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Ishikawa A, Koba Y, Furuta T, Chang W, Yonai S, Matsumoto S, Hashimoto S, Hirai Y, Sato T. Monte carlo simulation study on the dose and dose-averaged linear energy transfer distributions in carbon ion radiotherapy. Radiol Phys Technol 2024; 17:553-560. [PMID: 38570400 DOI: 10.1007/s12194-024-00798-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 03/12/2024] [Accepted: 03/15/2024] [Indexed: 04/05/2024]
Abstract
Dose-averaged linear energy transfer (LETd) is conventionally evaluated from the relative biological effectiveness (RBE)-LETd fitted function used in the treatment planning system. In this study, we calculated the physical doses and their linear energy transfer (LET) distributions for patterns of typical CIRT beams using Monte Carlo (MC) simulation. The LETd was then deduced from the MC simulation and compared with that obtained from the conventional method. The two types of LETd agreed well with each other, except around the distal end of the spread-out Bragg peak. Furthermore, an MC simulation was conducted with the material composition of water and realistic materials. The profiles of physical dose and LETd were in good agreement for both techniques. These results indicate that the previous studies to analyze the minimum LETd in CIRT cases are valid for practical situations, and the material composition conversion to water little affects the dose distribution in the irradiation field.
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Affiliation(s)
- Akihisa Ishikawa
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Ibaraki, 319-1195, Japan.
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba, 263-8555, Japan.
- Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan.
| | - Yusuke Koba
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Takuya Furuta
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Ibaraki, 319-1195, Japan
| | - Weishan Chang
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10, Higashiogu, Arakawa-Ku, Tokyo, 116-8551, Japan
| | - Shunsuke Yonai
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1, Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Shinnosuke Matsumoto
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10, Higashiogu, Arakawa-Ku, Tokyo, 116-8551, Japan
| | - Shintaro Hashimoto
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Ibaraki, 319-1195, Japan
| | - Yuta Hirai
- Department of Radiological Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10, Higashiogu, Arakawa-Ku, Tokyo, 116-8551, Japan
| | - Tatsuhiko Sato
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai-mura, Ibaraki, 319-1195, Japan
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Furuta T, Koba Y, Hashimoto S, Chang W, Yonai S, Matsumoto S, Ishikawa A, Sato T. Development of the DICOM-based Monte Carlo dose reconstruction system for a retrospective study on the secondary cancer risk in carbon ion radiotherapy. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac7998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/16/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Objective. A retrospective study on secondary cancer risk on carbon ion radiotherapy (CIRT) is ongoing at the Heavy Ion Medical Accelerator in Chiba (HIMAC). The reconstruction of the whole-body patient dose distribution is the key issue in the study because dose distribution only around the planning target volume was evaluated in the treatment planning system. Approach. We therefore developed a new dose reconstruction system based on the Particle and Heavy Ion Transport code System (PHITS) coupled with the treatment plan DICOM data set by extending the functionalities of RadioTherapy package based on PHITS (RT-PHITS). In the system, the geometry of patient-specific beam devices such as the range shifter, range compensator, and collimators as well as the individual patient’s body are automatically reconstructed. Various functions useful for retrospective analysis on the CIRT are implemented in the system, such as those for separately deducing dose contributions from different secondary particles and their origins. Main results. The accuracy of the developed system was validated by comparing the dose distribution to the experimental data measured in a water tank and using a treatment plan on an anthropomorphic phantom. Significance. The extended RT-PHITS will be used in epidemiological studies based on clinical data from HIMAC.
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Medical application of particle and heavy ion transport code system PHITS. Radiol Phys Technol 2021; 14:215-225. [PMID: 34195914 DOI: 10.1007/s12194-021-00628-0] [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: 05/28/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 12/15/2022]
Abstract
The Particle and Heavy Ion Transport code System (PHITS) is a general-purpose Monte Carlo simulation code that has been applied in various areas of medical physics. These include application in different types of radiotherapy, shielding calculations, application to radiation biology, and research and development of medical tools. In this article, the useful features of PHITS are explained by referring to actual examples of various medical applications.
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