基于蒙特卡罗(MC)方法的剂量计算算法已被普遍认为是可以在放射治疗中使用的最精确的计算工具。放射治疗中的MC模拟可分成两个部分,即对源的模拟和对实际患者的模拟。本文使用测量数据驱动的虚源模型建立了模拟直线加速器治疗头的虚拟源,通过与三维水箱中的测量数据比较,研究了虚拟源各种参数选择与计算精度之间的关系,表明考虑了初始光子源和次级光子源的综合影响,并选择合适的各种参数,由虚拟源出发的水模中的MC剂量分布可以与测量结果相一致,从而满足临床MC模拟的建模要求。 Dose calculation algorithms based on the Monte Carlo method have generally been considered the most accurate calculation tools that can be used in radiotherapy. The MC simulation in radiotherapy can be divided into two parts, namely the simulation of the source and the simulation of the actual patient. In this paper, we use the virtual data source driven by the measurement data to set up the virtual head of the simulation linear accelerator. By comparing with the measured data in the three-dimensional water tank, we study the relationship between the parameters of the virtual source and the calculation accuracy, Photon source and secondary photon source, and select appropriate parameters. The distribution of MC dose in the water phantom from the virtual source can be consistent with the measurement results to meet the modeling requirements of clinical MC simulation.