Dosimetry of secondary particles generated in therapeutic radiation fields

2015 Fiscal Year Final Research Report

• Project/Area Number: 25713047
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Partial Multi-year Fund
• Research Field: Radiation science
• Research Institution: National Institute of Radiological Sciences
• Principal Investigator: Kodaira Satoshi 国立研究開発法人放射線医学総合研究所, 研究基盤センター, 主任研究員 (00434324)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 医療被ばく / 放射線治療 / 二次粒子

Outline of Final Research Achievements

We have measured the secondary particles generated by the nuclear interactions with matters in the therapeutic radiation such as X-ray, proton and carbon beams. Especially, we have established the angular correction method for evaluating the dose of secondary particles quantitatively. For example, we found that the proton-induced secondary particles contribute to 20% in dose equivalent for primary protons. The production cross section depends on the nuclear charge of primary ions. The cross section for carbon beam is about 25 times higher than proton beam. On the other hand, the particle fluence giving 1 Gy dose for carbon beam is about 1/25 lower than proton beam. Therefore, in the viewpoint of dosimetry, we confirmed that the dose contribution of secondary particles for carbon beam is about 1/5 - 1/6 lower than proton beam.

Free Research Field

放射線物理学