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Failing T, Hensley FW, Keil B, Zink K. Investigations on the beam quality correction factor for ionization chambers in high-energy brachytherapy dosimetry. Phys Med Biol 2024; 69:165002. [PMID: 39009012 DOI: 10.1088/1361-6560/ad638b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 07/15/2024] [Indexed: 07/17/2024]
Abstract
Objective. To enhance the investigations on MC calculated beam quality correction factors of thimble ionization chambers from high-energy brachytherapy sources and to develop reliable reference conditions in source and detector setups in water.Approach. The response of five different ionization chambers from PTW-Freiburg and Standard Imaging was investigated for irradiation by a high dose rate Ir-192 Flexisource in water. For a setup in a Beamscan water phantom, Monte Carlo simulations were performed to calculate correction factors for the chamber readings. After exact positioning of source and detector the absorbed dose rate at the TG-43 reference point at one centimeter nominal distance from the source was measured using these factors and compared to the specification of the calibration certificate. The Monte Carlo calculations were performed using the restricted cema formalism to gain further insight into the chamber response. Calculations were performed for the sensitive volume of the chambers, determined by the methods currently used in investigations of dosimetry in magnetic fields.Main results. Measured dose rates and values from the calibration certificate agreed within the combined uncertainty (k= 2) for all chambers except for one case in which the full air cavity was simulated. The chambers showed a distinct directional dependence. With the restricted cema formalism calculations it was possible to examine volume averaging and energy dependence of the perturbation factors contributing to the beam quality correction factor also differential in energy.Significance. This work determined beam quality correction factors to measure the absorbed dose rate from a brachytherapy source in terms of absorbed dose to water for a variety of ionization chambers. For the accurate dosimetry of brachytherapy sources with ionization chambers it is advisable to use correction factors based on the sensitive volume of the chambers and to take account for the directional dependence of chamber response.
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Affiliation(s)
- T Failing
- Institute of Medical Physics and Radiation Protection (IMPS), University of Applied Sciences, Gießen, Germany
| | - F W Hensley
- Department for Radiotherapy and Radiooncology, University Medical Center Heidelberg, Heidelberg, Germany
| | - B Keil
- Institute of Medical Physics and Radiation Protection (IMPS), University of Applied Sciences, Gießen, Germany
- Department for Diagnostic and Interventional Radiology, Philipps-University Marburg, Marburg, Germany
- LOEWE Research Cluster for Advanced Medical Physics in Imaging and Therapy (ADMIT), TH Mittelhessen University of Applied Sciences, Giessen, Germany
| | - K Zink
- Institute of Medical Physics and Radiation Protection (IMPS), University of Applied Sciences, Gießen, Germany
- LOEWE Research Cluster for Advanced Medical Physics in Imaging and Therapy (ADMIT), TH Mittelhessen University of Applied Sciences, Giessen, Germany
- Department for Radiotherapy and Radiooncology, University Medical Center Giessen-Marburg, Marburg, Germany
- Marburg Iontherapy Center (MIT), Marburg, Germany
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Kalinowski J, Enger SA. RapidBrachyTG43: A Geant4-based TG-43 parameter and dose calculation module for brachytherapy dosimetry. Med Phys 2024; 51:3746-3757. [PMID: 38252746 DOI: 10.1002/mp.16948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/05/2023] [Accepted: 12/19/2023] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND The AAPM TG-43U1 formalism remains the clinical standard for dosimetry of low- and high-energy γ $\gamma$ -emitting brachytherapy sources. TG-43U1 and related reports provide consensus datasets of TG-43 parameters derived from various published measured data and Monte Carlo simulations. These data are used to perform standardized and fast dose calculations for brachytherapy treatment planning. PURPOSE Monte Carlo TG-43 dosimetry parameters are commonly derived to characterize novel brachytherapy sources. RapidBrachyTG43 is a module of RapidBrachyMCTPS, a Monte Carlo-based treatment planning system, designed to automate this process, requiring minimal user input to prepare Geant4-based Monte Carlo simulations for a source. RapidBrachyTG43 may also perform a TG-43 dose to water-in-water calculation for a plan, substantially accelerating the same calculation performed using RapidBrachyMCTPS's Monte Carlo dose calculation engine. METHODS TG-43 parametersS K / A $S_K/A$ , Λ $\Lambda$ ,g L ( r ) $g_L(r)$ , andF ( r , θ ) $F(r,\theta)$ were calculated using three commercial source models, one each of125 $^{125}$ I,192 $^{192}$ Ir, and60 $^{60}$ Co, and were benchmarked to published data. TG-43 dose to water was calculated for a clinical breast brachytherapy plan and was compared to a Monte Carlo dose calculation with all patient tissues, air, and catheters set to water. RESULTS TG-43 parameters for the three simulated sources agreed with benchmark datasets within tolerances specified by the High Energy Brachytherapy Dosimetry working group. A gamma index comparison between the TG-43 and Monte Carlo dose-to-water calculations with a dose difference and difference to agreement criterion of 1%/1 mm yielded a 98.9% pass rate, with all relevant dose volume histogram metrics for the plan agreeing within 1%. Performing a TG-43-based dose calculation provided an acceleration of dose-to-water calculation by a factor of 165. CONCLUSIONS Determination of TG-43 parameter data for novel brachytherapy sources may now be facilitated by RapidBrachyMCTPS. These parameter datasets and existing consensus or published datasets may also be used to determine the TG-43 dose for a plan in RapidBrachyMCTPS.
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Affiliation(s)
- Jonathan Kalinowski
- Medical Physics Unit, Faculty of Medicine, Department of Oncology, McGill University, Montréal, Québec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
| | - Shirin A Enger
- Medical Physics Unit, Faculty of Medicine, Department of Oncology, McGill University, Montréal, Québec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
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Oliver S, Giménez-Alventosa V, Berumen F, Gimenez V, Beaulieu L, Ballester F, Vijande J. Benchmark of the PenRed Monte Carlo framework for HDR brachytherapy. Z Med Phys 2023; 33:511-528. [PMID: 36509574 PMCID: PMC10751717 DOI: 10.1016/j.zemedi.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/28/2022] [Accepted: 11/02/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE The purpose of this study is to validate the PenRed Monte Carlo framework for clinical applications in brachytherapy. PenRed is a C++ version of Penelope Monte Carlo code with additional tallies and utilities. METHODS AND MATERIALS Six benchmarking scenarios are explored to validate the use of PenRed and its improved bachytherapy-oriented capabilities for HDR brachytherapy. A new tally allowing the evaluation of collisional kerma for any material using the track length kerma estimator and the possibility to obtain the seed positions, weights and directions processing directly the DICOM file are now implemented in the PenRed distribution. The four non-clinical test cases developed by the Joint AAPM-ESTRO-ABG-ABS WG-DCAB were evaluated by comparing local and global absorbed dose differences with respect to established reference datasets. A prostate and a palliative lung cases, were also studied. For them, absorbed dose ratios, global absorbed dose differences, and cumulative dose-volume histograms were obtained and discussed. RESULTS The air-kerma strength and the dose rate constant corresponding to the two sources agree with the reference datatests within 0.3% (Sk) and 0.1% (Λ). With respect to the first three WG-DCAB test cases, more than 99.8% of the voxels present local (global) differences within ±1%(±0.1%) of the reference datasets. For test Case 4 reference dataset, more than 94.9%(97.5%) of voxels show an agreement within ±1%(±0.1%), better than similar benchmarking calculations in the literature. The track length kerma estimator scorer implemented increases the numerical efficiency of brachytherapy calculations two orders of magnitude, while the specific brachytherapy source allows the user to avoid the use of error-prone intermediate steps to translate the DICOM information into the simulation. In both clinical cases, only minor absorbed dose differences arise in the low-dose isodoses. 99.8% and 100% of the voxels have a global absorbed dose difference ratio within ±0.2% for the prostate and lung cases, respectively. The role played by the different segmentation and composition material in the bone structures was discussed, obtaining negligible absorbed dose differences. Dose-volume histograms were in agreement with the reference data. CONCLUSIONS PenRed incorporates new tallies and utilities and has been validated for its use for detailed and precise high-dose-rate brachytherapy simulations.
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Affiliation(s)
- Sandra Oliver
- Instituto de Seguridad Industrial, Radiofísica y Medioambiental (ISIRYM), Universitat Politècnica de València, Camí de Vera s/n, 46022 València, Spain.
| | - Vicent Giménez-Alventosa
- Escuela de Ciencias, Ingeniería y Diseño, Universidad Europea de Valencia, Paseo de la Alameda 7, 46010 València, Spain; Instituto de Instrumentación para Imagen Molecular (I3M), Centro mixto CSIC - Universitat Politècnica de València, Camí de Vera s/n, 46022 València, Spain
| | - Francisco Berumen
- Département de Radio-Oncologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, QC, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, QC, Canada
| | - Vicente Gimenez
- Departament de Física Teórica and IFIC, Universitat de València-CSIC, Dr. Moliner, 50, 46100 Burjassot, València, Spain
| | - Luc Beaulieu
- Département de Radio-Oncologie et Axe oncologie du Centre de recherche du CHU de Québec, CHU de Québec, Québec, QC, Canada; Département de Physique, de Génie Physique et d'Optique et Centre de Recherche sur le Cancer, Université Laval, Québec, QC, Canada
| | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear. IRIMED, IIS-La Fe-Universitat de Valencia, 46100 Burjassot, Spain
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear. IRIMED, IIS-La Fe-Universitat de Valencia, 46100 Burjassot, Spain; Instituto de Física Corpuscular, IFIC (UV-CSIC), 46100 Burjassot, Spain
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Wu J, Kang S, Wang P, Li J, Wang X. Monte Carlo dosimetry of the 60Co sources of a new GZP3 HDR afterloading system. Radiat Oncol 2023; 18:13. [PMID: 36670476 PMCID: PMC9854037 DOI: 10.1186/s13014-023-02207-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 01/14/2023] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The purpose of this work was to obtain the dosimetric parameters of the new GZP3 60Co high-dose-rate afterloading system launched by the Nuclear Power Institute of China, which is comprised of two different 60Co sources. METHODS The Monte Carlo software Geant4 and EGSnrc were employed to derive accurate calculations of the dosimetric parameters of the new GZP3 60Co brachytherapy source in the range of 0-10 cm, following the formalism proposed by American Association of Physicists in Medicine reports TG43 and TG43U1. Results of the two Monte Carlo codes were compared to verify the accuracy of the data. The source was located in the center of a 30-cm-radius theoretical sphere water phantom. RESULTS For channels 1 and 2 of the new GZP3 60Co afterloading system, the results of the dose-rate constant (Λ) were 1.115 cGy h-1 U-1 and 1.112 cGy h-1 U-1, and for channel 3 they were 1.116 cGy h-1 U-1 and 1.113 cGy h-1 U-1 according to the Geant4 and EGSnrc, respectively. The radial dose function in the range of 0.25-10.0 cm in a longitudinal direction was calculated, and the fitting formulas for the function were obtained. The polynomial function for the radial dose function and the anisotropy function (1D and 2D) with a [Formula: see text] of 0°-175° and an r of 0.5-10.0 cm were obtained. The curves of the radial function and the anisotropy function fitted well compared with the two Monte Carlo software. CONCLUSION These dosimetric data sets can be used as input data for TPS calculations and quality control for the new GZP3 60Co afterloading system.
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Affiliation(s)
- Junxiang Wu
- grid.54549.390000 0004 0369 4060Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Radiation Oncology Key Laboratory of Sichuan Province, Chengdu, 610041 China
| | - Shengwei Kang
- grid.54549.390000 0004 0369 4060Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Radiation Oncology Key Laboratory of Sichuan Province, Chengdu, 610041 China
| | - Pei Wang
- grid.54549.390000 0004 0369 4060Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Radiation Oncology Key Laboratory of Sichuan Province, Chengdu, 610041 China
| | - Jie Li
- grid.54549.390000 0004 0369 4060Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Radiation Oncology Key Laboratory of Sichuan Province, Chengdu, 610041 China
| | - Xianliang Wang
- grid.54549.390000 0004 0369 4060Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Radiation Oncology Key Laboratory of Sichuan Province, Chengdu, 610041 China
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GEC-ESTRO ACROP recommendations on calibration and traceability of HE HDR-PDR photon-emitting brachytherapy sources at the hospital level. Radiother Oncol 2022; 176:108-117. [PMID: 36167195 DOI: 10.1016/j.radonc.2022.09.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 09/14/2022] [Indexed: 12/14/2022]
Abstract
The vast majority of radiotherapy departments in Europe using brachytherapy (BT) perform temporary implants of high- or pulsed-dose rate (HDR-PDR) sources with photon energies higher than 50 keV. Such techniques are successfully applied to diverse pathologies and clinical scenarios. These recommendations are the result of Working Package 21 (WP-21) initiated within the BRAchytherapy PHYsics Quality Assurance System (BRAPHYQS) GEC-ESTRO working group with a focus on HDR-PDR source calibration. They provide guidance on the calibration of such sources, including practical aspects and issues not specifically accounted for in well-accepted societal recommendations, complementing the BRAPHYQS WP-18 Report dedicated to low energy BT photon emitting sources (seeds). The aim of this report is to provide a European-wide standard in HDR-PDR BT source calibration at the hospital level to maintain high quality patient treatments.
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Fulkerson RK, Perez‐Calatayud J, Ballester F, Buzurovic I, Kim Y, Niatsetski Y, Ouhib Z, Pai S, Rivard MJ, Rong Y, Siebert F, Thomadsen BR, Weigand F. Surface brachytherapy: Joint report of the AAPM and the GEC‐ESTRO Task Group No. 253. Med Phys 2020; 47:e951-e987. [DOI: 10.1002/mp.14436] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 02/06/2023] Open
Affiliation(s)
- Regina K. Fulkerson
- Department of Medical Physics University of Wisconsin–Madison Madison WI53705 USA
| | - Jose Perez‐Calatayud
- Radiotherapy Department La Fe Hospital Valencia46026 Spain
- Radiotherapy Department Clinica Benidorm Alicante03501 Spain
| | - Facundo Ballester
- Department of Atomic, Molecular and Nuclear Physics University of Valencia Burjassot46100 Spain
| | - Ivan Buzurovic
- Dana‐Farber/Brigham and Women’s Cancer Center Harvard Medical School Boston MA02115 USA
| | - Yongbok Kim
- Department of Radiation Oncology University of Arizona Tucson AZ85724 USA
| | - Yury Niatsetski
- R&D Elekta Brachytherapy Waardgelder 1 Veenendaal3903 DD Netherlands
| | - Zoubir Ouhib
- Radiation Oncology Department Lynn Regional Cancer CenterBoca Raton Community Hospital Boca Raton FL33486 USA
| | - Sujatha Pai
- Radion Inc. 20380 Town Center Lane, Suite 135 Cupertino CA95014 USA
| | - Mark J. Rivard
- Department of Radiation Oncology Alpert Medical School Brown University Providence RI02903 USA
| | - Yi Rong
- Department of Radiation Oncology University of California Davis Comprehensive Cancer Center Sacramento CA95817 USA
| | - Frank‐André Siebert
- UK S‐HCampus Kiel, Klinik fur Strahlentherapie (Radioonkologie) Arnold‐Heller‐Str. 3Haus 50 KielD‐24105 Germany
| | - Bruce R. Thomadsen
- Department of Medical Physics University of Wisconsin–Madison Madison WI53705 USA
| | - Frank Weigand
- Carl Zeiss Meditec AG Rudolf‐Eber‐Straße 11 Oberkochen73447 Germany
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Dosimetric investigation of a new high dose rate 192Ir brachytherapy source, IRAsource, by Monte Carlo method. Rep Pract Oncol Radiother 2020; 25:139-145. [PMID: 32051681 DOI: 10.1016/j.rpor.2019.12.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 11/11/2019] [Accepted: 12/23/2019] [Indexed: 11/23/2022] Open
Abstract
Purpose The purpose of the present study was to perform an independent calculation of dosimetric parameters associated with a new 192Ir brachytherapy source model, IRAsource. Materials and methods The parameters of air kerma strength (AKS), dose rate constant (DRC), geometry function (GF), radial dose function (RDF), as well as two-dimensional (2D) anisotropy function (AF) of IRAsource 192Ir source model were calculated in this study. The MC n-particle extended (MCNPX) code was also employed for simulating high dose rate (HDR), IRAsource and 192Ir source; and formalism was used for calculating dosimetry parameters based on task group number 43 updated report (TG-43 U1). Results The results of this study were consistent with the ones reported about the IRAsource source by Sarabiasl et al. The AKS per 1 mCi activity and the DRC values were also equal to 3.65 cGycm2 h-1 mCi-1 and 1.094 cGyh-1U-1; respectively. The comparison of the results of the DRC and the RDF reported by Sarabiasl et al. also validated the 192Ir IRAsource simulation in this study. Moreover, the AFs of IRAsource source model were in a good agreement with those of Sarabiasl et al. at different distances, which could be attributed to identical geometries. Conclusion In line with those reported by Sarabiasl et al., the results of this study confirmed the IRAsource 192Ir source for clinical uses. The calculated dosimetric parameters of the IRAsource source could be utilized in clinical practices as input data sets or for validation of treatment planning system calculations.
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Measurements and Monte Carlo calculation of radial dose and anisotropy functions of BEBIG 60Co high-dose-rate brachytherapy source in a bounded water phantom. J Contemp Brachytherapy 2020; 11:563-572. [PMID: 31969915 PMCID: PMC6964345 DOI: 10.5114/jcb.2019.91224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/03/2019] [Indexed: 11/17/2022] Open
Abstract
Purpose The study compared the experimentally measured radial dose function, g(r), and anisotropy function, F(r,θ), of a BEBIG 60Co (Co0.A86) high-dose-rate (HDR) source in an in-house designed water phantom with egs_brachy Monte Carlo (MC) calculated values. MC results available in the literature were only for unbounded phantoms, and there are no currently published data in the literature for experimental data compared to MC calculations for a bounded phantom. Material and methods egs_brachy is a fast EGSnrc application designed for brachytherapy applications. For unbounded phantom calculation, we considered a cylindrical phantom with a length and diameter of 80 cm and used liquid water. These egs_brachy calculated TG43U1 parameters were compared with the consensus data. Upon its validation, we experimentally measured g(r) and F(r,θ) in a precisely machined 30 × 30 × 30 cm3 water phantom using TLD-100 and EBT2 Gafchromic Film and compared it with the egs_brachy results of the same geometry. Results The TG43U1 dosimetric dataset calculated using egs_brachy was compared with published data for an unbounded phantom, and found to be in good agreement within 2%. From our experimental results of g(r) and F(r,θ), the observed variation with the egs_brachy code calculation is found to be within the acceptable experimental uncertainties of 3%. Conclusions In this study, we validated the egs_brachy calculation of the TG43U1 dataset for the BEBIG 60Co source for an unbounded geometry. Subsequently, we measured the g(r) and F(r,θ) for the same source using an in-house water phantom. In addition, we validated these experimental results with the values calculated using the egs_brachy MC code, with the same geometry and similar phantom material as used in the experimental methods.
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Rivard MJ, Ballester F, Butler WM, DeWerd LA, Ibbott GS, Meigooni AS, Melhus CS, Mitch MG, Nath R, Papagiannis P. Supplement 2 for the 2004 update of the AAPM Task Group No. 43 Report: Joint recommendations by the AAPM and GEC-ESTRO. Med Phys 2017. [DOI: 10.1002/mp.12430] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Mark J. Rivard
- Department of Radiation Oncology; Tufts University School of Medicine; Boston MA 02111 USA
| | - Facundo Ballester
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED); Instituto de Investigación Sanitaria La Fe (IIS-La Fe)-Universitat de Valéncia; Bujassot 46100 Spain
| | - Wayne M. Butler
- Schiffler Cancer Center; Wheeling Hospital; Wheeling WV 26003 USA
| | - Larry A. DeWerd
- Accredited Dosimetry and Calibration Laboratory; University of Wisconsin; Madison WI 53706 USA
| | - Geoffrey S. Ibbott
- Department of Radiation Physics; M.D. Anderson Cancer Center; Houston TX 77030 USA
| | - Ali S. Meigooni
- Comprehensive Cancer Centers of Nevada; Las Vegas NV 89169 USA
| | - Christopher S. Melhus
- Department of Radiation Oncology; Tufts University School of Medicine; Boston MA 02111 USA
| | - Michael G. Mitch
- Radiation Physics Division; National Institute of Standards and Technology; Gaithersburg MD 20899 USA
| | - Ravinder Nath
- Department of Therapeutic Radiology; Yale University School of Medicine; New Haven CT 06510 USA
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Smith BR, Micka JA, Aima M, DeWerd LA, Culberson WS. Air-kerma strength determination of an HDR 192
Ir source including a geometric sensitivity study of the seven-distance method. Med Phys 2017; 44:311-320. [DOI: 10.1002/mp.12017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 11/07/2016] [Accepted: 11/11/2016] [Indexed: 11/06/2022] Open
Affiliation(s)
- Blake R. Smith
- Department of Medical Physics, School of Medicine and Public Health; University of Wisconsin-Madison; Madison Wisconsin 53705 USA
| | - John A. Micka
- Department of Medical Physics, School of Medicine and Public Health; University of Wisconsin-Madison; Madison Wisconsin 53705 USA
| | - Manik Aima
- Department of Medical Physics, School of Medicine and Public Health; University of Wisconsin-Madison; Madison Wisconsin 53705 USA
| | - Larry A. DeWerd
- Department of Medical Physics, School of Medicine and Public Health; University of Wisconsin-Madison; Madison Wisconsin 53705 USA
| | - Wesley S. Culberson
- Department of Medical Physics, School of Medicine and Public Health; University of Wisconsin-Madison; Madison Wisconsin 53705 USA
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Sahoo S, Selvam TP, Sharma SD, Das T, Dey AC, Patil BN, Sastri KVS. Dosimetry of indigenously developed (192)Ir high-dose rate brachytherapy source: An EGSnrc Monte Carlo study. J Med Phys 2016; 41:115-22. [PMID: 27217623 PMCID: PMC4871000 DOI: 10.4103/0971-6203.181639] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Clinical application using high-dose rate (HDR) (192)Ir sources in remote afterloading technique is a well-established treatment method. In this direction, Board of Radiation and Isotope Technology (BRIT) and Bhabha Atomic Research Centre, India, jointly indigenously developed a remote afterloading machine and (192)Ir HDR source. The two-dimensional (2D) dose distribution and dosimetric parameters of the BRIT (192)Ir HDR source are generated using EGSnrc Monte Carlo code system in a 40 cm dia × 40 cm height cylindrical water phantom. The values of air-kerma strength and dose rate constant for BRIT (192)Ir HDR source are 9.894 × 10(-8) ± 0.06% UBq(-1) and 1.112 ± 0.11% cGyh(-1)U(-1), respectively. The values of radial dose function (gL(r)) of this source compare well with the corresponding values of BEBIG, Flexisource, and GammaMed 12i source models. This is because of identical active lengths of the sources (3.5 mm) and the comparable phantom dimensions. A comparison of gL(r) values of BRIT source with microSelectron-v1 show differences about 2% at r = 6 cm and up to 13% at r = 12 cm, which is due to differences in phantom dimensions involved in the calculations. The anisotropy function of BRIT (192)Ir HDR source is comparable with the corresponding values of microSelectron-v1 (classic) HDR source.
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Affiliation(s)
- Sridhar Sahoo
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Navi Mumbai, Maharashtra, India
| | - T Palani Selvam
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Navi Mumbai, Maharashtra, India
| | - S D Sharma
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Navi Mumbai, Maharashtra, India
| | - Trupti Das
- Board of Radiation Isotope and Technology, Vashi, Navi Mumbai, Maharashtra, India
| | - A C Dey
- Board of Radiation Isotope and Technology, Vashi, Navi Mumbai, Maharashtra, India
| | - B N Patil
- Board of Radiation Isotope and Technology, Vashi, Navi Mumbai, Maharashtra, India
| | - K V S Sastri
- Board of Radiation Isotope and Technology, Vashi, Navi Mumbai, Maharashtra, India
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Monte Carlo dosimetry of the IRAsource high dose rate 192Ir brachytherapy source. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2016; 39:413-22. [DOI: 10.1007/s13246-016-0429-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/17/2016] [Indexed: 10/22/2022]
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Physics: Low-Energy Brachytherapy Physics. Brachytherapy 2016. [DOI: 10.1007/978-3-319-26791-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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A modified dose calculation formalism for electronic brachytherapy sources. Brachytherapy 2015; 14:405-8. [PMID: 25766247 DOI: 10.1016/j.brachy.2015.01.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 11/23/2022]
Abstract
PURPOSE To propose a modification of the current dose calculation formalism introduced in the Task Group No. 43 Report (TG-43) to accommodate an air-kerma rate standard for electronic brachytherapy sources as an alternative to an air-kerma strength standard. METHODS Electronic brachytherapy sources are miniature x-ray tubes emitting low energies with high-dose-rates. The National Institute of Standards and Technology (NIST) has introduced a new primary air-kerma rate standard for one of these sources, in contrast to air-kerma strength. A modification of the TG-43 protocol for calculation of dose-rate distributions around electronic brachytherapy sources including sources in an applicator is presented. It cannot be assumed that the perturbations from sources in an applicator are negligible, and thus, the applicator is incorporated in the formalism. The modified protocol mimics the fundamental methodology of the original TG-43 formalism, but now incorporates the new NIST-traceable source strength metric of air-kerma rate at 50 cm and introduces a new subscript, i, to denote the presence of an applicator used in treatment delivery. Applications of electronic brachytherapy sources for surface brachytherapy are not addressed in this Technical Note since they are well documented in other publications. RESULTS A modification of the AAPM TG-43 protocol has been developed to accommodate an air-kerma rate standard for electronic brachytherapy sources as an alternative to an air-kerma strength standard. CONCLUSIONS The modified TG-43 formalism allows dose calculations to be performed using a new NIST-traceable source strength metric and introduces the concept of applicator-specific formalism parameters denoted with subscript, i.
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Lucas PA, Aubineau-Lanièce I, Lourenço V, Vermesse D, Cutarella D. Using LiF:Mg,Cu,P TLDs to estimate the absorbed dose to water in liquid water around an 192Ir brachytherapy source. Med Phys 2014; 41:011711. [PMID: 24387503 DOI: 10.1118/1.4851636] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
PURPOSE The absorbed dose to water is the fundamental reference quantity for brachytherapy treatment planning systems and thermoluminescence dosimeters (TLDs) have been recognized as the most validated detectors for measurement of such a dosimetric descriptor. The detector response in a wide energy spectrum as that of an (192)Ir brachytherapy source as well as the specific measurement medium which surrounds the TLD need to be accounted for when estimating the absorbed dose. This paper develops a methodology based on highly sensitive LiF:Mg,Cu,P TLDs to directly estimate the absorbed dose to water in liquid water around a high dose rate (192)Ir brachytherapy source. METHODS Different experimental designs in liquid water and air were constructed to study the response of LiF:Mg,Cu,P TLDs when irradiated in several standard photon beams of the LNE-LNHB (French national metrology laboratory for ionizing radiation). Measurement strategies and Monte Carlo techniques were developed to calibrate the LiF:Mg,Cu,P detectors in the energy interval characteristic of that found when TLDs are immersed in water around an (192)Ir source. Finally, an experimental system was designed to irradiate TLDs at different angles between 1 and 11 cm away from an (192)Ir source in liquid water. Monte Carlo simulations were performed to correct measured results to provide estimates of the absorbed dose to water in water around the (192)Ir source. RESULTS The dose response dependence of LiF:Mg,Cu,P TLDs with the linear energy transfer of secondary electrons followed the same variations as those of published results. The calibration strategy which used TLDs in air exposed to a standard N-250 ISO x-ray beam and TLDs in water irradiated with a standard (137)Cs beam provided an estimated mean uncertainty of 2.8% (k = 1) in the TLD calibration coefficient for irradiations by the (192)Ir source in water. The 3D TLD measurements performed in liquid water were obtained with a maximum uncertainty of 11% (k = 1) found at 1 cm from the source. Radial dose values in water were compared against published results of the American Association of Physicists in Medicine and the European Society for Radiotherapy and Oncology and no significant differences (maximum value of 3.1%) were found within uncertainties except for one position at 9 cm (5.8%). At this location the background contribution relative to the TLD signal is relatively small and an unexpected experimental fluctuation in the background estimate may have caused such a large discrepancy. CONCLUSIONS This paper shows that reliable measurements with TLDs in complex energy spectra require a study of the detector dose response with the radiation quality and specific calibration methodologies which model accurately the experimental conditions where the detectors will be used. The authors have developed and studied a method with highly sensitive TLDs and contributed to its validation by comparison with results from the literature. This methodology can be used to provide direct estimates of the absorbed dose rate in water for irradiations with HDR (192)Ir brachytherapy sources.
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Affiliation(s)
- P Avilés Lucas
- CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette, France
| | - I Aubineau-Lanièce
- CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette, France
| | - V Lourenço
- CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette, France
| | - D Vermesse
- CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette, France
| | - D Cutarella
- CEA, LIST, Laboratoire National Henri Becquerel, 91191 Gif-sur-Yvette, France
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Vijande J, Granero D, Perez-Calatayud J, Ballester F. Monte Carlo dosimetric study of the medium dose rate CSM40 source. Appl Radiat Isot 2013; 82:283-8. [DOI: 10.1016/j.apradiso.2013.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 08/01/2013] [Accepted: 09/09/2013] [Indexed: 11/28/2022]
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17
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Kirisits C, Rivard MJ, Baltas D, Ballester F, De Brabandere M, van der Laarse R, Niatsetski Y, Papagiannis P, Hellebust TP, Perez-Calatayud J, Tanderup K, Venselaar JLM, Siebert FA. Review of clinical brachytherapy uncertainties: analysis guidelines of GEC-ESTRO and the AAPM. Radiother Oncol 2013; 110:199-212. [PMID: 24299968 PMCID: PMC3969715 DOI: 10.1016/j.radonc.2013.11.002] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/30/2013] [Accepted: 11/04/2013] [Indexed: 11/21/2022]
Abstract
Background and purpose A substantial reduction of uncertainties in clinical brachytherapy should result in improved outcome in terms of increased local control and reduced side effects. Types of uncertainties have to be identified, grouped, and quantified. Methods A detailed literature review was performed to identify uncertainty components and their relative importance to the combined overall uncertainty. Results Very few components (e.g., source strength and afterloader timer) are independent of clinical disease site and location of administered dose. While the influence of medium on dose calculation can be substantial for low energy sources or non-deeply seated implants, the influence of medium is of minor importance for high-energy sources in the pelvic region. The level of uncertainties due to target, organ, applicator, and/or source movement in relation to the geometry assumed for treatment planning is highly dependent on fractionation and the level of image guided adaptive treatment. Most studies to date report the results in a manner that allows no direct reproduction and further comparison with other studies. Often, no distinction is made between variations, uncertainties, and errors or mistakes. The literature review facilitated the drafting of recommendations for uniform uncertainty reporting in clinical BT, which are also provided. The recommended comprehensive uncertainty investigations are key to obtain a general impression of uncertainties, and may help to identify elements of the brachytherapy treatment process that need improvement in terms of diminishing their dosimetric uncertainties. It is recommended to present data on the analyzed parameters (distance shifts, volume changes, source or applicator position, etc.), and also their influence on absorbed dose for clinically-relevant dose parameters (e.g., target parameters such as D90 or OAR doses). Publications on brachytherapy should include a statement of total dose uncertainty for the entire treatment course, taking into account the fractionation schedule and level of image guidance for adaptation. Conclusions This report on brachytherapy clinical uncertainties represents a working project developed by the Brachytherapy Physics Quality Assurances System (BRAPHYQS) subcommittee to the Physics Committee within GEC-ESTRO. Further, this report has been reviewed and approved by the American Association of Physicists in Medicine.
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Affiliation(s)
- Christian Kirisits
- Department of Radiotherapy, Comprehensive Cancer Center, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Austria.
| | - Mark J Rivard
- Department of Radiation Oncology, Tufts University School of Medicine, Boston, USA
| | - Dimos Baltas
- Department of Medical Physics & Engineering, Sana Klinikum Offenbach, Germany
| | | | | | | | | | | | - Taran Paulsen Hellebust
- Department of Medical Physics, Oslo University Hospital, The Radium Hospital, Oslo, Norway; Department of Physics, University of Oslo, Oslo, Norway
| | | | | | - Jack L M Venselaar
- Department of Medical Physics and Engineering, Instituut Verbeeten, Tilburg, The Netherlands
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Anjomrouz M, Sadeghi M, Haddadi A. Monte Carlo characterization of 169Yb as a high-dose-rate source for brachytherapy application by FLUKA code. J Appl Clin Med Phys 2013; 14:4298. [PMID: 23835393 PMCID: PMC5714526 DOI: 10.1120/jacmp.v14i4.4298] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 03/03/2013] [Accepted: 03/09/2013] [Indexed: 11/23/2022] Open
Abstract
Higher initial dose rate and simplifying HDR room treatment of 169Yb element among other brachytherapy sources has led to investigating its feasibility as high‐dose‐rate seed. In this work, Monte Carlo calculation was performed to obtain dosimetric parameters of 169Yb, Model M42 source at different radial distances according to AAPM TG‐43U1 and HEBD Report about HDR sources in both air vacuum and spherical homogeneous water phantom. The deposited energy resulted by FLUKA as Monte Carlo code using binning estimators around 169Yb source was converted into radial dose rate distribution in polar coordinates surrounding the brachytherapy source. The results indicate a dose rate constant of 1.14±0.04cGy.h−1.U−1 with approximate uncertainty of 0.04%, air kerma strength, 1.082±2.6E−06U.mCi−1 and anisotropy function ranging from 0.386 to 1.00 for radial distances of 0.5–10 cm and polar angles of 0°–180°. Overall, FLUKA dosimetric outputs were benchmarked with those published by Cazeca et al. via MCNP5 as one of validate dosimetry datasets related to 169Yb HDR source. As a result, it seems that FLUKA code can be applicable as a valuable tool to Monte Carlo evaluation of novel HDR brachytherapy sources. PACS number: 87.15.ak
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Affiliation(s)
- Marzieh Anjomrouz
- Medical Radiation Engineering Department, Science and Research Branch, Islamic Azad University, Tehran, Iran.
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Perez-Calatayud J, Ballester F, Das RK, Dewerd LA, Ibbott GS, Meigooni AS, Ouhib Z, Rivard MJ, Sloboda RS, Williamson JF. Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO. Med Phys 2012; 39:2904-29. [PMID: 22559663 DOI: 10.1118/1.3703892] [Citation(s) in RCA: 196] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Jose Perez-Calatayud
- Radiotherapy Department, La Fe Polytechnic and University Hospital, Valencia, Spain
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Monte Carlo dosimetric study of the Flexisource Co-60 high dose rate source. J Contemp Brachytherapy 2012; 4:34-44. [PMID: 23346138 PMCID: PMC3551374 DOI: 10.5114/jcb.2012.27950] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 01/23/2012] [Accepted: 02/23/2012] [Indexed: 11/20/2022] Open
Abstract
Purpose Recently, a new HDR 60Co brachytherapy source, Flexisource Co-60, has been developed (Nucletron B.V. Veenendaal, The Netherlands). This study aims to obtain dosimetric data for this source for its use in clinical practice as required by AAPM and ESTRO. Material and methods Two Monte Carlo radiation transport codes were used: Penelope2008 and GEANT4. The source was centrally-positioned in a 100 cm radius water phantom. Absorbed dose and collisional kerma were obtained using 0.01 cm (close) and 0.1 cm (far) sized voxels to provide high-resolution dosimetry near (far from) the source. Dose rate distributions obtained with the two Monte Carlo codes were compared. Results and Discussion Simulations performed with those two radiation transport codes showed an agreement typically within 0.2% for r > 0.8 cm and up to 2% closer to the source. Detailed results of dose distributions are being made available. Conclusions Dosimetric data are provided for the new Flexisource Co-60 source. These data are meant to be used in treatment planning systems in clinical practice.
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Davis BJ, Horwitz EM, Lee WR, Crook JM, Stock RG, Merrick GS, Butler WM, Grimm PD, Stone NN, Potters L, Zietman AL, Zelefsky MJ. American Brachytherapy Society consensus guidelines for transrectal ultrasound-guided permanent prostate brachytherapy. Brachytherapy 2012; 11:6-19. [PMID: 22265434 DOI: 10.1016/j.brachy.2011.07.005] [Citation(s) in RCA: 326] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 07/23/2011] [Accepted: 07/26/2011] [Indexed: 10/14/2022]
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Sharma SD, Kumar S, Srinivasan P, Chourasiya G. Establishment of air kerma reference standard for low dose rate Cs-137 brachytherapy sources. J Appl Clin Med Phys 2011; 12:3553. [PMID: 22089009 PMCID: PMC5718750 DOI: 10.1120/jacmp.v12i4.3553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2011] [Revised: 04/26/2011] [Accepted: 04/25/2011] [Indexed: 01/18/2023] Open
Abstract
A guarded cylindrical graphite ionization chamber of nominal volume 1000 cm3 was designed and fabricated for use as a reference standard for low-dose rate 137Cs brachytherapy sources. The air kerma calibration coefficient (N(K)) of this ionization chamber was estimated analytically using Burlin's general cavity theory, as well as by the Monte Carlo simulation and validated experimentally using Amersham CDCS-J-type 137Cs reference source. In the analytical method, the N(K) was calculated for 662 keV gamma rays of 137Cs brachytherapy source. In the Monte Carlo method, the geometry of the measurement setup and physics-related input data of the 137Cs source and the surrounding material were simulated using the Monte Carlo N-Particle code. The photon energy fluence was used to arrive at the reference air kerma rate (RAKR) using mass energy absorption coefficient. The energy deposition rates were used to simulate the value of charge rate in the ionization chamber, and the N(K) was determined. The analytical and Monte Carlo values of N(K) of the cylindrical graphite ionization chamber for 137Cs brachytherapy source are in agreement within 1.07%. The deviation of analytical and Monte Carlo values from experimental values of N(K) is 0.36% and 0.72%, respectively. This agreement validates the analytical value, and establishes this chamber as a reference standard for RAKR or AKS measurement of 137Cs brachytherapy sources.
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Affiliation(s)
- Sunil Dutt Sharma
- Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Anushaktinagar, Mumbai-400094, India.
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Sadeghi M, Taghdiri F, Saidi P. Dosimetric characteristics of the ¹⁹²Ir high-dose-rate afterloading brachytherapy source. Jpn J Radiol 2011; 29:324-9. [PMID: 21717300 DOI: 10.1007/s11604-011-0562-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Accepted: 01/10/2011] [Indexed: 11/30/2022]
Abstract
PURPOSE For the treatment of some cancerous tumors using brachytherapy, an American Association of Physicists in Medicine (AAPM) Task Group No. 43U1 report recommends that the dosimetric parameters of a new brachytherapy source must be determined in two experimental and Monte Carlo theoretical methods before using each new source clinically. This study presents the results of Monte Carlo calculations of the dosimetric parameters for a Ir2.A85-2 brachytherapy source design. MATERIALS AND METHODS Version 5 of the (MCNP) Monte Carlo radiation transport code was used to calculate the dosimetry parameters around the source. RESULTS The Monte Carlo calculated dose rate constant, Λ, of the Ir2.A85-2 source was found to be 1.113 ± 0.033 cGyU(-1)h(-1). Also in this study, the line-source radial dose function, g ( l )(r) and the anisotropy function, F(r,θ), have been calculated at distances from 0.5 to 10 cm. The results of these calculations have been compared with the published data for the same source. CONCLUSION All the results are in good concordance with previously published data, with a few exceptions in small angles and short distances. The dosimetric parameters calculated in this work can be used as input data in a treatment planning system (TPS) for exact brachytherapy treatment planning or to verify the calculations of the TPS used in brachytherapy.
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Affiliation(s)
- Mahdi Sadeghi
- Agricultural, Medical, and Industrial Research School, Nuclear Science and Technology Research Institute, PO Box 31485/498, Karaj, Tehran, Iran.
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DeWerd LA, Ibbott GS, Meigooni AS, Mitch MG, Rivard MJ, Stump KE, Thomadsen BR, Venselaar JLM. A dosimetric uncertainty analysis for photon-emitting brachytherapy sources: report of AAPM Task Group No. 138 and GEC-ESTRO. Med Phys 2011; 38:782-801. [PMID: 21452716 PMCID: PMC3033879 DOI: 10.1118/1.3533720] [Citation(s) in RCA: 180] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 12/06/2010] [Accepted: 12/14/2010] [Indexed: 11/07/2022] Open
Abstract
This report addresses uncertainties pertaining to brachytherapy single-source dosimetry preceding clinical use. The International Organization for Standardization (ISO) Guide to the Expression of Uncertainty in Measurement (GUM) and the National Institute of Standards and Technology (NIST) Technical Note 1297 are taken as reference standards for uncertainty formalism. Uncertainties in using detectors to measure or utilizing Monte Carlo methods to estimate brachytherapy dose distributions are provided with discussion of the components intrinsic to the overall dosimetric assessment. Uncertainties provided are based on published observations and cited when available. The uncertainty propagation from the primary calibration standard through transfer to the clinic for air-kerma strength is covered first. Uncertainties in each of the brachytherapy dosimetry parameters of the TG-43 formalism are then explored, ending with transfer to the clinic and recommended approaches. Dosimetric uncertainties during treatment delivery are considered briefly but are not included in the detailed analysis. For low- and high-energy brachytherapy sources of low dose rate and high dose rate, a combined dosimetric uncertainty <5% (k=1) is estimated, which is consistent with prior literature estimates. Recommendations are provided for clinical medical physicists, dosimetry investigators, and source and treatment planning system manufacturers. These recommendations include the use of the GUM and NIST reports, a requirement of constancy of manufacturer source design, dosimetry investigator guidelines, provision of the lowest uncertainty for patient treatment dosimetry, and the establishment of an action level based on dosimetric uncertainty. These recommendations reflect the guidance of the American Association of Physicists in Medicine (AAPM) and the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) for their members and may also be used as guidance to manufacturers and regulatory agencies in developing good manufacturing practices for sources used in routine clinical treatments.
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Affiliation(s)
- Larry A DeWerd
- Department of Medical Physics and Accredited Dosimetry Calibration Laboratory, University of Wisconsin, Madison, Wisconsin 53706, USA
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Granero D, Vijande J, Ballester F, Rivard MJ. Dosimetry revisited for the HDR I192r brachytherapy source model mHDR-v2. Med Phys 2010; 38:487-94. [DOI: 10.1118/1.3531973] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Morton G, Walker-Dilks C, Baldassarre F, D’Souza D, Falkson C, Batchelar D, Gutierrez E, Bak K. Delivery of Brachytherapy for Cervical Cancer: Organisational and Technical Advice to Facilitate High-quality Care. Clin Oncol (R Coll Radiol) 2010; 22:605-14. [DOI: 10.1016/j.clon.2010.05.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/26/2010] [Accepted: 05/20/2010] [Indexed: 11/29/2022]
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Rivard MJ, Beaulieu L, Mourtada F. Enhancements to commissioning techniques and quality assurance of brachytherapy treatment planning systems that use model-based dose calculation algorithmsa). Med Phys 2010; 37:2645-58. [DOI: 10.1118/1.3429131] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Evaluation of interpolation methods for TG-43 dosimetric parameters based on comparison with Monte Carlo data for high-energy brachytherapy sources. J Contemp Brachytherapy 2010; 2:28-32. [PMID: 28031740 PMCID: PMC5183640 DOI: 10.5114/jcb.2010.13715] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 03/02/2010] [Indexed: 12/02/2022] Open
Abstract
Purpose The aim of this work was to determine dose distributions for high-energy brachytherapy sources at spatial locations not included in the radial dose function gL(r) and 2D anisotropy function F(r,θ) table entries for radial distance r and polar angle θ. The objectives of this study are as follows: 1) to evaluate interpolation methods in order to accurately derive gL(r) and F(r,θ) from the reported data; 2) to determine the minimum number of entries in gL(r) and F(r,θ) that allow reproduction of dose distributions with sufficient accuracy. Material and methods Four high-energy photon-emitting brachytherapy sources were studied: 60Co model Co0.A86, 137Cs model CSM-3, 192Ir model Ir2.A85-2, and 169Yb hypothetical model. The mesh used for r was: 0.25, 0.5, 0.75, 1, 1.5, 2–8 (integer steps) and 10 cm. Four different angular steps were evaluated for F(r,θ): 1°, 2°, 5° and 10°. Linear-linear and logarithmic-linear interpolation was evaluated for gL(r). Linear-linear interpolation was used to obtain F(r,θ) with resolution of 0.05 cm and 1°. Results were compared with values obtained from the Monte Carlo (MC) calculations for the four sources with the same grid. Results Linear interpolation of gL(r) provided differences ≤ 0.5% compared to MC for all four sources. Bilinear interpolation of F(r,θ) using 1° and 2° angular steps resulted in agreement ≤ 0.5% with MC for 60Co, 192Ir, and 169Yb, while 137Cs agreement was ≤ 1.5% for θ < 15°. Conclusions The radial mesh studied was adequate for interpolating gL(r) for high-energy brachytherapy sources, and was similar to commonly found examples in the published literature. For F(r,θ) close to the source longitudinal-axis, polar angle step sizes of 1°-2° were sufficient to provide 2% accuracy for all sources.
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Cazeca MJ, Medich DC, Munro JJ. Monte Carlo characterization of a new Yb-169 high dose rate source for brachytherapy application. Med Phys 2010; 37:1129-36. [DOI: 10.1118/1.3301607] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Meigooni AS, Wright C, Koona RA, Awan SB, Granero D, Perez-Calatayud J, Ballester F. TG-43 U1 based dosimetric characterization of model 67-6520 Cs-137 brachytherapy source. Med Phys 2010; 36:4711-9. [PMID: 19928102 DOI: 10.1118/1.3224462] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Brachytherapy treatment has been a cornerstone for management of various cancer sites, particularly for the treatment of gynecological malignancies. In low dose rate brachytherapy treatments, 137Cs sources have been used for several decades. A new 137Cs source design has been introduced (model 67-6520, source B3-561) by Isotope Products Laboratories (IPL) for clinical application. The goal of the present work is to implement the TG-43 U1 protocol in the characterization of the aforementioned 137Cs source. METHODS The dosimetric characteristics of the IPL 137Cs source are measured using LiF thermoluminescent dosimeters in a Solid Water phantom material and calculated using Monte Carlo simulations with the GEANT4 code in Solid Water and liquid water. The dose rate constant, radial dose function, and two-dimensional anisotropy function of this source model were obtained following the TG-43 U1 recommendations. In addition, the primary and scatter dose separation (PSS) formalism that could be used in convolution/superposition methods to calculate dose distributions around brachytherapy sources in heterogeneous media was studied. RESULTS The measured and calculated dose rate constants of the IPL 137Cs source in Solid Water were found to be 0.930 (+/-7.3%) and 0.928 (+/-2.6%) cGy h(-1) U(-1), respectively. The agreement between these two methods was within our experimental uncertainties. The Monte Carlo calculated value in liquid water of the dose rate constant was null set=0.948 (+/-2.6%) cGy h(-1) U(-1). Similarly, the agreement between measured and calculated radial dose functions and the anisotropy functions was found to be within +/-5%. In addition, the tabulated data that are required to characterize the source using the PSS formalism were derived. CONCLUSIONS In this article the complete dosimetry of the newly designed 137Cs IPL source following the AAPM TG-43 U1 dosimetric protocol and the PSS formalism is provided.
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Affiliation(s)
- Ali S Meigooni
- Department of Radiation Medicine, North Shore University Hospital, 300 Community Drive, Manhasset, New York 11030, USA.
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Dosimetric characterization of an 192Ir brachytherapy source with the Monte Carlo code PENELOPE. Phys Med 2009; 26:132-9. [PMID: 20034828 DOI: 10.1016/j.ejmp.2009.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 10/28/2009] [Accepted: 11/04/2009] [Indexed: 11/22/2022] Open
Abstract
Monte Carlo calculations are highly spread and settled practice to calculate brachytherapy sources dosimetric parameters. In this study, recommendations of the AAPM TG-43U1 report have been followed to characterize the Varisource VS2000 (192)Ir high dose rate source, provided by Varian Oncology Systems. In order to obtain dosimetric parameters for this source, Monte Carlo calculations with PENELOPE code have been carried out. TG-43 formalism parameters have been presented, i.e., air kerma strength, dose rate constant, radial dose function and anisotropy function. Besides, a 2D Cartesian coordinates dose rate in water table has been calculated. These quantities are compared to this source reference data, finding results in good agreement with them. The data in the present study complement published data in the next aspects: (i) TG-43U1 recommendations are followed regarding to phantom ambient conditions and to uncertainty analysis, including statistical (type A) and systematic (type B) contributions; (ii) PENELOPE code is benchmarked for this source; (iii) Monte Carlo calculation methodology differs from that usually published in the way to estimate absorbed dose, leaving out the track-length estimator; (iv) the results of the present work comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques, in regards to dose rate uncertainty values and established differences between our results and reference data. The results stated in this paper provide a complete parameter collection, which can be used for dosimetric calculations as well as a means of comparison with other datasets from this source.
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Selvam TP, Sahoo S, Vishwakarma RS. EGSnrc-based Monte Carlo dosimetry of CSA1 and CSA2 137Cs brachytherapy source models. Med Phys 2009; 36:3870-9. [PMID: 19810459 DOI: 10.1118/1.3176936] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE AAPM TG-56 recommends the use of a specific dosimetric dataset for each brachytherapy source model. In this study, a full dosimetric dataset for indigenously developed 137Cs source models, namely, the CSA1 and CSA2, in accordance with the AAPM TG-43U1 formalism is presented. The study includes calculation of dose-to-kerma ratio D/K in water around these sources including stainless steel encapsulated 137Cs sources such as RTR, 3M, and selectron/LDR 137Cs. METHODS The Monte Carlo-based EGSnrcMP code system is employed for modeling the sources in vacuum and in water. Calculations of air-kerma strength, S(K) for the investigated sources and collision kerma in water along the transverse axis of the RTR source are based on the FLURZnrc code. Simulations of water-kerma and dose in water for the CSA1, CSA2, RTR, 3M, and selectron/ LDR 137Cs sources are carried out using the DOSRZnrc code. In DOSRZnrc calculations, water-kerma and dose are scored in a cylindrical water phantom having dimensions of 80 cm diameter x 80 cm height. RESULTS The calculated dose-rate constants for the CSA1 and CSA2 sources are 0.945(1) and 1.023(1) cGy/(h U), respectively. The calculated value of S(K) per unit source activity, S(K)/A for the CSA1 and CSA2 sources is 7.393(7) x 10(-8) cGy cm2/(h Bq). The EGSnrcMP-based collision kerma rates for the RTR source along the transverse axis (0.25-10 cm) agree with the corresponding GEANT4-based published values within 0.5%. Anisotropy profiles of the CSA1 and CSA2 sources are significantly different from those of other sources. For the selectron/LDR single pellet 137Cs spherical source (modeled as a cylindrical pellet with dimensions similar to the seed selectron), the values of D/K at 1 and 1.25 mm from the capsule are 1.023(1) and 1.029(1), respectively. The value of D/K at 1 mm from the CSA1, CSA2, RTR, and 3M 137Cs source capsules (all sources have an external radius of 1.5 mm) is 1.017(1) and this ratio is applicable to axial positions z = 0 to z = -L/2. This is in contrast to a published GEANT4-based Monte Carlo dosimetric study on RTR and 3M 137Cs sources wherein the authors have assumed that collision kerma is approximately equal to absorbed dose at 1 mm from the source capsules. Collision kerma is approximately equal to absorbed dose for distances > or = 2 mm from source capsules as opposed to > or = 1 mm reported in published studies. A detailed electron transport is necessary up to 2 mm from source capsules. CONCLUSIONS The Monte Carlo-calculated dose-rate data for the CSA1 and CSA2 sources can be used as input data for treatment planning or to verify the calculations by radiotherapy treatment planning system.
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Affiliation(s)
- T Palani Selvam
- Radiological Physics and Advisory Division, Health, Safety and Environment Group, Bhabha Atomic Research Centre, Mumbai 400094, India.
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Antonovic L, Gustafsson H, Carlsson GA, Carlsson Tedgren A. Evaluation of a lithium formate EPR dosimetry system for dose measurements around 192Ir brachytherapy sources. Med Phys 2009; 36:2236-47. [PMID: 19610313 DOI: 10.1118/1.3110068] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
A dosimetry system using lithium formate monohydrate (HCO2Li x H2O) as detector material and electron paramagnetic resonance (EPR) spectroscopy for readout has been used to measure absorbed dose distributions around clinical 192Ir sources. Cylindrical tablets with diameter of 4.5 mm, height of 4.8 mm, and density of 1.26 g/cm3 were manufactured. Homogeneity test and calibration of the dosimeters were performed in a 6 MV photon beam. 192Ir irradiations were performed in a PMMA phantom using two different source models, the GammaMed Plus HDR and the microSelectron PDR-v1 model. Measured absorbed doses to water in the PMMA phantom were converted to the corresponding absorbed doses to water in water phantoms of dimensions used by the treatment planning systems (TPSs) using correction factors explicitly derived for this experiment. Experimentally determined absorbed doses agreed with the absorbed doses to water calculated by the TPS to within +/-2.9%. Relative standard uncertainties in the experimentally determined absorbed doses were estimated to be within the range of 1.7%-1.3% depending on the radial distance from the source, the type of source (HDR or PDR), and the particular absorbed doses used. This work shows that a lithium formate dosimetry system is well suited for measurements of absorbed dose to water around clinical HDR and PDR 192Ir sources. Being less energy dependent than the commonly used thermoluminescent lithium fluoride (LiF) dosimeters, lithium formate monohydrate dosimeters are well suited to measure absorbed doses in situations where the energy dependence cannot easily be accounted for such as in multiple-source irradiations to verify treatment plans. Their wide dynamic range and linear dose response over the dose interval of 0.2-1000 Gy make them suitable for measurements on sources of the strengths used in clinical applications. The dosimeter size needs, however, to be reduced for application to single-source dosimetry.
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Affiliation(s)
- Laura Antonovic
- Department of Medical and Health Sciences, Radiation Physics, Faculty of Health Sciences, Linköping University, SE-581 85 Linköping, Sweden
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34
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Ballester F, Granero D, Pérez-Calatayud J, Melhus CS, Rivard MJ. Evaluation of high-energy brachytherapy source electronic disequilibrium and dose from emitted electrons. Med Phys 2009; 36:4250-6. [DOI: 10.1118/1.3194754] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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35
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Petrokokkinos L, Moutsatsos A, Karaiskos P, Kouridou V, Pantelis E, Papagiannis P, Seimenis I. On the use of VIP gel dosimetry in HDR brachytherapy. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/164/1/012051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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36
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Tedgren ÅC, Carlsson GA. Influence of phantom material and dimensions on experimental I192r dosimetry. Med Phys 2009; 36:2228-35. [DOI: 10.1118/1.3121508] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Rivard MJ, Venselaar JLM, Beaulieu L. The evolution of brachytherapy treatment planning. Med Phys 2009; 36:2136-53. [DOI: 10.1118/1.3125136] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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38
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Granero D, Pérez-Calatayud J, Ballester F. Monte Carlo study of the dose rate distributions for the Ir2.A85-2 and Ir2.A85-1 Ir-192 afterloading sources. Med Phys 2008; 35:1280-7. [PMID: 18491521 DOI: 10.1118/1.2868766] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The two most commonly used modalities of cancer treatment in clinical brachytherapy practice today are high dose rate (HDR) and pulsed dose rate (PDR) brachytherapy. In a clinical treatment, quality dose rate distribution data sets of the brachytherapy sources are required for each source model. The purpose of this study is to obtain detailed dose rate distributions around the new BEBIG HDR and PDR Ir-192 brachytherapy sources. These distributions will then be used as input data in the treatment planning systems dedicated to brachytherapy and its calculations can be verified. The Monte Carlo method was used to obtain the dose rate distributions around the sources studied, taking into account the AAPM-ESTRO recent recommendations. A complete dosimetric data set for the BEBIG Ir-192 HDR and PDR sources, types Ir2.A85-2 and Ir2.A85-1, were obtained. This dosimetric data set is composed of the TG-43 dosimetric functions and parameters and along-away dose rate table to facilitate quality control of treatment planning systems.
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Affiliation(s)
- D Granero
- Physics Section, Radiation Oncology Department, La Fe University Hospital, Valencia, Spain
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39
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Ibbott G, Ma CM, Rogers DWO, Seltzer SM, Williamson JF. Anniversary paper: fifty years of AAPM involvement in radiation dosimetry. Med Phys 2008; 35:1418-27. [PMID: 18491537 DOI: 10.1118/1.2868765] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
This article reviews the involvement of the AAPM in various aspects of radiation dosimetry over its 50 year history, emphasizing the especially important role that external beam dosimetry played in the early formation of the organization. Topics covered include the AAPM's involvement with external beam and x-ray dosimetry protocols, brachytherapy dosimetry, primary standards laboratories, accredited dosimetry chains, and audits for machine calibrations through the Radiological Physics Center.
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Affiliation(s)
- G Ibbott
- Radiological Physics Center University of M. D. Anderson Cancer Center, Houston, Texas 77030-4009, USA
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40
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Williamson JF. Current brachytherapy quality assurance guidance: does it meet the challenges of emerging image-guided technologies? Int J Radiat Oncol Biol Phys 2008; 71:S18-22. [PMID: 18406923 DOI: 10.1016/j.ijrobp.2007.07.2388] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 07/15/2007] [Accepted: 07/17/2007] [Indexed: 11/28/2022]
Abstract
In the past decade, brachytherapy has shifted from the traditional surgical paradigm to more modern three-dimensional image-based planning and delivery approaches. The role of intraoperative and multimodality image-based planning is growing. Published American Association of Physicists in Medicine, American College of Radiology, European Society for Therapeutic Radiology and Oncology, and International Atomic Energy Agency quality assurance (QA) guidelines largely emphasize the QA of planning and delivery devices rather than processes. These protocols have been designed to verify compliance with major performance specifications and are not risk based. With some exceptions, complete and clinically practical guidance exists for sources, QA instrumentation, non-image-based planning systems, applicators, remote afterloading systems, dosimetry, and calibration. Updated guidance is needed for intraoperative imaging systems and image-based planning systems. For non-image-based brachytherapy, the American Association of Physicists in Medicine Task Group reports 56 and 59 provide reasonable guidance on procedure-specific process flow and QA. However, improved guidance is needed even for established procedures such as ultrasound-guided prostate implants. Adaptive replanning in brachytherapy faces unsolved problems similar to that of image-guided adaptive external beam radiotherapy.
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Affiliation(s)
- Jeffrey F Williamson
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA23298, USA.
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Williamson JF, Dunscombe PB, Sharpe MB, Thomadsen BR, Purdy JA, Deye JA. Quality assurance needs for modern image-based radiotherapy: recommendations from 2007 interorganizational symposium on "quality assurance of radiation therapy: challenges of advanced technology". Int J Radiat Oncol Biol Phys 2008; 71:S2-12. [PMID: 18406928 DOI: 10.1016/j.ijrobp.2007.08.080] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/28/2007] [Accepted: 08/31/2007] [Indexed: 11/24/2022]
Abstract
This report summarizes the consensus findings and recommendations emerging from 2007 Symposium, "Quality Assurance of Radiation Therapy: Challenges of Advanced Technology." The Symposium was held in Dallas February 20-22, 2007. The 3-day program, which was sponsored jointly by the American Society for Therapeutic Radiology and Oncology (ASTRO), American Association of Physicists in Medicine (AAPM), and National Cancer Institute (NCI), included >40 invited speakers from the radiation oncology and industrial engineering/human factor communities and attracted nearly 350 attendees, mostly medical physicists. A summary of the major findings follows. The current process of developing consensus recommendations for prescriptive quality assurance (QA) tests remains valid for many of the devices and software systems used in modern radiotherapy (RT), although for some technologies, QA guidance is incomplete or out of date. The current approach to QA does not seem feasible for image-based planning, image-guided therapies, or computer-controlled therapy. In these areas, additional scientific investigation and innovative approaches are needed to manage risk and mitigate errors, including a better balance between mitigating the risk of catastrophic error and maintaining treatment quality, complimenting the current device-centered QA perspective by a more process-centered approach, and broadening community participation in QA guidance formulation and implementation. Industrial engineers and human factor experts can make significant contributions toward advancing a broader, more process-oriented, risk-based formulation of RT QA. Healthcare administrators need to appropriately increase personnel and ancillary equipment resources, as well as capital resources, when new advanced technology RT modalities are implemented. The pace of formalizing clinical physics training must rapidly increase to provide an adequately trained physics workforce for advanced technology RT. The specific recommendations of the Symposium included the following. First, the AAPM, in cooperation with other advisory bodies, should undertake a systematic program to update conventional QA guidance using available risk-assessment methods. Second, the AAPM advanced technology RT Task Groups should better balance clinical process vs. device operation aspects--encouraging greater levels of multidisciplinary participation such as industrial engineering consultants and use-risk assessment and process-flow techniques. Third, ASTRO should form a multidisciplinary subcommittee, consisting of physician, physicist, vendor, and industrial engineering representatives, to better address modern RT quality management and QA needs. Finally, government and private entities committed to improved healthcare quality and safety should support research directed toward addressing QA problems in image-guided therapies.
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Affiliation(s)
- Jeffrey F Williamson
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA 23298, USA.
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42
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Granero D, Pérez-Calatayud J, Ballester F. Technical note: Dosimetric study of a new Co-60 source used in brachytherapy. Med Phys 2007; 34:3485-8. [PMID: 17926951 DOI: 10.1118/1.2759602] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The purpose of this study is to obtain the dosimetric parameters of a new Co-60 source used in high dose rate brachytherapy and manufactured by BEBIG (Eckert & Ziegler BEBIG GmbH, Germany). The Monte Carlo method has been used to obtain the dose rate distribution in the updated TG-43U1 formalism of the American Association of Physicists in Medicine. In addition, to aid the quality control process on treatment planning systems (TPS), a two-dimensional rectangular dose rate table, coherent with the TG-43U1 dose calculation formalism, is given. These dosimetric data sets can be used as input data of the TPS calculations and to validate them.
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Affiliation(s)
- D Granero
- Physics Section, Radiation Oncology Department, La Fe University Hospital, Avenida Campanar 21, E46009 Valencia, Spain
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Toye WC, Das KR, Todd SP, Kenny MB, Franich RD, Johnston PN. An experimental MOSFET approach to characterize (192)Ir HDR source anisotropy. Phys Med Biol 2007; 52:5329-39. [PMID: 17762089 DOI: 10.1088/0031-9155/52/17/015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The dose anisotropy around a (192)Ir HDR source in a water phantom has been measured using MOSFETs as relative dosimeters. In addition, modeling using the EGSnrc code has been performed to provide a complete dose distribution consistent with the MOSFET measurements. Doses around the Nucletron 'classic' (192)Ir HDR source were measured for a range of radial distances from 5 to 30 mm within a 40 x 30 x 30 cm(3) water phantom, using a TN-RD-50 MOSFET dosimetry system with an active area of 0.2 mm by 0.2 mm. For each successive measurement a linear stepper capable of movement in intervals of 0.0125 mm re-positioned the MOSFET at the required radial distance, while a rotational stepper enabled angular displacement of the source at intervals of 0.9 degrees . The source-dosimeter arrangement within the water phantom was modeled using the standardized cylindrical geometry of the DOSRZnrc user code. In general, the measured relative anisotropy at each radial distance from 5 mm to 30 mm is in good agreement with the EGSnrc simulations, benchmark Monte Carlo simulation and TLD measurements where they exist. The experimental approach employing a MOSFET detection system of small size, high spatial resolution and fast read out capability allowed a practical approach to the determination of dose anisotropy around a HDR source.
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Affiliation(s)
- W C Toye
- Radiation Oncology Victoria, Melbourne, Australia.
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