Project/Area Number |
18K15647
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Research Category |
Grant-in-Aid for Early-Career Scientists
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Allocation Type | Multi-year Fund |
Review Section |
Basic Section 52040:Radiological sciences-related
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Research Institution | Kyoto Prefectural University of Medicine (2021) Tokyo Women's Medical University (2018-2020) |
Principal Investigator |
Hiroaki Matsubara 京都府立医科大学, 医学(系)研究科(研究院), 講師 (10598288)
|
Project Period (FY) |
2018-04-01 – 2022-03-31
|
Project Status |
Completed (Fiscal Year 2021)
|
Budget Amount *help |
¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
|
Keywords | 放射線治療 / 中性子線量 / ソフトエラー / 植込み型心臓デバイス / 全身照射 / 原子核反応 / 医学物理学 / 全身照射(TBI) / 医学物理 / 速中性子障害 / 植込み型除細動器 |
Outline of Final Research Achievements |
Malfunctions occurred in cardiac implantable electronic devices (CIEDs) in radiotherapy have been studied. Although several clinical guidelines recommend that direct irradiation should be avoided and that total accumulated dose should be within 2-5 Gy, there is no consensus in terms of tolerance dose. The present study performed two kinds of studies. Firstly, it was found that number of malfunctions in CIEDs is proportional to neutron dose. The proportionality was deduced from a simple theory of nuclear reaction, was observed from analysis using data in literature, and was confirmed by the consistency with other results in literature. Secondly, it was reported that no malfunction was observed when non-neutron producing beam was directly irradiated with low dose-rate with low accumulated dose up to at 20 Gy, indicating that the direct irradiation itself is not an essential risk. The result suggests that total body irradiation could be feasible and safe for a patient having a CIED.
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Academic Significance and Societal Importance of the Research Achievements |
二人に一人ががんになる時代となり、ペースメーカ等の心臓デバイスを植え込んだがん患者が放射線治療を受けるケースも増えてきた。これまではデバイスの誤作動機構が不明であったため、デバイスに放射線が入らないように照射方法等を工夫するしかなかったが、微量な放射線でも誤作動するケースが散見された。本研究はそのような低線量でのデバイス誤作動を物理機構に基づき定量的に解明し、どの放射線がどのくらい安全かという指標を初めて提示した。またデバイスの誤作動要因を切り分けて考えることで、これまでは危険と考えられて忌避されてきた全身照射の治療も安全に施行できる可能性を示唆し、デバイス装着患者の治療機会改善に貢献した。
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