Evaluation of Radiation Quality with Nano-Site Size for Neutron Capture Therapy Field

中子俘获治疗场纳米尺寸辐射质量评价

基本信息

批准号：
14370280
负责人：
ONIZUKA Yoshihiko
金额：
$ 7.62万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

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.

京都大学反应堆（KUR）的硼中子捕获疗法（BNCT）接受了90多名患者的治疗，此后开始了该临床的1987年。随后，通过使用上皮中子的利用来显着改善剂量分布。但是，应解决的问题发生在辐射场的剂量评估中，其中混合了热中子，表现中子和快速中子和伽玛射线。用配对电离室和黄金箔辐射的激活方法进行数量评估，但它们的结果并没有表现出良好的一致性。物理剂量和生物剂量量之间的关系不是确定的。该问题的解决方案是通过在这项研究中使用微型测定法进行微观能量矿床来完成的。 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.与含硼（50ppm）壁的组织中的组织当量比例计数器（TEPC）测量，与通常的组织等效壁相比，与含硼的壁一起评估了它们的差异。可以决定thethernal和上皮中子的剂量贡献量。评估了人体幻影的深度变化，并获得了BNCT的基本数据，我们强调，我们的研究结果通过使用响应功能清除了物理和生物剂量之间的关系。