected obstacle avoidance; and (4) provides several rapid response maneuvers. Acquired knowledge from the sensed environment is correlated with the forehand knowledge of the recorded environment (terrain, cultural features, threats, and targets), which is then used to determine an appropriate evasive maneuver if a nonconformity of the sensed and recorded environments is observed. This four-fold research effort was evaluated in both fixed-based and moving-based real-time piloted simulations, thereby, providing a practical demonstration for evaluating pilot acceptance of the automated concepts, supervisory override, manual operation, and re-engagement of the automatic system. Volume one describes the major components of the guidance and control laws as well as the results of the piloted simulations. Volume two describes the complete mathematical model of the fully automatic guidance system for rotorcraft NOE flight following planned flight profiles.

  17. Impact of Different CT Slice Thickness on Clinical Target Volume for 3D Conformal Radiation Therapy

    International Nuclear Information System (INIS)

    Prabhakar, Ramachandran; Ganesh, Tharmar; Rath, Goura K.; Julka, Pramod K.; Sridhar, Pappiah S.; Joshi, Rakesh C.; Thulkar, Sanjay

    2009-01-01

    The purpose of this study was to present the variation of clinical target volume (CTV) with different computed tomography (CT) slice thicknesses and the impact of CT slice thickness on 3-dimensional (3D) conformal radiotherapy treatment planning. Fifty patients with brain tumors were selected and CT scans with 2.5-, 5-, and 10-mm slice thicknesses were performed with non-ionic contrast enhancement. The patients were selected with tumor volume ranging from 2.54 cc to 222 cc. Three-dimensional treatment planning was performed for all three CT datasets. The target coverage and the isocenter shift between the treatment plans for different slice thickness were correlated with the tumor volume. An important observation from our study revealed that for volume 25 cc, the target underdosage was less than 6.7% for 5-mm slice thickness and 8% for 10-mm slice thickness. For 3D conformal radiotherapy treatment planning (3DCRT), a CT slice thickness of 2.5 mm is optimum for tumor volume 25 cc

  18. Dependence of Achievable Plan Quality on Treatment Technique and Planning Goal Refinement: A Head-and-Neck Intensity Modulated Radiation Therapy Application

    International Nuclear Information System (INIS)

    Qi, X. Sharon; Ruan, Dan; Lee, Steve P.; Pham, Andrew; Kupelian, Patrick; Low, Daniel A.; Steinberg, Michael; Demarco, John

    2015-01-01

    Purpose: To develop a practical workflow for retrospectively analyzing target and normal tissue dose–volume endpoints for various intensity modulated radiation therapy (IMRT) delivery techniques; to develop technique-specific planning goals to improve plan consistency and quality when feasible. Methods and Materials: A total of 165 consecutive head-and-neck patients from our patient registry were selected and retrospectively analyzed. All IMRT plans were generated using the same dose–volume guidelines for TomoTherapy (Tomo, Accuray), TrueBeam (TB, Varian) using fixed-field IMRT (TB-IMRT) or RAPIDARC (TB-RAPIDARC), or Siemens Oncor (Siemens-IMRT, Siemens). A MATLAB-based dose–volume extraction and analysis tool was developed to export dosimetric endpoints for each patient. With a fair stratification of patient cohort, the variation of achieved dosimetric endpoints was analyzed among different treatment techniques. Upon identification of statistically significant variations, technique-specific planning goals were derived from dynamically accumulated institutional data. Results: Retrospective analysis showed that although all techniques yielded comparable target coverage, the doses to the critical structures differed. The maximum cord doses were 34.1 ± 2.6, 42.7 ± 2.1, 43.3 ± 2.0, and 45.1 ± 1.6 Gy for Tomo, TB-IMRT, TB-RAPIDARC, and Siemens-IMRT plans, respectively. Analyses of variance showed significant differences for the maximum cord doses but no significant differences for other selected structures among the investigated IMRT delivery techniques. Subsequently, a refined technique-specific dose–volume guideline for maximum cord dose was derived at a confidence level of 95%. The dosimetric plans that failed the refined technique-specific planning goals were reoptimized according to the refined constraints. We observed better cord sparing with minimal variations for the target coverage and other organ at risk sparing for the Tomo cases, and higher

  19. New South Wales coal strategy. Volume 1 - strategic plan. Volume 2 - industry review

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    The committee has concluded that while the outlook for coal demand growth is less optimistic than it was in 1981, nonetheless significant additional opportunities will arise in the medium term and that proper planning will place New South Wales in a strong position to take advantage of them.

  20. Planning of elimination of emergency consequences

    Directory of Open Access Journals (Sweden)

    S. Kovalenko

    2015-05-01

    Full Text Available Introduction. The volume of useful information in the planning of elimination of emergency consequences process is reasonable to assess with calculatory problems and mathematical models. Materials and methods. The expert survey method is used to calculate quantitative values of probability and to determine the optimal solution before the information in condition is received. Results. It is determined that the quality of the solution of elimination emergency consequences depends primarily on the number of factors that are taken into account in particular circumstances of the situation; on the level of information readiness of control bodies to take decision to eliminate emergency consequences as soon as possible and to consider several options for achieving reasonableness and concreteness of a particular decision. The ratio between volume of useful information collected and processed during operation planning which is required for identifying optimal solution is calculated. This ratio allows to construct a graph of probability of identifying a solution in existing environment and probability value of identifying optimal solution before information in P*condition is obtained. This graph also shows the ratio volume of useful information collected and processed during operation planning and necessary volume of information for identifying optimal solution. Conclusion. The results of this research can be used for improving control bodies decisions to ensure safe working conditions for employees of food industry.

  1. 1995 Solid Waste 30-year volume summary

    International Nuclear Information System (INIS)

    Valero, O.J.; DeForest, T.J.; Templeton, K.J.

    1995-06-01

    This document, prepared by Pacific Northwest Laboratory (PNL) under the direction of Westinghouse Hanford Company (WHC), provides a description of the annual low-level mixed waste (LLMW) and transuranic/transuranic mixed solid waste (TRU-TRUM) volumes expected to be managed by Hanford's Solid Waste Central Waste Complex (CWC) over the next 30 years. The waste generation sources and waste categories are also described. This document is intended to be used as a reference for short- and long-term planning of the Hanford treatment, storage, and disposal (TSD) activities over the next several decades. By estimating the waste volumes that will be generated in the future, facility planners can determine the timing of key waste management activities, evaluate alternative treatment strategies, and plan storage and disposal capacities. In addition, this document can be used by other waste sites and the general public to gain a better understanding of the types and volumes of waste that will be managed at Hanford

  2. 1995 Solid Waste 30-year volume summary

    Energy Technology Data Exchange (ETDEWEB)

    Valero, O.J. [Westinghouse Hanford Co., Richland, WA (United States); DeForest, T.J.; Templeton, K.J. [Pacific Northwest Lab., Richland, WA (United States)

    1995-06-01

    This document, prepared by Pacific Northwest Laboratory (PNL) under the direction of Westinghouse Hanford Company (WHC), provides a description of the annual low-level mixed waste (LLMW) and transuranic/transuranic mixed solid waste (TRU-TRUM) volumes expected to be managed by Hanford`s Solid Waste Central Waste Complex (CWC) over the next 30 years. The waste generation sources and waste categories are also described. This document is intended to be used as a reference for short- and long-term planning of the Hanford treatment, storage, and disposal (TSD) activities over the next several decades. By estimating the waste volumes that will be generated in the future, facility planners can determine the timing of key waste management activities, evaluate alternative treatment strategies, and plan storage and disposal capacities. In addition, this document can be used by other waste sites and the general public to gain a better understanding of the types and volumes of waste that will be managed at Hanford.

  3. Brief Report: Understanding Intention to Be Physically Active and Physical Activity Behaviour in Adolescents from a Low Socio-Economic Status Background: An Application of the Theory of Planned Behaviour

    Science.gov (United States)

    Duncan, Michael J.; Rivis, Amanda; Jordan, Caroline

    2012-01-01

    The aim of this brief report is to report on the utility of the Theory of Planned Behaviour (TPB) for predicting the physical activity intentions and behaviour of British adolescents from lower-than-average socio-economic backgrounds. A prospective questionnaire design was employed with 197, 13-14 year olds (76 males, 121 females). At time 1…

  4. Evaluation of Peritumoral Edema in the Delineation of Radiotherapy Clinical Target Volumes for Glioblastoma

    International Nuclear Information System (INIS)

    Chang, Eric L.; Akyurek, Serap; Avalos, Tedde C; Rebueno, Neal C; Spicer, Chris C; Garcia, John C; Famiglietti, Robin; Allen, Pamela K.; Chao, K.S. Clifford; Mahajan, Anita; Woo, Shiao Y.; Maor, Moshe H.

    2007-01-01

    Purpose: To evaluate the spatial relationship between peritumoral edema and recurrence pattern in patients with glioblastoma (GBM). Methods and Materials: Forty-eight primary GBM patients received three-dimensional conformal radiotherapy that did not intentionally include peritumoral edema within the clinical target volume between July 2000 and June 2001. All 48 patients have subsequently recurred, and their original treatment planning parameters were used for this study. New theoretical radiation treatment plans were created for the same 48 patients, based on Radiation Therapy Oncology Group (RTOG) target delineation guidelines that specify inclusion of peritumoral edema. Target volume and recurrent tumor coverage, as well as percent volume of normal brain irradiated, were assessed for both methods of target delineation using dose-volume histograms. Results: A comparison between the location of recurrent tumor and peritumoral edema volumes from all 48 cases failed to show correlation by linear regression modeling (r 2 0.0007; p = 0.3). For patients with edema >75 cm 3 , the percent volume of brain irradiated to 46 Gy was significantly greater in treatment plans that intentionally included peritumoral edema compared with those that did not (38% vs. 31%; p = 0.003). The pattern of failure was identical between the two sets of plans (40 central, 3 in-field, 3 marginal, and 2 distant recurrence). Conclusion: Clinical target volume delineation based on a 2-cm margin rather than on peritumoral edema did not seem to alter the central pattern of failure for patients with GBM. For patients with peritumoral edema >75 cm 3 , using a constant 2-cm margin resulted in a smaller median percent volume of brain being irradiated to 30 Gy, 46 Gy, and 50 Gy compared with corresponding theoretical RTOG plans that deliberately included peritumoral edema

  5. SU-E-J-88: Margin Reduction of Level II/III Planning Target Volume for Image-Guided Simultaneous Integrated Boost Head-And-Neck Treatment

    International Nuclear Information System (INIS)

    Can, S; Neylon, J; Qi, S; Santhanam, A; Low, D

    2014-01-01

    Purpose: To investigate the feasibility of improved normal tissue sparing for head-and-neck (H'N) image-guided radiotherapy (IGRT) by employing tighter CTV-to-PTV margins for target level II/III though a GPU-based deformable image registration and dose accumulation framework. Methods: Ten H'N simultaneous integrated boost cases treated on TomoTherapy were retrospectively analyzed. Weekly kVCT scans in addition to daily MVCT scans were acquired for each patient. Reduced margin plans were generated with 0- mm margin for level II and III PTV (while 3-5 mm margin for PTV1) and compared with the standard margin plan using 3-5mm margin to all CTV1-3 (reference plan). An in-house developed GPU-based 3D image deformation tool was used to register and deform the weekly KVCTs with the planning CT and determine the delivered mean/minimum/maximum dose, dose volume histograms (DVHs), etc. Results: Compared with the reference plans, the averaged cord maximum, the right and left parotid doses reduced by 22.7 %, 16.5 %, and 9 % respectively in the reduced margin plans. The V95 for PTV2 and PTV3 were found within 2 and 5% between the reference and tighter margin plans. For the reduced margin plans, the averaged cumulative mean doses were consistent with the planned dose for PTV1, PTV2 and PTV3 within 1.5%, 1.7% and 1.4%. Similar dose variations of the delivered dose were seen for the reference and tighter margin plans. The delivered maximum and mean doses for the cord were 3.55 % and 2.37% higher than the planned doses; a 5 % higher cumulative mean dose for the parotids was also observed for the delivered dose than the planned doses in both plans. Conclusion: By imposing tighter CTV-to-PTV margins for level II and III targets for H'N irradiation, acceptable cumulative doses were achievable when coupled with weekly kVCT guidance while improving normal structure sparing

  6. Dosimetric Comparison of Real-Time MRI-Guided Tri-Cobalt-60 Versus Linear Accelerator-Based Stereotactic Body Radiation Therapy Lung Cancer Plans.

    Science.gov (United States)

    Wojcieszynski, Andrzej P; Hill, Patrick M; Rosenberg, Stephen A; Hullett, Craig R; Labby, Zacariah E; Paliwal, Bhudatt; Geurts, Mark W; Bayliss, R Adam; Bayouth, John E; Harari, Paul M; Bassetti, Michael F; Baschnagel, Andrew M

    2017-06-01

    Magnetic resonance imaging-guided radiation therapy has entered clinical practice at several major treatment centers. Treatment of early-stage non-small cell lung cancer with stereotactic body radiation therapy is one potential application of this modality, as some form of respiratory motion management is important to address. We hypothesize that magnetic resonance imaging-guided tri-cobalt-60 radiation therapy can be used to generate clinically acceptable stereotactic body radiation therapy treatment plans. Here, we report on a dosimetric comparison between magnetic resonance imaging-guided radiation therapy plans and internal target volume-based plans utilizing volumetric-modulated arc therapy. Ten patients with early-stage non-small cell lung cancer who underwent radiation therapy planning and treatment were studied. Following 4-dimensional computed tomography, patient images were used to generate clinically deliverable plans. For volumetric-modulated arc therapy plans, the planning tumor volume was defined as an internal target volume + 0.5 cm. For magnetic resonance imaging-guided plans, a single mid-inspiratory cycle was used to define a gross tumor volume, then expanded 0.3 cm to the planning tumor volume. Treatment plan parameters were compared. Planning tumor volumes trended larger for volumetric-modulated arc therapy-based plans, with a mean planning tumor volume of 47.4 mL versus 24.8 mL for magnetic resonance imaging-guided plans ( P = .08). Clinically acceptable plans were achievable via both methods, with bilateral lung V20, 3.9% versus 4.8% ( P = .62). The volume of chest wall receiving greater than 30 Gy was also similar, 22.1 versus 19.8 mL ( P = .78), as were all other parameters commonly used for lung stereotactic body radiation therapy. The ratio of the 50% isodose volume to planning tumor volume was lower in volumetric-modulated arc therapy plans, 4.19 versus 10.0 ( P guided tri-cobalt-60 radiation therapy is capable of delivering lung high

  7. The effect of volume-of-interest misregistration on quantitative planar activity and dose estimation

    International Nuclear Information System (INIS)

    Song, N; Frey, E C; He, B

    2010-01-01

    In targeted radionuclide therapy (TRT), dose estimation is essential for treatment planning and tumor dose response studies. Dose estimates are typically based on a time series of whole-body conjugate view planar or SPECT scans of the patient acquired after administration of a planning dose. Quantifying the activity in the organs from these studies is an essential part of dose estimation. The quantitative planar (QPlanar) processing method involves accurate compensation for image degrading factors and correction for organ and background overlap via the combination of computational models of the image formation process and 3D volumes of interest defining the organs to be quantified. When the organ VOIs are accurately defined, the method intrinsically compensates for attenuation, scatter and partial volume effects, as well as overlap with other organs and the background. However, alignment between the 3D organ volume of interest (VOIs) used in QPlanar processing and the true organ projections in the planar images is required. The aim of this research was to study the effects of VOI misregistration on the accuracy and precision of organ activity estimates obtained using the QPlanar method. In this work, we modeled the degree of residual misregistration that would be expected after an automated registration procedure by randomly misaligning 3D SPECT/CT images, from which the VOI information was derived, and planar images. Mutual information-based image registration was used to align the realistic simulated 3D SPECT images with the 2D planar images. The residual image misregistration was used to simulate realistic levels of misregistration and allow investigation of the effects of misregistration on the accuracy and precision of the QPlanar method. We observed that accurate registration is especially important for small organs or ones with low activity concentrations compared to neighboring organs. In addition, residual misregistration gave rise to a loss of precision

  8. Automated gamma knife radiosurgery treatment planning with image registration, data-mining, and Nelder-Mead simplex optimization

    International Nuclear Information System (INIS)

    Lee, Kuan J.; Barber, David C.; Walton, Lee

    2006-01-01

    Gamma knife treatments are usually planned manually, requiring much expertise and time. We describe a new, fully automatic method of treatment planning. The treatment volume to be planned is first compared with a database of past treatments to find volumes closely matching in size and shape. The treatment parameters of the closest matches are used as starting points for the new treatment plan. Further optimization is performed with the Nelder-Mead simplex method: the coordinates and weight of the isocenters are allowed to vary until a maximally conformal plan specific to the new treatment volume is found. The method was tested on a randomly selected set of 10 acoustic neuromas and 10 meningiomas. Typically, matching a new volume took under 30 seconds. The time for simplex optimization, on a 3 GHz Xeon processor, ranged from under a minute for small volumes ( 30 000 cubic mm,>20 isocenters). In 8/10 acoustic neuromas and 8/10 meningiomas, the automatic method found plans with conformation number equal or better than that of the manual plan. In 4/10 acoustic neuromas and 5/10 meningiomas, both overtreatment and undertreatment ratios were equal or better in automated plans. In conclusion, data-mining of past treatments can be used to derive starting parameters for treatment planning. These parameters can then be computer optimized to give good plans automatically

  9. The Syed temporary interstitial iridium gynaecological implant: an inverse planning system

    International Nuclear Information System (INIS)

    Fung, Albert Y.C.

    2002-01-01

    Patients with advanced gynaecological cancer are often treated with a temporary interstitial implant using the Syed template and Ir-192 ribbons at the Memorial Sloan-Kettering Cancer Center. Urgency in planning is great. We created a computerized inverse planning system for the Syed temporary gynaecological implant, which optimized the ribbon strengths a few seconds after catheter digitization. Inverse planning was achieved with simulated annealing. We discovered that hand-drawn target volumes had drawbacks; hence instead of producing a grid of points based on target volume, the optimization points were generated directly from the catheter positions without requiring an explicit target volume. Since all seeds in the same ribbon had the same strength, the minimum doses were located at both ends of the implant. Optimization points generated at both ends ensured coverage of the whole implant. Inverse planning took only a few seconds, and generated plans that provide a good starting point for manual improvement. (author)

  10. Comparison of backgrounds in OSO-7 and SMM spectrometers and short-term activation in SMM

    Science.gov (United States)

    Dunphy, P. P.; Forrest, D. J.; Chupp, E. L.; Share, G. H.

    1989-01-01

    The backgrounds in the OSO-7 Gamma-Ray Monitor and the Solar Maximum Mission Gamma-Ray Spectrometer are compared. After scaling to the same volume, the background spectra agree to within 30 percent. This shows that analyses which successfully describe the background in one detector can be applied to similar detectors of different sizes and on different platforms. The background produced in the SMM spectrometer by a single trapped-radiation belt passage is also studied. This background is found to be dominated by a positron-annihilation line and a continuum spectrum with a high energy cutoff at 5 MeV.

  11. SU-E-J-79: Internal Tumor Volume Motion and Volume Size Assessment Using 4D CT Lung Data

    Energy Technology Data Exchange (ETDEWEB)

    Jurkovic, I [University of Texas Health Science Center at San Antonio, San Antonio, TX (United States); Stathakis, S; Li, Y; Patel, A; Vincent, J; Papanikolaou, N; Mavroidis, P [Cancer Therapy and Research Center University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States)

    2014-06-01

    Purpose: To assess internal tumor volume change through breathing cycle and associated tumor motion using the 4DCT data. Methods: Respiration induced volume change through breathing cycle and associated motion was analyzed for nine patients that were scanned during the different respiratory phases. The examined datasets were the maximum and average intensity projections (MIP and AIP) and the 10 phases of the respiratory cycle. The internal target volume (ITV) was delineated on each of the phases and the planning target volume (PTV) was then created by adding setup margins to the ITV. Tumor motion through the phases was assessed using the acquired 4DCT dataset, which was then used to determine if the margins used for the ITV creation successfully encompassed the tumor in three dimensions. Results: Results showed that GTV motion along the superior inferior axes was the largest in all the cases independent of the tumor location and/or size or the use of abdomen compression. The extent of the tumor motion was found to be connected with the size of the GTV. The smallest GTVs exhibited largest motion vector independent of the tumor location. The motion vector size varied through the phases depending on the tumor size and location and it was smallest for phases 20 and 30. The smaller the volume of the delineated GTV, the greater its volume difference through the different respiratory phases was. The average GTV volume change was largest for the phases 60 and 70. Conclusion: Even if GTV is delineated using both AIP and MIP datasets, its motion extent will exceed the used margins especially for the very small GTV volumes. When the GTV size is less than 10 cc it is recommended to use fusion of the GTVs through all the phases to create the planning ITV.

  12. A novel method for the evaluation of uncertainty in dose-volume histogram computation.

    Science.gov (United States)

    Henríquez, Francisco Cutanda; Castrillón, Silvia Vargas

    2008-03-15

    Dose-volume histograms (DVHs) are a useful tool in state-of-the-art radiotherapy treatment planning, and it is essential to recognize their limitations. Even after a specific dose-calculation model is optimized, dose distributions computed by using treatment-planning systems are affected by several sources of uncertainty, such as algorithm limitations, measurement uncertainty in the data used to model the beam, and residual differences between measured and computed dose. This report presents a novel method to take them into account. To take into account the effect of associated uncertainties, a probabilistic approach using a new kind of histogram, a dose-expected volume histogram, is introduced. The expected value of the volume in the region of interest receiving an absorbed dose equal to or greater than a certain value is found by using the probability distribution of the dose at each point. A rectangular probability distribution is assumed for this point dose, and a formulation that accounts for uncertainties associated with point dose is presented for practical computations. This method is applied to a set of DVHs for different regions of interest, including 6 brain patients, 8 lung patients, 8 pelvis patients, and 6 prostate patients planned for intensity-modulated radiation therapy. Results show a greater effect on planning target volume coverage than in organs at risk. In cases of steep DVH gradients, such as planning target volumes, this new method shows the largest differences with the corresponding DVH; thus, the effect of the uncertainty is larger.

  13. Estimation of pneumonitis risk in three-dimensional treatment planning using dose-volume histogram analysis

    International Nuclear Information System (INIS)

    Oetzel, Dieter; Schraube, Peter; Hensley, Frank; Sroka-Perez, Gabriele; Menke, Markus; Flentje, Michael

    1995-01-01

    Purpose: Investigations to study correlations between the estimations of biophysical models in three dimensional (3D) treatment planning and clinical observations are scarce. The development of clinically symptomatic pneumonitis in the radiotherapy of thoracic malignomas was chosen to test the predictive power of Lyman's normal tissue complication probability (NTCP) model for the assessment of side effects for nonuniform irradiation. Methods and Materials: In a retrospective analysis individual computed-tomography-based 3D dose distributions of a random sample of (46(20)) patients with lung/esophageal cancer were reconstructed. All patients received tumor doses between 50 and 60 Gy in a conventional treatment schedule. Biological isoeffective dose-volume histograms (DVHs) were used for the calculation of complication probabilities after applying Lyman's and Kutcher's DVH-reduction algorithm. Lung dose statistics were performed for single lung (involved ipsilateral and contralateral) and for the lung as a paired organ. Results: In the lung cancer group, about 20% of the patients (9 out of 46) developed pneumonitis 3-12 (median 7.5) weeks after completion of radiotherapy. For the majority of these lung cancer patients, the involved ipsilateral lung received a much higher dose than the contralateral lung, and the pneumonitis patients had on average a higher lung exposure with a doubling of the predicted complication risk (38% vs. 20%). The lower lung exposure for the esophagus patients resulted in a mean lung dose of 13.2 Gy (lung cancer: 20.5 Gy) averaged over all patients in correlation with an almost zero complication risk and only one observed case of pneumonitis (1 out of 20). To compare the pneumonitis risk estimations with observed complication rates, the patients were ranked into bins of mean ipsilateral lung dose. Particularly, in the bins with the highest patient numbers, a good correlation was achieved. Agreement was not reached for the lung functioning as

  14. High-Frequency Jet Ventilation for Complete Target Immobilization and Reduction of Planning Target Volume in Stereotactic High Single-Dose Irradiation of Stage I Non-Small Cell Lung Cancer and Lung Metastases

    International Nuclear Information System (INIS)

    Fritz, Peter; Kraus, Hans-Joerg; Muehlnickel, Werner; Sassmann, Volker; Hering, Werner; Strauch, Konstantin

    2010-01-01

    Purpose: To demonstrate the feasibility of complete target immobilization by means of high-frequency jet ventilation (HFJV); and to show that the saving of planning target volume (PTV) on the stereotactic body radiation therapy (SBRT) under HFJV, compared with SBRT with respiratory motion, can be predicted with reliable accuracy by computed tomography (CT) scans at peak inspiration phase. Methods and Materials: A comparison regarding different methods for defining the PTV was carried out in 22 patients with tumors that clearly moved with respiration. A movement span of the gross tumor volume (GTV) was defined by fusing respiration-correlated CT scans. The PTV enclosed the GTV positions with a safety margin throughout the breathing cycle. To create a PTV from CT scans acquired under HFJV, the same margins were drawn around the immobilized target. In addition, peak inspiration phase CT images (PIP-CTs) were used to approximate a target immobilized by HFJV. Results: The resulting HFJV-PTVs were between 11.6% and 45.4% smaller than the baseline values calculated as respiration-correlated CT-PTVs (median volume reduction, 25.4%). Tentative planning by means of PIP-CT PTVs predicted that in 19 of 22 patients, use of HFJV would lead to a reduction in volume of ≥20%. Using this threshold yielded a positive predictive value of 0.89, as well as a sensitivity of 0.94 and a specificity of 0.5. Conclusions: In all patients, SBRT under HFJV provided a reliable immobilization of the GTVs and achieved a reduction in PTVs, regardless of patient compliance. Tentative planning facilitated the selection of patients who could better undergo radiation in respiratory standstill, both with greater accuracy and lung protection.

  15. Planning target volumes for radiotherapy: how much margin is needed?

    International Nuclear Information System (INIS)

    Antolak, John A.; Rosen, Isaac I.

    1999-01-01

    Purpose: The radiotherapy planning target volume (PTV) encloses the clinical target volume (CTV) with anisotropic margins to account for possible uncertainties in beam alignment, patient positioning, organ motion, and organ deformation. Ideally, the CTV-PTV margin should be determined solely by the magnitudes of the uncertainties involved. In practice, the clinician usually also considers doses to abutting healthy tissues when deciding on the size of the CTV-PTV margin. This study calculates the ideal size of the CTV-PTV margin when only physical position uncertainties are considered. Methods and Materials: The position of the CTV for any treatment is assumed to be described by independent Gaussian distributions in each of the three Cartesian directions. Three strategies for choosing a CTV-PTV margin are analyzed. The CTV-PTV margin can be based on: 1. the probability that the CTV is completely enclosed by the PTV; 2. the probability that the projection of the CTV in the beam's eye view (BEV) is completely enclosed by the projection of the PTV in the BEV; and 3. the probability that a point on the edge of the CTV is within the PTV. Cumulative probability distributions are derived for each of the above strategies. Results: Expansion of the CTV by 1 standard deviation (SD) in each direction results in the CTV being entirely enclosed within the PTV 24% of the time; the BEV projection of the CTV is enclosed within the BEV projection of the PTV 39% of the time; and a point on the edge of the CTV is within the PTV 84% of the time. To have the CTV enclosed entirely within the PTV 95% of the time requires a margin of 2.8 SD. For the BEV projection of the CTV to be within the BEV projection of the PTV 95% of the time requires a margin of 2.45 SD. To have any point on the surface of the CTV be within the PTV 95% of the time requires a margin of 1.65 SD. Conclusion: In the first two strategies for selecting a margin, the probability of finding the CTV within the PTV is

  16. Evaluation of IMRT plans for prostate treatment using energies of 6 MV and 15 MV

    International Nuclear Information System (INIS)

    Guimaraes, Lucas Francisco C.; Silva, Murilo C. da; Silveira, Paula J.; Flosi, Adriana A.; Boccaletti, Karina W.

    2013-01-01

    This study aims to evaluate and compare radiotherapy plans with intensity-modulated radiation therapy (IMRT) for prostate cancer treatments optimized for photon energies of 6 MV and 15 MV. We retrospectively evaluated 29 patients with prostate cancer, planned with IMRT technique with prescribed dose of 78 Gy. The initial plan was done for the two photon energies, keeping the same optimization parameters and comparing maximum, minimum and modal PTV doses, conformity and homogeneity indexes, dose gradients, isodoses volumes of 30, 40, 50, 60, and 70 Gy, and the total number of monitor units. It was found that the plans are equivalent regarding higher isodose volumes, conformity and homogeneity indexes, maximum, minimum and modal PTV doses. However, for 6 MV plans there was a considerable increase in both number of monitor units and volume lower isodose volumes, especially the 30 Gy. (author)

  17. Multicriteria optimization informed VMAT planning

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Huixiao; Craft, David L.; Gierga, David P., E-mail: dgierga@partners.org

    2014-04-01

    We developed a patient-specific volumetric-modulated arc therapy (VMAT) optimization procedure using dose-volume histogram (DVH) information from multicriteria optimization (MCO) of intensity-modulated radiotherapy (IMRT) plans. The study included 10 patients with prostate cancer undergoing standard fractionation treatment, 10 patients with prostate cancer undergoing hypofractionation treatment, and 5 patients with head/neck cancer. MCO-IMRT plans using 20 and 7 treatment fields were generated for each patient on the RayStation treatment planning system (clinical version 2.5, RaySearch Laboratories, Stockholm, Sweden). The resulting DVH of the 20-field MCO-IMRT plan for each patient was used as the reference DVH, and the extracted point values of the resulting DVH of the MCO-IMRT plan were used as objectives and constraints for VMAT optimization. Weights of objectives or constraints of VMAT optimization or both were further tuned to generate the best match with the reference DVH of the MCO-IMRT plan. The final optimal VMAT plan quality was evaluated by comparison with MCO-IMRT plans based on homogeneity index, conformity number of planning target volume, and organ at risk sparing. The influence of gantry spacing, arc number, and delivery time on VMAT plan quality for different tumor sites was also evaluated. The resulting VMAT plan quality essentially matched the 20-field MCO-IMRT plan but with a shorter delivery time and less monitor units. VMAT plan quality of head/neck cancer cases improved using dual arcs whereas prostate cases did not. VMAT plan quality was improved by fine gantry spacing of 2 for the head/neck cancer cases and the hypofractionation-treated prostate cancer cases but not for the standard fractionation–treated prostate cancer cases. MCO-informed VMAT optimization is a useful and valuable way to generate patient-specific optimal VMAT plans, though modification of the weights of objectives or constraints extracted from resulting DVH of MCO

  18. Reducing DRIFT backgrounds with a submicron aluminized-mylar cathode

    Science.gov (United States)

    Battat, J. B. R.; Daw, E.; Dorofeev, A.; Ezeribe, A. C.; Fox, J. R.; Gauvreau, J.-L.; Gold, M.; Harmon, L.; Harton, J.; Lafler, R.; Landers, J.; Lauer, R. J.; Lee, E. R.; Loomba, D.; Lumnah, A.; Matthews, J.; Miller, E. H.; Mouton, F.; Murphy, A. St. J.; Paling, S. M.; Phan, N.; Sadler, S. W.; Scarff, A.; Schuckman, F. G.; Snowden-Ifft, D.; Spooner, N. J. C.; Walker, D.

    2015-09-01

    Background events in the DRIFT-IId dark matter detector, mimicking potential WIMP signals, are predominantly caused by alpha decays on the central cathode in which the alpha particle is completely or partially absorbed by the cathode material. We installed a 0.9 μm thick aluminized-mylar cathode as a way to reduce the probability of producing these backgrounds. We study three generations of cathode (wire, thin-film, and radiologically clean thin-film) with a focus on the ratio of background events to alpha decays. Two independent methods of measuring the absolute alpha decay rate are used to ensure an accurate result, and agree to within 10%. Using alpha range spectroscopy, we measure the radiologically cleanest cathode version to have a contamination of 3.3±0.1 ppt 234U and 73±2 ppb 238U. This cathode reduces the probability of producing an RPR from an alpha decay by a factor of 70±20 compared to the original stainless steel wire cathode. First results are presented from a texturized version of the cathode, intended to be even more transparent to alpha particles. These efforts, along with other background reduction measures, have resulted in a drop in the observed background rate from 500/day to 1/day. With the recent implementation of full-volume fiducialization, these remaining background events are identified, allowing for background-free operation.

  19. Comparison of 3D CRT and IMRT Tratment Plans

    Science.gov (United States)

    Bakiu, Erjona; Telhaj, Ervis; Kozma, Elvisa; Ruçi, Ferdinand; Malkaj, Partizan

    2013-01-01

    Plans of patients with prostate tumor have been studied. These patients have been scanned in the CT simulator and the images have been sent to the Focal, the system where the doctor delineates the tumor and the organs at risk. After that in the treatment planning system XiO there are created for the same patients three dimensional conformal and intensity modulated radiotherapy treatment plans. The planes are compared according to the dose volume histograms. It is observed that the plans with IMRT technique conform better the isodoses to the planning target volume and protect more the organs at risk, but the time needed to create such plans and to control it is higher than 3D CRT. So it necessary to decide in which patients to do one or the other technique depending on the full dose given to PTV and time consuming in genereral. PMID:24167395

  20. A study on planning organ at risk volume for the rectum using cone beam computed tomography in the treatment of prostate cancer

    International Nuclear Information System (INIS)

    Prabhakar, Ramachandran; Oates, Richard; Jones, Daryl; Kron, Tomas; Cramb, Jim; Foroudi, Farshad; Geso, Moshi; Gill, Suki

    2014-01-01

    In this study, we analyzed planning organ at risk volume (PRV) for the rectum using a series of cone beam computed tomographies (CBCTs) acquired during the treatment of prostate cancer and evaluated the dosimetric effect of different PRV definitions. Overall, 21 patients with prostate cancer were treated radically with 78 Gy in 39 fractions had in total 418 CBCTs, each acquired at the end of the first 5 fractions and then every alternate fraction. The PRV was generated from the Boolean sum volume of the rectum obtained from first 5 fractions (PRV-CBCT-5) and from all CBCTs (PRV-CBCT-All). The PRV margin was compared at the superior, middle, and inferior slices of the contoured rectum to compare PRV-CBCT-5 and PRV-CBCT-All. We also compared the dose received by the planned rectum (Rectum-computed tomography [CT]), PRV-CBCT-5, PRV-CBCT-All, and average rectum (CBCT-AV-dose-volume histogram [DVH]) at critical dose levels. The average measured rectal volume for all 21 patients for Rectum-CT, PRV-CBCT-5, and PRV-CBCT-All was 44.3 ± 15.0, 92.8 ± 40.40, and 121.5 ± 36.7 cm 3 , respectively. For PRV-CBCT-All, the mean ± standard deviation displacement in the anterior, posterior, right, and left lateral directions in centimeters was 2.1 ± 1.1, 0.9 ± 0.5, 0.9 ± 0.8, and 1.1 ± 0.7 for the superior rectum; 0.8 ± 0.5, 1.1 ± 0.5, 1.0 ± 0.5, and 1.0 ± 0.5 for the middle rectum; and 0.3 ± 0.3; 0.9 ± 0.5; 0.4 ± 0.2, and 0.5 ± 0.3 for the inferior rectum, respectively. The first 5 CBCTs did not predict the PRV for individual patients. Our study shows that the PRV margin is different for superior, middle, and the inferior parts of the rectum, it is wider superiorly and narrower inferiorly. A uniform PRV margin does not represent the actual rectal variations during treatment for all treatment fractions. The large variation in interpatient rectal size implies a potential role for adaptive radiotherapy for prostate cancer

  1. Large Deployable Reflector (LDR) system concept and technology definition study. Volume 2: Technology assessment and technology development plan

    Science.gov (United States)

    Agnew, Donald L.; Jones, Peter A.

    1989-01-01

    A study was conducted to define reasonable and representative LDR system concepts for the purpose of defining a technology development program aimed at providing the requisite technological capability necessary to start LDR development by the end of 1991. This volume presents thirteen technology assessments and technology development plans, as well as an overview and summary of the LDR concepts. Twenty-two proposed augmentation projects are described (selected from more than 30 candidates). The five LDR technology areas most in need of supplementary support are: cryogenic cooling; astronaut assembly of the optically precise LDR in space; active segmented primary mirror; dynamic structural control; and primary mirror contamination control. Three broad, time-phased, five-year programs were synthesized from the 22 projects, scheduled, and funding requirements estimated.

  2. Hyperthermia treatment planning

    International Nuclear Information System (INIS)

    Lagendijk, J.J.W.

    2000-01-01

    The development of hyperthermia, the treatment of tumours with elevated temperatures in the range of 40-44 deg. C with treatment times over 30 min, greatly benefits from the development of hyperthermia treatment planning. This review briefly describes the state of the art in hyperthermia technology, followed by an overview of the developments in hyperthermia treatment planning. It particularly highlights the significant problems encountered with heating realistic tissue volumes and shows how treatment planning can help in designing better heating technology. Hyperthermia treatment planning will ultimately provide information about the actual temperature distributions obtained and thus the tumour control probabilities to be expected. This will improve our understanding of the present clinical results of thermoradiotherapy and thermochemotherapy, and will greatly help both in optimizing clinical heating technology and in designing optimal clinical trials. (author)

  3. Gulf of Mexico sales 157 and 161: Central and Western Planning areas. Final environmental impact statement: Volume 2, Sections IV.D through IX

    International Nuclear Information System (INIS)

    1995-01-01

    This volume of the environmental impact statement for sales in the Gulf of Mexico presents information dealing with impacts on the costal regions due to planned operations of the petroleum industry. Topics discussed include: impacts on sensitive coastal environments; coastal barrier beaches and associated dunes; wetlands; offshore resources; water quality; air quality; impacts to aquatic environments; impacts on marine birds; impacts on archaeological resources; impacts on socioeconomic conditions; topography; and analysis of a large oil spill

  4. Inverse treatment planning based on MRI for HDR prostate brachytherapy

    International Nuclear Information System (INIS)

    Citrin, Deborah; Ning, Holly; Guion, Peter; Li Guang; Susil, Robert C.; Miller, Robert W.; Lessard, Etienne; Pouliot, Jean; Xie Huchen; Capala, Jacek; Coleman, C. Norman; Camphausen, Kevin; Menard, Cynthia

    2005-01-01

    Purpose: To develop and optimize a technique for inverse treatment planning based solely on magnetic resonance imaging (MRI) during high-dose-rate brachytherapy for prostate cancer. Methods and materials: Phantom studies were performed to verify the spatial integrity of treatment planning based on MRI. Data were evaluated from 10 patients with clinically localized prostate cancer who had undergone two high-dose-rate prostate brachytherapy boosts under MRI guidance before and after pelvic radiotherapy. Treatment planning MRI scans were systematically evaluated to derive a class solution for inverse planning constraints that would reproducibly result in acceptable target and normal tissue dosimetry. Results: We verified the spatial integrity of MRI for treatment planning. MRI anatomic evaluation revealed no significant displacement of the prostate in the left lateral decubitus position, a mean distance of 14.47 mm from the prostatic apex to the penile bulb, and clear demarcation of the neurovascular bundles on postcontrast imaging. Derivation of a class solution for inverse planning constraints resulted in a mean target volume receiving 100% of the prescribed dose of 95.69%, while maintaining a rectal volume receiving 75% of the prescribed dose of <5% (mean 1.36%) and urethral volume receiving 125% of the prescribed dose of <2% (mean 0.54%). Conclusion: Systematic evaluation of image spatial integrity, delineation uncertainty, and inverse planning constraints in our procedure reduced uncertainty in planning and treatment

  5. Evaluation of a commercial automatic treatment planning system for prostate cancers.

    Science.gov (United States)

    Nawa, Kanabu; Haga, Akihiro; Nomoto, Akihiro; Sarmiento, Raniel A; Shiraishi, Kenshiro; Yamashita, Hideomi; Nakagawa, Keiichi

    2017-01-01

    Recent developments in Radiation Oncology treatment planning have led to the development of software packages that facilitate automated intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) planning. Such solutions include site-specific modules, plan library methods, and algorithm-based methods. In this study, the plan quality for prostate cancer generated by the Auto-Planning module of the Pinnacle 3 radiation therapy treatment planning system (v9.10, Fitchburg, WI) is retrospectively evaluated. The Auto-Planning module of Pinnacle 3 uses a progressive optimization algorithm. Twenty-three prostate cancer cases, which had previously been planned and treated without lymph node irradiation, were replanned using the Auto-Planning module. Dose distributions were statistically compared with those of manual planning by the paired t-test at 5% significance level. Auto-Planning was performed without any manual intervention. Planning target volume (PTV) dose and dose to rectum were comparable between Auto-Planning and manual planning. The former, however, significantly reduced the dose to the bladder and femurs. Regression analysis was performed to examine the correlation between volume overlap between bladder and PTV divided by the total bladder volume and resultant V70. The findings showed that manual planning typically exhibits a logistic way for dose constraint, whereas Auto-Planning shows a more linear tendency. By calculating the Akaike information criterion (AIC) to validate the statistical model, a reduction of interoperator variation in Auto-Planning was shown. We showed that, for prostate cancer, the Auto-Planning module provided plans that are better than or comparable with those of manual planning. By comparing our results with those previously reported for head and neck cancer treatment, we recommend the homogeneous plan quality generated by the Auto-Planning module, which exhibits less dependence on anatomic complexity

  6. SU-E-T-96: An Analysis of VMAT SBRT Lung Treatment Plans

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, D; James, J; Wang, B; Dunlap, N; Woo, S; Silverman, C; Dragun, A; El-Ghamry, M [Univ Louisville, Louisville, KY (United States)

    2015-06-15

    Purpose: To present an analysis of 218 lung sbrt treatment plans delivered using Varian Eclipse RapidArc software and delivered with Varian linear accelerators. Methods: A retrospective analysis of treatment plans generated using the Varian Eclipse PRO RapidArc VMAT optimization and AAA photon beam calculation algorithms was done for 218 plans delivered using Varian Trilogy and TrueBeam linear accelerators. Some of the patients were enrolled in the RTOG 0813 and RTOG 0915 lung protocols. All of the patients’ plans were optimized using the guidelines outlined by these protocols. The plans presented were normalized so that 95% of the PTV volume received 100% of the prescribed dose. Results: The dose co formality constraints from the RTOG protocols and the number of plans within those constraints were:Tumor dose between 60% of maximum dose and 90% of maximum: 218/218 = 100%.Volume of 105% tumor dose outside put less than 15% of the PTV volume: 218/218 = 100%.Maximum dose 2 cm away from PTV within protocol table guidelines: No minor deviation: 188/218 = 86.2%. No major deviation: 216/218 = 99.1%.Ratio of 50% dose volume to PTV volume less than R50 in protocol table: No minor deviation 148/218 = 67.9%. No major deviation: 213/218 = 97.7%.Percent of lung receiving 20 Gy less than 10% (no minor violation): 218/218 = 100%.99% of PTV receiving at least 90% of the tumor dose: 214/218 = 98.2%. Conclusion: Varian RapidArc VMAT can successfully deliver lung SBRT treatments as outlined in the RTOG 0813 and 0915 protocols. The largest deviations were seen in the R50 constraints for the larger PTV volumes.

  7. System Development of Estimated Figures of Volume Production Plan

    Science.gov (United States)

    Brazhnikov, Maksim A.; Khorina, Irina V.; Minina, Yulia I.; Kolyasnikova, Lyudmila V.; Streltsov, Aleksey V.

    2016-01-01

    The relevance of this problem is primarily determined by a necessity of improving production efficiency in conditions of innovative development of the economy and implementation of Import Substitution Program. The purpose of the article is development of set of criteria and procedures for the comparative assessment of alternative volume production…

  8. 77 FR 8751 - Guidance for Decommissioning Planning During Operations

    Science.gov (United States)

    2012-02-15

    ..., 40, 50, 70, and 72 [NRC-2011-0286] Guidance for Decommissioning Planning During Operations AGENCY... Guide, DG-4014, ``Decommissioning Planning During Operations'' in the Federal Register with a public... Guide DG-4014, ``Decommissioning Planning During Operations.'' This DG refers to NUREG-1757 Volume 3...

  9. Low Energy Neutrino Astronomy in the future large-volume liquid-scintillator detector LENA

    International Nuclear Information System (INIS)

    Wurm, Michael; Feilitzsch, F V; Goeger-Neff, M; Lewke, T; Undagoitia, T Marrodan; Oberauer, L; Potzel, W; Todor, S; Winter, J

    2008-01-01

    The recent successes in neutrino physics prove that liquid-scintillator detectors allow to combine high energy resolution, efficient means of background reduction, and a large detection volume. In the planned LENA (Low Energy Neutrino Astronomy) experiment, a target mass of 50 kt will enable the investigation of a variety of terrestrial and astrophysical neutrino sources. The high-statistics spectroscopy of geoneutrinos, solar neutrinos and supernova neutrinos will provide new insights in the heat production processes of Earth and Sun, and the workings of a gravitational collapse. The same measurements will as well investigate neutrino properties as oscillation parameters and mass hierarchy. A first spectroscopic measurement of the low flux of diffuse supernova neutrino background is within the sensitivity of the LENA detector. Finally, a life-time limit of several 1034 years can be set to the proton decay into proton and anti-neutrino, testing the predictions of SUSY theory. The present contribution includes a review of the scientific studies that were performed in the last years as well as a report on currently on-going R and D activities.

  10. Low Energy Neutrino Astronomy in the future large-volume liquid-scintillator detector LENA

    Energy Technology Data Exchange (ETDEWEB)

    Wurm, Michael; Feilitzsch, F V; Goeger-Neff, M; Lewke, T; Undagoitia, T Marrodan; Oberauer, L; Potzel, W; Todor, S; Winter, J [E15 Chair for Astroparticle Physics, Technische Universitat Miinchen, Physik Department, James-Franck-Str., D-85748 Garching (Germany)

    2008-11-01

    The recent successes in neutrino physics prove that liquid-scintillator detectors allow to combine high energy resolution, efficient means of background reduction, and a large detection volume. In the planned LENA (Low Energy Neutrino Astronomy) experiment, a target mass of 50 kt will enable the investigation of a variety of terrestrial and astrophysical neutrino sources. The high-statistics spectroscopy of geoneutrinos, solar neutrinos and supernova neutrinos will provide new insights in the heat production processes of Earth and Sun, and the workings of a gravitational collapse. The same measurements will as well investigate neutrino properties as oscillation parameters and mass hierarchy. A first spectroscopic measurement of the low flux of diffuse supernova neutrino background is within the sensitivity of the LENA detector. Finally, a life-time limit of several 1034 years can be set to the proton decay into proton and anti-neutrino, testing the predictions of SUSY theory. The present contribution includes a review of the scientific studies that were performed in the last years as well as a report on currently on-going R and D activities.

  11. Model State Plan Characteristics. A Guide for Refining State Plans for Career Education.

    Science.gov (United States)

    Mitchell, Anita

    This guide for refining state plans for career education was developed to assist states in revision of their state plans to satisfy requirements of Public Law 95-207. The guide is divided into fourteen chapters. Chapter 1, the introduction, contains background information on the assessment conducted to develop the guidelines. (A full report of…

  12. How many sets of 4DCT images are sufficient to determine internal target volume for liver radiotherapy?

    International Nuclear Information System (INIS)

    Xi Mian; Liu Mengzhong; Zhang Li; Li Qiaoqiao; Huang Xiaoyan; Liu Hui; Hu Yonghong

    2009-01-01

    Background and purpose: To determine the feasibility of using limited four-dimensional computed tomography (4DCT) images for treatment planning. Materials and methods: The 4DCT scans of 16 patients with hepatocellular carcinoma (HCC) were analyzed. Gross tumor volumes (GTVs) were manually contoured on all 10 respiratory phases, and different internal clinical target volumes (ICTVs) were derived by encompassing volumes of the respective CTVs. Volume, position, and shape of ICTVs were calculated and compared. Results: The ICTV 2phases , ICTV 3phases , ICTV 4phases , and ICTV 6phases all showed excellent agreement with ICTV 10phases , and the ICTV 2phases encompassed ICTV 10phases by 94.1 ± 1.8% on average. The 3D shift between the centers of mass of the ICTVs was only 0.6 mm. The surface distance between ICTV 10phases and ICTV 2phases was 1.7 ± 0.8 mm in the left-right (LR) and anteroposterior (AP) directions. Conclusions: Contouring two extreme phases at end-inhalation and end-exhalation is a reasonably safe and labor-saving method of deriving ITV for liver radiotherapy with low and medium tumor motion amplitude (≤1.6 cm). Whether the larger tumor movement affects the results is the subject of ongoing research.

  13. A critical evaluation of the planning target volume for 3-d conformal radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Tinger, Alfred; Michalski, Jeff M.; Cheng, Abel; Low, Daniel A.; Zhu, Ron; Bosch, Walter R.; Purdy, James A.; Perez, Carlos A.

    1996-01-01

    Purpose: The goal was to determine an adequate planning target volume (PTV) margin for three-dimensional conformal radiotherapy (3D CRT) of prostate cancer. The uncertainty in the internal positions of the prostate and seminal vesicles and the uncertainty in the treatment set-ups for a single group of patients was measured. Methods: Weekly computed tomography (CT) scans of the pelvis (n=38) and daily electronic portal images (n=1225) were reviewed for six patients who received seven-field 3D CRT for prostate cancer. The weekly CT scans were registered in three dimensions to the original treatment planning CT scan using commercially available software. This registration permitted measurement of the motion in the center-of-volume (COV) of the prostate and seminal vesicles throughout the course of therapy. The daily portal images (PI) were registered to the corresponding simulation films to measure the set-up displacement for each of the seven fields. The field displacements were then entered into a matrix program which calculated the isocenter displacement by a least squares method. The uncertainty in the internal positions of the prostate and seminal vesicles (standard deviation of the motions) was added to the uncertainty in the set-up (standard deviation of the isocenter displacements) in quadrature to arrive at a total uncertainty. Positive directions were defined in the left, anterior, and superior directions. A discussion of an adequate PTV was based on these results. Results: The mean magnitude of motion for the COV of the prostate ± the standard deviation was 0 ± 1 mm in the left-right (LR) direction, 0.5 ± 2.8 mm in the anterior-posterior (AP) direction, and 0.5 ± 3.5 mm in the superior-inferior (SI) direction. The mean magnitude of motion for the COV of the seminal vesicles ± the standard deviation was -0.3 ± 1.5 mm in the LR, 0.6 ± 4.1 mm in the AP, and 0.7 ± 2.3 mm in the SI directions, respectively. For all patients the mean isocenter

  14. Effects of Manufacturing Firm’s Capacity Planning on Performance of the Firm

    Directory of Open Access Journals (Sweden)

    Kifordu Anthony

    2017-12-01

    Full Text Available This study investigated capacity planning and performance in the manufacturing sector in the Southeastern States of Nigeria based on selected Brewing industries. The population of the study was 740 staff of the brewing industry in South-Eastearn Nigeria. The sample size of 509 was obtained using a Taro Yamani’s statistical formula. The study used questionnaire and oral interview guide for data gathering. A test- retest stood completed using Spearman’s rank correlation, giving a coefficient of 0.9. Findings revealed that capacity planning significantly enriched economic performance of the industry studied. There existed a strong affirmative relationship among capacity necessities planning and resources requirements planning. The paper suggested use of capacity planning as a technique to improve all performance factors. Similarly, performance advantage subsist from the correlation of volume requirements plans and resources requirements planning. The paper summarily held the position that volume preparation improved the economic performance in the industry under review. This inferred that goals achievement is possible. Likewise, the finding of substantial constructive association between volume supplies planning and resources supplies planning inferred an affirmative communication between the variables. This meant that resources supplies planning which was a method of organizing the detailed production plans could lead to an improvement of capacity supplies planning. That is to say, they are taking future decisions on the substances required for production capability of the brewing facility.

  15. SU-E-T-437: Four-Dimensional Treatment Planning for Lung VMAT-SBRT

    International Nuclear Information System (INIS)

    Hashimoto, M; Takashina, M; Koizumi, M; Oohira, S; Ueda, Y; Miyazaki, M; Isono, M; Masaoka, A; Teshima, T

    2015-01-01

    Purpose: To assess optimal treatment planning approach of Volumetric Modulated Arc Therapy for lung Stereotactic Body Radiation Therapy (VMAT-SBRT). Methods: Subjects were 10 patients with lung cancer who had undergone 4DCT. The internal target volume (ITV) volume ranged from 2.6 to 16.5cm 3 and the tumor motion ranged from 0 to 2cm. From 4DCT, which was binned into 10 respiratory phases, 4 image data sets were created; maximum intensity projection (MIP), average intensity projection (AIP), AIP with the ITV replaced by 0HU (RITV-AIP) and RITV-AIP with the planning target volume (PTV) minus the internal target volume was set to −200 HU (HR-AIP). VMAT-SBRT plans were generated on each image set for a patient. 48Gy was prescribed to 95% of PTV. The plans were recalculated on all phase images of 4DCT and the dose distributions were accumulated using a deformable image registration software MIM Maestro™ as the 4D calculated dose to the gross tumor volume (GTV). The planned dose to the ITV and 4D calculated dose to the GTV were compared. Results: In AIP plan, 10 patients average of all dose parameters (D1%, D-mean, and D99%) discrepancy were 1Gy or smaller. MIP and RITV-AIP plans resulted in having common tendency and larger discrepancy than AIP plan. The 4D dose was lower than the planned dose, and 10 patients average of all dose parameters discrepancy were in range 1.3 to 2.6Gy. HR-AIP plan had the largest discrepancy in our trials. 4D calculated D1%, D-mean, and D99% were resulted in 3.0, 4.1, and 6.1Gy lower than the expected in plan, respectively. Conclusion: For all patients, the dose parameters expected in AIP plan approximated to 4D calculated. Using AIP image set seems optimal treatment planning approach of VMAT-SBRT for a mobile tumor. Funding Support: This work was supported by the Japan Society for the Promotion of Science Core-to-Core program (No. 23003)

  16. Treatment planning for MLC based robotic radiosurgery for brain metastases: plan comparison with circular fields and suggestions for planning strategies

    Directory of Open Access Journals (Sweden)

    Schmitt Daniela

    2017-09-01

    Full Text Available To evaluate the possible range of application of the new InCise2 MLC for the CyberKnife M6 system in brain radiosurgery, a plan comparison was made for 10 brain metastases sized between 1.5 and 9cm3 in 10 patients treated in a single fraction each. The target volumes consist of a PTV derived by expanding the GTV by 1mm and were chosen to have diversity in the cohort regarding regularity of shape, location and the structures needed to be blocked for beam transmission in the vicinity. For each case, two treatment plans were optimized: one using the MLC and one using the IRIS-collimator providing variable circular fields. Plan re-quirements were: dose prescription to the 70% isodose line (18 or 20Gy, 100% GTV coverage, ≥98% PTV coverage, undisturbed central high dose region (95% of maximum dose and a conformity index as low as possible. Plan com-parison parameters were: conformity index (CI, high-dose gradient index (GIH, low-dose gradient index (GIL, total number of monitor units (MU and expected treatment time (TT. For all cases, clinically acceptable plans could be gen-erated with the following results (mean±SD for CI, GIH, GIL, MU and TT, respectively for the MLC plans: 1.09±0.03, 2.77±0.26, 2.61±0.08, 4514±830MU and 27±5min and for the IRIS plans: 1.05±0.01, 3.00±0.35, 2.46±0.08, 8557±1335MU and 42±7min. In summary, the MLC plans were on average less conformal and had a shallower dose gradient in the low dose region, but a steeper dose gradient in the high dose region. This is accompanied by a smaller vol-ume receiving 10Gy. A plan by plan comparison shows that usage of the MLC can spare about one half of the MUs and one third of treatment time. From these experiences and results suggestions for MLC planning strategy can be de-duced.

  17. INDOT Technical Training Plan : Appendix H

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  18. INDOT Technical Training Plan : Appendix L

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  19. INDOT Technical Training Plan : Appendix D

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  20. INDOT Technical Training Plan : Appendix A

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  1. INDOT Technical Training Plan : Appendix G

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  2. INDOT Technical Training Plan : Appendix P

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  3. INDOT Technical Training Plan : Appendix I

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  4. INDOT Technical Training Plan : Appendix M

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  5. INDOT Technical Training Plan : Appendix F

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  6. INDOT Technical Training Plan : Appendix E

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  7. INDOT Technical Training Plan : Appendix O

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  8. INDOT Technical Training Plan : Appendix J

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  9. INDOT Technical Training Plan : Appendix K

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  10. INDOT Technical Training Plan : Appendix B

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  11. INDOT Technical Training Plan : Appendix N

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  12. INDOT Technical Training Plan : Appendix C

    Science.gov (United States)

    2012-04-01

    The study provides the background documents necessary for the development of a Technical Training Plan and makes recommendations for the content and structure of such a plan for the District Operations, Operations, Capital Program Management, and Eng...

  13. Volumetric image-guidance: Does routine usage prompt adaptive re-planning? An institutional review

    International Nuclear Information System (INIS)

    Tanyi, James A.; Fuss, Martin H.

    2008-01-01

    Purpose. To investigate how the use of volumetric image-guidance using an on-board cone-beam computed tomography (CBCT) system impacts on the frequency of adaptive re-planning. Material and methods. Treatment courses of 146 patients who have undergone a course of external beam radiation therapy (EBRT) using volumetric CBCT image-guidance were analyzed. Target locations included the brain, head and neck, chest, abdomen, as well as prostate and non-prostate pelvis. The majority of patients (57.5%) were treated with hypo-fractionated treatment regimens (three to 15 fraction courses). The frequency of image-guidance ranged from daily (87.7%) to weekly or twice weekly. The underlying medical necessity for adaptive re-planning as well as frequency and consequences of plan adaptation to dose-volume parameters was assessed. Results. Radiation plans of 34 patients (23.3%) were adapted at least once (up to six time) during their course of EBRT as a result of image-guidance CBCT review. Most common causes for adaptive planning were: tumor change (mostly shrinkage: 10 patients; four patients more than one re-plan), change in abdominal girth (systematic change in hollow organ filling; n=7, two patients more than one re-plan), weight loss (n=5), and systematic target setup deviation from simulation (n=5). Adaptive re-plan was required mostly for conventionally fractionated courses; only 5 patient plans undergoing hypo-fractionated treatment were adjusted. In over 91% of adapted plans, the dose-volume parameters did deviate from the prescribed plan parameters by more than 5% for at least 10% of the target volume, or organs-at-risk in close proximity to the target volume. Discussion. Routine use of volumetric image-guidance has in our practice increased the demand for adaptive re-planning. Volumetric CBCT image-guidance provides sufficient imaging information to reliably predict the need for dose adjustment. In the vast majority of cases evaluated, the initial and adapted dose-volume

  14. Naked singularities in four-dimensional string backgrounds

    International Nuclear Information System (INIS)

    Mohammedi, N.

    1993-04-01

    It is shown that gauged nonlinear sigma models can be always deformed by terms proportional to the field strength of the gauge fields (nonminimal gauging). These deformations can be interpreted as perturbations, by marginal operators, of conformal coset models. When applied to the SL(2, R)xSU(2)/U(1)xU(1)) WZWN model, a large class of four-dimensional curved spacetime backgrounds are obtained. In particular, a naked singularity may form at a time when the volume of the universe is different from zero. (orig.)

  15. Dose-volume considerations in stereotaxic brain radiation therapy

    International Nuclear Information System (INIS)

    Houdek, P.V.; Schwade, J.G.; Pisciotta, V.J.; Medina, A.J.; Lewin, A.A.; Abitbol, A.A.; Serago, C.F.

    1988-01-01

    Although brain radiation therapy experience suggests that a gain in the therapeutic ratio may be achieved by optimizing the dose-volume relationship, no practical system for quantitative assessment of dose-volume data has been developed. This presentation describes the rationale for using the integral dose function for this purpose and demonstrates that with the use of a conventional treatment planning computer and a series of computed tomographic scans, first-order optimization of the dose-volume function can be accomplished in two steps: first, high-dose volume is minimized by selecting an appropriate treatment technique and tumor margin, and then dosage is maximized by calculating the brain tolerance dose as a function of the irradiated volume

  16. Revised management plan, milestone plan, cost plan, and manpower plan. Sixth and seventh monthly status reports, October 1-November 30, 1978

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1978-01-01

    The following are included: project background and discussion, technical progress reports for all subtasks, contract management summary report, milestone schedule and status report, milestone log, cost plans, cost management reports, manpower plans, and manpower management reports. The following appendices are included: selection of heat pumps simulation locations, economic computations, fuel costs, system studies, recommended methodology for calculating residential load models, potential performance of heat pumps, data required from cooling contractors, cooling locations, thermal outputs: cooling, recommended inputs for the 25 ton advanced cooling simulation study, meteorological data, and contract modification. (MHR)

  17. Qualitative values of radioactivity, area and volumetric: Application on phantoms (target and background)

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Rahman Al-Shakhrah, Issa [Department of Physics, University of Jordan, Queen Rania Street, Amman (Jordan)], E-mail: issashak@yahoo.com

    2009-04-15

    The visualization of a lesion depends on the contrast between the lesion and surrounding background (T/B; (target/background) ratio). For imaging in vivo not only is the radioactivity in the target organ important, but so too is the ratio of radioactivity in the target versus that in the background. Nearly all studies reported in the literature have dealt with the surface index, as a standard factor to study the relationship between the target (tissue or organ) and the background. It is necessary to know the ratio between the volumetric activity of lesions (targets) and normal tissues (background) instead of knowing the ratio between the area activity, the volume index being a more realistic factor than the area index as the targets (tissues or organs) are real volumes that have surfaces. The intention is that this work should aid in approaching a quantitative relationship and differentiation between different tissues (target/background or abnormal/normal tissues). For the background, square regions of interest (Rios) (11x11 pixels in size) were manually drawn by the observer at locations far from the border of the plastic cylinder (simulated organ), while an isocontour region with 50% threshold was drawn automatically over the cylinder. The total number of counts and pixels in each of these regions was calculated. The relationship between different phantom parameters, cylinder (target) depth, area activity ratio (background/target, A(B/T)) and real volumetric activity ratio (background/target, V(B/T)), was demonstrated. Variations in the area and volumetric activity ratio values with respect to the depth were deduced. To find a realistic value of the ratio, calibration charts have been constructed that relate the area and real volumetric ratios as a function of depth of the tissues and organs. Our experiments show that the cross-sectional area of the cylinder (applying a threshold 50% isocontour) has a weak dependence on the activity concentrations of the

  18. Qualitative values of radioactivity, area and volumetric: Application on phantoms (target and background)

    International Nuclear Information System (INIS)

    Abdel-Rahman Al-Shakhrah, Issa

    2009-01-01

    The visualization of a lesion depends on the contrast between the lesion and surrounding background (T/B; (target/background) ratio). For imaging in vivo not only is the radioactivity in the target organ important, but so too is the ratio of radioactivity in the target versus that in the background. Nearly all studies reported in the literature have dealt with the surface index, as a standard factor to study the relationship between the target (tissue or organ) and the background. It is necessary to know the ratio between the volumetric activity of lesions (targets) and normal tissues (background) instead of knowing the ratio between the area activity, the volume index being a more realistic factor than the area index as the targets (tissues or organs) are real volumes that have surfaces. The intention is that this work should aid in approaching a quantitative relationship and differentiation between different tissues (target/background or abnormal/normal tissues). For the background, square regions of interest (Rios) (11x11 pixels in size) were manually drawn by the observer at locations far from the border of the plastic cylinder (simulated organ), while an isocontour region with 50% threshold was drawn automatically over the cylinder. The total number of counts and pixels in each of these regions was calculated. The relationship between different phantom parameters, cylinder (target) depth, area activity ratio (background/target, A(B/T)) and real volumetric activity ratio (background/target, V(B/T)), was demonstrated. Variations in the area and volumetric activity ratio values with respect to the depth were deduced. To find a realistic value of the ratio, calibration charts have been constructed that relate the area and real volumetric ratios as a function of depth of the tissues and organs. Our experiments show that the cross-sectional area of the cylinder (applying a threshold 50% isocontour) has a weak dependence on the activity concentrations of the

  19. Quantitative dosimetric verification of an IMRT planning and delivery system

    International Nuclear Information System (INIS)

    Low, D.A.; Mutic, S.; Dempsey, J.F.; Gerber, R.L.; Bosch, W.R.; Perez, C.A.; Purdy, J.A.

    1998-01-01

    Background and purpose: The accuracy of dose calculation and delivery of a commercial serial tomotherapy treatment planning and delivery system (Peacock, NOMOS Corporation) was experimentally determined. Materials and methods: External beam fluence distributions were optimized and delivered to test treatment plan target volumes, including three with cylindrical targets with diameters ranging from 2.0 to 6.2 cm and lengths of 0.9 through 4.8 cm, one using three cylindrical targets and two using C-shaped targets surrounding a critical structure, each with different dose distribution optimization criteria. Computer overlays of film-measured and calculated planar dose distributions were used to assess the dose calculation and delivery spatial accuracy. A 0.125 cm 3 ionization chamber was used to conduct absolute point dosimetry verification. Thermoluminescent dosimetry chips, a small-volume ionization chamber and radiochromic film were used as independent checks of the ion chamber measurements. Results: Spatial localization accuracy was found to be better than ±2.0 mm in the transverse axes (with one exception of 3.0 mm) and ±1.5 mm in the longitudinal axis. Dosimetric verification using single slice delivery versions of the plans showed that the relative dose distribution was accurate to ±2% within and outside the target volumes (in high dose and low dose gradient regions) with a mean and standard deviation for all points of -0.05% and 1.1%, respectively. The absolute dose per monitor unit was found to vary by ±3.5% of the mean value due to the lack of consideration for leakage radiation and the limited scattered radiation integration in the dose calculation algorithm. To deliver the prescribed dose, adjustment of the monitor units by the measured ratio would be required. Conclusions: The treatment planning and delivery system offered suitably accurate spatial registration and dose delivery of serial tomotherapy generated dose distributions. The quantitative dose

  20. Wien Automatic System Planning (WASP) Package. A computer code for power generating system expansion planning. Version WASP-III Plus. User's manual. Volume 1: Chapters 1-11

    International Nuclear Information System (INIS)

    1995-01-01

    (FIXSYS plants); user control of the distribution of capital cost expenditures during the construction period (if required to be different from the general 'S' curve distribution used as default). The present document has been produced to support use of the WASP-Ill Plus computer code and to illustrate the capabilities of the program. This Manual is organized in two separate volumes. This first one includes 11 main chapters describing how to use the WASP-Ill Plus computer program. Chapter 1 gives a summary description and some background information about the program. Chapter 2 introduces some concepts, mainly related to the computer requirements imposed by the program, that are used throughout the Manual. Chapters 3 to 9 describe how to execute each of the various programs (or modules) of the WASP-Ill Plus package. The description for each module shows the user how to prepare the Job Control statements and input data needed to execute the module and how to interpret the printed output produced. The iterative process that should be followed in order to obtain the 'optimal solution' for a WASP case study is covered in Chapters 6 to 8. Chapter 10 explains the use of an auxiliary program of the WASP package which is mainly intended for saving computer time. Lastly, Chapter 11 recapitulates the use of WASP-Ill Plus for executing a generation expansion planning study; describes the several phases normally involved in this type of study; and provides the user with practical hints about the most important aspects that need to be verified at each phase while executing the various WASP modules

  1. Environmental Monitoring Plan

    Energy Technology Data Exchange (ETDEWEB)

    Holland, R.C. [Science Applications International Corp., San Diego, CA (United States)

    1993-07-01

    This Environmental Monitoring Plan was written to fulfill the requirements of Department of Energy (DOE) Order 5400.1 and DOE Environmental Regulatory Guide DOE/EH 0173T. This Plan documents the background, organizational structure, and methods used for effluent monitoring and environmental surveillance at Sandia National Laboratories/California. The design, rationale, and historical results of the environmental monitoring system are discussed in detail. Throughout the Plan, recommendations for improvements to the monitoring system are made. This revision to the Environmental Monitoring Plan was written to document the changes made to the Monitoring Program during 1992. Some of the data (most notably the statistical analyses of past monitoring data) has not been changed.

  2. Environmental Monitoring Plan

    International Nuclear Information System (INIS)

    Holland, R.C.

    1993-07-01

    This Environmental Monitoring Plan was written to fulfill the requirements of Department of Energy (DOE) Order 5400.1 and DOE Environmental Regulatory Guide DOE/EH 0173T. This Plan documents the background, organizational structure, and methods used for effluent monitoring and environmental surveillance at Sandia National Laboratories/California. The design, rationale, and historical results of the environmental monitoring system are discussed in detail. Throughout the Plan, recommendations for improvements to the monitoring system are made. This revision to the Environmental Monitoring Plan was written to document the changes made to the Monitoring Program during 1992. Some of the data (most notably the statistical analyses of past monitoring data) has not been changed

  3. Mars power system concept definition study. Volume 2: Appendices

    Science.gov (United States)

    Littman, Franklin D.

    1994-01-01

    This report documents the work performed by Rockwell International's Rocketdyne Division on NASA Contract No. NAS3-25808 (Task Order No. 16) entitled 'Mars Power System Definition Study'. This work was performed for NASA's Lewis Research Center (LeRC). The report is divided into two volumes as follows: Volume 1 - Study Results; and Volume 2 - Appendices. The results of the power system characterization studies, operations studies, and technology evaluations are summarized in Volume 1. The appendices include complete, standalone technology development plans for each candidate power system that was investigated.

  4. Efficacy of virtual block objects in reducing the lung dose in helical tomotherapy planning for cervical oesophageal cancer: a planning study.

    Science.gov (United States)

    Ito, Makoto; Shimizu, Hidetoshi; Aoyama, Takahiro; Tachibana, Hiroyuki; Tomita, Natsuo; Makita, Chiyoko; Koide, Yutaro; Kato, Daiki; Ishiguchi, Tsuneo; Kodaira, Takeshi

    2018-04-04

    Intensity-modulated radiotherapy is useful for cervical oesophageal carcinoma (CEC); however, increasing low-dose exposure to the lung may lead to radiation pneumonitis. Nevertheless, an irradiation technique that avoids the lungs has never been examined due to the high difficulty of dose optimization. In this study, we examined the efficacy of helical tomotherapy that can restrict beamlets passing virtual blocks during dose optimization computing (block plan) in reducing the lung dose. Fifteen patients with CEC were analysed. The primary/nodal lesion and prophylactic nodal region with adequate margins were defined as the planning target volume (PTV)-60 Gy and PTV-48 Gy, respectively. Nineteen plans per patient were made and compared (total: 285 plans), including non-block and block plans with several shapes and sizes. The most appropriate block model was semi-circular, 8 cm outside of the tracheal bifurcation, with a significantly lower lung dose compared to that of non-block plans; the mean lung volumes receiving 5 Gy, 10 Gy, 20 Gy, and the mean lung dose were 31.3% vs. 48.0% (p block and non-block plans were comparable in terms of the homogeneity and conformity indexes of PTV-60 Gy: 0.05 vs. 0.04 (p = 0.100) and 0.82 vs. 0.85 (p = 0.616), respectively. The maximum dose of the spinal cord planning risk volume increased slightly (49.4 Gy vs. 47.9 Gy, p = 0.002). There was no significant difference in the mean doses to the heart and the thyroid gland. Prolongation of the delivery time was less than 1 min (5.6 min vs. 4.9 min, p = 0.010). The block plan for CEC could significantly reduce the lung dose, with acceptable increment in the spinal dose and a slightly prolonged delivery time.

  5. Circumpolar Biodiversity Monitoring Programme coastal biodiversity monitoring background paper

    Science.gov (United States)

    McLennan, Donald; Anderson, Rebecca D.; Wegeberg, S.; Pettersvik Arvnes, Maria; Sergienko, Liudmila; Behe, Carolina; Moss-Davies, Pitseolak; Fritz, S.; Markon, Carl J.; Christensen, T.; Barry, T.; Price, C.

    2016-01-01

    In 2014, the United States (U.S.) and Canada agreed to act as co-lead countries for the initial development of the Coastal Expert Monitoring Group (CEMG) as part of the Circumpolar Biodiversity Monitoring Program (CBMP, www. cbmp.is) under the Arctic Council’s Conservation of Arctic Flora and Fauna (CAFF, www.caff.is) working group. The CAFF Management Board approved Terms of Reference for the CEMG in the spring of 2014. The primary goal of the CEMG is to develop a long term, integrated, multi-disciplinary, circumpolar Arctic Coastal Biodiversity Monitoring Plan (the Coastal Plan) that relies on science and Traditional Knowledge, and has direct and relevant application for communities, industry, government decision makers, and other users. In addition to the monitoring plan, the CAFF working group has asked the CBMP, and thus the CEMG, to develop an implementation plan that identifies timeline, costs, organizational structure and partners. This background paper provides a platform for the guidance for the development of the Coastal Plan and is produced by the CEMG with assistance from a number of experts in multiple countries.

  6. Planning Target Volume D95 and Mean Dose Should Be Considered for Optimal Local Control for Stereotactic Ablative Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lina [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhou, Shouhao [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Balter, Peter [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Shen, Chan [Department of Health Service Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gomez, Daniel R.; Welsh, James D.; Lin, Steve H. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-07-15

    Purpose: To identify the optimal dose parameters predictive for local/lobar control after stereotactic ablative radiation therapy (SABR) in early-stage non-small cell lung cancer (NSCLC). Methods and Materials: This study encompassed a total of 1092 patients (1200 lesions) with NSCLC of clinical stage T1-T2 N0M0 who were treated with SABR of 50 Gy in 4 fractions or 70 Gy in 10 fractions, depending on tumor location/size, using computed tomography-based heterogeneity corrections and a convolution superposition calculation algorithm. Patients were monitored by chest CT or positron emission tomography/CT and/or biopsy after SABR. Factors predicting local/lobar recurrence (LR) were determined by competing risk multivariate analysis. Continuous variables were divided into 2 subgroups at cutoff values identified by receiver operating characteristic curves. Results: At a median follow-up time of 31.7 months (interquartile range, 14.8-51.3 months), the 5-year time to local recurrence within the same lobe and overall survival rates were 93.8% and 44.8%, respectively. Total cumulative number of patients experiencing LR was 40 (3.7%), occurring at a median time of 14.4 months (range, 4.8-46 months). Using multivariate competing risk analysis, independent predictive factors for LR after SABR were minimum biologically effective dose (BED{sub 10}) to 95% of planning target volume (PTVD95 BED{sub 10}) ≤86 Gy (corresponding to PTV D95 physics dose of 42 Gy in 4 fractions or 55 Gy in 10 fractions) and gross tumor volume ≥8.3 cm{sup 3}. The PTVmean BED{sub 10} was highly correlated with PTVD95 BED{sub 10.} In univariate analysis, a cutoff of 130 Gy for PTVmean BED{sub 10} (corresponding to PTVmean physics dose of 55 Gy in 4 fractions or 75 Gy in 10 fractions) was also significantly associated with LR. Conclusions: In addition to gross tumor volume, higher radiation dose delivered to the PTV predicts for better local/lobar control. We recommend that both PTVD95 BED

  7. Evaluation of an artificial intelligence guided inverse planning system: Clinical case study

    International Nuclear Information System (INIS)

    Yan Hui; Yin Fangfang; Willett, Christopher

    2007-01-01

    Purpose: An artificial intelligence (AI) guided method for parameter adjustment of inverse planning was implemented on a commercial inverse treatment planning system. For evaluation purpose, four typical clinical cases were tested and the results from both plans achieved by automated and manual methods were compared. Methods and materials: The procedure of parameter adjustment mainly consists of three major loops. Each loop is in charge of modifying parameters of one category, which is carried out by a specially customized fuzzy inference system. A physician prescribed multiple constraints for a selected volume were adopted to account for the tradeoff between prescription dose to the PTV and dose-volume constraints for critical organs. The searching process for an optimal parameter combination began with the first constraint, and proceeds to the next until a plan with acceptable dose was achieved. The initial setup of the plan parameters was the same for each case and was adjusted independently by both manual and automated methods. After the parameters of one category were updated, the intensity maps of all fields were re-optimized and the plan dose was subsequently re-calculated. When final plan arrived, the dose statistics were calculated from both plans and compared. Results: For planned target volume (PTV), the dose for 95% volume is up to 10% higher in plans using the automated method than those using the manual method. For critical organs, an average decrease of the plan dose was achieved. However, the automated method cannot improve the plan dose for some critical organs due to limitations of the inference rules currently employed. For normal tissue, there was no significant difference between plan doses achieved by either automated or manual method. Conclusion: With the application of AI-guided method, the basic parameter adjustment task can be accomplished automatically and a comparable plan dose was achieved in comparison with that achieved by the manual

  8. Evaluation of an artificial intelligence guided inverse planning system: clinical case study.

    Science.gov (United States)

    Yan, Hui; Yin, Fang-Fang; Willett, Christopher

    2007-04-01

    An artificial intelligence (AI) guided method for parameter adjustment of inverse planning was implemented on a commercial inverse treatment planning system. For evaluation purpose, four typical clinical cases were tested and the results from both plans achieved by automated and manual methods were compared. The procedure of parameter adjustment mainly consists of three major loops. Each loop is in charge of modifying parameters of one category, which is carried out by a specially customized fuzzy inference system. A physician prescribed multiple constraints for a selected volume were adopted to account for the tradeoff between prescription dose to the PTV and dose-volume constraints for critical organs. The searching process for an optimal parameter combination began with the first constraint, and proceeds to the next until a plan with acceptable dose was achieved. The initial setup of the plan parameters was the same for each case and was adjusted independently by both manual and automated methods. After the parameters of one category were updated, the intensity maps of all fields were re-optimized and the plan dose was subsequently re-calculated. When final plan arrived, the dose statistics were calculated from both plans and compared. For planned target volume (PTV), the dose for 95% volume is up to 10% higher in plans using the automated method than those using the manual method. For critical organs, an average decrease of the plan dose was achieved. However, the automated method cannot improve the plan dose for some critical organs due to limitations of the inference rules currently employed. For normal tissue, there was no significant difference between plan doses achieved by either automated or manual method. With the application of AI-guided method, the basic parameter adjustment task can be accomplished automatically and a comparable plan dose was achieved in comparison with that achieved by the manual method. Future improvements to incorporate case

  9. Safety Specialist Manpower, Manpower Resources. Volumes II and III.

    Science.gov (United States)

    Booz Allen and Hamilton, Inc., Washington, DC.

    These second and third volumes of a four-volume study of manpower in state highway safety programs over the next decade estimate manpower resources by state and in national aggregate and describe present and planned training programs for safety specialists. For each educational level, both total manpower and manpower actually available for…

  10. Automated Planning of Tangential Breast Intensity-Modulated Radiotherapy Using Heuristic Optimization

    International Nuclear Information System (INIS)

    Purdie, Thomas G.; Dinniwell, Robert E.; Letourneau, Daniel; Hill, Christine; Sharpe, Michael B.

    2011-01-01

    Purpose: To present an automated technique for two-field tangential breast intensity-modulated radiotherapy (IMRT) treatment planning. Method and Materials: A total of 158 planned patients with Stage 0, I, and II breast cancer treated using whole-breast IMRT were retrospectively replanned using automated treatment planning tools. The tools developed are integrated into the existing clinical treatment planning system (Pinnacle 3 ) and are designed to perform the manual volume delineation, beam placement, and IMRT treatment planning steps carried out by the treatment planning radiation therapist. The automated algorithm, using only the radio-opaque markers placed at CT simulation as inputs, optimizes the tangential beam parameters to geometrically minimize the amount of lung and heart treated while covering the whole-breast volume. The IMRT parameters are optimized according to the automatically delineated whole-breast volume. Results: The mean time to generate a complete treatment plan was 6 min, 50 s ± 1 min 12 s. For the automated plans, 157 of 158 plans (99%) were deemed clinically acceptable, and 138 of 158 plans (87%) were deemed clinically improved or equal to the corresponding clinical plan when reviewed in a randomized, double-blinded study by one experienced breast radiation oncologist. In addition, overall the automated plans were dosimetrically equivalent to the clinical plans when scored for target coverage and lung and heart doses. Conclusion: We have developed robust and efficient automated tools for fully inversed planned tangential breast IMRT planning that can be readily integrated into clinical practice. The tools produce clinically acceptable plans using only the common anatomic landmarks from the CT simulation process as an input. We anticipate the tools will improve patient access to high-quality IMRT treatment by simplifying the planning process and will reduce the effort and cost of incorporating more advanced planning into clinical practice.

  11. Quantitative assessment of inter-clinician variability of target volume delineation for medulloblastoma: quality assurance for the SIOP PNET 4 trial protocol

    International Nuclear Information System (INIS)

    Coles, Charlotte E.; Hoole, Andrew C.F.; Harden, Susan V; Burnet, Neil G.; Twyman, Nicola; Taylor, Roger E.; Kortmann, Rolf D.; Williams, Michael V.

    2003-01-01

    Background and purpose: To assess inter-clinician variability amongst specialist paediatric radiation oncologists in delineating clinical target volumes for treating medulloblastoma as a quality assurance exercise prior to the introduction of the SIOP PNET 4 trial protocol of conformal radiotherapy to the posterior fossa and tumour bed. Patients and methods: Participants from 17 UK centres attended an educational meeting and then completed a clinical planning exercise to outline: (1) the whole posterior fossa and (2) the tumour bed. Quantitative analysis of the volumes, lengths, spatial positioning and axial planes for each individual was carried out and variation between individuals analysed. Results: Outlining of the posterior fossa was reasonably consistent, although most variation was seen in defining the superior border of the tentorium. A major difference was the decision whether or not to include the post-surgical meningocoele in the clinical target volume (CTV). The CTV for the tumour bed was under treated by all participants due to lack of inclusion of pre-operative tumour extent. Conclusions: This exercise demonstrated several ambiguities in the draft protocol and highlighted particular areas of inter-clinician variation. Consequently the protocol was revised and improved to take account of these findings. We recommend that planning exercises, in conjunction with education and training, should be implemented before the start of any new radiotherapy trial. In the future, the use of image transfer will allow prospective peer review of target volumes before treatment commences. These measures are essential to ensure that alterations in clinical practice are achieved in a uniform way

  12. The impact of direct aperture optimization on plan quality and efficiency in complex head and neck IMRT

    Directory of Open Access Journals (Sweden)

    Sabatino Marcello

    2012-01-01

    Full Text Available Abstract Background Conventional step&shoot intensity modulated radio therapy (IMRT approaches potentially lead to treatment plans with high numbers of segments and monitor units (MU and, therefore, could be time consuming at the linear accelerator. Direct optimization methods are able to reduce the complexity without degrading the quality of the plan. The aim of this study is the evaluation of different IMRT approaches at standardized conditions for head and neck tumors. Method For 27 patients with carcinomas in the head and neck region a planning study with a 2-step-IMRT system (KonRad, a direct optimization system (Panther DAO and a mixture of both approaches (MasterPlan DSS was created. In order to avoid different prescription doses for boost volumes a simple standardization was realized. The dose was downscaled to 50 Gy to the planning target volume (PTV which included the primary tumor as well as the bilateral lymphatic drainage (cervical and supraclavicular. Dose restrictions for the organs at risk (OAR were downscaled to this prescription from high dose concepts up to 72 Gy. Those limits were defined as planning objectives while reaching definable PTV coverage with a standardized field setup. The parameters were evaluated from the corresponding dose volume histogram (DVH. Special attention was paid to the efficiency of the method, measured by means of calculated MU and required segments. Statistical tests of significance were applied to quantify the differences between the evaluated systems. Results PTV coverage for all systems in terms of V90% and V95% fell short of the requested 100% and 95%, respectively, but were still acceptable (range: 98.7% to 99.1% and 94.2% to 94.7%. Overall for OAR sparing and the burden of healthy tissue with low doses no technique was superior for all evaluated parameters. Differences were found for the number of segments where the direct optimization systems generated less segments. Lowest average numbers of

  13. The muon veto of the Dortmund low-background facility

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, Marcel; Goessling, Claus; Kroeninger, Kevin; Nitsch, Christian [TU Dortmund, Physik EIV, D-44221 Dortmund (Germany)

    2016-07-01

    The Dortmund Low Background Facility (DLB) is a low-background gamma-ray spectrometry system with an artificial overburden built at ground level. It uses a high-purity germanium detector with a relative efficiency of 60 %, which is set up inside a massive shielding. The outer shielding consists of barite concrete and cast iron, corresponding to ten meters of water equivalent (mw.e.), and houses a multi-layer lead castle as an inner shielding, that features borated polyethylene as a neutron absorber. Additionally an active muon veto is installed to reduce cosmic-induced contributions to the spectrum. The remarkably lowered background of the DLB compared to an unshielded spectrometer, allows radio-purity screening measurements for material preselection with sensitivities better than 1 Bq/kg. This talk focusses on the muon veto of the DLB. Its basic concept and its benefits for low-background operation are described. Also its current status of development and future upgrade plans are presented.

  14. Background factors related to and/or influencing occupation in mentally disordered offenders.

    Science.gov (United States)

    Lindstedt, Helena; Ivarsson, Ann-Britt; Söderlund, Anne

    2006-09-01

    Knowledge of background and occupational related factors of mentally disordered offenders are missing. It is essential to understand these issues when planning discharge from forensic psychiatric hospital care to enable community dwelling. One aim was to investigate mentally disordered offenders' background factors, confidence in and how they value occupations. Another aim was to investigate MDOs background factors' in relation to and the influences on Occupational Performance and Social Participation. Data was collected with an explorative, correlative design after informed consent, from 74 mentally disordered offenders (mean age 34,2) cared for in forensic psychiatric hospitals. Assessments were Allen Cognitive Level Screen, Capability to Perform Daily Occupations, Interview Schedule of Social Interaction, Manchester Short Assessment of Quality of Life, Self-efficacy Scale and Importance scale. Eight background factors were assembled from the individual forensic psychiatric investigation. Most of the investigated background factors relate to and half of them influence occupational performance, particular the cognitive aspect of occupational performance. The influences on occupation originate from adulthood, such as suffering from schizophrenia, psycho/social problems, and having performed violent crimes. These findings indicate that staff in forensic hospital care should initiate rehabilitation with knowledge about MDOs' complex daily occupations. For avoiding information bias, information gathering preceding treatment planning should be performed in collaboration between caring staff and mentally disordered offenders.

  15. Evaluation of DVH-based treatment plan verification in addition to gamma passing rates for head and neck IMRT

    International Nuclear Information System (INIS)

    Visser, Ruurd; Wauben, David J.L.; Groot, Martijn de; Steenbakkers, Roel J.H.M.; Bijl, Henk P.; Godart, Jeremy; Veld, Aart A. van’t; Langendijk, Johannes A.; Korevaar, Erik W.

    2014-01-01

    Background and purpose: Treatment plan verification of intensity modulated radiotherapy (IMRT) is generally performed with the gamma index (GI) evaluation method, which is difficult to extrapolate to clinical implications. Incorporating Dose Volume Histogram (DVH) information can compensate for this. The aim of this study was to evaluate DVH-based treatment plan verification in addition to the GI evaluation method for head and neck IMRT. Materials and methods: Dose verifications of 700 subsequent head and neck cancer IMRT treatment plans were categorised according to gamma and DVH-based action levels. Fractionation dependent absolute dose limits were chosen. The results of the gamma- and DVH-based evaluations were compared to the decision of the medical physicist and/or radiation oncologist for plan acceptance. Results: Nearly all treatment plans (99.7%) were accepted for treatment according to the GI evaluation combined with DVH-based verification. Two treatment plans were re-planned according to DVH-based verification, which would have been accepted using the evaluation alone. DVH-based verification increased insight into dose delivery to patient specific structures increasing confidence that the treatment plans were clinically acceptable. Moreover, DVH-based action levels clearly distinguished the role of the medical physicist and radiation oncologist within the Quality Assurance (QA) procedure. Conclusions: DVH-based treatment plan verification complements the GI evaluation method improving head and neck IMRT-QA

  16. Symptom dimensions are associated with progressive brain volume changes in schizophrenia

    NARCIS (Netherlands)

    Collin, G.; Derks, E. M.; van Haren, N. E. M.; Schnack, H. G.; Hulshoff Pol, H. E.; Kahn, R. S.; Cahn, W.

    2012-01-01

    Background: There is considerable variation in progressive brain volume changes in schizophrenia. Whether this is related to the clinical heterogeneity that characterizes the illness remains to be determined. This study examines the relationship between change in brain volume over time and

  17. Business plan competition

    CERN Multimedia

    2007-01-01

    "Venture – Companies for tomorrow" is a business plan competition, which supports students and other junior entrepreneurs in developing their business plans. The sixth edition of the competition is now taking place. Venture 2008 highlights: - prize money totalling CHF 150’000; - possibility to optimize business ideas and business plans with the help of experienced coaches: around 200 coaches are available, with a wide range of backgrounds, entrepreneurs as well as venture capitalists; -\tpossibility to present business ideas and business plans to potential investors ("Investor Days" - 17 January and 7 May); - active involvement in the start-up community; -\tcontribution to potential independence. The competition consists of two phases: Phase I, Business idea, Deadline for submission of business idea: 5 December 2007 (online at http://www.venture.ch). Award Ceremony: 17 January 2008 Phase II, Business plan Deadline for submission of business plan: 2 April 2008 (online at...

  18. Background of Individual Education Plans (IEPs) Policy in Some Countries: A Review

    Science.gov (United States)

    Alkahtani, Mohammed Ali; Kheirallah, Sahar Abdelfattah

    2016-01-01

    This paper seeks to provide a cogent outline of the current policies that six separate countries have on Individual Education Plans (IEPs), identifying the key features in each system. The chosen countries are Australia (Queen Island), Canada (British Columbia), New Zealand, the United Kingdom, the United States of America, and Saudi Arabia. The…

  19. Sampling based motion planning with reachable volumes: Application to manipulators and closed chain systems

    KAUST Repository

    McMahon, Troy

    2014-09-01

    © 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.

  20. Sampling based motion planning with reachable volumes: Application to manipulators and closed chain systems

    KAUST Repository

    McMahon, Troy; Thomas, Shawna; Amato, Nancy M.

    2014-01-01

    © 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.

  1. Measurement of normal ocular volume by the use of computed ...

    African Journals Online (AJOL)

    Background: Reduction or increase in ocular volume may indicate ocular pathology. Unfortunately the reference values utilized for ocular volume had been that of non-Africans. It is therefore pertinent to have a reference value of normal for Africans. Objective: To document the computer tomography (CT) scan measured ...

  2. Development of Secondary Route Bridge Design Plan Guides

    Science.gov (United States)

    2018-03-03

    The objective of this study is to develop a set of bridge plan guides for low-volume traffic roads. The purpose of the plans is to facilitate construction of new structures suitable for local agencies. The designs are to specifically address common l...

  3. Evaluation and comparison of New 4DCT based strategies for proton treatment planning for lung tumors

    International Nuclear Information System (INIS)

    Wang, Ning; Patyal, Baldev; Ghebremedhin, Abiel; Bush, David

    2013-01-01

    To evaluate different strategies for proton lung treatment planning based on four-dimensional CT (4DCT) scans. Twelve cases, involving only gross tumor volumes (GTV), were evaluated. Single image sets of (1) maximum intensity projection (MIP3) of end inhale (EI), middle exhale (ME) and end exhale (EE) images; (2) average intensity projection (AVG) of all phase images; and (3) EE images from 4DCT scans were selected as primary images for proton treatment planning. Internal target volumes (ITVs) outlined by a clinician were imported into MIP3, AVG, and EE images as planning targets. Initially, treatment uncertainties were not included in planning. Each plan was imported into phase images of 4DCT scans. Relative volumes of GTVs covered by 95% of prescribed dose and mean ipsilateral lung dose of a phase image obtained by averaging the dose in inspiration and expiration phases were used to evaluate the quality of a plan for a particular case. For comparing different planning strategies, the mean of the averaged relative volumes of GTVs covered by 95% of prescribed dose and its standard deviation for each planning strategy for all cases were used. Then, treatment uncertainties were included in planning. Each plan was recalculated in phase images of 4DCT scans. Same strategies were used for plan evaluation except dose-volume histograms of the planning target volumes (PTVs) instead of GTVs were used and the mean and standard deviation of the relative volumes of PTVs covered by 95% of prescribed dose and the ipsilateral lung dose were used to compare different planning strategies. MIP3 plans without treatment uncertainties yielded 96.7% of the mean relative GTV covered by 95% of prescribed dose (standard deviations of 5.7% for all cases). With treatment uncertainties, MIP3 plans yielded 99.5% of mean relative PTV covered by 95% of prescribed dose (standard deviations of 0.7%). Inclusion of treatment uncertainties improved PTV dose coverage but also increased the ipsilateral

  4. MO-D-BRC-02: Auto-Planning

    International Nuclear Information System (INIS)

    Xia, P.

    2016-01-01

    Treatment planning is a central part of radiation therapy, including delineation in tumor volumes and critical organs, setting treatment goals of prescription doses to the tumor targets and tolerance doses to the critical organs, and finally generation of treatment plans to meet the treatment goals. National groups like RTOG have led the effort to standardize treatment goals of the prescription doses to the tumor targets and tolerance doses to the critical organs based on accumulated knowledge from decades of abundant clinical trial experience. The challenge for each clinical department is how to achieve or surpass these set goals within the time constraints of clinical practice. Using fifteen testing cases from different treatment sites such as head and neck, prostate with and without pelvic lymph nodes, SBRT spine, we will present clinically utility of advanced planning tools, including knowledge based, automatic based, and multiple criteria based tools that are clinically implemented. The objectives of this session are: Understand differences among these three advanced planning tools Provide clinical assessments on the utility of the advanced planning tools Discuss clinical challenges of treatment planning with large variations in tumor volumes and their relationships with adjacent critical organs. Ping Xia received research grant from Philips. Jackie Wu received research grant from Varian; P. Xia, Research support by Philips and Varian; Q. Wu, NIH, Varian Medical

  5. MO-D-BRC-02: Auto-Planning

    Energy Technology Data Exchange (ETDEWEB)

    Xia, P. [The Cleveland Clinic Foundation (United States)

    2016-06-15

    Treatment planning is a central part of radiation therapy, including delineation in tumor volumes and critical organs, setting treatment goals of prescription doses to the tumor targets and tolerance doses to the critical organs, and finally generation of treatment plans to meet the treatment goals. National groups like RTOG have led the effort to standardize treatment goals of the prescription doses to the tumor targets and tolerance doses to the critical organs based on accumulated knowledge from decades of abundant clinical trial experience. The challenge for each clinical department is how to achieve or surpass these set goals within the time constraints of clinical practice. Using fifteen testing cases from different treatment sites such as head and neck, prostate with and without pelvic lymph nodes, SBRT spine, we will present clinically utility of advanced planning tools, including knowledge based, automatic based, and multiple criteria based tools that are clinically implemented. The objectives of this session are: Understand differences among these three advanced planning tools Provide clinical assessments on the utility of the advanced planning tools Discuss clinical challenges of treatment planning with large variations in tumor volumes and their relationships with adjacent critical organs. Ping Xia received research grant from Philips. Jackie Wu received research grant from Varian; P. Xia, Research support by Philips and Varian; Q. Wu, NIH, Varian Medical.

  6. 18F-Fdg-PET-guided Planning and Re-Planning (Adaptive) Radiotherapy in Head and Neck Cancer: Current State of Art.

    Science.gov (United States)

    Farina, Eleonora; Ferioli, Martina; Castellucci, Paolo; Farina, Arianna; Zanirato Rambaldi, Giuseppe; Cilla, Savino; Cammelli, Silvia; Fanti, Stefano; Morganti, Alessio G

    2017-12-01

    A review of the literature is proposed as a contribution to current knowledge on technical, physical, and clinical issues about PET-guided planning and re-planning radiotherapy (RT) in head and neck cancer. PubMed and Scopus electronic databases were searched for articles including clinical trials. Search terms were "gross tumor volume (GTV) delineation", "head and neck cancer", "radiotherapy", "adaptive radiotherapy" in combination with "PET". A 18 F-FDG-PET and CT-scan comparison in GTV definition for RT planning of head and neck cancer was shown in twenty-seven clinical trials with a total of 712 patients. Only two clinical trials focused on PET-guided adaptive radiotherapy (ART) with a total of 31 patients. 18 F-FDG-PET is able to achieve an accurate and precise definition of GTV boundaries during RT planning, especially in combination with CT-scan. ART strategies are proposed to evaluate tumor volume changes, plan boost irradiation on metabolically active residual neoplasm and protect organs at risk (OaRs). Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  7. Savannah River Site Environmental Implementation Plan

    International Nuclear Information System (INIS)

    1989-01-01

    Formal sitewide environmental planning at the . Savannah River Site (SRS) began in 1986 with the development and adoption of the Strategic Environmental Plan. The Strategic Environmental Plan describes the philosophy, policy, and overall program direction of environmental programs for the operation of the SRS. The Strategic Environmental Plan (Volume 2) provided the basis for development of the Environmental Implementation Plan (EIP). The EIP is the detailed, comprehensive environmental master plan for operating contractor organizations at the SRS. The EIP provides a process to ensure that all environmental requirements and obligations are being met by setting specific measurable goals and objectives and strategies for implementation. The plan is the basis for justification of site manpower and funding requests for environmental projects and programs over a five-year planning period

  8. Savannah River Site Environmental Implementation Plan

    Energy Technology Data Exchange (ETDEWEB)

    1989-08-01

    Formal sitewide environmental planning at the . Savannah River Site (SRS) began in 1986 with the development and adoption of the Strategic Environmental Plan. The Strategic Environmental Plan describes the philosophy, policy, and overall program direction of environmental programs for the operation of the SRS. The Strategic Environmental Plan (Volume 2) provided the basis for development of the Environmental Implementation Plan (EIP). The EIP is the detailed, comprehensive environmental master plan for operating contractor organizations at the SRS. The EIP provides a process to ensure that all environmental requirements and obligations are being met by setting specific measurable goals and objectives and strategies for implementation. The plan is the basis for justification of site manpower and funding requests for environmental projects and programs over a five-year planning period.

  9. The target volume concept at the recording of external beam radiotherapy

    International Nuclear Information System (INIS)

    Quast, U.; Glaeser, L.

    1981-01-01

    With the aim of complete, exact and reproducible manual recording and documentation of external beam radiotherapy a concept is proposed providing treatment planning and recording related to space and time for target volumes of different order corresponding to Ist, IInd or IIIrd part of treatment course, regarding all dose limiting organs at risk. The record consists of the dosage plan for medical treatment planning, the treatment plan for physical dose distribution planning and the treatment record of absorbed doses delivered as well as a checklist for patient and machine set-up, and labels for intended actions during treatment development. A clear arrangement of the record form in logical order was found, demanding exact specification of target(s) and beam(s) and their relation in space and time; asking for verbal and graphical description of target volumes, organs at risk, patient positioning, beam portals and dose reference points in terms of patients' anatomy; emphasizing the most important medical data by marked areas and leaving enough empty space for additional data, remarks or comments. During several years of clinical use these record forms proved to be suitable for all cases of external beam therapy, for complex situations of target volumes and treatment-scheduling, for all treatment techniques and radiation qualities and for all ways of physical treatment planning. They can be extended to automatic treatment verification, monitoring and recording as well as to the application of in-vivo-measurements of absorbed doses. (orig.) [de

  10. SU-F-T-447: The Impact of Treatment Planning Methods On RapidPlan Modeling for Rectum Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lu, S; Peng, J; Li, K; Wang, J; Hu, W [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China)

    2016-06-15

    Purpose: To investigate the dose volume histogram (DVH) prediction varieties based on intensity modulate radiotherapy (IMRT) plan or volume arc modulate radiotherapy (VMAT) plan models on the RapidPlan. Methods: Two DVH prediction models were generated in this study, including an IMRT model trained from 83 IMRT rectum plans and a VMAT model trained from 60 VMAT rectum plans. In the internal validation, 20 plans from each training database were selected to verify the clinical feasibility of the model. Then, 10 IMRT plans (PIMRT-by-IMRT-model) generated from IMRT model and 10 IMRT plans generated from VMAT model (PIMRT-by-VMAT-model) were compared on the dose to organs at risk (OAR), which included bladder, left and right femoral heads. The similar comparison was also performed on the VMAT plans generated from IMRT model (PVMAT-by-IMRT-model) and VMAT plans generated from VMAT (PVMAT-by-VMAT-model) model. Results: For the internal validation, all plans from IMRT or VMAT model shows significantly improvement on OAR sparing compared with the corresponded clinical ones. Compared to the PIMRT-by-VMAT-model, the PIMRT-by-IMRT-model has a reduction of 6.90±3.87%(p<0.001) on V40 6.63±3.62%(p<0.001) on V45 and 4.74±2.26%(p<0.001) on V50 in bladder; and a mean dose reduction of 2.12±1.75Gy(p=0.004) and 2.84±1.53Gy(p<0.001) in right and left femoral head, respectively. There was no significant difference on OAR sparing between PVMAT-by-IMRT-model and PVMAT-by-VMAT-model. Conclusion: The IMRT model for the rectal cancer in the RapidPlan can be applied to for VMAT planning. However, the VMAT model is not suggested to use in the IMRT planning. Cautions should be taken that the planning model based on some technique may not feasible to other planning techniques.

  11. Radiological emergencies - planning and preparedness

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-12-31

    This information and training film in three parts deals with the technical background for emergency planning, emergency planning concepts and emergency preparedness. It describes the technical characteristics of radiological emergencies on which important emergency planning concepts are based and the purpose of those concepts. The film also demonstrates how emergency organizations must work together to ensure adequate preparedness. The programme reflects the standards, guidance and recommendations of the International Atomic Energy Agency

  12. Pancreatic cancer planning: Complex conformal vs modulated therapies

    International Nuclear Information System (INIS)

    Chapman, Katherine L.; Witek, Matthew E.; Chen, Hongyu; Showalter, Timothy N.; Bar-Ad, Voichita; Harrison, Amy S.

    2016-01-01

    To compare the roles of intensity-modulated radiation therapy (IMRT) and volumetric- modulated arc therapy (VMAT) therapy as compared to simple and complex 3-dimensional chemoradiotherpy (3DCRT) planning for resectable and borderline resectable pancreatic cancer. In all, 12 patients who received postoperative radiotherapy (8) or neoadjuvant concurrent chemoradiotherapy (4) were evaluated retrospectively. Radiotherapy planning was performed for 4 treatment techniques: simple 4-field box, complex 5-field 3DCRT, 5 to 6-field IMRT, and single-arc VMAT. All volumes were approved by a single observer in accordance with Radiation Therapy Oncology Group (RTOG) Pancreas Contouring Atlas. Plans included tumor/tumor bed and regional lymph nodes to 45 Gy; with tumor/tumor bed boosted to 50.4 Gy, at least 95% of planning target volume (PTV) received the prescription dose. Dose-volume histograms (DVH) for multiple end points, treatment planning, and delivery time were assessed. Complex 3DCRT, IMRT, and VMAT plans significantly (p < 0.05) decreased mean kidney dose, mean liver dose, liver (V 30 , V 35 ), stomach (D 10 %), stomach (V 45 ), mean right kidney dose, and right kidney (V 15 ) as compared with the simple 4-field plans that are most commonly reported in the literature. IMRT plans resulted in decreased mean liver dose, liver (V 35 ), and left kidney (V 15 , V 18 , V 20 ). VMAT plans decreased small bowel (D 10 %, D 15 %), small bowel (V 35 , V 45 ), stomach (D 10 %, D 15 %), stomach (V 35 , V 45 ), mean liver dose, liver (V 35 ), left kidney (V 15 , V 18 , V 20 ), and right kidney (V 18 , V 20 ). VMAT plans significantly decreased small bowel (D 10 %, D 15 %), left kidney (V 20 ), and stomach (V 45 ) as compared with IMRT plans. Treatment planning and delivery times were most efficient for simple 4-field box and VMAT. Excluding patient setup and imaging, average treatment delivery was within 10 minutes for simple and complex 3DCRT, IMRT, and VMAT treatments. This article

  13. Fast in vivo volume dose reconstruction via reference dose perturbation

    International Nuclear Information System (INIS)

    Lu, Weiguo; Chen, Mingli; Mo, Xiaohu; Parnell, Donald; Olivera, Gustavo; Galmarini, Daniel

    2014-01-01

    Purpose: Accurate on-line reconstruction of in-vivo volume dose that accounts for both machine and patient discrepancy is not clinically available. We present a simple reference-dose-perturbation algorithm that reconstructs in-vivo volume dose fast and accurately. Methods: We modelled the volume dose as a function of the fluence map and density image. Machine (output variation, jaw/leaf position errors, etc.) and patient (setup error, weight loss, etc.) discrepancies between the plan and delivery were modelled as perturbation of the fluence map and density image, respectively. Delivered dose is modelled as perturbation of the reference dose due to change of the fluence map and density image. We used both simulated and clinical data to validate the algorithm. The planned dose was used as the reference. The reconstruction was perturbed from the reference and accounted for output-variations and the registered daily image. The reconstruction was compared with the ground truth via isodose lines and the Gamma Index. Results: For various plans and geometries, the volume doses were reconstructed in few seconds. The reconstruction generally matched well with the ground truth. For the 3%/3mm criteria, the Gamma pass rates were 98% for simulations and 95% for clinical data. The differences mainly appeared on the surface of the phantom/patient. Conclusions: A novel reference-dose-perturbation dose reconstruction model is presented. The model accounts for machine and patient discrepancy from planning. The algorithm is simple, fast, yet accurate, which makes online in-vivo 3D dose reconstruction clinically feasible.

  14. DNFSB Recommendation 94-1 Hanford Site Integrated Stabilization Management Plan. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, E.W.

    1995-10-01

    The US Department of Energy (DOE) has developed an Integrated Program Plan (IPP) to address concerns identified in Defense Nuclear Facilities Safety Board Recommendation 94-1. The IPP describes the actions that DOE plans to implement at its various sites to convert excess fissile materials to forms or conditions suitable for safe interim storage. The baseline IPP was issued as DOE`s Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 94-1 Implementation Plan (IP), which was transmitted to the DNFSB on February 28, 1995. The IPP is being further developed to include complex-wide requirements for research and development and a long-range facility requirements section. The planned additions to the baseline IPP are being developed based on a systems engineering approach that integrates facilities and capabilities at the various DOE sites and focuses on attaining safe interim storage with minimum safety risks and environmental impacts. Each affected DOE site has developed a Site Integrated Stabilization Management Plan (SISMP) to identify individual site plans to implement the DNFSB Recommendation 94-1 and to provide a basis for formulating planned additions to the IPP. The SISMPs were developed based on the objectives, requirements, and commitments identified in the baseline DNFSB Recommendation 94-1 IPP. The SISMPs will be periodically updated to reflect improved integration between DOE sites as identified during the IPP systems engineering evaluations.

  15. DNFSB Recommendation 94-1 Hanford Site Integrated Stabilization Management Plan. Volume 1

    International Nuclear Information System (INIS)

    Gerber, E.W.

    1995-10-01

    The US Department of Energy (DOE) has developed an Integrated Program Plan (IPP) to address concerns identified in Defense Nuclear Facilities Safety Board Recommendation 94-1. The IPP describes the actions that DOE plans to implement at its various sites to convert excess fissile materials to forms or conditions suitable for safe interim storage. The baseline IPP was issued as DOE's Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 94-1 Implementation Plan (IP), which was transmitted to the DNFSB on February 28, 1995. The IPP is being further developed to include complex-wide requirements for research and development and a long-range facility requirements section. The planned additions to the baseline IPP are being developed based on a systems engineering approach that integrates facilities and capabilities at the various DOE sites and focuses on attaining safe interim storage with minimum safety risks and environmental impacts. Each affected DOE site has developed a Site Integrated Stabilization Management Plan (SISMP) to identify individual site plans to implement the DNFSB Recommendation 94-1 and to provide a basis for formulating planned additions to the IPP. The SISMPs were developed based on the objectives, requirements, and commitments identified in the baseline DNFSB Recommendation 94-1 IPP. The SISMPs will be periodically updated to reflect improved integration between DOE sites as identified during the IPP systems engineering evaluations

  16. Science Planning and Orbit Classification for Solar Probe Plus

    Science.gov (United States)

    Kusterer, M. B.; Fox, N. J.; Rodgers, D. J.; Turner, F. S.

    2016-12-01

    There are a number of challenges for the Science Planning Team (SPT) of the Solar Probe Plus (SPP) Mission. Since SPP is using a decoupled payload operations approach, tight coordination between the mission operations and payload teams will be required. The payload teams must manage the volume of data that they write to the spacecraft solid-state recorders (SSR) for their individual instruments for downlink to the ground. Making this process more difficult, the geometry of the celestial bodies and the spacecraft during some of the SPP mission orbits cause limited uplink and downlink opportunities. The payload teams will also be required to coordinate power on opportunities, command uplink opportunities, and data transfers from instrument memory to the spacecraft SSR with the operation team. The SPT also intend to coordinate observations with other spacecraft and ground based systems. To solve these challenges, detailed orbit activity planning is required in advance for each orbit. An orbit planning process is being created to facilitate the coordination of spacecraft and payload activities for each orbit. An interactive Science Planning Tool is being designed to integrate the payload data volume and priority allocations, spacecraft ephemeris, attitude, downlink and uplink schedules, spacecraft and payload activities, and other spacecraft ephemeris. It will be used during science planning to select the instrument data priorities and data volumes that satisfy the orbit data volume constraints and power on, command uplink and data transfer time periods. To aid in the initial stages of science planning we have created an orbit classification scheme based on downlink availability and significant science events. Different types of challenges arise in the management of science data driven by orbital geometry and operational constraints, and this scheme attempts to identify the patterns that emerge.

  17. Fuzzy hidden Markov chains segmentation for volume determination and quantitation in PET

    Energy Technology Data Exchange (ETDEWEB)

    Hatt, M [INSERM U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Bat 2bis (I3S), 5 avenue Foch, Brest, 29609 (France); Lamare, F [INSERM U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Bat 2bis (I3S), 5 avenue Foch, Brest, 29609, (France); Boussion, N [INSERM U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Bat 2bis (I3S), 5 avenue Foch, Brest, 29609 (France); Turzo, A [INSERM U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Bat 2bis (I3S), 5 avenue Foch, Brest, 29609 (France); Collet, C [Ecole Nationale Superieure de Physique de Strasbourg (ENSPS), ULP, Strasbourg, F-67000 (France); Salzenstein, F [Institut d' Electronique du Solide et des Systemes (InESS), ULP, Strasbourg, F-67000 (France); Roux, C [INSERM U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Bat 2bis (I3S), 5 avenue Foch, Brest, 29609 (France); Jarritt, P [Medical Physics Agency, Royal Victoria Hospital, Belfast (United Kingdom); Carson, K [Medical Physics Agency, Royal Victoria Hospital, Belfast (United Kingdom); Rest, C Cheze-Le [INSERM U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Bat 2bis (I3S), 5 avenue Foch, Brest, 29609 (France); Visvikis, D [INSERM U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Bat 2bis (I3S), 5 avenue Foch, Brest, 29609 (France)

    2007-07-21

    Accurate volume of interest (VOI) estimation in PET is crucial in different oncology applications such as response to therapy evaluation and radiotherapy treatment planning. The objective of our study was to evaluate the performance of the proposed algorithm for automatic lesion volume delineation; namely the fuzzy hidden Markov chains (FHMC), with that of current state of the art in clinical practice threshold based techniques. As the classical hidden Markov chain (HMC) algorithm, FHMC takes into account noise, voxel intensity and spatial correlation, in order to classify a voxel as background or functional VOI. However the novelty of the fuzzy model consists of the inclusion of an estimation of imprecision, which should subsequently lead to a better modelling of the 'fuzzy' nature of the object of interest boundaries in emission tomography data. The performance of the algorithms has been assessed on both simulated and acquired datasets of the IEC phantom, covering a large range of spherical lesion sizes (from 10 to 37 mm), contrast ratios (4:1 and 8:1) and image noise levels. Both lesion activity recovery and VOI determination tasks were assessed in reconstructed images using two different voxel sizes (8 mm{sup 3} and 64 mm{sup 3}). In order to account for both the functional volume location and its size, the concept of % classification errors was introduced in the evaluation of volume segmentation using the simulated datasets. Results reveal that FHMC performs substantially better than the threshold based methodology for functional volume determination or activity concentration recovery considering a contrast ratio of 4:1 and lesion sizes of <28 mm. Furthermore differences between classification and volume estimation errors evaluated were smaller for the segmented volumes provided by the FHMC algorithm. Finally, the performance of the automatic algorithms was less susceptible to image noise levels in comparison to the threshold based techniques. The

  18. Intensity-modulated radiotherapy in patients with locally advanced rectal cancer reduces volume of bowel treated to high dose levels

    International Nuclear Information System (INIS)

    Urbano, M. Teresa Guerrero; Henrys, Anthony J.; Adams, Elisabeth J.; Norman, Andrew R.; Bedford, James L.; Harrington, Kevin J.; Nutting, Christopher M.; Dearnaley, David P.; Tait, Diana M.

    2006-01-01

    Purpose: To investigate the potential for intensity-modulated radiotherapy (IMRT) to spare the bowel in rectal tumors. Methods and Materials: The targets (pelvic nodal and rectal volumes), bowel, and bladder were outlined in 5 patients. All had conventional, three-dimensional conformal RT and forward-planned multisegment three-field IMRT plans compared with inverse-planned simultaneous integrated boost nine-field equally spaced IMRT plans. Equally spaced seven-field and five-field and five-field, customized, segmented IMRT plans were also evaluated. Results: Ninety-five percent of the prescribed dose covered at least 95% of both planning target volumes using all but the conventional plan (mean primary and pelvic planning target volume receiving 95% of the prescribed dose was 32.8 ± 13.7 Gy and 23.7 ± 4.87 Gy, respectively), reflecting a significant lack of coverage. The three-field forward planned IMRT plans reduced the volume of bowel irradiated to 45 Gy and 50 Gy by 26% ± 16% and 42% ± 27% compared with three-dimensional conformal RT. Additional reductions to 69 ± 51 cm 3 to 45 Gy and 20 ± 21 cm 3 to 50 Gy were obtained with the nine-field equally spaced IMRT plans-64% ± 11% and 64% ± 20% reductions compared with three-dimensional conformal RT. Reducing the number of beams and customizing the angles for the five-field equally spaced IMRT plan did not significantly reduce bowel sparing. Conclusion: The bowel volume irradiated to 45 Gy and 50 Gy was significantly reduced with IMRT, which could potentially lead to less bowel toxicity. Reducing the number of beams did not reduce bowel sparing and the five-field customized segmented IMRT plan is a reasonable technique to be tested in clinical trials

  19. Planned home compared with planned hospital births: Mode of delivery and Perinatal mortality rates, an observational study

    NARCIS (Netherlands)

    Kooy, J. (Jacoba); E. Birnie (Erwin); S. Denktaş (Semiha); E.A.P. Steegers (Eric); G.J. Bonsel (Gouke)

    2017-01-01

    textabstractBackground: To compare the mode of delivery between planned home versus planned hospital births and to determine if differences in intervention rates could be interpreted as over- or undertreatment. Methods: Intervention and perinatal mortality rates were obtained for 679,952 low-risk

  20. Helical Tomotherapy Planning for Left-Sided Breast Cancer Patients With Positive Lymph Nodes: Comparison to Conventional Multiport Breast Technique

    International Nuclear Information System (INIS)

    Goddu, S. Murty; Chaudhari, Summer; Mamalui-Hunter, Maria; Pechenaya, Olga L.; Pratt, David; Mutic, Sasa; Zoberi, Imran; Jeswani, Sam; Powell, Simon N.; Low, Daniel A.

    2009-01-01

    Purpose: To evaluate the feasibility of using helical tomotherapy for locally advanced left-sided breast cancer. Methods and Materials: Treatment plans were generated for 10 left-sided breast cancer patients with positive lymph nodes comparing a multiport breast (three-dimensional) technique with the tomotherapy treatment planning system. The planning target volumes, including the chest wall/breast, supraclavicular, axillary, and internal mammary lymph nodes, were contoured. The treatment plans were generated on the tomotherapy treatment planning system to deliver 50.4 Gy to the planning target volume. To spare the contralateral tissues, directional blocking was applied to the right breast and right lung. The optimization goals were to protect the lungs, heart, and right breast. Results: The tomotherapy plans increased the minimal dose to the planning target volume (minimal dose received by 99% of target volume = 46.2 ± 1.3 Gy vs. 27.9 ± 17.1 Gy) while improving the dose homogeneity (dose difference between the minimal dose received by 5% and 95% of the planning target volume = 7.5 ± 1.8 Gy vs. 37.5 ± 26.9 Gy). The mean percentage of the left lung volume receiving ≥20 Gy in the tomotherapy plans decreased from 32.6% ± 4.1% to 17.6% ± 3.5%, while restricting the right-lung mean dose to <5 Gy. However, the mean percentage of volume receiving ≥5 Gy for the total lung increased from 25.2% ± 4.2% for the three-dimensional technique to 46.9% ± 8.4% for the tomotherapy plan. The mean volume receiving ≥35 Gy for the heart decreased from 5.6% ± 4.8% to 2.2% ± 1.5% in the tomotherapy plans. However, the mean heart dose for tomotherapy delivery increased from 7.5 ± 3.4 Gy to 12.2 ± 1.8 Gy. Conclusion: The tomotherapy plans provided better dose conformity and homogeneity than did the three-dimensional plans for treatment of left-sided breast tumors with regional lymph node involvement, while allowing greater sparing of the heart and left lung from doses

  1. Automatic treatment planning implementation using a database of previously treated patients

    International Nuclear Information System (INIS)

    Moore, J A; Evans, K; Yang, W; Herman, J; McNutt, T

    2014-01-01

    Purpose: Using a database of prior treated patients, it is possible to predict the dose to critical structures for future patients. Automatic treatment planning speeds the planning process by generating a good initial plan from predicted dose values. Methods: A SQL relational database of previously approved treatment plans is populated via an automated export from Pinnacle 3 . This script outputs dose and machine information and selected Regions of Interests as well as its associated Dose-Volume Histogram (DVH) and Overlap Volume Histograms (OVHs) with respect to the target structures. Toxicity information is exported from Mosaiq and added to the database for each patient. The SQL query is designed to ask the system for the lowest achievable dose for a specified region of interest (ROI) for each patient with a given volume of that ROI being as close or closer to the target than the current patient. Results: The additional time needed to calculate OVHs is approximately 1.5 minutes for a typical patient. Database lookup of planning objectives takes approximately 4 seconds. The combined additional time is less than that of a typical single plan optimization (2.5 mins). Conclusions: An automatic treatment planning interface has been successfully used by dosimetrists to quickly produce a number of SBRT pancreas treatment plans. The database can be used to compare dose to individual structures with the toxicity experienced and predict toxicities before planning for future patients.

  2. 1987 Oak Ridge model conference: Proceedings: Volume 3, Health and safety

    International Nuclear Information System (INIS)

    1987-01-01

    See the abstract for Volume I for general information on the conference. Topics discussed in Volume III include the use of models in handling hazardous materials, communication at waste sites, asbestos, regulatory decisions, emergency planning, training programs, occupational hazards, and protection of subcontractors

  3. Figure/ground analogy for integrated sustainability & planning

    CSIR Research Space (South Africa)

    Beyers, C

    2006-12-01

    Full Text Available This article proposes a figure ground analogy as alternative way of conceptually integrating sustainability and planning. Within this framework planners are challenged to creatively consider planning practice and thought against a background...

  4. Use of the functional imaging modalities, f MRI r CBV and PET FDG, alters radiation therapy 3-D treatment planning in patients with malignant gliomas

    International Nuclear Information System (INIS)

    Fitzek, M.; Pardo, F.S.; Busierre, M.; Lev, M.; Fischman, A.; Denny, N.; Hanser, B.; Rosen, B.R.; Smith, A.; Aronen, H.

    1995-01-01

    Background: Malignant gliomas present one of the most difficult challenges to definitive radiation therapy, not only with respect to local control, but also with respect to clinical functional status. While tumor target volume definitions for malignant gliomas are often based on CT and conventional MRI, the functional imaging modalities, echo planar r CBV (regional cerebral blood volume mapping) and 18F-fluorodeoxyglucose PET, are more sensitive modalities for the detection of neovascularization, perhaps one of the earliest signs of glial tumor initiation and progression. Methods: In order to address the clinical utility of functional imaging in radiation therapy 3-D treatment planning, we compared tumor target volume definitions and overall dosimetry in patients either undergoing co-registration of conventional Gadolinium-enhanced MRI, or co-registration of functional imaging modalities, prior to radiation therapy 3-D treatment planning. Fourteen patients were planned using 3-D radiation therapy treatment planning, either with or without inclusion of data on functional imaging. All patients received proton beam, as well as megavoltage x-ray radiation therapy, with the ratio of photon:proton optimized to the individual clinical case at hand. Both PET FDG and f MRI scans were obtained postoperatively pre-radiation, during radiation therapy, one month following completion of radiation therapy, and at three month follow-up intervals. Dose volume histograms were constructed in order to assess dose optimization, not only with respect to tumor, but also with respect to normal tissue tolerance (e.g., motor strip, dominant speech area, brainstem, optic nerves). Results: In 5 of 14 cases, functional imaging modalities, as compared with conventional MRI and CT, contributed additional information that was useful in radiation therapy treatment planning. In general, both fMRI rCBV and PET FDG uptake decreased during the course of radiation therapy. In 1 patient, however, fMRI r

  5. Radiation planning comparison for superficial tissue avoidance in radiotherapy for soft tissue sarcoma of the lower extremity

    International Nuclear Information System (INIS)

    Griffin, Anthony M.; Euler, Colleen I.; Sharpe, Michael B.; Ferguson, Peter C.; Wunder, Jay S.; Bell, Robert S.; Chung, Peter W.M.; Catton, Charles N.; O'Sullivan, Brian

    2007-01-01

    Purpose: Three types of preoperative radiotherapy (RT) plans for extremity soft tissue sarcoma were compared to determine the amount of dose reduction possible to the planned surgical skin flaps required for tumor resection and wound closure, without compromising target coverage. Methods and Materials: Twenty-four untreated patients with large, deep, lower extremity STS treated with preoperative RT and limb salvage surgery had their original conventional treatment plans re-created. The same clinical target volume was used for all three plans. The future surgical skin flaps were created virtually through contouring by the treating surgeon and regarded as an organ at risk. The original, conformal, and intensity-modulated RT (IMRT) plans were created to deliver 50 Gy in 25 fractions to the clinical target volume. Clinical target volume and organ-at-risk dose-volume histograms were calculated and the plans compared for conformality, target coverage, and dose sparing. Results: The mean dose to the planned skin flaps was 42.62 Gy (range, 30.24-48.65 Gy) for the original plans compared with 40.12 Gy (range, 24.24-47.26 Gy) for the conformal plans and 26.71 Gy (range, 22.31-31.91 Gy) for the IMRT plans (p = 0.0008). An average of 86.4% (range, 53.2-97.4%) of the planned skin flaps received ≥30 Gy in the original plans compared with 83.4% (range, 36.2-96.2%) in the conformal plans and only 34.0% (range, 22.5-53.3%) in the IMRT plans (p = 0.0001). IMRT improved target conformality compared with the original and conformal plans (1.27, 2.34, and 1.76, respectively, p = 0.0001). Conclusion: In a retrospective review, preoperative IMRT substantially lowered the dose to the future surgical skin flaps, sparing a greater percentage of this structure's volume without compromising target (tumor) coverage

  6. Estimating traffic volume on Wyoming low volume roads using linear and logistic regression methods

    Directory of Open Access Journals (Sweden)

    Dick Apronti

    2016-12-01

    Full Text Available Traffic volume is an important parameter in most transportation planning applications. Low volume roads make up about 69% of road miles in the United States. Estimating traffic on the low volume roads is a cost-effective alternative to taking traffic counts. This is because traditional traffic counts are expensive and impractical for low priority roads. The purpose of this paper is to present the development of two alternative means of cost-effectively estimating traffic volumes for low volume roads in Wyoming and to make recommendations for their implementation. The study methodology involves reviewing existing studies, identifying data sources, and carrying out the model development. The utility of the models developed were then verified by comparing actual traffic volumes to those predicted by the model. The study resulted in two regression models that are inexpensive and easy to implement. The first regression model was a linear regression model that utilized pavement type, access to highways, predominant land use types, and population to estimate traffic volume. In verifying the model, an R2 value of 0.64 and a root mean square error of 73.4% were obtained. The second model was a logistic regression model that identified the level of traffic on roads using five thresholds or levels. The logistic regression model was verified by estimating traffic volume thresholds and determining the percentage of roads that were accurately classified as belonging to the given thresholds. For the five thresholds, the percentage of roads classified correctly ranged from 79% to 88%. In conclusion, the verification of the models indicated both model types to be useful for accurate and cost-effective estimation of traffic volumes for low volume Wyoming roads. The models developed were recommended for use in traffic volume estimations for low volume roads in pavement management and environmental impact assessment studies.

  7. Solid waste 30-year volume summary

    International Nuclear Information System (INIS)

    Valero, O.J.; Armacost, L.L.; DeForest, T.J.; Templeton, K.J.; Williams, N.C.

    1994-06-01

    A 30-year forecast of the solid waste volumes to be generated or received at the US Department of Energy Hanford Site is described in this report. The volumes described are low-level mixed waste (LLMW) and transuranic/transuranic mixed (TRU/TRUM) waste that will require treatment, storage, and disposal at Hanford's Solid Waste Operations Complex (SWOC) during the 30-year period from FY 1994 through FY 2023. The data used to complete this document were collected from onsite and offsite waste generators who currently, or are planning to, ship solid wastes to the Hanford Site. An analysis of the data suggests that over 300,000 m 3 of LLMW and TRU/TRUM waste will be managed at Hanford's SWOC over the next 30 years. An extensive effort was made this year to collect this information. The 1993 solid waste forecast was used as a starting point, which identified approximately 100,000 m 3 of LLMW and TRU/TRUM waste to be sent to the SWOC. After analyzing the forecast waste volume, it was determined that additional waste was expected from the tank waste remediation system (TWRS), onsite decontamination and decommissioning (D ampersand D) activities, and onsite remedial action (RA) activities. Data presented in this report establish a starting point for solid waste management planning. It is recognized that forecast estimates will vary (typically increasing) as facility planning and missions continue to change and become better defined, but the information presented still provides useful insight into Hanford's future solid waste management requirements

  8. SU-F-T-337: Accounting for Patient Motion During Volumetric Modulated Ac Therapy (VMAT) Planning for Post Mastectomy Chest Wall Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, M; Fontenot, J [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States); Heins, D [Louisiana State University, Baton Rouge, LA (United States)

    2016-06-15

    Purpose: To evaluate two dose optimization strategies for maintaining target volume coverage of inversely-planned post mastectomy radiotherapy (PMRT) plans during patient motion. Methods: Five patients previously treated with VMAT for PMRT at our clinical were randomly selected for this study. For each patient, two plan optimization strategies were compared. Plan 1 was optimized to a volume that included the physician’s planning target volume (PTV) plus an expansion up to 0.3 cm from the bolus surface. Plan 2 was optimized to the PTV plus an expansion up to 0.3 cm from the patient surface (i.e., not extending into the bolus). VMAT plans were optimized to deliver 95% of the prescription to 95% of the PTV while sparing organs at risk based on clinical dose limits. PTV coverage was then evaluated following the simulation of patient shifts by 1.0 cm in the anterior and posterior directions using the treatment planning system. Results: Posterior patient shifts produced a difference in D95% of around 11% in both planning approaches from the non-shifted dose distributions. Coverage of the medial and lateral borders of the evaluation volume was reduced in both the posteriorly shifted plans (Plan 1 and Plan 2). Anterior patient shifts affected Plan 2 more than Plan 1 with a difference in D95% of 1% for Plan 1 versus 6% for Plan 2 from the non-shifted dose distributions. The least variation in PTV dose homogeneity for both shifts was obtained with Plan 1. However, all posteriorly shifted plans failed to deliver 95% of the prescription to 95% of the PTV. Whereas, only a few anteriorly shifted plans failed this criteria. Conclusion: The results of this study suggest both planning volume methods are sensitive to patient motion, but that a PTV extended into a bolus volume is slightly more robust for anterior patient shifts.

  9. SU-F-T-337: Accounting for Patient Motion During Volumetric Modulated Ac Therapy (VMAT) Planning for Post Mastectomy Chest Wall Irradiation

    International Nuclear Information System (INIS)

    Hernandez, M; Fontenot, J; Heins, D

    2016-01-01

    Purpose: To evaluate two dose optimization strategies for maintaining target volume coverage of inversely-planned post mastectomy radiotherapy (PMRT) plans during patient motion. Methods: Five patients previously treated with VMAT for PMRT at our clinical were randomly selected for this study. For each patient, two plan optimization strategies were compared. Plan 1 was optimized to a volume that included the physician’s planning target volume (PTV) plus an expansion up to 0.3 cm from the bolus surface. Plan 2 was optimized to the PTV plus an expansion up to 0.3 cm from the patient surface (i.e., not extending into the bolus). VMAT plans were optimized to deliver 95% of the prescription to 95% of the PTV while sparing organs at risk based on clinical dose limits. PTV coverage was then evaluated following the simulation of patient shifts by 1.0 cm in the anterior and posterior directions using the treatment planning system. Results: Posterior patient shifts produced a difference in D95% of around 11% in both planning approaches from the non-shifted dose distributions. Coverage of the medial and lateral borders of the evaluation volume was reduced in both the posteriorly shifted plans (Plan 1 and Plan 2). Anterior patient shifts affected Plan 2 more than Plan 1 with a difference in D95% of 1% for Plan 1 versus 6% for Plan 2 from the non-shifted dose distributions. The least variation in PTV dose homogeneity for both shifts was obtained with Plan 1. However, all posteriorly shifted plans failed to deliver 95% of the prescription to 95% of the PTV. Whereas, only a few anteriorly shifted plans failed this criteria. Conclusion: The results of this study suggest both planning volume methods are sensitive to patient motion, but that a PTV extended into a bolus volume is slightly more robust for anterior patient shifts.

  10. Dosimetric benefit of adaptive re-planning in pancreatic cancer stereotactic body radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yongbao [Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing (China); Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); Hoisak, Jeremy D.P.; Li, Nan; Jiang, Carrie [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Tian, Zhen [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); Gautier, Quentin; Zarepisheh, Masoud [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Wu, Zhaoxia; Liu, Yaqiang [Department of Engineering Physics, Tsinghua University, Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing (China); Jia, Xun [Center for Advanced Radiotherapy Technologies University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); and others

    2015-01-01

    Stereotactic body radiotherapy (SBRT) shows promise in unresectable pancreatic cancer, though this treatment modality has high rates of normal tissue toxicity. This study explores the dosimetric utility of daily adaptive re-planning with pancreas SBRT. We used a previously developed supercomputing online re-planning environment (SCORE) to re-plan 10 patients with pancreas SBRT. Tumor and normal tissue contours were deformed from treatment planning computed tomographies (CTs) and transferred to daily cone-beam CT (CBCT) scans before re-optimizing each daily treatment plan. We compared the intended radiation dose, the actual radiation dose, and the optimized radiation dose for the pancreas tumor planning target volume (PTV) and the duodenum. Treatment re-optimization improved coverage of the PTV and reduced dose to the duodenum. Within the PTV, the actual hot spot (volume receiving 110% of the prescription dose) decreased from 4.5% to 0.5% after daily adaptive re-planning. Within the duodenum, the volume receiving the prescription dose decreased from 0.9% to 0.3% after re-planning. It is noteworthy that variation in the amount of air within a patient's stomach substantially changed dose to the PTV. Adaptive re-planning with pancreas SBRT has the ability to improve dose to the tumor and decrease dose to the nearby duodenum, thereby reducing the risk of toxicity.

  11. Knowledge-based prediction of plan quality metrics in intracranial stereotactic radiosurgery

    Energy Technology Data Exchange (ETDEWEB)

    Shiraishi, Satomi; Moore, Kevin L., E-mail: kevinmoore@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California 92093 (United States); Tan, Jun [Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas 75490 (United States); Olsen, Lindsey A. [Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States)

    2015-02-15

    Purpose: The objective of this work was to develop a comprehensive knowledge-based methodology for predicting achievable dose–volume histograms (DVHs) and highly precise DVH-based quality metrics (QMs) in stereotactic radiosurgery/radiotherapy (SRS/SRT) plans. Accurate QM estimation can identify suboptimal treatment plans and provide target optimization objectives to standardize and improve treatment planning. Methods: Correlating observed dose as it relates to the geometric relationship of organs-at-risk (OARs) to planning target volumes (PTVs) yields mathematical models to predict achievable DVHs. In SRS, DVH-based QMs such as brain V{sub 10Gy} (volume receiving 10 Gy or more), gradient measure (GM), and conformity index (CI) are used to evaluate plan quality. This study encompasses 223 linear accelerator-based SRS/SRT treatment plans (SRS plans) using volumetric-modulated arc therapy (VMAT), representing 95% of the institution’s VMAT radiosurgery load from the past four and a half years. Unfiltered models that use all available plans for the model training were built for each category with a stratification scheme based on target and OAR characteristics determined emergently through initial modeling process. Model predictive accuracy is measured by the mean and standard deviation of the difference between clinical and predicted QMs, δQM = QM{sub clin} − QM{sub pred}, and a coefficient of determination, R{sup 2}. For categories with a large number of plans, refined models are constructed by automatic elimination of suspected suboptimal plans from the training set. Using the refined model as a presumed achievable standard, potentially suboptimal plans are identified. Predictions of QM improvement are validated via standardized replanning of 20 suspected suboptimal plans based on dosimetric predictions. The significance of the QM improvement is evaluated using the Wilcoxon signed rank test. Results: The most accurate predictions are obtained when plans are

  12. Knowledge-based prediction of plan quality metrics in intracranial stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Shiraishi, Satomi; Moore, Kevin L.; Tan, Jun; Olsen, Lindsey A.

    2015-01-01

    Purpose: The objective of this work was to develop a comprehensive knowledge-based methodology for predicting achievable dose–volume histograms (DVHs) and highly precise DVH-based quality metrics (QMs) in stereotactic radiosurgery/radiotherapy (SRS/SRT) plans. Accurate QM estimation can identify suboptimal treatment plans and provide target optimization objectives to standardize and improve treatment planning. Methods: Correlating observed dose as it relates to the geometric relationship of organs-at-risk (OARs) to planning target volumes (PTVs) yields mathematical models to predict achievable DVHs. In SRS, DVH-based QMs such as brain V 10Gy (volume receiving 10 Gy or more), gradient measure (GM), and conformity index (CI) are used to evaluate plan quality. This study encompasses 223 linear accelerator-based SRS/SRT treatment plans (SRS plans) using volumetric-modulated arc therapy (VMAT), representing 95% of the institution’s VMAT radiosurgery load from the past four and a half years. Unfiltered models that use all available plans for the model training were built for each category with a stratification scheme based on target and OAR characteristics determined emergently through initial modeling process. Model predictive accuracy is measured by the mean and standard deviation of the difference between clinical and predicted QMs, δQM = QM clin − QM pred , and a coefficient of determination, R 2 . For categories with a large number of plans, refined models are constructed by automatic elimination of suspected suboptimal plans from the training set. Using the refined model as a presumed achievable standard, potentially suboptimal plans are identified. Predictions of QM improvement are validated via standardized replanning of 20 suspected suboptimal plans based on dosimetric predictions. The significance of the QM improvement is evaluated using the Wilcoxon signed rank test. Results: The most accurate predictions are obtained when plans are stratified based on

  13. SU-F-T-611: Critical Analysis and Efficacy of Linac Based (Beam Modulator) and Cyberknife Treatment Plans for Acoustic Neuroma/schwannoma

    International Nuclear Information System (INIS)

    KP, Karrthick; Kataria, T; Thiyagarajan, R; Selvan, T; Abhishek, A

    2016-01-01

    Purpose: To study the critical analysis and efficacy of Linac and Cyberknife (CK) treatment plans for acoustic neuroma/schwannoma. Methods: Twelve of acoustic neuroma/schwannoma patients were taken for these study that. Treatment plans were generated in Multiplan treatment planning system (TPS) for CK using 5,7.5 and 10mm diameter collimators. Target volumes were in the range of 0.280 cc to 9.256 cc. Prescription dose (Rx) ranges from 1150cGy to 1950cGy delivered over 1 to 3 Fractions. For same patients stereotactic Volumetric modulated arc plans were generated using Elekta Linac with MLC thickness of 4mm in Monaco TPS. Appropriate calculation algorithms and grid size were used with same Rx and organ at risk (OAR) constrains for both Linac and CK plans. Treatment plans were developed to achieve at least 95% of the target volume to receive the Rx. The dosimetric indices such as conformity index (CI), coverage, OAR dose and volume receiving 50% of Rx (V50%) were used to evaluate the plans. Results: Target volumes ranges from 0.280 cc to 3.5cc shows the CI of 1.16±0.109 and 1.53±0.360 for cyberknife and Linac plans respectively. For small volume targets, the OARs were well spared in CK plans. There are no significant differences in CI and OAR doses were observed between CK and Linac plans that have the target volume >3.5 cc. Perhaps the V50% were lesser in CK plans, and found to be 12.8± 8.4 and 22.8 ± 15.0 for CK and Linac respectively. Conclusion: The analysis shows the importance of collimator size for small volume targets. The target volumes >3.5 cc can be treated in Linac as comparable with CK. For targets <3.5cc CK plans showed superior plan quality with better CI and OAR sparing than the Linac based plans. Further studies may require evaluating the clinical advantage of CK robotic system.

  14. System analysis of shallow land burial. Volume 2: technical background. Technical report, 26 November 1979-23 January 1981

    International Nuclear Information System (INIS)

    Lester, D.; Buckley, D.; Donelson, S.; Dura, V.; Hecht, M.

    1981-03-01

    This is volume two of a three volume set detailing the activities and results of the System Analysis of Shallow Land Burial Project. Activities under four project tasks are described: Task 1 - Identify Potential Radionuclide Release Pathways, Task 2 - Systems Model for Shallow Land Burial of Low-Level Waste, Task 3 - Sensitivity and Optimization Study and Task 4 - Reference Facility Dose Assessment

  15. Restricted Field IMRT Dramatically Enhances IMRT Planning for Mesothelioma

    International Nuclear Information System (INIS)

    Allen, Aaron M.; Schofield, Deborah; Hacker, Fred; Court, Laurence E.; Czerminska, Maria M.S.

    2007-01-01

    Purpose: To improve the target coverage and normal tissue sparing of intensity-modulated radiotherapy (IMRT) for mesothelioma after extrapleural pneumonectomy. Methods and Materials: Thirteen plans from patients previously treated with IMRT for mesothelioma were replanned using a restricted field technique. This technique was novel in two ways. It limited the entrance beams to 200 o around the target and three to four beams per case had their field apertures restricted down to the level of the heart or liver to further limit the contralateral lung dose. New constraints were added that included a mean lung dose of <9.5 Gy and volume receiving ≥5 Gy of <55%. Results: In all cases, the planning target volume coverage was excellent, with an average of 97% coverage of the planning target volume by the target dose. No change was seen in the target coverage with the new technique. The heart, kidneys, and esophagus were all kept under tolerance in all cases. The average mean lung dose, volume receiving ≥20 Gy, and volume receiving ≥5 Gy with the new technique was 6.6 Gy, 3.0%, and 50.8%, respectively, compared with 13.8 Gy, 15%, and 90% with the previous technique (p < 0.0001 for all three comparisons). The maximal value for any case in the cohort was 8.0 Gy, 7.3%, and 57.5% for the mean lung dose, volume receiving ≥20 Gy, and volume receiving ≥5 Gy, respectively. Conclusion: Restricted field IMRT provides an improved method to deliver IMRT to a complex target after extrapleural pneumonectomy. An upcoming Phase I trial will provide validation of these results

  16. Provider volume and outcomes for oncological procedures.

    LENUS (Irish Health Repository)

    Killeen, S D

    2012-02-03

    BACKGROUND: Oncological procedures may have better outcomes if performed by high-volume providers. METHODS: A review of the English language literature incorporating searches of the Medline, Embase and Cochrane collaboration databases was performed. Studies were included if they involved a patient cohort from 1984 onwards, were community or population based, and assessed health outcome as a dependent variable and volume as an independent variable. The studies were also scored quantifiably to assess generalizability with respect to any observed volume-outcome relationship and analysed according to organ system; numbers needed to treat were estimated where possible. RESULTS: Sixty-eight relevant studies were identified and a total of 41 were included, of which 13 were based on clinical data. All showed either an inverse relationship, of variable magnitude, between provider volume and mortality, or no volume-outcome effect. All but two clinical reports revealed a statistically significant positive relationship between volume and outcome; none demonstrated the opposite. CONCLUSION: High-volume providers have a significantly better outcome for complex cancer surgery, specifically for pancreatectomy, oesphagectomy, gastrectomy and rectal resection.

  17. A planning comparison of 7 irradiation options allowed in RTOG 1005 for early-stage breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Guang-Pei, E-mail: gpchen@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Liu, Feng [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); White, Julia [Department of Radiation Oncology, The Ohio State University, Columbus, OH (United States); Vicini, Frank A. [Michigan Healthcare Professionals/21st Century Oncology, Farmington Hills, MI (United States); Freedman, Gary M. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Arthur, Douglas W. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA (United States); Li, X. Allen [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2015-04-01

    This study compared the 7 treatment plan options in achieving the dose-volume criteria required by the Radiation Therapy Oncology Group (RTOG) 1005 protocol. Dosimetry plans were generated for 15 representative patients with early-stage breast cancer (ESBC) based on the protocol-required dose-volume criteria for each of the following 7 treatment options: 3D conformal radiotherapy (3DCRT), whole-breast irradiation (WBI) plus 3DCRT lumpectomy boost, 3DCRT WBI plus electron boost, 3DCRT WBI plus intensity-modulated radiation therapy (IMRT) boost, IMRT WBI plus 3DCRT boost, IMRT WBI plus electron boost, IMRT WBI plus IMRT boost, and simultaneous integrated boost (SIB) with IMRT. A variety of dose-volume parameters, including target dose conformity and uniformity and normal tissue sparing, were compared for these plans. For the patients studied, all plans met the required acceptable dose-volume criteria, with most of them meeting the ideal criteria. When averaged over patients, most dose-volume goals for all plan options can be achieved with a positive gap of at least a few tenths of standard deviations. The plans for all 7 options are generally comparable. The dose-volume goals required by the protocol can in general be easily achieved. IMRT WBI provides better whole-breast dose uniformity than 3DCRT WBI does, but it causes no significant difference for the dose conformity. All plan options are comparable for lumpectomy dose uniformity and conformity. Patient anatomy is always an important factor when whole-breast dose uniformity and conformity and lumpectomy dose conformity are considered.

  18. Reduction in cardiac volume during chemoradiotherapy for patients with esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lutkenhaus, Lotte J., E-mail: l.j.lutkenhaus@amc.uva.nl; Kamphuis, Martijn; Wieringen, Niek van; Hulshof, Maarten C.C.M.; Bel, Arjan

    2013-11-15

    We investigated the change in cardiac volume over the course of chemoradiotherapy in 26 patients treated for esophageal cancer, using cone beam CT imaging. The cardiac volume reduced significantly, with a median reduction of 8%. A significant relationship with planned cardiac dose was not found.

  19. Reduction in cardiac volume during chemoradiotherapy for patients with esophageal cancer

    International Nuclear Information System (INIS)

    Lutkenhaus, Lotte J.; Kamphuis, Martijn; Wieringen, Niek van; Hulshof, Maarten C.C.M.; Bel, Arjan

    2013-01-01

    We investigated the change in cardiac volume over the course of chemoradiotherapy in 26 patients treated for esophageal cancer, using cone beam CT imaging. The cardiac volume reduced significantly, with a median reduction of 8%. A significant relationship with planned cardiac dose was not found

  20. Monte Carlo simulations for the optimisation of low-background Ge detector designs

    Energy Technology Data Exchange (ETDEWEB)

    Hakenmueller, Janina; Heusser, Gerd; Maneschg, Werner; Schreiner, Jochen; Simgen, Hardy; Stolzenburg, Dominik; Strecker, Herbert; Weber, Marc; Westernmann, Jonas [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Laubenstein, Matthias [Laboratori Nazionali del Gran Sasso, Via G. Acitelli 22, 67100 Assergi L' Aquila (Italy)

    2015-07-01

    Monte Carlo simulations for the low-background Ge spectrometer Giove at the underground laboratory of MPI-K, Heidelberg, are presented. In order to reduce the cosmogenic background at the present shallow depth (15 m w.e.) the shielding of the spectrometer includes an active muon veto and a passive shielding (lead and borated PE layers). The achieved background suppression is comparable to Ge spectrometers operated in much greater depth. The geometry of the detector and the shielding were implemented using the Geant4-based toolkit MaGe. The simulations were successfully optimised by determining the correct diode position and active volume. With the help of the validated Monte Carlo simulation the contribution of the single components to the overall background can be examined. This includes a comparison between simulated results and measurements with different fillings of the sample chamber. Having reproduced the measured detector background in the simulation provides the possibility to improve the background by reverse engineering of the passive and active shield layers in the simulation.