| Project/Area Number |
14370280
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Radiation science
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| Research Institution | Kyushu University |
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Principal Investigator |
ONIZUKA Yoshihiko Kyushu University, School of Health Sciences, Faculty of Medicine, Professor, 医学部・保健学科, 教授 (30160899)
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| Project Period (FY) |
2002 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥11,900,000 (Direct Cost: ¥11,900,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2003: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2002: ¥8,300,000 (Direct Cost: ¥8,300,000)
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| Keywords | Microdosimetry / Neutron Capture Therapy / Radiation Quality / Heavy Water / Radiation T therapy / TEPC / 中性子捕捉療法 / 組織等価比例計算数管 / 中性子 / 捕捉療法 / 硼素 / 線量 / マイクロドジメントリー |
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| Research Abstract |
Boron neutron capture therapies (BNCT) at Kyoto university reactor (KUR) were treated for more than 90 patients after that that clinical was begun for 1987.After then, dose distribution was improved remarkably by the utilization of the epitheimal neutron. But, the problem which should be solved occurred in the dose evaluation of the irradiation field in which thermal neutron, epithermal neutron and fast neutron and a gamma ray were mixed. Quantity evaluations were done with the pair ionization chambers and the activation method of gold foil irradiation, But their results didn't show good agreement. Relation between the amount of physics dose and the amount of biological dose isn't definite. The solution of this problem was done by using the technique of the microdosimetry for the microscopic energy deposit in this research. When the energy of the proton recoiled by the neutron became smaller than 10 keV, the proton captured the electron, and it changed to neutral hydrogen and usual appraisal method couldn't be solved it.
Because lineal energy which was similar to LET could be measured, the technique of microdosimetiy Frequency and dose mean lineal energies were evaluated as a function of lineal energy. They were measured with an tissue equivalent proportion counter(TEPC) in the organization which had boron containing (50ppm) wall, and RBE were obtained Difference from the usual tissue equivalent wall were evaluated in comparison with boron containing wall. The amount of dose contribution for thetherrnal and the epithennal neutron could be decided. Changes by the depth in human body phantom were evaluated, and the fundamental data of BNCT were obtained We emphasize that our research result cleared relations between physical and biological dose by using the response function.
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