质子治疗被动散射系统束流横向扩展的蒙特卡罗模拟

Study of Beam Spreading for Passive Beam Delivery System in Proton Therapy Using Monte Carlo Simulation

关键词:  质子治疗  蒙特卡罗模拟  束流扩展

Key words:  proton therapy  Monte Carlo simulation  beam spreading

摘要:

[目的]质子固有的物理特性为治疗肿瘤提供了理想的方法。与主动式相比,被动式质子束流横向扩展有很多优势。为达到最佳治疗目的,对被动式质子束流横向扩展方式的几种方法进行了模拟。[方法]利用蒙特卡罗(Monte Carlo)方法计算质子经过一个或两个散射体后的束流分布特性,并与解析计算的结果进行比较,讨论3种方法在束流利用率和束流扩展半径方面的差别。[结果]双散射体方法较单散射体方法在束流利用率和束流扩展半径方面具有明显优势。[结论]考虑束流利用率,平均能量损失及形成距离,双环双散射体方法是被动散射体方法中比较好的方法。

Abstract:

[Objective] The physical properties of proton provide ideal method for cancer treatment.Passive proton beams for spreading method has many advantages compared with the active beam delivery system.The passive beam spreading methods were simulated in this paper to achieve the best treatment.[Methods] The beam of passive beam delivery system with one or two foils was investigated using the Monte Carlo method, and the results were compared with analytical computation under the same condition.The difference on the efficiency and the radius of the proton beam by three methods was compared.[Results] The efficiency of beam and the radius of beam spreading are higher with double scattering foils than other methods [Conclusion] Dual-ring double scattering method is the best one in this three passive scattering system by considering the efficiency, energy loss and distance.