清华同源双束医用加速器成像剂量分布蒙卡模拟

摘要

目的:使用蒙特卡罗方法模拟计算清华同源双束医用加速器KV级能量成像束在肺部模型中剂量分布.方法:使用清华同源双束医用加速器KV级能量成像束机头蒙卡模型得到相空间文件；以此相空间为源,使用蒙卡DOSXYZnrc程序建立肺部模型,计算肺部模体中成像剂量；使用MATLAB编程处理剂量数据,得到百分深度剂量(percent depthdose,PDD)、离轴比(offaxis ratio,OAR)和等剂量曲线(isodose curve).结果:得到了清华同源双束医用加速器KV级能量成像束在肺部模型中剂量分布曲线.结论:先计算不同模拟参数下的加速器机头相空间文件并保存再进行剂量计算,能极大节约整个计算流程耗费的时间；该模拟得到的成像剂量分布曲线可指导评价成像剂量对肺部器官损伤；加速器机头模型可用于其它器官成像剂量分布计算等后续研究.%Objective: To apply Monte Carlo method in simulating the Tsinghua Homo-Source Dual-Beam medical accelerator and calculating KV energy X-ray image dose distribution in simple lung model. Methods: Using Monte Carlo's BEAMnrc program to simulate the head of Tsinghua Homo-source Dual-beam Medical Accelerator for obtaining the Phase Space file which should be saved for the source of the next step; Using Monte Carlo's DOSXYZnrc program to simulate the Lung model and calculate the image dose; Using MATLAB program to deal with the dose data for obtaining the the percent depth dose (PDD), off axis ratio (OAR) and isodose curve. Results: The Tsinghua Homo-source Dual-beam medical accelerator KV energy X-ray image dose distribution in Lung model was obtained. Conclusions: It is useful to save the Accelerator's Phase Space files under different simulated parameters for reducing the time of the image dose distribution calculated procedure. The image dose distribution can be used to evaluate the damage to the Lung organ. The Accelerator's Monte Carlo model can be used in future researches on the image dose distribution.