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Píriz GH, Gonzalez-Sprinberg GA, Ballester F, Vijande J. Dosimetry of Large Field Valencia applicators for Cobalt-60-based brachytherapy. Med Phys 2024. [PMID: 38507246 DOI: 10.1002/mp.17035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/19/2024] [Accepted: 02/26/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND Non-melanoma skin cancer is one of the most common types of cancer and one of the main approaches is brachytherapy. For small lesions, the treatment of this cancer with brachytherapy can be done with two commercial applicators, one of these is the Large Field Valencia Applicators (LFVA). PURPOSE The aim of this study is to test the capabilities of the LFVA to use clinically 60Co sources instead of the 192Ir ones. This study was designed for the same dwell positions and weights for both sources. METHODS The Penelope Monte Carlo code was used to evaluate dose distribution in a water phantom when a 60Co source is considered. The LFVA design and the optimized dwell weights reported for the case of 192Ir are maintained with the only exception of the dwell weight of the central position, that was increased. 2D dose distributions, field flatness, symmetry and the leakage dose distribution around the applicator were calculated. RESULTS When comparing the dose distributions of both sources, field flatness and symmetry remain unchanged. The only evident difference is an increase of the penumbra regions for all depths when using the 60Co source. Regarding leakage, the maximum dose within the air volume surrounding the applicator is in the order of 20% of the prescription dose for the 60Co source, but it decreases to less than 5% at about 1 cm distance. CONCLUSIONS Flatness and symmetry remains unaltered as compared with 192Ir sources, while an increase in leakage has been observed. This proves the feasibility of using the LFVA in a larger range of clinical applications.
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Affiliation(s)
- Gustavo H Píriz
- Medical Physics Unit, Faculty of Sciences, University of the Republic, Montevideo, Uruguay
| | | | - Facundo Ballester
- Departamento de Física Atómica, Molecular y Nuclear, Universitat de Valencia (UV), Burjassot, Spain
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED), Ins-tituto de Investigación Sanitaria La Fe (IIS-La Fe), Universitat de Valencia (UV), València, Spain
| | - Javier Vijande
- Departamento de Física Atómica, Molecular y Nuclear, Universitat de Valencia (UV), Burjassot, Spain
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED), Ins-tituto de Investigación Sanitaria La Fe (IIS-La Fe), Universitat de Valencia (UV), València, Spain
- Instituto de Física Corpuscular, IFIC (UV-CSIC), Burjassot, Spain
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Hadadi A, Ghanavati S. 75Se - A promising alternative to 192Ir for potential use in the skin cancer brachytherapy: A Monte Carlo simulation study using FLUKA code. Appl Radiat Isot 2023; 197:110786. [PMID: 37023694 DOI: 10.1016/j.apradiso.2023.110786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/18/2023] [Accepted: 03/21/2023] [Indexed: 03/31/2023]
Abstract
This study aimed to evaluate the possibility of utilizing the HDR 75Se source for skin cancer brachytherapy. In this work, based on the BVH-20 skin applicator, two cup-shaped applicators, without and with the flattening filter, were modeled. To obtain the optimal flattening filter shape, an approach based on the MC simulation in combination with an analytical estimation was used. Then, the dose distributions for 75Se-applicators were generated using MC simulations in water, and their dosimetric characterizations such as flatness, symmetry, and penumbra were evaluated. Furthermore, the radiation leakage in the backside of the applicators was estimated by additional MC simulation. Finally, to evaluate the treatment times, calculations were performed for two 75Se-applicators assuming 5 Gy per fraction. The flatness, symmetry, and penumbra values for the 75Se-applicator without the flattening filter were estimated to be 13.7%, 1.05, and 0.41 cm respectively. The corresponding values for 75Se-applicator with the flattening filter were estimated to be 1.6%, 1.06, and 0.10 cm respectively. The radiation leakage value at a distance of 2 cm from the applicator surface was calculated to be 0.2% and 0.4% for the 75Se-applicator without and with the flattening filter respectively. Our results showed that the treatment time for the 75Se-applicator is comparable with that of the 192Ir-Leipzig applicator. The findings revealed that the dosimetric parameters of the 75Se applicator are comparable with the 192Ir skin applicator. Overall, the 75Se source can be an alternative to 192Ir sources for HDR brachytherapy of skin cancer.
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Rodríguez Villalba S, Guirado LLorente D, Sanz Cazorla A, Perez-Calatayud J, Rembielak A. HDR brachytherapy in keratinocyte skin carcinomas - Single center experience with analysis of clinical, dosimetric, and radiobiological factors in acute skin toxicity. Brachytherapy 2023; 22:108-119. [PMID: 36376228 DOI: 10.1016/j.brachy.2022.10.003] [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: 06/07/2022] [Revised: 09/09/2022] [Accepted: 10/07/2022] [Indexed: 11/13/2022]
Abstract
PURPOSE Radiotherapy techniques have been utilized to treat keratinocyte skin carcinoma (KSC). The objective of this study was to report the results of patients with KSC treated with HDR brachytherapy, with a variety of techniques and applicators. A statistical analysis of clinical, radiobiological, and technical factors has been made to analyze those factors related to skin acute toxicity, focused on acute epithelitis G3. METHODS AND MATERIALS Between February 2005 and August 2020, 93 patients with 120 histologically proven KSC have been treated in our Institution. BT treatment has been performed using superficial BT/plesiotherapy (Valencia applicator (22%), flaps (48%), customized molds (4%) or interstitial techniques (26%)). The indications of BT were primary/definitive in 38 treatments (32%) or adjuvant/postoperative in 82 (68%). In 14 (17%) of the 82 operated patients a skin graft. Mean comparison t tests were performed for quantitative variables, and percentage comparison Chi2 tests for qualitative. Multivariate binomial logistic regression models were done. RESULTS Median follow-up was 36.5 months (range 5-141). Local control was achieved in 110 treatments (92%). Acute toxicity, dermatitis, was G1 7%; G2, 57% and G3 38%. The main factors statistically associated to the appearance of dermatitis G3 were the total dose, the volume treated, and the use of manufactured flaps. The main protective factor against dermatitis G3 was implant of skin graft. CONCLUSIONS In KSC BT the use of manufactured flap is accompanied by greater EG3, only with a relationship with the volume of treatment and total dose.
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Affiliation(s)
| | - Damian Guirado LLorente
- Instituto de Investigación Biosanitaria (Ibs.Granada). Unidad de Radiofísica, Hospital Universitario Clínico San Cecilio. Granada, Spain; CIBER de Epidemiología y Salud Pública (CIBERESP), Granada, Spain.
| | | | - José Perez-Calatayud
- Radiotherapy Department, Hospital Clínica Benidorm, Benidorm, Alicante, Spain; Radiotherapy Department, La Fe University and Polytechnic Hospital. Valencia, Spain.
| | - Agata Rembielak
- The Christie NHS Foundation Trust, Manchester, UK; The University of Manchester, Manchester, UK.
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4
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Valdes‐Cortez C, Niatsetski Y, Perez‐Calatayud J, Ballester F, Vijande J. A Monte Carlo study of the relative biological effectiveness in surface brachytherapy. Med Phys 2022; 49:5576-5588. [DOI: 10.1002/mp.15774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/11/2022] [Accepted: 05/15/2022] [Indexed: 11/07/2022] Open
Affiliation(s)
| | - Yury Niatsetski
- R&D Elekta Brachytherapy Waardgelder 1, 3905 TH Veenendaal The Netherlands
| | - Jose Perez‐Calatayud
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED) Instituto de Investigación Sanitaria La Fe (IIS‐La Fe)‐Universitat de Valencia (UV)
- Radiotherapy Department La Fe Hospital Valencia Spain
- Radiotherapy Department Hospital Clinica Benidorm Alicante Spain
| | - 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 Valencia (UV)
- Department of Atomic, Molecular and Nuclear Physics University of Valencia Burjassot Spain
| | - Javier Vijande
- Unidad Mixta de Investigación en Radiofísica e Instrumentación Nuclear en Medicina (IRIMED) Instituto de Investigación Sanitaria La Fe (IIS‐La Fe)‐Universitat de Valencia (UV)
- Department of Atomic, Molecular and Nuclear Physics University of Valencia Burjassot Spain
- Instituto de Física Corpuscular IFIC (UV‐CSIC) Burjassot Spain
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5
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Tsao M, Barnes E, Karam I, Rembielak A. Hypofractionated Radiation Therapy in Keratinocyte Carcinoma. Clin Oncol (R Coll Radiol) 2022; 34:e218-e224. [DOI: 10.1016/j.clon.2022.02.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 02/02/2022] [Accepted: 02/18/2022] [Indexed: 12/20/2022]
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Draeger E, Pinkham DW, Chen ZJ, Tien CJ. Clinically-implementable template plans for multidwell treatments using Leipzig-style applicators in 192Ir surface brachytherapy. Brachytherapy 2020; 20:401-409. [PMID: 33288488 DOI: 10.1016/j.brachy.2020.09.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/16/2020] [Accepted: 09/19/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE Multiple dwell positions ("multidwell") within a Leipzig-style applicator can be used to increase dose uniformity and treatment area. Model-based dose calculation algorithms (MBDCAs) are necessary for accurate calculations involving these applicators because of their nonwater equivalency and complex geometry. The purpose of this work was to create template plans from MBDCA calculations and present their dwell times and positions for users of these applicators without access to MBDCAs. METHODS AND MATERIALS The Leipzig-style solid applicator model within our treatment planning system was used to design template plans. Five template plans, normalized to 0.3 cm depth within a water phantom, were optimized using the treatment planning system MBDCA. Each template plan contained unique dwell positions, times, and active lengths (0.5-1.5 cm). A single-dwell distribution was optimized for comparison. The stem of this applicator stops within the shell; therefore, one template plan contained an intrafraction rotation to determine the largest dose distribution achievable. Effects of imperfect applicator rotation were quantified by inserting rotational offsets and comparing the V100%, D95%, and minimum dose coverage for planning target volumes created from 80%/90% isodose lines. RESULTS The 90% (80%) isodose line dimensions at 0.3 cm depth for single-dwell increased from 0.94 × 0.97 (1.53 × 1.57) cm2 to 2.09 × 1.24 (2.75 × 1.88) cm2 in the largest template plan. Manually inserted angular offsets up to ±10° for the template plan requiring rotation preserved V100%, D95%, and minimum dose within 2.0%, 1.9%, and 8.0%, respectively. CONCLUSION A set of template plans was created to provide accessibility to the multidwell methodology, even for users without access to MBDCAs. Each template plan should be reviewed before clinical implementation.
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Affiliation(s)
- Emily Draeger
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT.
| | - Daniel W Pinkham
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
| | - Zhe Jay Chen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
| | - Christopher J Tien
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
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Niroomand‐Rad A, Chiu‐Tsao S, Grams MP, Lewis DF, Soares CG, Van Battum LJ, Das IJ, Trichter S, Kissick MW, Massillon‐JL G, Alvarez PE, Chan MF. Report of AAPM Task Group 235 Radiochromic Film Dosimetry: An Update to TG‐55. Med Phys 2020; 47:5986-6025. [DOI: 10.1002/mp.14497] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 09/15/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
| | | | | | | | | | | | - Indra J. Das
- Radiation Oncology Northwestern University Memorial Hospital Chicago IL USA
| | - Samuel Trichter
- New York‐Presbyterian HospitalWeill Cornell Medical Center New York NY USA
| | | | - Guerda Massillon‐JL
- Instituto de Fisica Universidad Nacional Autonoma de Mexico Mexico City Mexico
| | - Paola E. Alvarez
- Imaging and Radiation Oncology Core MD Anderson Cancer Center Houston TX USA
| | - Maria F. Chan
- Memorial Sloan Kettering Cancer Center Basking Ridge NJ USA
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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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Ghobadi P, Farhood B, Ghorbani M, Mohseni M. Design and characterization of flattening filter for high dose rate 192Ir and 60Co Leipzig applicators used in skin cancer brachytherapy: A Monte Carlo study. Comput Biol Med 2020; 123:103878. [PMID: 32658791 DOI: 10.1016/j.compbiomed.2020.103878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/21/2020] [Accepted: 06/21/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE This study aimed to design optimal flattening filters for high dose rate (HDR) 192Ir and 60Co Leipzig applicators which are used to treat skin cancer. MATERIALS AND METHODS MCNPX Monte Carlo code was used to design flattening filters for Leipzig applicators with inner diameters of 1, 2 and 3 cm. Then, their dosimetric characterizations such as dose distribution, dose profile, percentage depth dose, flatness, symmetry and homogeneity were evaluated in a 20 × 20 × 20 cm3 water phantom and compared with those without the flattening filter. RESULTS The flattening filter thickness varied from 0 mm (at the edge) to the maximum values of 0.30, 1.18, and 2.41 mm for the 192Ir Leipzig applicators of H1, H2, and H3 type, respectively. This quantity has maximum values of 0.96, 6.27, and 12.31 mm for the 60Co double wall applicators of D1, D2, and D3 type, respectively. The dose profile flatness values for the H1, H2, and H3 192Ir Leipzig applicators with the optimal flattening filters were 0.76, 1.26, and 1.85%, respectively. Furthermore, the dose profile flatness values for the D1, D2, and D3 60Co double wall applicators with the optimal flattening filters were 1.11, 2.10 and 3.12%, respectively. The dose profile symmetry values obtained from various source-applicator combinations were less than 1.02. Compared to the applicators without flattening filter, the homogeneity values for the H1, H2, and H3 192Ir Leipzig applicators with the optimal flattening filters were improved 1.68, 6.51, and 13.17 times, respectively, and for the D1, D2, and D3 60Co double wall applicators were improved 1.23, 6.21 and 9.54 times, respectively. CONCLUSION The findings revealed that the inhomogeneous dose distribution resulted from the Leipzig applicators without the optimal flattening filter at the treatment surface could be improved by insertion of optimal lead flattening filters between the sources and treatment surface.
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Affiliation(s)
- Parvin Ghobadi
- Department of Medical Physics and Radiology, Faculty of Paramedical Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Bagher Farhood
- Department of Medical Physics and Radiology, Faculty of Paramedical Sciences, Kashan University of Medical Sciences, Kashan, Iran.
| | - Mahdi Ghorbani
- Biomedical Engineering and Medical Physics Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mehran Mohseni
- Department of Medical Physics and Radiology, Faculty of Paramedical Sciences, Kashan University of Medical Sciences, Kashan, Iran
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The American Brachytherapy society consensus statement for skin brachytherapy. Brachytherapy 2020; 19:415-426. [PMID: 32409128 DOI: 10.1016/j.brachy.2020.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/24/2020] [Accepted: 04/07/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE Keratinocyte carcinoma (KC, previously nonmelanoma skin cancer) represents the most common cancer worldwide. While surgical treatment is commonly utilized, various radiation therapy techniques are available including external beam and brachytherapy. As such, the American Brachytherapy Society has created an updated consensus statement regarding the use of brachytherapy in the treatment of KCs. METHODS Physicians and physicists with expertise in skin cancer and brachytherapy created a consensus statement for appropriate patient selection, data, dosimetry, and utilization of skin brachytherapy and techniques based on a literature search and clinical experience. RESULTS Guidelines for patient selection, evaluation, and dose/fractionation schedules to optimize outcomes for patients with KC undergoing brachytherapy are presented. Studies of electronic brachytherapy are emerging, although limited long-term data or comparative data are available. Radionuclide-based brachytherapy represents an appropriate option for patients with small KCs with multiple techniques available. CONCLUSIONS Skin brachytherapy represents a standard of care option for appropriately selected patients with KC. Radionuclide-based brachytherapy represents a well-established technique; however, the current recommendation is that electronic brachytherapy be used for KC on prospective clinical trial or registry because of a paucity of mature data.
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Tien CJ, Pinkham DW, Chen ZJ. Feasibility of using multiple-dwell positions in 192Ir Leipzig-style brachytherapy surface applicators to expand target coverage and clinical application. Brachytherapy 2020; 19:532-543. [PMID: 32327342 DOI: 10.1016/j.brachy.2020.03.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 03/04/2020] [Accepted: 03/04/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE Leipzig-style applicators for surface brachytherapy are traditionally used with a single-source dwell position. This study explores the feasibility of using multiple-source dwell positions ("multidwell") to improve the dose coverage and applicability of Leipzig-style applicators. METHODS AND MATERIALS A virtual model of the Leipzig-style applicator was commissioned for a model-based dose calculation algorithm (MBDCA) and compared against American Association of Physicists in Medicine working group 186 benchmarking data sets and ionization chamber point measurements. An absolute dosimetry technique based on radiochromic film was used to validate both single-dwell and multidwell plans. RESULTS Dose distributions generated from the MBDCA-based virtual model were consistent with working group data sets, ion chamber measurements, and radiochromic film analysis. In one multidwell configuration, at 3 mm prescription depth, the 80% isodose width was increased to 25 mm, compared with 15 mm in the same dimension for a single-dwell delivery. In the same multidwell configuration, the flatness, measured as >98% isodose line, was more than doubled to 8 mm, compared with 3 mm in the same dimension. For multidwell plans, 2-D planar agreement between radiochromic film and MBDCA exceeded 93% in gamma analysis (3%/1 mm criteria). Submillimeter positional agreement was found, with a total dosimetric uncertainty of 4.5% estimated for the entire system. CONCLUSIONS Leipzig-style surface applicators with multiple-source dwell positions have been benchmarked against radiochromic film dosimetry. Results show that the clinically viable coverage area can be increased significantly.
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Affiliation(s)
- Christopher J Tien
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT.
| | - Daniel W Pinkham
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
| | - Zhe Jay Chen
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
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Rogers B, Lawrence J, Chmura J, Ehler E, Ferreira C. Dosimetric characterization of a novel 90Y source for use in the conformal superficial brachytherapy device. Phys Med 2020; 72:52-59. [PMID: 32200298 DOI: 10.1016/j.ejmp.2020.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/16/2020] [Accepted: 03/01/2020] [Indexed: 12/12/2022] Open
Abstract
PURPOSE To characterize the dose distribution in water of a novel beta-emitting brachytherapy source for use in a Conformal Superficial Brachytherapy (CSBT) device. METHODS AND MATERIALS Yttrium-90 (90Y) sources were designed for use with a uniquely designed CSBT device. Depth dose and planar dose measurements were performed for bare sources and sources housed within a 3D printed source holder. Monte Carlo simulated dose rate distributions were compared to film-based measurements. Gamma analysis was performed to compare simulated and measured dose rates from seven 90Y sources placed simultaneously using the CSBT device. RESULTS The film-based maximum measured surface dose rate for a bare source in contact with the surface was 3.35 × 10-7 cGy s-1 Bq-1. When placed in the source holder, the maximum measured dose rate was 1.41 × 10-7 cGy s-1 Bq-1. The Monte Carlo simulated depth dose rates were within 10% or 0.02 cm of the measured dose rates for each depth of measurement. The maximum film surface dose rate measured using a seven-source configuration within the CSBT device was 1.78 × 10-7 cGy s-1 Bq-1. Measured and simulated dose rate distribution of the seven-source configuration were compared by gamma analysis and yielded a passing rate of 94.08%. The gamma criteria were 3% for dose-difference and 0.07056 cm for distance-to-agreement. The estimated measured dose rate uncertainty was 5.34%. CONCLUSIONS 90Y is a unique source that can be optimally designed for a customized CSBT device. The rapid dose falloff provided a high dose gradient, ideal for treatment of superficial lesions. The dose rate uncertainty of the 90Y-based CSBT device was within acceptable brachytherapy standards and warrants further investigation.
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Affiliation(s)
- Brent Rogers
- University of Minnesota Medical School, Department of Radiation Oncology, United States.
| | - Jessica Lawrence
- University of Minnesota, College of Veterinary Medicine and Masonic Cancer Center, United States
| | - Jennifer Chmura
- University of Minnesota, Medical Devices Center, United States
| | - Eric Ehler
- University of Minnesota Medical School, Department of Radiation Oncology, United States
| | - Clara Ferreira
- University of Minnesota Medical School, Department of Radiation Oncology, United States
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Murphy L. The dosimetric effect of variations in source position on treatments using Leipzig-style brachytherapy skin applicators. Biomed Phys Eng Express 2020; 6:015031. [PMID: 33438619 DOI: 10.1088/2057-1976/ab6ecf] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Leipzig-style skin brachytherapy applicators are an excellent choice for the treatment of small surface lesions, since they can be used with a high dose rate source to produce a tightly constrained treatment field on the desired area of the skin. The dosimetry of these applicators is challenging to independently verify due to their small dimensions, complex energy spectrum and steep dose gradients. In particular the close proximity of the brachytherapy source to the treatment region is cause for concern, since small variations in the position of the radioactive source may significantly affect the resulting dose distribution. The aim of this work was to assess the dosimetry of these applicators using three independently techniques and use these results to examine the effect of variation in source position on the dose distribution. Simulation of different sized applicators in conjunction with a Gammamed + Ir192 source was performed using the EGSnrc Monte Carlo code. Dose distributions at the prescription depth and at the surface generated by Monte Carlo were compared to the outputs of a commercially available treatment planning system and measurements using radiochromic film. Source displacements of up to 0.5 mm in the vertical direction, 0.65 mm in the horizontal direction, and rotations of the source by up to 5° were all simulated. Changes in dose of over 6% at the prescription point and reductions in coverage at the 100% isodose level of several millimetres were observed even for small shifts of the source from its intended position. This work demonstrates that variation in the position of the radiation source is the dominant source of uncertainty in the use of these types of applicators. Centres wishing to perform treatments using these applicators are advised to take steps to control the uncertainty and ensure it remains at an acceptable level.
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Affiliation(s)
- Liam Murphy
- Department of Radiotherapy, NHS Grampian, Aberdeen, United Kingdom
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Callaghan CM, Adams Q, Flynn RT, Wu X, Xu W, Kim Y. Systematic Review of Intensity-Modulated Brachytherapy (IMBT): Static and Dynamic Techniques. Int J Radiat Oncol Biol Phys 2019; 105:206-221. [DOI: 10.1016/j.ijrobp.2019.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/27/2019] [Accepted: 04/11/2019] [Indexed: 02/06/2023]
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Individual 3-dimensional printed mold for treating hard palate carcinoma with brachytherapy: A clinical report. J Prosthet Dent 2018; 121:690-693. [PMID: 30503148 DOI: 10.1016/j.prosdent.2018.06.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 06/11/2018] [Accepted: 06/11/2018] [Indexed: 12/17/2022]
Abstract
This clinical report describes the use of a 3-dimensional (3D) printer to create an individual mold for delivering high-dose-rate interventional radiotherapy for hard palate cancer. The maxillary teeth and palate were scanned with an intraoral scanner (3Shape TRIOS 3). The scan was transformed into a mesh using the standard tessellation language (STL) format and aligned with Digital Imaging and Communications in Medicine (DICOM) computed tomography (CT) images using free Blue Sky Plan 4 planning software. A mold was generated by tracing a guideline around the gingival margins of the maxillary teeth and palate on the scan mesh in accordance with established parameters. All data were imported into computer-aided design (CAD) software. For this patient, 3 parallel 2.2-mm-diameter ducts were placed 10 mm from each other in the mold mesh. A CT scan of the patient's mouth with the mold in place was used for treatment planning. Treatment was delivered by means of microSelectron digital afterloading.
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Gimenez-Alventosa V, Gimenez V, Ballester F, Vijande J, Andreo P. Correction factors for ionization chamber measurements with the 'Valencia' and 'large field Valencia' brachytherapy applicators. Phys Med Biol 2018; 63:125004. [PMID: 29726409 DOI: 10.1088/1361-6560/aac27a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Treatment of small skin lesions using HDR brachytherapy applicators is a widely used technique. The shielded applicators currently available in clinical practice are based on a tungsten-alloy cup that collimates the source-emitted radiation into a small region, hence protecting nearby tissues. The goal of this manuscript is to evaluate the correction factors required for dose measurements with a plane-parallel ionization chamber typically used in clinical brachytherapy for the 'Valencia' and 'large field Valencia' shielded applicators. Monte Carlo simulations have been performed using the PENELOPE-2014 system to determine the absorbed dose deposited in a water phantom and in the chamber active volume with a Type A uncertainty of the order of 0.1%. The average energies of the photon spectra arriving at the surface of the water phantom differ by approximately 10%, being 384 keV for the 'Valencia' and 343 keV for the 'large field Valencia'. The ionization chamber correction factors have been obtained for both applicators using three methods, their values depending on the applicator being considered. Using a depth-independent global chamber perturbation correction factor and no shift of the effective point of measurement yields depth-dose differences of up to 1% for the 'Valencia' applicator. Calculations using a depth-dependent global perturbation factor, or a shift of the effective point of measurement combined with a constant partial perturbation factor, result in differences of about 0.1% for both applicators. The results emphasize the relevance of carrying out detailed Monte Carlo studies for each shielded brachytherapy applicator and ionization chamber.
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Affiliation(s)
- V Gimenez-Alventosa
- Instituto de Instrumentación para Imagen Molecular (I3M), Centro Mixto CSIC-Universitat Politècnica de València, 46022 Valencia, Spain
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Guinot JL, Rembielak A, Perez-Calatayud J, Rodríguez-Villalba S, Skowronek J, Tagliaferri L, Guix B, Gonzalez-Perez V, Valentini V, Kovacs G. GEC-ESTRO ACROP recommendations in skin brachytherapy. Radiother Oncol 2018; 126:377-385. [PMID: 29455924 DOI: 10.1016/j.radonc.2018.01.013] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 01/18/2018] [Indexed: 01/21/2023]
Abstract
PURPOSE The aim of this publication is to compile available literature data and expert experience regarding skin brachytherapy (BT) in order to produce general recommendations on behalf of the GEC-ESTRO Group. METHODS We have done an exhaustive review of published articles to look for general recommendations. RESULTS Randomized controlled trials, systemic reviews and meta-analysis are lacking in literature and there is wide variety of prescription techniques successfully used across the radiotherapy centers. BT can be delivered as superficial application (also called contact BT or plesiotherapy) or as interstitial for tumours thicker than 5 mm within any surface, including very irregular. In selected cases, particularly in tumours located within curved surfaces, BT can be advantageous modality from dosimetric and planning point of view when compared to external beam radiotherapy. The general rule in skin BT is that the smaller the target volume, the highest dose per fraction and the shortest overall length of treatment can be used. CONCLUSION Skin cancer incidence is rising worldwide. BT offers an effective non-invasive or minimally invasive and relative short treatment that particularly appeals to elder and frail population.
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Affiliation(s)
- Jose L Guinot
- Department of Radiation Oncology, Foundation Instituto Valenciano de Oncologia (I.V.O.), Valencia, Spain
| | - Agata Rembielak
- Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Jose Perez-Calatayud
- Department of Radiation Oncology, La Fe University Hospital-IRIMED, Valencia, Spain
| | | | - Janusz Skowronek
- Brachytherapy Department, Greater Poland Cancer Centre, Poznań, Poland; Electroradiology Department, Poznan University of Medical Sciences, Poland
| | - Luca Tagliaferri
- Polo Scienze Oncologiche ed Ematologiche, Istituto di Radiologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Benjamin Guix
- Department of Radiation Oncology, Foundation IMOR, Barcelona, Spain
| | - Victor Gonzalez-Perez
- Department of Radiation Physics, Foundation Instituto Valenciano de Oncologia (I.V.O.), Valencia, Spain
| | - Vincenzo Valentini
- Polo Scienze Oncologiche ed Ematologiche, Istituto di Radiologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - György Kovacs
- Interdisciplinary Brachytherapy Unit, UKSH CL, Lübeck, Germany
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18
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High-dose-rate brachytherapy in the treatment of skin Kaposi sarcoma. J Contemp Brachytherapy 2017; 9:561-565. [PMID: 29441101 PMCID: PMC5807994 DOI: 10.5114/jcb.2017.72053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 11/18/2017] [Indexed: 11/17/2022] Open
Abstract
Purpose The aim of the study is to review our experience in treatment of Kaposi sarcoma (KS) lesions with high-dose-rate (HDR) brachytherapy. Material and methods We present five new KS lesions (three patients) that were treated in our hospital from May 2016 to February 2017 with HDR brachytherapy using Valencia applicators. The treatment was delivered in 5 Gy fractions over five sessions, on alternate days. Total dose of 25 Gy (EQD2 31.25 Gy) was delivered. All patients were male, Caucasian, without a history of HIV, organ transplantation, or current immunosuppressive therapy. The median age was 76 years. Results All lesions (100%) were located in lower limbs (60% in the ankle, 20% in the leg, and 20% in the foot), and their development was progressive. No lesion was greater than 2 cm (range, 0.5-1.5 cm). With a median follow-up of 15 months, all patients had a complete response to the treatment, with no evidence of local recurrence or tumor progression. Most of the patients (80%) had no acute toxicity; only one patient developed erythema grade 2. Conclusions HDR brachytherapy could be a good option of treatment for these types of lesions, especially in elderly patients, or when cosmetic results are not good after surgery. Brachytherapy with the Valencia applicator, using hypofractionated regimen provides excellent results in terms of cosmetic and local control, and furthermore, facilitates treatment compliance, which is very relevant in elderly patients. HDR brachytherapy offers a simple, safe, quick, and attractive non-surgical treatment option.
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19
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Kim HN, Lee JH, Park HB, Kim HJ, Cho SO. Surface applicator of a miniature X-ray tube for superficial electronic brachytherapy of skin cancer. Med Phys 2017; 45:29-36. [DOI: 10.1002/mp.12656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 10/13/2017] [Accepted: 10/23/2017] [Indexed: 12/12/2022] Open
Affiliation(s)
- Hyun Nam Kim
- Department of Nuclear and Quantum Engineering; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Ju Hyuk Lee
- Department of Nuclear and Quantum Engineering; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Han Beom Park
- Department of Nuclear and Quantum Engineering; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
| | - Hyun Jin Kim
- Department of Radiation Oncology; Asan Medical Center; Seoul 05505 Korea
| | - Sung Oh Cho
- Department of Nuclear and Quantum Engineering; Korea Advanced Institute of Science and Technology; Daejeon 305-701 Korea
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20
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Anagnostopoulos G, Andrássy M, Baltas D. The Bebig Valencia-type skin applicators: Dosimetric study and implementation of a dosimetric hybrid technique. Brachytherapy 2017. [DOI: 10.1016/j.brachy.2017.04.243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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21
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Dose comparison between TG-43–based calculations and radiochromic film measurements of the Freiburg flap applicator used for high-dose-rate brachytherapy treatments of skin lesions. Brachytherapy 2017; 16:1065-1072. [DOI: 10.1016/j.brachy.2017.06.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 06/24/2017] [Accepted: 06/26/2017] [Indexed: 11/19/2022]
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22
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Rodríguez S, Arenas M, Gutierrez C, Richart J, Perez-Calatayud J, Celada F, Santos M, Rovirosa A. Recommendations of the Spanish brachytherapy group (GEB) of Spanish Society of Radiation Oncology (SEOR) and the Spanish Society of Medical Physics (SEFM) for high-dose rate (HDR) non melanoma skin cancer brachytherapy. Clin Transl Oncol 2017; 20:431-442. [PMID: 28808925 DOI: 10.1007/s12094-017-1733-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 07/28/2017] [Indexed: 12/13/2022]
Abstract
Clinical indications of brachytherapy in non-melanoma skin cancers, description of applicators and dosimetry recommendations are described based on the literature review, clinical practice and experience of Spanish Group of Brachytherapy and Spanish Society of Medical Physics reported in the XIV Annual Consensus Meeting on Non Melanoma Skin Cancer Brachytherapy held in Benidorm, Alicante (Spain) on October 21st, 2016. All the recommendations for which consensus was achieved are highlighted in blue. Regular and small surfaces may be treated with Leipzig, Valencia, flap applicators or electronic brachytherapy (EBT). For irregular surfaces, customized molds or interstitial implants should be employed. The dose is prescribed at a maximum depth of 3-4 mm of the clinical target volume/planning target volume (CTV/PTV) in all cases except in flaps or molds in which 5 mm is appropriate. Interstitial brachytherapy should be used for CTV/PTV >5 mm. Different total doses and fraction sizes are used with very similar clinical and toxicity results. Hypofractionation is very useful twice or 3 times a week, being comfortable for patients and practical for Radiotherapy Departments. In interstitial brachytherapy 2 fractions twice a day are applied.
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Affiliation(s)
- S Rodríguez
- Radiation Oncology Department, Hospital Clínica Benidorm, Av. Alfonso Puchades 8, 30501, Benidorm, Alicante, Spain.
| | - M Arenas
- Radiation Oncology Department, Hospital Universitari Sant Joan de Reus, Tarragona, Spain
| | - C Gutierrez
- Radiation Oncology Department, Institut Català d'Oncologia, Hospitalet de Llobregat, Catalonia, Spain
| | - J Richart
- Radiation Oncology Department, Hospital Clínica Benidorm, Av. Alfonso Puchades 8, 30501, Benidorm, Alicante, Spain
| | - J Perez-Calatayud
- Radiation Oncology Department, Hospital La Fe-IRIMED, Valencia, Spain
| | - F Celada
- Radiation Oncology Department, Hospital La Fe-IRIMED, Valencia, Spain
| | - M Santos
- Radiation Oncology Department, Hospital Clínica Benidorm, Av. Alfonso Puchades 8, 30501, Benidorm, Alicante, Spain
| | - A Rovirosa
- Radiation Oncology Department, ICMHO, Hospital Clínic I Universitari, Barcelona, Spain
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23
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Safigholi H, Meigooni AS, Song WY. Comparison of192Ir,169Yb, and60Co high-dose rate brachytherapy sources for skin cancer treatment. Med Phys 2017; 44:4426-4436. [DOI: 10.1002/mp.12335] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 04/18/2017] [Accepted: 04/23/2017] [Indexed: 02/06/2023] Open
Affiliation(s)
- Habib Safigholi
- Department of Medical Physics; Odette Cancer Centre; Sunnybrook Research Institute; Sunnybrook Hospital; University of Toronto; Toronto ON Canada
- Department of Electrical Engineering; Shiraz Branch; Islamic Azad University; Shiraz Iran
| | - Ali S. Meigooni
- School of Allied Health Science; University of Nevada Las Vegas (UNLV); Las Vegas NV USA
| | - William Y. Song
- Department of Medical Physics; Odette Cancer Centre; Sunnybrook Research Institute; Sunnybrook Hospital; University of Toronto; Toronto ON Canada
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Nath R, Rivard MJ, DeWerd LA, Dezarn WA, Thompson Heaton H, Ibbott GS, Meigooni AS, Ouhib Z, Rusch TW, Siebert FA, Venselaar JLM. Guidelines by the AAPM and GEC-ESTRO on the use of innovative brachytherapy devices and applications: Report of Task Group 167. Med Phys 2017; 43:3178-3205. [PMID: 27277063 DOI: 10.1118/1.4951734] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Although a multicenter, Phase III, prospective, randomized trial is the gold standard for evidence-based medicine, it is rarely used in the evaluation of innovative devices because of many practical and ethical reasons. It is usually sufficient to compare the dose distributions and dose rates for determining the equivalence of the innovative treatment modality to an existing one. Thus, quantitative evaluation of the dosimetric characteristics of innovative radiotherapy devices or applications is a critical part in which physicists should be actively involved. The physicist's role, along with physician colleagues, in this process is highlighted for innovative brachytherapy devices and applications and includes evaluation of (1) dosimetric considerations for clinical implementation (including calibrations, dose calculations, and radiobiological aspects) to comply with existing societal dosimetric prerequisites for sources in routine clinical use, (2) risks and benefits from a regulatory and safety perspective, and (3) resource assessment and preparedness. Further, it is suggested that any developed calibration methods be traceable to a primary standards dosimetry laboratory (PSDL) such as the National Institute of Standards and Technology in the U.S. or to other PSDLs located elsewhere such as in Europe. Clinical users should follow standards as approved by their country's regulatory agencies that approved such a brachytherapy device. Integration of this system into the medical source calibration infrastructure of secondary standard dosimetry laboratories such as the Accredited Dosimetry Calibration Laboratories in the U.S. is encouraged before a source is introduced into widespread routine clinical use. The American Association of Physicists in Medicine and the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) have developed guidelines for the safe and consistent application of brachytherapy using innovative devices and applications. The current report covers regulatory approvals, calibration, dose calculations, radiobiological issues, and overall safety concerns that should be addressed during the commissioning stage preceding clinical use. These guidelines are based on review of requirements of the U.S. Nuclear Regulatory Commission, U.S. Department of Transportation, International Electrotechnical Commission Medical Electrical Equipment Standard 60601, U.S. Food and Drug Administration, European Commission for CE Marking (Conformité Européenne), and institutional review boards and radiation safety committees.
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Affiliation(s)
- Ravinder Nath
- Department of Therapeutic Radiology, School of Medicine, Yale University, New Haven, Connecticut 06510
| | - Mark J Rivard
- Department of Radiation Oncology, School of Medicine, Tufts University, Boston, Massachusetts 02111
| | - Larry A DeWerd
- Accredited Dosimetry and Calibration Laboratory, University of Wisconsin, Madison, Wisconsin 53706
| | - William A Dezarn
- Department of Radiation Oncology, School of Medicine, Wake Forest University, Winston-Salem, North Carolina 27157
| | | | - Geoffrey S Ibbott
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030
| | - Ali S Meigooni
- Comprehensive Cancer Centers of Nevada, Las Vegas, Nevada 89169
| | - Zoubir Ouhib
- Radiation Oncology, Lynn Regional Cancer Center, Delray Beach, Florida 33484
| | - Thomas W Rusch
- Xoft, Inc., A Subsidiary of iCAD, Inc., San Jose, California 95134
| | - Frank-André Siebert
- Clinic of Radiotherapy, Universitätsklinikum Schleswig-Holstein, Campus Kiel, Kiel 24105, Germany
| | - Jack L M Venselaar
- Department of Medical Physics and Engineering, Instituut Verbeeten, Tilburg LA 5000, The Netherlands
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Delishaj D, Rembielak A, Manfredi B, Ursino S, Pasqualetti F, Laliscia C, Orlandi F, Morganti R, Fabrini MG, Paiar F. Non-melanoma skin cancer treated with high-dose-rate brachytherapy: a review of literature. J Contemp Brachytherapy 2016; 8:533-540. [PMID: 28115960 PMCID: PMC5241375 DOI: 10.5114/jcb.2016.64112] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 11/01/2016] [Indexed: 11/18/2022] Open
Abstract
PURPOSE The incidence of non-melanoma skin cancer (NMSC) has been increasing over the past 30 years. There are different treatment options and surgical excision is the most frequent treatment due to its low rates of recurrence. Radiotherapy is an effective alternative of surgery, and brachytherapy (BT) might be a better therapeutic option due to high radiation dose concentration to the tumor with rapid dose fall-off resulting in normal tissues sparing. The aim of this review was to evaluate the local control, toxicity, and cosmetic outcomes in NMSC treated with high-dose-rate BT (HDR-BT). MATERIAL AND METHODS In May 2016, a systematic search of bibliographic database of PubMed, Web of Science, Scopus, and Cochrane Library with a combination of key words of "skin cancer", "high dose rate brachytherapy", "squamous cell carcinoma", "basal cell carcinoma", and "non melanoma skin cancer" was performed. In this systematic review, we included randomized trials, non-randomized trials, prospective and retrospective studies in patients affected by NMSC treated with HDR-BT. RESULTS Our searches generated a total of 85 results, and through a process of screening, 10 publications were selected for the review. Brachytherapy was well tolerated with acceptable toxicity and high local control rates (median: 97%). Cosmetic outcome was reported in seven study and consisted in an excellent and good cosmetic results in 94.8% of cases. CONCLUSIONS Based on the review data, we can conclude that the treatment of NMSC with HDR-BT is effective with excellent and good cosmetics results, even in elderly patients. The hypofractionated course appears effective with very good local disease control. More data with large-scale randomized controlled trials are needed to assess the efficacy and safety of brachytherapy.
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Affiliation(s)
- Durim Delishaj
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
| | - Agata Rembielak
- Clinical Oncologist, The Christie NHS Foundation Trust, Manchester, M20 4BX, United Kingdom
| | - Bruno Manfredi
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
| | - Stefano Ursino
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
| | - Francesco Pasqualetti
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
| | - Concetta Laliscia
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
| | - Francesca Orlandi
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
| | - Riccardo Morganti
- Department of Experimental and Clinical Medicine, Section of Statistics – University of Pisa, Pisa, Italy
| | - Maria Grazia Fabrini
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
| | - Fabiola Paiar
- Department of Translational Medicine, Division of Radiation Oncology – University of Pisa, Pisa, Italy
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Commissioning and quality assurance procedures for the HDR Valencia skin applicators. J Contemp Brachytherapy 2016; 8:441-447. [PMID: 27895687 PMCID: PMC5116455 DOI: 10.5114/jcb.2016.63387] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/17/2016] [Indexed: 11/17/2022] Open
Abstract
The Valencia applicators (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden) are cup-shaped tungsten applicators with a flattening filter used to collimate the radiation produced by a high-dose-rate (HDR) 192Ir source, and provide a homogeneous absorbed dose at a given depth. This beam quality provides a good option for the treatment of skin lesions at shallow depth (3-4 mm). The user must perform commissioning and periodic testing of these applicators to guarantee the proper and safe delivery of the intended absorbed dose, as recommended in the standards in radiation oncology. In this study, based on AAPM and GEC-ESTRO guidelines for brachytherapy units and our experience, a set of tests for the commissioning and periodic testing of the Valencia applicators is proposed. These include general considerations, verification of the manufacturer documentation and physical integrity, evaluation of the source-to-indexer distance and reproducibility, setting the library plan in the treatment planning system, evaluation of flatness and symmetry, absolute output and percentage depth dose verification, independent calculation of the treatment time, and visual inspection of the applicator before each treatment. For each test, the proposed methodology, equipment, frequency, expected results, and tolerance levels (when applicable) are provided.
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27
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Villalba SR, Perez-Calatayud MJ, Bautista JA, Carmona V, Celada F, Tormo A, García-Martinez T, Richart J, Ortega MS, Silla M, Ballester F, Perez-Calatayud J. Novel simple templates for reproducible positioning of skin applicators in brachytherapy. J Contemp Brachytherapy 2016; 8:344-8. [PMID: 27648089 PMCID: PMC5018523 DOI: 10.5114/jcb.2016.61713] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 07/18/2016] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Esteya and Valencia surface applicators are designed to treat skin tumors using brachytherapy. In clinical practice, in order to avoid errors that may affect the treatment outcome, there are two issues that need to be carefully addressed. First, the selected applicator for the treatment should provide adequate margin for the target, and second, the applicator has to be precisely positioned before each treatment fraction. In this work, we describe the development and use of a new acrylic templates named Template La Fe-ITIC. They have been designed specifically to help the clinical user in the selection of the correct applicator, and to assist the medical staff in reproducing the positioning of the applicator. These templates are freely available upon request. MATERIAL AND METHODS Templates that were developed by University and Polytechnic Hospital La Fe (La Fe) and Hospital Clínica Benidorm (ITIC) in cooperation with Elekta, consist of a thin sheet made of transparent acrylic. For each applicator, a crosshair and two different circles are drawn on these templates: the inner one corresponds to the useful beam, while the outer one represents the external perimeter of the applicator. The outer circle contains slits that facilitate to draw a circle on the skin of the patient for exact positioning of the applicator. In addition, there are two perpendicular rulers to define the adequate margin. For each applicator size, a specific template was developed. RESULTS The templates have been used successfully in our institutions for more than 50 patients' brachytherapy treatments. They are currently being used for Esteya and Valencia applicators. CONCLUSIONS The template La Fe-ITIC is simple and practical. It improves both the set-up time and reproducibility. It helps to establish the adequate margins, an essential point in the clinical outcome.
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Affiliation(s)
| | | | | | - Vicente Carmona
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia
| | - Francisco Celada
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia
| | - Alejandro Tormo
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia
| | | | - José Richart
- Radiotherapy Department, Clínica Benidorm, Benidorm
| | | | - Magda Silla
- Dermatology Department, Clínica Benidorm, Benidorm
| | - Facundo Ballester
- Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot, Spain
| | - Jose Perez-Calatayud
- Radiotherapy Department, Clínica Benidorm, Benidorm; Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia
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Granero D, Candela-Juan C, Vijande J, Ballester F, Perez-Calatayud J, Jacob D, Mourtada F. Technical Note: Dosimetry of Leipzig and Valencia applicators without the plastic cap. Med Phys 2016; 43:2087. [DOI: 10.1118/1.4944784] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Candela-Juan C, Niatsetski Y, van der Laarse R, Granero D, Ballester F, Perez-Calatayud J, Vijande J. Design and characterization of a new high-dose-rate brachytherapy Valencia applicator for larger skin lesions. Med Phys 2016; 43:1639. [DOI: 10.1118/1.4943381] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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30
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Delishaj D, Laliscia C, Manfredi B, Ursino S, Pasqualetti F, Lombardo E, Perrone F, Morganti R, Paiar F, Fabrini MG. Non-melanoma skin cancer treated with high-dose-rate brachytherapy and Valencia applicator in elderly patients: a retrospective case series. J Contemp Brachytherapy 2015; 7:437-44. [PMID: 26816500 PMCID: PMC4716125 DOI: 10.5114/jcb.2015.55746] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 10/22/2015] [Indexed: 11/17/2022] Open
Abstract
PURPOSE The incidence of non-melanoma skin cancer (NMSC) has been increasing over the past 30 years. Basal cell carcinoma and squamous cell carcinoma are the two most common subtypes of NMSC. The aim of this study was to estimate tumour control, toxicity, and aesthetic events in elderly patients treated with high-dose-rate (HDR) brachytherapy (BT) using Valencia applicator. MATERIAL AND METHODS From January 2012 to May 2015, 57 lesions in 39 elderly eligible patients were enrolled. All the lesions had a diameter ≤ 25 mm (median: 12.5 mm) and a depth ≤ 4 mm. The appropriate Valencia applicator, 2 or 3 cm in diameter was used. The prescribed dose was 40 Gy in 8 fractions (5 Gy/fraction) in 48 lesions (group A), and 50 Gy in 10 fractions (5 Gy/fraction) in 9 lesions (group B), delivered 2/3 times a week. The biological effective dose (BED) was 60 Gy and 75 Gy, respectively. RESULTS After median follow-up of 12 months, 96.25% lesions showed a complete response and only two cases presented partial remission. Radiation Therapy Oncology Group - European Organization for Research and Treatment of Cancer (RTOG/EORTC) G 1-2 acute toxicities were observed in 63.2% of the lesions: 56.3% in group A and 77.7% in group B. Late G1-G2 toxicities was observed in 19.3% of the lesions: 18.8% in group A and 22.2% in group B, respectively. No G3 or higher acute or late toxicities occurred. In 86% of the lesions, an excellent cosmetic result was observed (87.5% in group A and 77.8% in group B). Six lesions had a good cosmetic outcome and only 2.3% presented a fair cosmetic impact. CONCLUSIONS The treatment of NMSC with HDR-BT using Valencia surface applicator is effective with excellent and good cosmetics results in elderly patients. The hypofractionated course appears effective and no statistical differences were observed between the two groups analysed.
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Affiliation(s)
| | | | | | | | | | | | | | - Riccardo Morganti
- Section of Statistics, Azienda Ospedaliero Universitaria Pisana, University of Pisa, Pisa, Italy
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Safigholi H, Song WY, Meigooni AS. Optimum radiation source for radiation therapy of skin cancer. J Appl Clin Med Phys 2015; 16:219–227. [PMID: 26699302 PMCID: PMC5690147 DOI: 10.1120/jacmp.v16i5.5407] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 04/23/2015] [Accepted: 04/15/2015] [Indexed: 01/23/2023] Open
Abstract
Several different applicators have been designed for treatment of skin cancers, such as scalp, hand, and legs using Ir‐192 HDR brachytherapy sources (IR‐HDRS), miniature electronic brachytherapy sources (eBT), and external electron beam radiation therapy (EEBRT). Although, all of these methodologies may deliver the desired radiation dose to the skin, but the dose to the underlying bone may become the limiting factor for selection of the optimum treatment technique. In this project, dose to the underlying bone has been evaluated as a function of the radiation type, thickness of the bone, and thickness of the soft tissue on top of bone, assuming the same radiation dose delivery to the skin. These evaluations are performed using Monte Carlo (MC) simulation technique with MCNP5 code. The results of these investigations indicate that, for delivery of the same skin dose with a 50 keV eBT, 4 MeV or 6 MeV EEBRT techniques, the average doses received by the underlying bones are 5.31, 2, or 1.75 times the dose received from IR‐HDRS technique, respectively. These investigations indicate that, for the treatment of skin cancer condition with bone immediately beneath skin, the eBT technique may not be the most suitable technique, as it may lead to excessive bone dose relative to IR‐HDRS and 6 MeV or 4 MeV electron beams. PACS number: 87.53.Jw, 87.55.K‐
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Affiliation(s)
- Habib Safigholi
- Odette Cancer Centre, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, University of Toronto.
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Ouhib Z, Kasper M, Perez Calatayud J, Rodriguez S, Bhatnagar A, Pai S, Strasswimmer J. Aspects of dosimetry and clinical practice of skin brachytherapy: The American Brachytherapy Society working group report. Brachytherapy 2015; 14:840-58. [PMID: 26319367 DOI: 10.1016/j.brachy.2015.06.005] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/21/2015] [Accepted: 06/17/2015] [Indexed: 11/16/2022]
Abstract
PURPOSE Nonmelanoma skin cancers (NMSCs) are the most common type of human malignancy. Although surgical techniques are the standard treatment, radiation therapy using photons, electrons, and brachytherapy (BT) (radionuclide-based and electronic) has been an important mode of treatment in specific clinical situations. The purpose of this work is to provide a clinical and dosimetric summary of the use of BT for the treatment of NMSC and to describe the different BT approaches used in treating cutaneous malignancies. METHODS AND MATERIALS A group of experts from the fields of radiation oncology, medical physics, and dermatology, who specialize in managing cutaneous malignancies reviewed the literature and compiled their clinical experience regarding the clinical and dosimetric aspects of skin BT. RESULTS A dosimetric and clinical review of both high dose rate ((192)Ir) and electronic BT treatment including surface, interstitial, and custom mold applicators is given. Patient evaluation tools such as staging, imaging, and patient selection criteria are discussed. Guidelines for clinical and dosimetric planning, appropriate margin delineation, and applicator selection are suggested. Dose prescription and dose fractionation schedules, as well as prescription depth are discussed. Commissioning and quality assurance requirements are also outlined. CONCLUSIONS Given the limited published data for skin BT, this article is a summary of the limited literature and best practices currently in use for the treatment of NMSC.
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Affiliation(s)
- Zoubir Ouhib
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton, FL.
| | - Michael Kasper
- Department of Radiation Oncology, Lynn Cancer Institute, Boca Raton, FL
| | - Jose Perez Calatayud
- Department of Radiation Oncology, Hospital La Fe, Valencia, Spain; Department of Radiation Oncology, Hospital Clinica Benidorm, Alicante, Spain
| | - Silvia Rodriguez
- Department of Radiation Oncology, Hospital Clinica Benidorm, Alicante, Spain
| | - Ajay Bhatnagar
- Department of Radiation Oncology, 21st Century Oncology Inc., Casa Grande, Arizona
| | - Sujatha Pai
- Department of Radiation Oncology, Targeted Radiation Therapy Institute, Pleasanton, CA
| | - John Strasswimmer
- Department of Biochemistry, Florida Atlantic University College of Medicine, Boca Raton, FL; Department of Dermatology, Florida Atlantic University College of Medicine, Boca Raton, FL
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Valdés CN, Píriz GH, Lozano E. Brachytherapy treatment planning commissioning: effect of the election of proper bibliography and finite size of TG-43 input data on standard treatments. J Appl Clin Med Phys 2015. [PMID: 26218990 PMCID: PMC5690009 DOI: 10.1120/jacmp.v16i4.4730] [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] [Indexed: 11/24/2022] Open
Abstract
The aim of this work is to evaluate the performance of a commercial brachytherapy treatment planning system (TPS) with TG‐43 Vendors Input Data (VID), analyze possible discrepancies with respect to a proper reference source and its implications for standard treatments, and judge the effectiveness of certain widespread recommended quality controls to find potential errors related with the interpolations of TG‐43 VID tables. The TPS evaluated was a BrachyVision 8.6 loaded with TG‐43 VID for a VariSource high‐dose‐rate 192Ir source (Vs2000). The reference data chosen were the TG‐43 data published in the literature. In the first step, we compared TG‐43 VID with respect to the chosen reference data. Next, we used percent dose‐rate differences in a point array matrix to compare the outcomes of the TPS on standard treatment setup with respect to an in‐house developed program (MATLAB R2009a‐based) loaded with the chosen full TG‐43 reference data. The cases with major discrepancies were evaluated using the gamma‐index analysis. The comparison with the reference data indicated a lack of sample in the angles between near to the tip (between 165<θ<180) and cable (0<θ<15) of the F(r,θ)VID, which causes a dose underestimation of approximately 17% in the investigated points due to inaccurate interpolations. The differences over 2% encompassed approximately 17% of the surrounding source volume. These results have special relevance in treatment using one applicator with a few dwell steps or in Fletcher treatments where 10% dose underestimates were identified within the tumor or in organs at risk, respectively. Our results suggest that the differences found in the TPS under study are created by a lack of information on the angles in high‐gradient zones in the F(r,θ)VID, which generates important differences in dosimetric results. In contrast, the gamma analysis shows very good results (between 90% and 100% of passed points) in the analyzed treatments (one dwell and Fletcher). Further studies are required to exclude the possibility of finding noticeable effects in the DVH of treatment plans caused by the discrepancies here described. To achieve more strict control over the TPS dose‐rate calculation, we recommend using QA test thinking in a source with nonaxial symmetry, adding a control point on the angles of the high‐dose gradient zones (e.g., between 0° and 15° and between 165° and 180°). More studies are required to achieve full understanding of the clinical implication of such discrepancies. PACS number: 87.55.Qr
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Sarrut D, Bardiès M, Boussion N, Freud N, Jan S, Létang JM, Loudos G, Maigne L, Marcatili S, Mauxion T, Papadimitroulas P, Perrot Y, Pietrzyk U, Robert C, Schaart DR, Visvikis D, Buvat I. A review of the use and potential of the GATE Monte Carlo simulation code for radiation therapy and dosimetry applications. Med Phys 2015; 41:064301. [PMID: 24877844 DOI: 10.1118/1.4871617] [Citation(s) in RCA: 229] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In this paper, the authors' review the applicability of the open-source GATE Monte Carlo simulation platform based on the GEANT4 toolkit for radiation therapy and dosimetry applications. The many applications of GATE for state-of-the-art radiotherapy simulations are described including external beam radiotherapy, brachytherapy, intraoperative radiotherapy, hadrontherapy, molecular radiotherapy, and in vivo dose monitoring. Investigations that have been performed using GEANT4 only are also mentioned to illustrate the potential of GATE. The very practical feature of GATE making it easy to model both a treatment and an imaging acquisition within the same framework is emphasized. The computational times associated with several applications are provided to illustrate the practical feasibility of the simulations using current computing facilities.
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Affiliation(s)
- David Sarrut
- Université de Lyon, CREATIS; CNRS UMR5220; Inserm U1044; INSA-Lyon; Université Lyon 1; Centre Léon Bérard, France
| | - Manuel Bardiès
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France and Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France
| | | | - Nicolas Freud
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, 69008 Lyon, France
| | | | - Jean-Michel Létang
- Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Centre Léon Bérard, 69008 Lyon, France
| | - George Loudos
- Department of Medical Instruments Technology, Technological Educational Institute of Athens, Athens 12210, Greece
| | - Lydia Maigne
- UMR 6533 CNRS/IN2P3, Université Blaise Pascal, 63171 Aubière, France
| | - Sara Marcatili
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France and Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France
| | - Thibault Mauxion
- Inserm, UMR1037 CRCT, F-31000 Toulouse, France and Université Toulouse III-Paul Sabatier, UMR1037 CRCT, F-31000 Toulouse, France
| | - Panagiotis Papadimitroulas
- Department of Biomedical Engineering, Technological Educational Institute of Athens, 12210, Athens, Greece
| | - Yann Perrot
- UMR 6533 CNRS/IN2P3, Université Blaise Pascal, 63171 Aubière, France
| | - Uwe Pietrzyk
- Institut für Neurowissenschaften und Medizin, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany and Fachbereich für Mathematik und Naturwissenschaften, Bergische Universität Wuppertal, 42097 Wuppertal, Germany
| | - Charlotte Robert
- IMNC, UMR 8165 CNRS, Universités Paris 7 et Paris 11, Orsay 91406, France
| | - Dennis R Schaart
- Delft University of Technology, Faculty of Applied Sciences, Radiation Science and Technology Department, Delft Mekelweg 15, 2629 JB Delft, The Netherlands
| | | | - Irène Buvat
- IMNC, UMR 8165 CNRS, Universités Paris 7 et Paris 11, 91406 Orsay, France and CEA/DSV/I2BM/SHFJ, 91400 Orsay, France
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Ballester-Sánchez R, Pons-Llanas O, Llavador-Ros M, Botella-Estrada R, Ballester-Cuñat A, Tormo-Micó A, Javier Celadá-Álvarez F, Rodríguez-Villalba S, Santos-Ortega M, Ballester-Pallarés F, Perez-Calatayud J. Depth determination of skin cancers treated with superficial brachytherapy: ultrasound vs. histopathology. J Contemp Brachytherapy 2015; 6:356-61. [PMID: 25834579 PMCID: PMC4300362 DOI: 10.5114/jcb.2014.47860] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 10/20/2014] [Accepted: 11/08/2014] [Indexed: 02/07/2023] Open
Abstract
PURPOSE The purpose of this study is to compare high frequency ultrasonography (HFUS) and histpathologic assessment done by punch biopsy in order to determine depth of basal cell carcinoma (BCC), in both superficial and nodular BCCs prior to brachytherapy treatment. MATERIAL AND METHODS This study includes 20 patients with 10 superficial and 10 nodular BCCs. First, punch biopsy was done to confirm the diagnosis and to measure tumour depth (Breslow rate). Subsequently, HFUS was done to measure tumour depth to search for correlation of these two techniques. RESULTS Neither clear tendency nor significance of the punch biopsy vs. HFUS depth determination is observed. Depth value differences with both modalities resulted patient dependent and then consequence of its uncertainty. Conceptually, HFUS should determine the macroscopic lesion (gross tumour volume - GTV), while punch biopsy is able to detect the microscopic extension (clinical target volume - CTV). Uncertainties of HFUS are difficult to address, while punch biopsy is done just on a small lesion section, not necessarily the deepest one. CONCLUSIONS According to the results, HFUS is less accurate at very shallow depths. Nodular cases present higher depth determination differences than superficial ones. In our clinical practice, we decided to prescribe at 3 mm depth when HFUS measurements give depth lesion values smaller than this value.
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Affiliation(s)
| | - Olga Pons-Llanas
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia
| | | | | | | | | | | | | | | | | | - Jose Perez-Calatayud
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia
- Radiotherapy Department, Benidorm Hospital, Alicante
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Clinical implementation of a new electronic brachytherapy system for skin brachytherapy. J Contemp Brachytherapy 2014; 6:417-23. [PMID: 25834587 PMCID: PMC4300364 DOI: 10.5114/jcb.2014.47996] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/02/2014] [Accepted: 12/22/2014] [Indexed: 12/25/2022] Open
Abstract
Although surgery is usually the first-line treatment for nonmelanoma skin cancers, radiotherapy (RT) may be indicated in selected cases. Radiation therapy as primary therapy can result in excellent control rates, cosmetics, and quality of life. Brachytherapy is a radiation treatment modality that offers the most conformal option to patients. A new modality for skin brachytherapy is electronic brachytherapy. This involves the placement of a high dose rate X-ray source directly in a skin applicator close to the skin surface, and therefore combines the benefits of brachytherapy with those of low energy X-ray radiotherapy. The Esteya electronic brachytherapy system is specifically designed for skin surface brachytherapy procedures. The purpose of this manuscript is to describe the clinical implementation of the new Esteya electronic brachytherapy system, which may provide guidance for users of this system. The information covered includes patient selection, treatment planning (depth evaluation and margin determination), patient marking, and setup. The justification for the hypofractionated regimen is described and compared with others protocols in the literature. Quality assurance (QA) aspects including daily testing are also included. We emphasize that these are guidelines, and clinical judgment and experience must always prevail in the care of patients, as with any medical treatment. We conclude that clinical implementation of the Esteya brachytherapy system is simple for patients and providers, and should allow for precise and safe treatment of nonmelanoma skin cancers.
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Park JM, Kim IH, Ye SJ, Kim K. Evaluation of treatment plans using various treatment techniques for the radiotherapy of cutaneous Kaposi's sarcoma developed on the skin of feet. J Appl Clin Med Phys 2014; 15:4970. [PMID: 25493522 PMCID: PMC5711114 DOI: 10.1120/jacmp.v15i6.4970] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 08/03/2014] [Accepted: 07/28/2014] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study was to investigate the plan qualities of various treatment modalities for the radiotherapy of cutaneous Kaposi's sarcoma developed on the skin of the foot. A total of six virtual targets were generated on the skin of the foot in CT images. Five types of treatment plans were generated using photon beams (PB), electron beams (EB), high‐dose‐rate (HDR) brachytherapy with a Freiburg flap applicator, intensity‐modulated radiation therapy (IMRT), and volumetric‐modulated arc therapy (VMAT) techniques. Plans for each of the six targets (single‐target plans) and also for the combined target consisting of the six single targets combined (multitarget plans) were generated. Dose‐volumetric analysis was performed for the targets and normal tissues. The averaged conformity index (CI) and homogeneity index (HI) values for each single target using PB, EB, HDR, IMRT, and VMAT techniques were 1.97, 2.39, 1.60, 4.60, and 0.80 and 1.05, 1.11, 1.52, 1.04, and 1.04, respectively. For the multitarget, the CI values were 3.99, 5.08, 1.38, 1.95, and 0.84, and the values of HI were 1.10, 1.36, 1.43, 1.06, and 1.04, respectively. The averaged mean doses to normal tissue were 2.5, 2.7, 3.6, 1.7, and 2.9 Gy for single‐target plans, and 21.3, 14.6, 14.2, 14.3, and 13.0 Gy for the multitarget plans, respectively. The VMAT demonstrated dosimetric advantages and better treatment efficiency over other techniques for the radiotherapy of multifocal skin disease of the feet. PACS number: 87.55.dk
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Granero D, Perez-Calatayud J, Vijande J, Ballester F, Rivard MJ. Limitations of the TG-43 formalism for skin high-dose-rate brachytherapy dose calculations. Med Phys 2014; 41:021703. [PMID: 24506594 DOI: 10.1118/1.4860175] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE In skin high-dose-rate (HDR) brachytherapy, sources are located outside, in contact with, or implanted at some depth below the skin surface. Most treatment planning systems use the TG-43 formalism, which is based on single-source dose superposition within an infinite water medium without accounting for the true geometry in which conditions for scattered radiation are altered by the presence of air. The purpose of this study is to evaluate the dosimetric limitations of the TG-43 formalism in HDR skin brachytherapy and the potential clinical impact. METHODS Dose rate distributions of typical configurations used in skin brachytherapy were obtained: a 5 cm × 5 cm superficial mould; a source inside a catheter located at the skin surface with and without backscatter bolus; and a typical interstitial implant consisting of an HDR source in a catheter located at a depth of 0.5 cm. Commercially available HDR(60)Co and (192)Ir sources and a hypothetical (169)Yb source were considered. The Geant4 Monte Carlo radiation transport code was used to estimate dose rate distributions for the configurations considered. These results were then compared to those obtained with the TG-43 dose calculation formalism. In particular, the influence of adding bolus material over the implant was studied. RESULTS For a 5 cm × 5 cm(192)Ir superficial mould and 0.5 cm prescription depth, dose differences in comparison to the TG-43 method were about -3%. When the source was positioned at the skin surface, dose differences were smaller than -1% for (60)Co and (192)Ir, yet -3% for (169)Yb. For the interstitial implant, dose differences at the skin surface were -7% for (60)Co, -0.6% for (192)Ir, and -2.5% for (169)Yb. CONCLUSIONS This study indicates the following: (i) for the superficial mould, no bolus is needed; (ii) when the source is in contact with the skin surface, no bolus is needed for either (60)Co and (192)Ir. For lower energy radionuclides like (169)Yb, bolus may be needed; and (iii) for the interstitial case, at least a 0.1 cm bolus is advised for (60)Co to avoid underdosing superficial target layers. For (192)Ir and (169)Yb, no bolus is needed. For those cases where no bolus is needed, its use might be detrimental as the lack of radiation scatter may be beneficial to the patient, although the 2% tolerance for dose calculation accuracy recommended in the AAPM TG-56 report is not fulfilled.
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Affiliation(s)
- Domingo Granero
- Department of Radiation Physics, ERESA, Hospital General Universitario, 46014 Valencia, Spain
| | - Jose Perez-Calatayud
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain
| | - Javier Vijande
- Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and IFIC (UV-CSIC), Paterna 46980, Spain
| | - Facundo Ballester
- Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain
| | - Mark J Rivard
- Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111
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Tormo A, Celada F, Rodriguez S, Botella R, Ballesta A, Kasper M, Ouhib Z, Santos M, Perez-Calatayud J. Non-melanoma skin cancer treated with HDR Valencia applicator: clinical outcomes. J Contemp Brachytherapy 2014; 6:167-72. [PMID: 25097557 PMCID: PMC4105643 DOI: 10.5114/jcb.2014.43247] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 02/18/2014] [Accepted: 06/26/2014] [Indexed: 11/17/2022] Open
Abstract
PURPOSE Radiotherapy (RT) has played a significant role in treating non melanoma skin cancer (NMSC). High-dose-rate brachytherapy (HDR-BT) approaches have a paramount relevance due to their adaptability, patient protection, and variable dose fractionation schedules. Several innovative applicators have been introduced to the brachytherapy community. The Valencia applicator is a new superficial device that improves the dose distribution compared with the Leipzig applicator. The purpose of this work is to assess the tumor control, cosmesis, and toxicity in patients with NMSC treated with the Valencia applicator and a new regimen of hypofractionation. MATERIAL AND METHODS From January 2008 to March 2010, 32 patients with 45 NMSC lesions were treated with the Valencia applicator in the Hospital La Fe. The gross tumor volume was visually assessed, but the tumor depth was evaluated using ultrasound imaging. All lesions for the selected cases were limited to 4 mm depth. The prescription dose was 42 Gy in 6 or 7 fractions (biologically effective dose [BED] ≈ 70 Gy), delivered twice a week. RESULTS Ninety-eight percent of the lesions were locally controlled at 47 months from treatment. Ninety-three percent of patients were out at least 36 months from treatment. The treatment was well tolerated in all cases. The highest skin toxicity was grade 1 RTOG/EORTC, having resolved with topical treatment at 4 weeks in all but one case which required 2 months. There were no grade 2 or higher late adverse events. CONCLUSIONS In patients with superficial basal cell carcinoma lesions less than 25 mm in maximum diameter, HDRBT treatment with the Valencia applicator using a hypofractionated regimen provides excellent results, for both cosmetic and local control at a minimum of 3 years follow-up. Moreover, the shorter hypofractionated regimen facilitates compliance, which is very relevant for the elderly patients in our series. Valencia applicators offer a simple, safe, quick, and attractive nonsurgical treatment option.
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Affiliation(s)
- Alejandro Tormo
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia, Spain
| | - Francisco Celada
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia, Spain
| | | | - Rafael Botella
- Dermatology Department, La Fe University and Polytechnic Hospital, Valencia, Spain
| | - Antonio Ballesta
- Radiotherapy Department, La Fe University and Polytechnic Hospital, Valencia, Spain
| | - Michael Kasper
- Radiation Oncology, Lynn Regional Cancer Center, Boca Raton, Florida, USA
| | - Zoubir Ouhib
- Radiation Oncology, Lynn Regional Cancer Center, Boca Raton, Florida, USA
| | - Manuel Santos
- Radiotherapy Department, Benidorm Hospital, Alicante, Spain
| | - Jose Perez-Calatayud
- Radiotherapy Department, Benidorm Hospital, Alicante, Spain
- Physics Section, Department of Radiation Oncology, La Fe University Hospital, Valencia, Spain
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Dosimetric characteristics of a new unit for electronic skin brachytherapy. J Contemp Brachytherapy 2014; 6:45-53. [PMID: 24790622 PMCID: PMC4003426 DOI: 10.5114/jcb.2014.40770] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 01/15/2014] [Accepted: 03/28/2014] [Indexed: 12/19/2022] Open
Abstract
Purpose Brachytherapy with radioactive high dose rate (HDR) 192Ir source is applied to small skin cancer lesions, using surface applicators, i.e. Leipzig or Valencia type. New developments in the field of radiotherapy for skin cancer include electronic brachytherapy. This technique involves the placement of an HDR X-ray source close to the skin, therefore combining the benefits of brachytherapy with the reduced shielding requirements and targeted energy of low energy X-rays. Recently, the Esteya® Electronic Brachytherapy System (Esteya EBS, Elekta AB-Nucletron, Stockholm, Sweden) has been developed specifically for HDR brachytherapy treatment of surface lesions. The system provides radionuclide free HDR brachytherapy by means of a small 69.5 kV X-ray source. The purpose of this study is to obtain the dosimetric characterization required for clinical implementation, providing the detailed methodology to perform the commissioning. Material and methods Flatness, symmetry and penumbra, percentage of depth dose (PDD), kV stability, HVL, output, spectrum, linearity, and leakage have been evaluated for a set of applicators (from 10 mm to 30 mm in diameter). Results Flatness and symmetry resulted better than 5% with around 1 mm of penumbra. The depth dose gradient is about 7%/mm. A kV value of 68.4 ± 1.0 kV (k = 1) was obtained, in good agreement with manufacturer data (69.5 kV). HVL was 1.85 mm Al. Dose rate for a typical 6 Gy to 7 Gy prescription resulted about 3.3 Gy/min and the leakage value was < 100 µGy/min. Conclusions The new Esteya® Electronic Brachytherapy System presents excellent flatness and penumbra as with the Valencia applicator case, combined with an improved PDD, allowing treatment of lesions of up to a depth of 5 mm in combination with reduced treatment duration. The Esteya unit allows HDR brachytherapy superficial treatment within a minimally shielded environment due its low energy.
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The use of Valencia applicators at extended source surface distances for irregular surface contours. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2014; 37:115-20. [PMID: 24532418 DOI: 10.1007/s13246-014-0251-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 02/02/2014] [Indexed: 10/25/2022]
Abstract
The use of Valencia applicators across irregular surface contours results in significant dose heterogeneities at the prescription depth. Investigations were carried out using extended source surface distances (standoff) to reduce these dose heterogeneities. Relative output factors were measured with a Roos chamber and Gafchromic EBT3 film was used to measure profiles and percentage depth doses at numerous standoff distances. The use of 20 mm standoff was found to reduce the relative difference in delivered dose across a 4 mm change in surface contour by 10.6% for the H2 applicator and 10.0% for the H3 applicator. The radiation became more penetrating with standoff and the field size larger, as expected. The results show that standoff can be used with the Valencia applicator to reduce dose heterogeneities across changes in surface contour.
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42
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Fulkerson RK, Micka JA, DeWerd LA. Dosimetric characterization and output verification for conical brachytherapy surface applicators. Part II. High dose rate 192Ir sources. Med Phys 2014; 41:022104. [PMID: 24506636 PMCID: PMC3987768 DOI: 10.1118/1.4862506] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 11/20/2013] [Accepted: 12/09/2013] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Historically, treatment of malignant surface lesions has been achieved with linear accelerator based electron beams or superficial x-ray beams. Recent developments in the field of brachytherapy now allow for the treatment of surface lesions with specialized conical applicators placed directly on the lesion. Applicators are available for use with high dose rate (HDR)(192)Ir sources, as well as electronic brachytherapy sources. Part I of this paper discussed the applicators used with electronic brachytherapy sources. Part II will discuss those used with HDR (192)Ir sources. Although the use of these applicators has gained in popularity, the dosimetric characteristics have not been independently verified. Additionally, there is no recognized method of output verification for quality assurance procedures with applicators like these. METHODS This work aims to create a cohesive method of output verification that can be used to determine the dose at the treatment surface as part of a quality assurance/commissioning process for surface applicators used with HDR electronic brachytherapy sources (Part I) and(192)Ir sources (Part II). Air-kerma rate measurements for the (192)Ir sources were completed with several models of small-volume ionization chambers to obtain an air-kerma rate at the treatment surface for each applicator. Correction factors were calculated using MCNP5 and EGSnrc Monte Carlo codes in order to determine an applicator-specific absorbed dose to water at the treatment surface from the measured air-kerma rate. Additionally, relative dose measurements of the surface dose distributions and characteristic depth dose curves were completed in-phantom. RESULTS Theoretical dose distributions and depth dose curves were generated for each applicator and agreed well with the measured values. A method of output verification was created that allows users to determine the applicator-specific dose to water at the treatment surface based on a measured air-kerma rate. CONCLUSIONS The novel output verification methods described in this work will reduce uncertainties in dose delivery for treatments with these kinds of surface applicators, ultimately improving patient care.
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Affiliation(s)
- Regina K Fulkerson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - John A Micka
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Larry A DeWerd
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705
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43
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Fulkerson RK, Micka JA, DeWerd LA. Dosimetric characterization and output verification for conical brachytherapy surface applicators. Part I. Electronic brachytherapy source. Med Phys 2014; 41:022103. [PMID: 24506635 PMCID: PMC3987645 DOI: 10.1118/1.4862505] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 11/20/2013] [Accepted: 12/16/2013] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Historically, treatment of malignant surface lesions has been achieved with linear accelerator based electron beams or superficial x-ray beams. Recent developments in the field of brachytherapy now allow for the treatment of surface lesions with specialized conical applicators placed directly on the lesion. Applicators are available for use with high dose rate (HDR)(192)Ir sources, as well as electronic brachytherapy sources. Part I of this paper will discuss the applicators used with electronic brachytherapy sources; Part II will discuss those used with HDR (192)Ir sources. Although the use of these applicators has gained in popularity, the dosimetric characteristics including depth dose and surface dose distributions have not been independently verified. Additionally, there is no recognized method of output verification for quality assurance procedures with applicators like these. Existing dosimetry protocols available from the AAPM bookend the cross-over characteristics of a traditional brachytherapy source (as described by Task Group 43) being implemented as a low-energy superficial x-ray beam (as described by Task Group 61) as observed with the surface applicators of interest. METHODS This work aims to create a cohesive method of output verification that can be used to determine the dose at the treatment surface as part of a quality assurance/commissioning process for surface applicators used with HDR electronic brachytherapy sources (Part I) and(192)Ir sources (Part II). Air-kerma rate measurements for the electronic brachytherapy sources were completed with an Attix Free-Air Chamber, as well as several models of small-volume ionization chambers to obtain an air-kerma rate at the treatment surface for each applicator. Correction factors were calculated using MCNP5 and EGSnrc Monte Carlo codes in order to determine an applicator-specific absorbed dose to water at the treatment surface from the measured air-kerma rate. Additionally, relative dose measurements of the surface dose distributions and characteristic depth dose curves were completed in-phantom. RESULTS Theoretical dose distributions and depth dose curves were generated for each applicator and agreed well with the measured values. A method of output verification was created that allows users to determine the applicator-specific dose to water at the treatment surface based on a measured air-kerma rate. CONCLUSIONS The novel output verification methods described in this work will reduce uncertainties in dose delivery for treatments with these kinds of surface applicators, ultimately improving patient care.
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Affiliation(s)
- Regina K Fulkerson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - John A Micka
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705
| | - Larry A DeWerd
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705
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Gauden R, Pracy M, Avery AM, Hodgetts I, Gauden S. HDR brachytherapy for superficial non-melanoma skin cancers. J Med Imaging Radiat Oncol 2012; 57:212-7. [PMID: 23551783 DOI: 10.1111/j.1754-9485.2012.02466.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Accepted: 07/21/2012] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Our initial experience using recommended high dose per fraction skin brachytherapy (BT) treatment schedules, resulted in poor cosmesis. This study aimed to assess in a prospective group of patients the use of Leipzig surface applicators for High Dose Rate (HDR) brachytherapy, for the treatment of small non-melanoma skin cancers (NMSC) using a protracted treatment schedule. METHOD Treatment was delivered by HDR brachytherapy with Leipzig applicators. 36 Gy, prescribed to between 3 to 4 mm, was given in daily 3 Gy fractions. Acute skin toxicity was evaluated weekly during irradiation using the Radiation Therapy Oncology Group criteria. Local response, late skin effects and cosmetic results were monitored at periodic intervals after treatment completion. RESULTS From March 2002, 200 patients with 236 lesions were treated. Median follow-up was 66 months (range 25-121 months). A total of 162 lesions were macroscopic, while in 74 cases, BT was given after resection because of positive microscopic margins. There were 121 lesions that were basal cell carcinomas, and 115 were squamous cell carcinomas. Lesions were located on the head and neck (198), the extremities (26) and trunk (12). Local control was 232/236 (98%). Four patients required further surgery to treat recurrence. Grade 1 acute skin toxicity was detected in 168 treated lesions (71%) and grade 2 in 81 (34%). Cosmesis was good or excellent in 208 cases (88%). Late skin hypopigmentation changes were observed in 13 cases (5.5%). CONCLUSION Delivering 36 Gy over 2 weeks to superficial NMSC using HDR brachytherapy is well tolerated and provides a high local control rate without significant toxicity.
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Affiliation(s)
- Ruth Gauden
- Launceston General Hospital, Launceston, Tasmania, Australia.
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45
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Stephen Gotts H. Comment on "correspondence factor for nucletron surface applicators". Med Phys 2012; 39:2947-8. [PMID: 22559665 DOI: 10.1118/1.3694510] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Vijande J, Ballester F, Ouhib Z, Granero D, Pujades-Claumarchirant MC, Perez-Calatayud J. Dosimetry comparison between TG-43 and Monte Carlo calculations using the Freiburg flap for skin high-dose-rate brachytherapy. Brachytherapy 2012; 11:528-35. [PMID: 22226080 DOI: 10.1016/j.brachy.2011.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 09/27/2011] [Accepted: 11/14/2011] [Indexed: 11/16/2022]
Abstract
PURPOSE The purpose of this work was to evaluate whether the delivered dose to the skin surface and at the prescription depth when using a Freiburg flap applicator is in agreement with the one predicted by the treatment planning system (TPS) using the TG-43 dose-calculation formalism. METHODS AND MATERIALS Monte Carlo (MC) simulations and radiochromic film measurements have been performed to obtain dose distributions with the source located at the center of one of the spheres and between two spheres. Primary and scatter dose contributions were evaluated to understand the role played by the scatter component. A standard treatment plan was generated using MC- and TG-43-based TPS applying the superposition principle. RESULTS The MC model has been validated by performing additional simulations in the same conditions but transforming air and Freiburg flap materials into water to match TG-43 parameters. Both dose distributions differ less than 1%. Scatter defect compared with TG-43 data is up to 15% when the source is located at the center of the sphere and up to 25% when the source is between two spheres. Maximum deviations between TPS- and MC-based distributions are of 5%. CONCLUSIONS The deviations in the TG-43-based dose distributions for a standard treatment plan with respect to the MC dose distribution calculated taking into account the composition and shape of the applicator and the surrounding air are lower than 5%. Therefore, this study supports the validity of the TPS used in clinical practice.
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Affiliation(s)
- Javier Vijande
- Department of Atomic, Molecular, and Nuclear Physics, University of Valencia, Burjassot, Spain.
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Granero D, Perez-Calatayud J, Ballester F, Ouhib Z. Radiation leakage study for the Valencia applicators. Phys Med 2011; 29:60-4. [PMID: 22169350 DOI: 10.1016/j.ejmp.2011.11.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Revised: 11/14/2011] [Accepted: 11/18/2011] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION AND PURPOSE The Valencia applicators which are accessories of the microSelectron-HDR afterloader (Nucletron, Veenendaal, The Netherlands) are designed to treat skin lesions. These cup-shaped applicators are an alternative to superficial/orthovoltage x-ray treatment units. They limit the irradiation to the required area using tungsten-alloy shielding, and are equipped with a tungsten-alloy flattering filter allowing the treatment of skin tumors, the oral cavity, vaginal cuff, etc. The tungsten-alloy thickness to shield radiation is not the same in all parts of the applicators. This fact led us to question whether the leakage radiation differs depending on where it is measured, and whether this may be relevant in some clinical cases. The purpose of this work is to study from the radiation protection point of view the radiation leakage of the Valencia applicators, and provide a solution for current users and for the manufacturer. METHODS AND MATERIALS Simulations based on the Monte Carlo (MC) method using the Geant4 code have been realized studying the dose rate distribution in air around the cup of the Valencia applicators. An experimental study with radiochromic film has also been done to measure the dose distribution in the back side of the applicators and to compare it with MC results. RESULTS AND CONCLUSIONS Radiation leakage of up to 170% of the prescribed dose has been found at the back surface of these applicators. Although this side is not usually directed to the patient, in some applications such as the treatment of a lesion on the nose, special care must be taken to avoid unexpected and unnecessary irradiation of the eyes. A possible solution could be to add additional shielding to the applicator in order to reduce this leakage or to put some shielding to protect the eyes. Additionally, a new concept design of the Valencia applicators using more shielding material in the applicator backside is proposed.
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Affiliation(s)
- D Granero
- Department of Radiation Physics, ERESA, Hospital General Universitario, E-46014 Valencia, Spain.
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Dosimetric evaluation of internal shielding in a high dose rate skin applicator. J Contemp Brachytherapy 2011; 3:32-35. [PMID: 27877198 PMCID: PMC5108835 DOI: 10.5114/jcb.2011.21041] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Accepted: 03/01/2011] [Indexed: 11/19/2022] Open
Abstract
Purpose The Valencia HDR applicators are accessories of the microSelectron HDR afterloading system (Nucletron) shaped as truncated cones. The base of the cone is either 2 or 3 cm diameter. They are intended to treat skin lesions, being the typical prescription depth 3 mm. In patients with eyelid lesions, an internal shielding is very useful to reduce the dose to the ocular globe. The purpose of this work was to evaluate the dose enhancement from potential backscatter and electron contamination due to the shielding. Material and methods Two methods were used: a) Monte Carlo simulation, performed with the GEANT4 code, 2 cm Valencia applicator was placed on the surface of a water phantom in which 2 mm lead slab was located at 3 mm depth; b) radiochromic EBT films, used to verify the Monte Carlo results, positioning the films at 1.5, 3, 5 and 7 mm depth, inside the phantom. Two irradiations, with and without the lead shielding slab, were carried out. Results The Monte Carlo results showed that due to the backscatter component from the lead, the dose level raised to about 200% with a depth range of 0.5 mm. Under the lead the dose level was enhanced to about 130% with a depth range of 1 mm. Two millimeters of lead reduce the dose under the slab with about 60%. These results agree with film measurements within uncertainties. Conclusions In conclusion, the use of 2 mm internal lead shielding in eyelid skin treatments with the Valencia applicators were evaluated using MC methods and EBT film dosimetry. The minimum bolus thickness that was needed above and below the shielding was 0.5 mm and 1 mm respectively, and the shielding reduced the absorbed dose delivered to the ocular globe by about 60%.
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Rivard MJ, Melhus CS, Granero D, Perez-Calatayud J, Ballester F. An approach to using conventional brachytherapy software for clinical treatment planning of complex, Monte Carlo-based brachytherapy dose distributionsa). Med Phys 2009; 36:1968-75. [DOI: 10.1118/1.3121510] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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