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Mizuno H, Nakaji T, Fukuda S, Kato S. End-to-end dosimetry audit for three-dimensional image-guided brachytherapy for cervical cancer. Phys Med 2024; 119:103321. [PMID: 38394979 DOI: 10.1016/j.ejmp.2024.103321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND End-to-end dosimetry audit for brachytherapy is challenging due to the steep dose gradient. However, it is an efficient method to detect unintended errors in actual clinical practice. PURPOSE We aimed to develop an on-site end-to-end test phantom for three-dimensional image-guided brachytherapy (IGBT) for cervical cancer. METHODS The test phantom we developed consisted of a water tank with an applicator/detector holder. The holder was designed to accommodate the applicator and insert an ionization chamber (PinPoint; PTW, Freiburg, Germany) to measure the dose at point A. Imaging and reconstruction were performed in the same way as performed for a patient. The feasibility of our test phantom was assessed in two different hospitals using tandem and ovoid (made of either metal or carbon) applicators that the hospitals provided. RESULTS The measured and calculated doses at point A were compared for each applicator. We observed that the values obtained using metal applicators were consistently lower, on an average by -2.3%, than the calculated values, while those obtained using carbon applicators were comparable to the calculated values. This difference can be attributed to the attenuation of the dose by the metal applicators, resulting in a lower dose at point A. The majority of treatment planning system, including the one used in this study, do not account for the material of applicator. CONCLUSIONS An end-to-end test phantom for IGBT was developed, tested, and applied in a dosimetry audit in hospitals and showed favorable results for evaluating the point A dose.
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Affiliation(s)
- Hideyuki Mizuno
- Radiation quality control section, QST Hospital, National Institutes for Quantum Science and Technology, Chiba, Japan.
| | - Taku Nakaji
- Radiation quality control section, QST Hospital, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Shigekazu Fukuda
- Radiation quality control section, QST Hospital, National Institutes for Quantum Science and Technology, Chiba, Japan
| | - Shingo Kato
- Saitama Medical University International Medical Centre, Hidaka, Saitama, Japan
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Palmer AL, Nash D, Polak W, Wilby S. Evaluation of a new radiochromic film dosimeter, Gafchomic EBT4, for VMAT, SABR and HDR treatment delivery verification. Phys Med Biol 2023; 68:175003. [PMID: 37499683 DOI: 10.1088/1361-6560/aceb48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 07/27/2023] [Indexed: 07/29/2023]
Abstract
Objective.To evaluate a new film for radiotherapy dosimetry, Gafchromic EBT4, compared to the current EBT3. To evaluate dose-response and verify test cases in MV external beam and HDR brachytherapy.Approach. Three lots (batches) of EBT4 and three lots of EBT3 films were calibrated at 6 MV over 0-1200 cGy range, using FilmQAPro software. Signal-to-noise of pixel value, reported dose (RD), and factors affecting dosimetry accuracy were evaluated (rotation of the film at scanning, energy response and post-exposure darkening). Both films were exposed to clinical treatment plans (VMAT prostate, SABR lung, single HDR source dwell, and 'pseudo' 3-channel HDR cervix brachytherapy). Film-RD was compared to TPS-calculated dose.Main results.EBT4 calibration curves had characteristics more favourable than EBT3 for radiation dosimetry, with improved signal to noise in film-RD of EBT4 compared to EBT3 (increase of average 46% in red and green channels at 500 cGy). Film rotation at scanning and post-exposure darkening was similar for the two films. The energy response of EBT4 is similar to EBT3. For all clinical case studies, EBT4 provided better agreement with the TPS-planned doses than EBT3. VMAT prostate gamma 3%/3 mm passing rate, EBT4 100.0% compared to EBT3 97.9%; SABR lung gamma 2%/2 mm, EBT4 99.6% and EBT3 97.9%; HDR cervix gamma 3%/2 mm, EBT4 97.7% and EBT3 95.0%.Significance.These results show EBT4 is superior to EBT3 for radiotherapy dosimetry validation of TPS plan delivery. Fundamental improvements in noise profile and calibration curve are reported for EBT4. All clinical test cases showed EBT4 provided equivalent or smaller difference in measured dose to TPS calculated dose than EBT3. Baseline data is presented on the achievable accuracy of film dosimetry in radiotherapy using the new Gafchromic EBT4 film.
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Affiliation(s)
- Antony L Palmer
- Medical Physics Dept, Portsmouth Hospitals University NHS Trust, Cosham, PO6 3LY, United Kingdom
| | - David Nash
- Medical Physics Dept, Portsmouth Hospitals University NHS Trust, Cosham, PO6 3LY, United Kingdom
| | - Wojciech Polak
- Medical Physics Dept, Portsmouth Hospitals University NHS Trust, Cosham, PO6 3LY, United Kingdom
| | - Sarah Wilby
- Medical Physics Dept, Portsmouth Hospitals University NHS Trust, Cosham, PO6 3LY, United Kingdom
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Milana M, Jelena M, Borislava P. Quality assurance of six cylindrical and two parallel plate chambers by radioactive check device: Influence of chamber age to its performance. Phys Med 2023; 112:102635. [PMID: 37480711 DOI: 10.1016/j.ejmp.2023.102635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 05/02/2023] [Accepted: 07/04/2023] [Indexed: 07/24/2023] Open
Abstract
PURPOSE To evaluate the performances of eight ionization chambers, (two types) manufactured in a time span of 14 years, with radioactive source devices and photon beams. METHODS The measurements were performed with six Farmer and two parallel plate ionization chambers with appropriate radioactive check devices and accompanying inserts. Some tests were performed with photon beams at linear accelerator. Physical visibility check, stability, linearity of response, directional dependence, determination of leakage current, ion recombination and polarity effect and influence of background radiation tests were conducted and analyzed. RESULTS The performance of all Farmer ionization chambers was in agreement to IEC standard as well as for parallel plate type chambers. Long-term stability of older planparallel chamber was somewhat worse than expected. CONCLUSION Radioactive check devices have proven to be easy to use in clinical environment. According to results of this work Farmer type ionization chambers showed good quality regardless of the time of production, which make them long-term suitable for clinical dosimetry in radiotherapy. Also, for parallel plate type of ionization chambers the results showed fine agreement with the IEC standard, except long-term stability for older chamber, which needs further investigation.
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Affiliation(s)
- Marjanovic Milana
- Radiotherapy Department, Oncology Institute of Vojvodina, Put dr Goldmana 4, 21204 Sremska Kamenica, Serbia; Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia.
| | - Moravčević Jelena
- Radiotherapy Department, Oncology Institute of Vojvodina, Put dr Goldmana 4, 21204 Sremska Kamenica, Serbia.
| | - Petrović Borislava
- Radiotherapy Department, Oncology Institute of Vojvodina, Put dr Goldmana 4, 21204 Sremska Kamenica, Serbia; Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovića 3, 21000 Novi Sad, Serbia.
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Tachibana H, Watanabe Y, Kurokawa S, Maeyama T, Hiroki T, Ikoma H, Hirashima H, Kojima H, Shiinoki T, Tanimoto Y, Shimizu H, Shishido H, Oka Y, Hirose TA, Kinjo M, Morozumi T, Kurooka M, Suzuki H, Saito T, Fujita K, Shirata R, Inada R, Yada R, Yamashita M, Kondo K, Hanada T, Takenaka T, Usui K, Okamoto H, Asakura H, Notake R, Kojima T, Kumazaki Y, Hatanaka S, Kikumura R, Nakajima M, Nakada R, Suzuki R, Mizuno H, Kawamura S, Nakamura M, Akimoto T. Multi-Institutional Study of End-to-End Dose Delivery Quality Assurance Testing for Image-Guided Brachytherapy Using a Gel Dosimeter. Brachytherapy 2022; 21:956-967. [PMID: 35902335 DOI: 10.1016/j.brachy.2022.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 06/15/2022] [Accepted: 06/19/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE To quantify dose delivery errors for high-dose-rate image-guided brachytherapy (HDR-IGBT) using an independent end-to-end dose delivery quality assurance test at multiple institutions. The novelty of our study is that this is the first multi-institutional end-to-end dose delivery study in the world. MATERIALS AND METHODS The postal audit used a polymer gel dosimeter in a cylindrical acrylic container for the afterloading system. Image acquisition using computed tomography, treatment planning, and irradiation were performed at each institution. Dose distribution comparison between the plan and gel measurement was performed. The percentage of pixels satisfying the absolute-dose gamma criterion was reviewed. RESULTS Thirty-five institutions participated in this study. The dose uncertainty was 3.6% ± 2.3% (mean ± 1.96σ). The geometric uncertainty with a coverage factor of k = 2 was 3.5 mm. The tolerance level was set to the gamma passing rate of 95% with the agreement criterion of 5% (global)/3 mm, which was determined from the uncertainty estimation. The percentage of pixels satisfying the gamma criterion was 90.4% ± 32.2% (mean ± 1.96σ). Sixty-six percent (23/35) of the institutions passed the verification. Of the institutions that failed the verification, 75% (9/12) had incorrect inputs of the offset between the catheter tip and indexer length in treatment planning and 17% (2/12) had incorrect catheter reconstruction in treatment planning. CONCLUSIONS The methodology should be useful for comprehensively checking the accuracy of HDR-IGBT dose delivery and credentialing clinical studies. The results of our study highlight the high risk of large source positional errors while delivering dose for HDR-IGBT in clinical practices.
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Affiliation(s)
- Hidenobu Tachibana
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
| | - Yusuke Watanabe
- School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Shogo Kurokawa
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
| | - Takuya Maeyama
- School of Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Tomoyuki Hiroki
- Department of Radiology, Tokai University Hospital, Isehara, Kanagawa, Japan
| | - Hideaki Ikoma
- Department of Radiation Technology, Ibaraki Prefectual Central Hospital, Kasama, Ibaraki, Japan
| | - Hideaki Hirashima
- Deparment of Radiation Oncology and Image-Applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan
| | - Hironori Kojima
- Department of Radiology, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan
| | - Takehiro Shiinoki
- Department of Radiation Oncology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan
| | - Yuuki Tanimoto
- Department of Radiology, Shikoku Cancer Center, Matsuyama, Ehime, Japan
| | - Hidetoshi Shimizu
- Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Aichi, Japan
| | - Hiroki Shishido
- Division of Radiology and Nuclear Medicine, Sapporo Medical University Hospital, Sapporo, Hokkaido, Japan
| | - Yoshitaka Oka
- Department of Radiology, Fukushima Medical University Hospital, Fukushima, Fukushima, Japan
| | - Taka-Aki Hirose
- Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Fukuoka, Japan
| | - Masashi Kinjo
- Department of Radiology, University of the Ryukyus Graduate School of Medical Science, Nishihara, Okinawa, Japan
| | - Takuya Morozumi
- Department of Radiology, Nagano Municipal Hospital, Nagano, Nagano, Japan
| | - Masahiko Kurooka
- Department of Radiation Therapy, Tokyo Medical University Hospital, Shinjuku, Tokyo, Japan
| | - Hidekazu Suzuki
- Department of Radiology, University of Yamanashi Hospital, Chuo, Yamanashi, Japan
| | - Tomohiko Saito
- Central Division of Radiology, Akita University Hospital, Akita, Akita, Japan
| | - Keiichi Fujita
- Department of Radiology, Asahi General Hospital, Asahi, Chiba, Japan
| | - Ryosuke Shirata
- Department of Radiation Oncology, Shonan Kamakura General Hospital, Kamakura, Kanagawa, Japan
| | - Ryuji Inada
- Department of Radiology, Kitasato University Hospital, Sagamihara, Kanagawa, Japan
| | - Ryuichi Yada
- Division of Radiation Oncology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Mikiko Yamashita
- Department of Radiological Technology, Kobe City Medical Center General Hospital, Kobe, Hyogo, Japan
| | - Kazuto Kondo
- Department of Radiological Technology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan
| | - Takashi Hanada
- Department of Radiology, Keio University School of Medicine, Shinjuku, Tokyo, Japan
| | - Tadashi Takenaka
- Department of Radiology, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan
| | - Keisuke Usui
- Department of Radiological Technology, Juntendo University, Faculty of Health Science, Bunkyo, Tokyo, Japan
| | - Hiroyuki Okamoto
- Radiation Safety and Quality Assurance Division, National Cancer Center Hospital, Chuo, Tokyo, Japan
| | - Hiroshi Asakura
- Radiation Oncology Center, Dokkyo Medical University Hospital, Shimotsuga, Tochigi, Japan
| | - Ryoichi Notake
- Department of Radiology, Tokyo Medical And Dental University, Medical Hospital, Bunkyo, Tokyo, Japan
| | - Toru Kojima
- Department of Radiation Oncology, Saitama Cancer Center, Ina, Saitama, Japan
| | - Yu Kumazaki
- Department of Radiation Oncology, Saitama Medical University International Medical Center, Hidaka, Saitama, Japan
| | - Shogo Hatanaka
- Department of Radiation Oncology, Saitama Medical Center, Saitama Medical University, Kawagoe, Saitama, Japan
| | - Riki Kikumura
- Department of Radiology, National Hospital Organization, Tokyo Medical Center, Meguro, Tokyo, Japan
| | - Masaru Nakajima
- Department of Radiation Oncology, The Cancer Institute Hospital Of JFCR, Koto, Tokyo, Japan
| | - Ryosei Nakada
- Radiation and Proton Therapy Center, Shizuoka Cancer Center, Nagaizumi, Shizuoka, Japan
| | - Ryusuke Suzuki
- Department of Medical physics, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Hideyuki Mizuno
- Quality control section, QST hospital, National Institutes for Quantum Science and Technology, Chiba, Chiba, Japan
| | - Shinji Kawamura
- Division of Radiological Sciences, Teikyo University Graduate School of Health Sciences, Omuta, Fukuoka, Japan
| | - Mistuhiro Nakamura
- Division of Medical Physics, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan
| | - Tetsuo Akimoto
- Department of Radiation Oncology, National Cancer Center Hospital East, Kashiwa, Chiba, Japan
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