1993 Fiscal Year Final Research Report Summary
Radiation Quality and Relative Biological Effectiveness of Proton Beams
| Project/Area Number |
03454278
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Radiation science
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| Research Institution | University of Tsukuba |
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Principal Investigator |
INADA Tetsuo Univ.Tsukuba, Inst.Basic Medical Sci., Professor, 基礎医学系, 教授 (50114038)
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| Co-Investigator(Kenkyū-buntansha) |
IWAKAWA Mayumi Univ.Tsukuba, Inst.Clinical Medical Sci., Lecturer, 臨床医学系, 講師 (30231723)
TATSUZAKI Hideo Univ.Tsukuba, Inst.Clinical Medical Sci., Lecturer, 臨床医学系, 講師 (20227101)
TADA Junichiro Univ.Tsukuba, Inst.Basic Medical Sci., Assistant, 基礎医学系, 助手 (40163464)
HAYAKAWA Yoshinori Univ.Tsukuba, Inst.Basic Medical Sci., Lecturer, 基礎医学系, 講師 (90101740)
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| Project Period (FY) |
1991 – 1993
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| Keywords | Radiation quality / LET / Mixed neutrons / Bragg peak / RBE / Dosimetry / Multi.cell spheroid / Cell inactivation |
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| Research Abstract |
Correlation of a wide range of published data from proton irradiation experiments on several biological materials has been achieved in terms of the radiation quality of proton beam and the precice end point of radiation effects.
Linear energy transfer (LET) of proton beams at the spread out bragg peak (SOBP) has been evaluated for several quality factors such as the initial energies, the width and irradiation position of SOBP and the field shaping devices. For the quality specification of proton beam, the initial energy should be categorized into three classes, below 100MeV, 100-200 Mev and above 200 MeV.The standard irradiation position is suggested to be the middle of 4-5cm width SOBP.The contamination of secondary radiations including neutrons should be estimated. Comparative study on RBE of proton beams is suggested to carry out under such limited conditions. In addition, the end point of biological effects should be definite and the dosimetry in small animal should be made within 3% for the standard radiations such as ^<60>Co gamma rays or 3-4 MVX rays. For these careful limitations, RBE value of proton beams applied to the deep seated tumor therapy is obtainable from 1.0 to 1.2.
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