重离子束均匀度的测定及治癌束流成形的模拟试验  

Determination of homogeneity of heavy ion beam and a simulation test of beam shaping for cancer therapy

作　　者：颉红梅[1] 卫增泉 李文建[1] 周光明[1] 陈卫强[1] 黄涛 

机构地区：[1]中国科学院近代物理研究所

出　　处：《核技术》1997年第4期230-234,共5页Nuclear Techniques

基　　金："九五"国家攀登计划(B)项目

摘　　要：采用５０μｍ厚聚碳酸酯薄膜、利用核径迹探测技术测得φ４０ｍｍ的２５ＭｅＶ／ｕ４０；Ａｒ１４；离子束的均匀度在散焦情况下为３２．７％，在“散焦＋样品旋转”情况下为５２．４％。还采用多层聚碳酸酯薄膜组件作为肿瘤块等效材料，进行了重离子束治癌束流成形模拟试验，通过对２５ＭｅＶ／ｕ４０；Ａｒ１４；离子束９个间隔的降能来移动其Ｂｒａｇｇ峰位，并在各个峰位上经过光阑赋予不同的束流截面，由不同层面上的截面可以构成一肿瘤块的椭球状。利用这种方法辐照聚碳酸酯薄膜组件，经化学蚀刻处理后，利用离子径迹小孔对普通光柱的透射与衍射，得到了类似于椭球形肿瘤的光球，光球范围就反映了重离子束能损集中的Ｂｒａｇｇ峰作用的部位。The homogeneity of 25MeV/u 40 Ar 14 ion beam (40mm) was measured with 50μm polycarbonate films by means of nuclear track detection. It was 32.7% for the case of defocus and 52.4% for “defocus+sample rotation”. A simulation test of beam shaping for heavy-ion cancer therapy was carried out with an assembly of multilayer polycarbonate films as the tumour equivalent material. The Bragg-peak was moved at nine locations through energy degradation of the heavy ions. The beam cross sections at each Bragg-peak location were defined by different apertures. Thus, an ellipsoid like tumour was formed from the cross-sections of different layers. A light-ball similar to the ellipsoid tumour was obtained by means of transmission and diffraction of a light column passing through ion track pores in the irradiated polycarbonate films after chemical etching. The sphere of the light-ball corresponded to the space effected by Bragg-peaks where the energy loss of heavy ions was concentrated.

关 键 词：重离子束治癌 束流均匀度 核径迹探测 肿瘤治疗 

分 类 号：R730.55[医药卫生—肿瘤]