Development of a new type proton irradiation system built in a rotating gantry

本研究的目的是提出一种用于质子癌症治疗的新型照射系统。该系统是为充分利用旋转龙门系统而开发的，该系统适用于选择对偶场轴线的各种旋转角度。这项研究主要有两个主题，以改善质子癌症治疗的现状，使其适用于任何希望使用它的人。一是开发一种更紧凑、更小、更简单和更便宜的系统，使从加速器提取的典型束流的强度分布修改为窄布拉格峰的铅笔形束流，以将扩展的靶体积宽度均匀照射到最高剂量。作为这项研究的结果，我们提出了一种新的能量滤光片，它既具有质子束横向扩散的散射系统的作用，又具有条脊滤光片的作用，用于调制Bragg曲线的范围。第二，开发一种简单的辐照方法，以提高质子束三维剂量分布的最高剂量区与靶区的一致性。结果表明，在三维剂量分布的布拉格峰扩散范围内，积极利用横向分布和轴向分布的非均匀性是非常重要的。

The object of this study is to propose a new type of an irradiation system for the proton cancer therapy. This system is developed to make good use of the rotating gantry system which is suitable to select various rotating angles of axis of opposing pair field. This study has main two subjects to improve the present state of the art of the proton cancer therapy to make it use for any person who will hope it.The fist is to develop a more compact, smaller, simpler and cheaper system to make the intensity distribution of a typical beam extracted from an accelerator as a penciliform beam with narrow Bragg-peak modify to uniformly irradiate the extended width of the target volume to the highest dose. As a result of this research, we proposed a new energy filter which plays both roles of a scattering system for transverse spreading of proton beam and of a bar ridge filter for modulating the range of the Bragg curve.The second is to develop a simple irradiation method to improve the conformity of the highest dose region of 3-D dose distribution of the proton beam to the target region. As a result, it was clearly shown that it is important to make positively use of non-uniformity of a transverse profile and of an axial profile within a spread of Bragg-peak of a 3-D dose distribution.