【摘要】 Monte Carlo方法常用于质子束剂量模拟以优化质子束临床治疗,合适的物理模型选择关系到Monte Carlo模拟结果的可靠性及模拟效率。本工作选取9个可用于质子模拟的Geant4物理模型,计算比较了质子束在多种介质中的剂量及次级粒子产额。结果表明:标准电磁物理模型、低能电磁Penelope模型和Livermore模型虽在模拟质子整体剂量分布上可接受,但在微观上缺失重粒子生成。参数化驱动模型LHEP的模拟时间最短,但与QGSP相同,均不能产生复杂重离子。QGSP_BIC_EMY模型较其他模型明显低估Bragg峰-入口剂量比和绝对剂量。QGSP_BERT模型、QGSP_BIC模型和FTFP_BERT模型较适合放疗质子束模拟。更多还原

【Abstract】 The Monte Carlo method is usually used to simulate the feature of the external radiotherapy of proton beam to optimize the clinical therapy scenario.The selection of a suitable physical model is very critical to ensure the correction and the efficiency of the simulation.This work studied nine Geant4 physical models,which are often used in the simulation of radiotherapy of proton beam with energy of 60-250 MeV.The dosagefeatures and the microcosmic secondary yields in different materials were compared.The result shows that,although the standard EM,the low energy Penelope model and the low energy Livermore model can output the right dose distribution,they can’t simulate the baryon yields.The parametrization driven model LHEP and the Quark gluon stringpre-compound model both can’t simulate the complex ion transportation.Thus the above five models are not enough for the research calculation in the radiation protection and the radiation damage.The QGSP_BIC_EMY model in Geant4 hadron therapy example is very bad for underestimating the dose ratio of Bragg peak to entrance and absolute dose.The QGSP_BERT model,QGSP_BIC model and FTFP_BERT model are suitable for the radiotherapy proton beam with energy of 60-250 MeV.更多还原