软调制双散射质子治疗束流配送系统

A Soft Modulating and Double Scattering Beam Delivery Systemfor Proton Therapy

质子治疗是一种新兴的放射治疗方法 ,它的主要优点是剂量分布特性优良 ,可以使高辐射剂量集中于肿瘤部位 ,减少对周围正常组织的损伤 .这一优点的实现主要依靠束流配送系统 ,它包含质子能量调节与调制、束流扩展和准直等功能 .现提出一种新的软调制双散射质子治疗束流配送系统 .其特点是利用程序控制质子能量变化以改变质子在体内的射程从而展宽Bragg峰 ,同时利用两次散射获得较大面积的均匀照射野 .它的优点是运行可靠、调节灵活 。

The proton therapy is a new developing method in the radiation oncology. The superior dose localization capabilities of proton beams suggest the possibility of depositing a higher dose into the cancer while reducing the unwanted radiation damage in surrounding normal tissues. The merit can be realized with the aid of the beam delivery system, whose functions are energy adjustment, energy modulation, beam spreading and collimation. In this paper a new soft modulating and double scattering beam delivery system is proposed. It uses a program controlled modulator to change proton energy and thereby the proton range in the body so that the Bragg peak is spread out. Moreover, a larger treatment field can be obtained with two scatterers. The delivery system has high reliability and flexibility, and is especially good for conformal therapy.