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

本研究的目的是提出一种新型的质子治疗癌症的照射系统。该系统充分利用了旋转门架系统的特点，适合于选择对向场轴线的各种旋转角度。本研究主要有两个主题，以改善质子癌症治疗的现有技术水平，使其用于任何希望使用它的人。第一是开发一种更紧凑，更小，一个简单和便宜的系统，使从加速器提取的典型光束的强度分布为具有窄布拉格的椭圆形光束，峰值修改以将目标体积的扩展宽度均匀地照射到最高剂量。作为本研究的结果，我们提出了一种新的能量过滤器，它既起到了散射系统的质子束的横向扩展和条形脊过滤器的布拉格曲线的范围调制的作用;第二是发展了一种简单的照射方法，以改善质子束的三维剂量分布的最高剂量区的目标区域的一致性。结果，清楚地表明，积极利用3-D剂量分布的布拉格峰扩展内的横向轮廓和轴向轮廓的非均匀性是重要的。

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.