| Project/Area Number |
61870042
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | Tokyo Medical & Dental University |
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Principal Investigator |
MATSUBARA Sho Tokyo Medical & Dental University, Lecturer, 医学部, 講師 (40014120)
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| Co-Investigator(Kenkyū-buntansha) |
加藤 二久 東京医科歯科大学, 歯学部, 助手 (70095107)
KUWABARA Yuji Tokyo Medical & Dental University, Assistant, 医学部, 助手 (00114752)
SHIBUYA Hitoshi Tokyo Medical & Dental University, Lecturer, 医学部, 講師 (10014292)
HORIUCHI Junichi Tokyo Medical & Dental University, Assistant Professor, 医学部, 助教授 (90013870)
KATOH Hisatsugu Tokyo Medical & Dental University Assistant
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1987: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1986: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | Chromosome aberrations / Biological dosimeter / Radiotherapy / Measurement to dose distribution / Electron beam / Neutron beam / Proton beam / 生物学的効果比 / 放射線誘発性染色体異常 / 線量分布 |
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| Research Abstract |
Chromosome analysis using peripheral lymphocytes is a sensitive and reliable indicator of the biological errect of radiation. In the present study, using this chromosome aberration analysis, we tried to investigate not only the dose response relation of chromosome aberration induction due to 14 MeV electron, 6 MeV neutron and 70 MeV proton beams but also the irradiation dose distribution within and around the radiation fiels.
At the electron beam irradiation, the depth dose curvr based upon chromosome aberration frequencies was found to be somewhat different from that obtained by physical method. The electron beam irratiation in the presence of contrast bedium disclosed a slight enhancement of radiation induced chtomosome aberration frequencies. The efficient induction of dicentrics and rings at the irradiation of neutrons comparted to those of <gamma> or X-rays, especially in a lower dose range, results in a dominant linear component in a linear quadratic model in the dose response relation of a chromosome aberration formation. The high RBE value obtained at lower neutron dose, especially along the margin of neutron beam portals may contribute to the induction of late effect in the normal tissue surrounding the tumow mass.
The dose response relationship in chromosome aberration induction due to 70 MeV proton beam gave rise to similar trend of its induction due to^<60>Co-<gamma> rays. Further, about two times increase of RBE in the peak area compared to the area near the incident was confirmed even in the modulated beam.
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