栅扫描重离子束治癌束流配送系统对运动靶区的适形放疗(Ⅱ)可行性实验

Conformal Irradiation to Moving Targets in Heavy Ion Radiotherapy with Raster-Scanning Beam Delivery System:(Ⅱ)Feasibility Experiments

在栅扫描束流配送系统下,进行了重离子束对运动靶体进行适形照射的可行性实验研究．利用实时修正束流扫描参数的方法,使得束流追踪靶体在横向上的运动；在纵向上利用一个机械驱动的束流降能装置(称深度扫描器)迅速调节束流能量,使得重离子束高剂量的Bragg峰区落在运动靶体需治疗的断层之上．实验结果表明：栅扫描器主动补偿靶体横向运动及深度扫描器补偿靶体纵向运动是可行的．

Within the framework of the pilot heavy-ion therapy system of advanced raster scanning technique, a feasibility study facility at GSI equipped with an active beam delivery on actively conformal heavy-ion irradiation to moving tumors has been experimentally conducted. Laterally, real-time corrections to the beam scanning parameters by the raster scanner, leading to an active beam tracing, compensate for the lateral motion of a target volume. Longitudinally, a mechanically driven wedge energy degrader （called depth scanner） is applied to adjust the beam energy so as to locate the high-dose Bragg peak of heavy ion beam to the slice under treatment for the moving target volume. It has been experimentally shown that compensations for lateral target motion by the raster scanner and longitudinal target shift by the depth scanner are feasible.