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Karger CP, Elter A, Dorsch S, Mann P, Pappas E, Oldham M. Validation of complex radiotherapy techniques using polymer gel dosimetry. Phys Med Biol 2024; 69:06TR01. [PMID: 38330494 DOI: 10.1088/1361-6560/ad278f] [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: 02/06/2023] [Accepted: 02/08/2024] [Indexed: 02/10/2024]
Abstract
Modern radiotherapy delivers highly conformal dose distributions to irregularly shaped target volumes while sparing the surrounding normal tissue. Due to the complex planning and delivery techniques, dose verification and validation of the whole treatment workflow by end-to-end tests became much more important and polymer gel dosimeters are one of the few possibilities to capture the delivered dose distribution in 3D. The basic principles and formulations of gel dosimetry and its evaluation methods are described and the available studies validating device-specific geometrical parameters as well as the dose delivery by advanced radiotherapy techniques, such as 3D-CRT/IMRT and stereotactic radiosurgery treatments, the treatment of moving targets, online-adaptive magnetic resonance-guided radiotherapy as well as proton and ion beam treatments, are reviewed. The present status and limitations as well as future challenges of polymer gel dosimetry for the validation of complex radiotherapy techniques are discussed.
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Affiliation(s)
- Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Alina Elter
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany
| | - Stefan Dorsch
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Philipp Mann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Evangelos Pappas
- Radiology & Radiotherapy Sector, Department of Biomedical Sciences, University of West Attica, Athens, Greece
| | - Mark Oldham
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
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Zhu L, Du Y, Peng Y, Xiang X, Wang X. End-to-End QA with Polymer Gel Dosimeter for Photon Beam Radiation Therapy. Gels 2023; 9:gels9030212. [PMID: 36975661 PMCID: PMC10048457 DOI: 10.3390/gels9030212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/14/2023] Open
Abstract
With the complexity and high demands on quality assurance (QA) of photon beam radiation therapy, end-to-end (E2E) QA is necessary to validate the entire treatment workflow from pre-treatment imaging to beam delivery. A polymer gel dosimeter is a promising tool for three-dimensional (3D) dose distribution measurement. The purpose of this study is to design a fast “one delivery” polymethyl methacrylate (PMMA) phantom with a polymer gel dosimeter for the E2E QA test of the photon beam. The one delivery phantom is composed of ten calibration cuvettes for the calibration curve measurement, two 10 cm gel dosimeter inserts for the dose distribution measurement, and three 5.5 cm gel dosimeters for the square field measurement. The one delivery phantom holder is comparable in size and shape to that of a human thorax and abdomen. In addition, an anthropomorphic head phantom was employed to measure the patient-specific dose distribution of a VMAT plan. The E2E dosimetry was verified by undertaking the whole RT procedure (immobilization, CT simulation, treatment planning, phantom set-up, imaged-guided registration, and beam delivery). The calibration curve, field size, and patient-specific dose were measured with a polymer gel dosimeter. The positioning error can be mitigated with the one-delivery PMMA phantom holder. The delivered dose measured with a polymer gel dosimeter was compared with the planned dose. The gamma passing rate is 86.64% with the MAGAT-f gel dosimeter. The results ascertain the feasibility of the one delivery phantom with a polymer gel dosimeter for a photon beam in E2E QA. The QA time can be reduced with the designed one delivery phantom.
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Affiliation(s)
- Libing Zhu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Yi Du
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiotherapy, Peking University Cancer Hospital & Institute, Beijing 100142, China
| | - Yahui Peng
- School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100044, China
| | - Xincheng Xiang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Xiangang Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
- Correspondence:
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3
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Watanabe Y, Maeyama T, Mizukami S, Tachibana H, Terazaki T, Takei H, Muraishi H, Gomi T, Hayashi SI. Verification of dose distribution in high dose-rate brachytherapy for cervical cancer using a normoxic N-vinylpyrrolidone polymer gel dosimeter. JOURNAL OF RADIATION RESEARCH 2022; 63:838-848. [PMID: 36109319 PMCID: PMC9726700 DOI: 10.1093/jrr/rrac053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 07/14/2022] [Indexed: 05/10/2023]
Abstract
The polymer gel dosimeter has been proposed for use as a 3D dosimeter for complex dose distribution measurement of high dose-rate (HDR) brachytherapy. However, various shapes of catheter/applicator for sealed radioactive source transport used in clinical cases must be placed in the gel sample. The absorbed dose readout for the magnetic resonance (MR)-based polymer gel dosimeters requires calibration data for the dose-transverse relaxation rate (R2) response. In this study, we evaluated in detail the dose uncertainty and dose resolution of three calibration methods, the multi-sample and distance methods using the Ir-192 source and the linear accelerator (linac) method using 6MV X-rays. The use of Ir-192 sources increases dose uncertainty with steep dose gradients. We clarified that the uniformly irradiated gel sample improved the signal-to-noise ratio (SNR) due to the large slice thickness of MR images and could acquire an accurate calibration curve using the linac method. The curved tandem and ovoid applicator used for intracavitary irradiation of HDR brachytherapy for cervical cancer were reproduced with a glass tube to verify the dose distribution. The results of comparison with the treatment planning system (TPS) calculation by gamma analysis on the 3%/2 mm criterion were in good agreement with a gamma pass rate of 90%. In addition, the prescription dose could be evaluated accurately. We conclude that it is easy to place catheter/applicator in the polymer gel dosimeters, making them a useful tool for verifying the 3D dose distribution of HDR brachytherapy with accurate calibration methods.
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Affiliation(s)
- Yusuke Watanabe
- Corresponding author. School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan. E-mail:
| | - Takuya Maeyama
- School of Science, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Shinya Mizukami
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Hidenobu Tachibana
- Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan
| | - Tsuyoshi Terazaki
- Department of Radiology, Yokohama City Minato Red Cross Hospital, 3-12-1 Shinyamashita, Naka-ku, Yokohama, Kanagawa, 231-8682, Japan
| | - Hideyuki Takei
- Quantum Life and Medical Science Directorate, National Institute for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba, 263-8555, Japan
| | - Hiroshi Muraishi
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Tsutomu Gomi
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0373, Japan
| | - Shin-ichiro Hayashi
- Faculty of Health Sciences, Hiroshima International University, 555-36 Kurosegakuendai, Higashihiroshima, Hiroshima, 739-2695, Japan
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De Deene Y. Radiation Dosimetry by Use of Radiosensitive Hydrogels and Polymers: Mechanisms, State-of-the-Art and Perspective from 3D to 4D. Gels 2022; 8:599. [PMID: 36135311 PMCID: PMC9498652 DOI: 10.3390/gels8090599] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/07/2022] [Accepted: 09/10/2022] [Indexed: 12/22/2022] Open
Abstract
Gel dosimetry was developed in the 1990s in response to a growing need for methods to validate the radiation dose distribution delivered to cancer patients receiving high-precision radiotherapy. Three different classes of gel dosimeters were developed and extensively studied. The first class of gel dosimeters is the Fricke gel dosimeters, which consist of a hydrogel with dissolved ferrous ions that oxidize upon exposure to ionizing radiation. The oxidation results in a change in the nuclear magnetic resonance (NMR) relaxation, which makes it possible to read out Fricke gel dosimeters by use of quantitative magnetic resonance imaging (MRI). The radiation-induced oxidation in Fricke gel dosimeters can also be visualized by adding an indicator such as xylenol orange. The second class of gel dosimeters is the radiochromic gel dosimeters, which also exhibit a color change upon irradiation but do not use a metal ion. These radiochromic gel dosimeters do not demonstrate a significant radiation-induced change in NMR properties. The third class is the polymer gel dosimeters, which contain vinyl monomers that polymerize upon irradiation. Polymer gel dosimeters are predominantly read out by quantitative MRI or X-ray CT. The accuracy of the dosimeters depends on both the physico-chemical properties of the gel dosimeters and on the readout technique. Many different gel formulations have been proposed and discussed in the scientific literature in the last three decades, and scanning methods have been optimized to achieve an acceptable accuracy for clinical dosimetry. More recently, with the introduction of the MR-Linac, which combines an MRI-scanner and a clinical linear accelerator in one, it was shown possible to acquire dose maps during radiation, but new challenges arise.
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Affiliation(s)
- Yves De Deene
- Liverpool & Macarthur Cancer Therapy Centres, Liverpool, NSW 1871, Australia; or
- Ingham Institute, Liverpool, NSW 2170, Australia
- School of Science, Western Sydney University, Penrith, NSW 2751, Australia
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Sun JC, Hsieh BT, Hsieh CM, Tsang YW, Cheng KY. Applying the N-isopropylacrylamide gel dosimeter to quantify dynamic dose effects: A feasibility study. Technol Health Care 2022; 30:413-424. [PMID: 35124616 PMCID: PMC9028750 DOI: 10.3233/thc-thc228038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND: The gel dosimeter is a chemical as well as a relative dosimeter. OBJECTIVE: To evaluate the feasibility of using N-isopropylacrylamide (NIPAM) gel dosimeter to observe the dynamic dose effects and quantification of the respiration, and to help determine the safety margins. METHODS: The NIPAM gel dosimeter combined with the dynamic phantom was used to simulate radiotherapy of lung or upper abdominal tumor. The field set to 4 × 5 cm2, simulate respiratory rate of 4 sec/cycle, and motion range 2 cm. MRI was used for reading, and MATLAB was used for analysis. The 3%/3 mm gamma passing rate > 95% was used as a clinical basis for evaluation. RESULTS: The dynamic dose curve was compared with 4 × 5, 4 × 4, 4 × 3 cm2 TPS, and gamma passing rates were 74.32%, 54.83%, 30.18%. Gamma mapping demonstrated that the highest dose region was similar to the result of the 4 × 4 cm2 TPS. After appropriate selection and comparing that the ⩾ 60% part of the dose curve with TPS, the gamma passing rate was 96.49%. CONCLUSIONS: Using the NIPAM gel dosimeter with dynamic phantom to simulate organ motion during respiration for dynamic dose measurement and quantified the dynamic dose effect is feasible. The results are consistent with clinical evaluation standards.
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Affiliation(s)
- Jung-Chang Sun
- Department of Radiation Oncology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Bor-Tsung Hsieh
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Chih-Ming Hsieh
- Department of Medical Imaging, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
| | - Yuk-Wah Tsang
- Department of Radiation Oncology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
- Department of Biomedical Engineering, Chung Yuan Christian University, Taoyuan, Taiwan
| | - Kai-Yuan Cheng
- Department of Medical Imaging and Radiological Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan
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Rabaeh KA, Hammoudeh IM, Oglat AA, Eyadeh MM, Abdel-Qader AJ, Aldweri FM, Awad SI. Polymer gel containing N,N′-methylene-bis-acrylamide (BIS) as a single monomer for radiotherapy dosimetry. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109522] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Elter A, Dorsch S, Thomas S, Hentschke CM, Floca RO, Runz A, Karger CP, Mann P. PAGAT gel dosimetry for everyone: gel production, measurement and evaluation. Biomed Phys Eng Express 2021; 7. [PMID: 34237712 DOI: 10.1088/2057-1976/ac12a5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 07/08/2021] [Indexed: 11/12/2022]
Abstract
Polymer gel (PG) dosimetry is a valuable tool to measure complex dose distributions in 3D with a high spatial resolution. However, due to complex protocols that need to be followed for in-house produced PGs and the high costs of commercially available gels, PG gels are only rarely applied in quality assurance procedures worldwide. In this work, we provide an introduction to perform highly standardized dosimetric PG experiments using PAGAT (PolyAcrylamide Gelatine gel fabricated at ATmospheric conditions) dosimetry gel. PAGAT gel can be produced at atmospheric conditions, at low costs and is evaluated using magnetic resonance imaging (MRI). The conduction of PG experiments is described in great detail including the gel production, treatment planning, irradiation, MRI evaluation and post-processing procedure. Furthermore, a plugin in an open source image processing tool for post-processing is provided free of charge that allows a standardized and reproducible analysis of PG experiments.
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Affiliation(s)
- A Elter
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - S Dorsch
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - S Thomas
- Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - C M Hentschke
- Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - R O Floca
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany.,Division of Medical Image Computing, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - A Runz
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - C P Karger
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - P Mann
- Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
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8
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Marot M, Elter A, Mann P, Schwahofer A, Lang C, Johnen W, Körber SA, Beuthien-Baumann B, Gillmann C. Technical Note: On the feasibility of performing dosimetry in target and organ at risk using polymer dosimetry gel and thermoluminescence detectors in an anthropomorphic, deformable, and multimodal pelvis phantom. Med Phys 2021; 48:5501-5510. [PMID: 34260079 DOI: 10.1002/mp.15096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/28/2021] [Accepted: 06/25/2021] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE To assess the feasibility of performing dose measurements in the target (prostate) and an adjacent organ at risk (rectum) using polymer dosimetry gel and thermoluminescence detectors (TLDs) in an anthropomorphic, deformable, and multimodal pelvis phantom (ADAM PETer). METHODS The 3D printed prostate organ surrogate of the ADAM PETer phantom was filled with polymer dosimetry gel. Nine TLD600 (LiF:Mg,Ti) were installed in 3 × 3 rows on a specifically designed 3D-printed TLD holder. The TLD holder was inserted into the rectum at the level of the prostate and fixed by a partially inflated endorectal balloon. Computed tomography (CT) images were taken and treatment planning was performed. A prescribed dose of 4.5 Gy was delivered to the planning target volume (PTV). The doses measured by the dosimetry gel in the prostate and the TLDs in the rectum ("measured dose") were compared to the doses calculated by the treatment planning system ("planned dose") on a voxel-by-voxel basis. RESULTS In the prostate organ surrogate, the 3D-γ-index was 97.7% for the 3% dose difference and 3 mm distance to agreement criterium. In the center of the prostate organ surrogate, measured and planned doses showed only minor deviations (<0.1 Gy, corresponding to a percentage error of 2.22%). On the edges of the prostate, slight differences between planned and measured doses were detected with a maximum deviation of 0.24 Gy, corresponding to 5.3% of the prescribed dose. The difference between planned and measured doses in the TLDs was on average 0.08 Gy (range: 0.02-0.21 Gy), corresponding to 1.78% of the prescribed dose (range: 0.44%-4.67%). CONCLUSIONS The present study demonstrates the feasibility of using polymer dosimetry gel and TLDs for 3D and 1D dose measurements in the prostate and the rectum organ surrogates in an anthropomorphic, deformable and multimodal phantom. The described methodology might offer new perspectives for end-to-end tests in image-guided adaptive radiotherapy workflows.
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Affiliation(s)
- Mathieu Marot
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Medicine, University of Heidelberg, Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Alina Elter
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,Faculty of Physics and Astronomy, University of Heidelberg, Heidelberg, Germany
| | - Philipp Mann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,HQ-Imaging GmbH, Heidelberg, Germany
| | - Andrea Schwahofer
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Clemens Lang
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Wibke Johnen
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Stefan A Körber
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Bettina Beuthien-Baumann
- Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Clarissa Gillmann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Heidelberg Institute for Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany.,National Center for Tumor Diseases (NCT), Heidelberg, Germany
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BrahimiMoussa S, Benamar M, LounisMokrani Z. Characterization of the chemical and structural modifications induced by gamma rays on the MAGIC polymer gel. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2019.108451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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10
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Elter A, Dorsch S, Mann P, Runz A, Johnen W, Spindeldreier CK, Klüter S, Karger CP. End-to-end test of an online adaptive treatment procedure in MR-guided radiotherapy using a phantom with anthropomorphic structures. ACTA ACUST UNITED AC 2019; 64:225003. [DOI: 10.1088/1361-6560/ab4d8e] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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11
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Resende TD, Lizar JC, Dos Santos FM, Borges LF, Pavoni JF. Study of the formulation optimization and reusability of a MAGAT gel dosimeter. Phys Med 2019; 63:105-111. [PMID: 31221401 DOI: 10.1016/j.ejmp.2019.05.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 05/23/2019] [Accepted: 05/25/2019] [Indexed: 01/29/2023] Open
Abstract
PURPOSE This study aims to optimize the formulation of a methacrylic acid gelatine and tetrakis (hydroxymethyl) phosphonium chloride (MAGAT) gel dosimeter to achieve acceptable dosimetric characteristics and the lowest final costs. This study also evaluates the reusability of the dosimeter. METHODS The MAGAT gel dosimeter formulation was optimized. Tetrakis (hydroxymethyl) phosphonium chloride (THPC) concentrations (2, 5, 8, 10, 20, and 65 mM), methacrylic acid (MA) concentrations (2.0, 2.5, 3.0, 3.5, and 4.0% w/w) and gelatin concentrations (4.36, 6.45, 8.36, and 10.45% w/w) were evaluated to provide an adequate dosimetric response. The final dosimeter formulation linearity and dose rate dependence were evaluated. The reutilization methodology of the optimized gel formulation, but containing 2 mM of THPC, which was previously irradiated with a dose of 2 Gy, is also presented. RESULTS The optimized mass concentration of the dosimeter consists of 88.60% deionized water, 8.36% gelatin, 3.00% of MA and 0.04% THPC (5 mM). It presents a linear response for doses up to 10 Gy with a 1.16 Gy-1 s-1 sensitivity. A maximum sensitivity variation of less than 4.0% was found when varying the dose rate of the radiation beams from 300 to 500 cGy/min. It was possible to reuse the dosimeter, however the sensitivity decreased by 15% from the first to the second irradiation. CONCLUSIONS A low-cost MAGAT gel dosimeter with optimized formulation that responds to radiation in a dose range of 0 to 10 Gy with small dose-rate dependence is presented. The MAGAT gel can be reused after a 2 Gy irradiation.
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Affiliation(s)
- Thiago Dias Resende
- Physics Department, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, 14040-901, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Jessica Caroline Lizar
- Physics Department, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, 14040-901, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Fred Müller Dos Santos
- Physics Department, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, 14040-901, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Leandro Federiche Borges
- Radiotherapy Service, Clinics Hospital of University of São Paulo Medical School at Ribeirão Preto, Av. Bandeirantes 3900, 14040-900, Monte Alegre, Ribeirão Preto, SP, Brazil
| | - Juliana Fernandes Pavoni
- Physics Department, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Av. Bandeirantes 3900, 14040-901, Monte Alegre, Ribeirão Preto, SP, Brazil; Radiotherapy Service, Clinics Hospital of University of São Paulo Medical School at Ribeirão Preto, Av. Bandeirantes 3900, 14040-900, Monte Alegre, Ribeirão Preto, SP, Brazil.
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12
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Chacón D, Vedelago J, Strumia MC, Valente M, Mattea F. Raman spectroscopy as a tool to evaluate oxygen effects on the response of polymer gel dosimetry. Appl Radiat Isot 2019; 150:43-52. [PMID: 31121487 DOI: 10.1016/j.apradiso.2019.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/04/2019] [Accepted: 05/06/2019] [Indexed: 12/23/2022]
Abstract
Currently, advanced dosimeters like polymer gels are capable of obtaining reliable and accurate 3D dose distributions from correlations with the different polymerization degrees induced by incident radiation. Samples of polymer gel dosimeters are commonly read out using magnetic resonance imaging or optical methods like visible light transmission or laser computed tomography. Alternatively, this work proposes and evaluates the implementation of Raman spectroscopy to provide direct information on the effect of oxygen permeating through the walls of phantoms on the polymerization initiated by irradiation in three types of polymer gel dosimeters, namely NIPAM, ITABIS and PAGAT. The aim of the present study is to provide better and complete interpretations using three different containers, adequate for integral, 2D and 3D dose mapping. Moreover, Raman spectroscopy has been used to analyze the well-known effect of oxygen inhibition on the different polymer gel dosimeters remarking the importance of avoiding air exposition during sample storage and readout. Dose-response curves for different polymer gels were obtained in terms of measurements with a calibrated ionization chamber. Additionally, dedicated Monte Carlo simulations were performed aimed at characterizing dose for different X-ray irradiation setups, providing also suitable information to evaluate oxygen diffusion through the sample wall. The obtained results were contrasted with optical transmission readout as well as Monte Carlo simulations attaining very good agreements for all dosimeter types.
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Affiliation(s)
- D Chacón
- Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIR(x)), FAMAF, Universidad Nacional de Córdoba, M. Allende s/n, Córdoba, Argentina; Departamento de Física, Universidad Nacional, Heredia, Costa Rica
| | - J Vedelago
- Instituto de Física Enrique Gaviola (IFEG) - CONICET, M. Allende s/n, Córdoba, Argentina; Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIR(x)), FAMAF, Universidad Nacional de Córdoba, M. Allende s/n, Córdoba, Argentina
| | - M C Strumia
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, CONICET, Córdoba, Argentina; Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada (IPQA), CONICET, Córdoba, Argentina
| | - M Valente
- Instituto de Física Enrique Gaviola (IFEG) - CONICET, M. Allende s/n, Córdoba, Argentina; Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIR(x)), FAMAF, Universidad Nacional de Córdoba, M. Allende s/n, Córdoba, Argentina; Centro de Física e Ingeniería en Medicina (CFIM) & Departamento de Ciencias Físicas, Universidad de La Frontera, Francisco Salazar 1145, Temuco, Chile
| | - F Mattea
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, CONICET, Córdoba, Argentina; Instituto de Investigación y Desarrollo en Ingeniería de Procesos y Química Aplicada (IPQA), CONICET, Córdoba, Argentina; Laboratorio de Investigación e Instrumentación en Física Aplicada a la Medicina e Imágenes por Rayos X (LIIFAMIR(x)), FAMAF, Universidad Nacional de Córdoba, M. Allende s/n, Córdoba, Argentina.
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Tanaka K, Sakurai Y, Hayashi SI, Kajimoto T, Uchida R, Tanaka H, Takata T, Bengua G, Endo S. Computational investigation of suitable polymer gel composition for the QA of the beam components of a BNCT irradiation field. Appl Radiat Isot 2017; 127:253-259. [PMID: 28683330 DOI: 10.1016/j.apradiso.2017.06.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 05/26/2017] [Accepted: 06/13/2017] [Indexed: 11/26/2022]
Abstract
This study investigated the optimum composition of the MAGAT polymer gel which is to be used in the quality assurance measurement of the thermal neutron, fast neutron and gamma ray components in the irradiation field used for boron neutron capture therapy at the Kyoto University Reactor. Simulations using the PHITS code showed that when combined with the gel, 6Li concentrations of 0, 10 and 100ppm were found to be potentially usable.
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Affiliation(s)
- Kenichi Tanaka
- Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan.
| | | | - Shin-Ichiro Hayashi
- Faculty of Health Sciences, Hiroshima International University, Higashi-Hiroshima, Japan
| | - Tsuyoshi Kajimoto
- Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan
| | - Ryohei Uchida
- Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Hiroki Tanaka
- Research Reactor Institute, Kyoto University, Kumatori, Japan
| | - Takushi Takata
- Research Reactor Institute, Kyoto University, Kumatori, Japan
| | - Gerard Bengua
- Auckland City Hospital, Park Rd, Grafton, Auckland, New Zealand
| | - Satoru Endo
- Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan
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