【摘要】 目的:对比研究蒙特卡罗(MC)算法模拟剂量数据、试验测量剂量数据以及仪器公司提供的剂量数据,分析研究剂量差异,探讨仪器公司提供的相空间文件(PSF)作为程序输入源的可行性。方法:使用瓦里安公司提供的Truebeam和IX机型的PSF,模拟4 cm×4 cm和10 cm×10 cm射野剂量分布,将模拟与装机测量得到的剂量分布与官方提供的剂量数据进行对比分析。结果:两种射野下,3种剂量数据的百分深度剂量误差较小,但在建成区存在不同大小误差;在5 cm、10 cm深度处,射野中心区离轴剂量符合度较好,半影区离轴剂量存在一定差异。结论:不同方法得到的百分深度剂量及离轴剂量分布,随着深度不同以及离轴距离远近存在一定误差,在研究这两种剂量分布时,可根据课题内容得到准确的研究结果。更多还原

【Abstract】 Objective: To compare the simulated dose data of Monte Carlo(MC) algorithm, the measured dose data in experiment and the provided dose data by instrument company, and analyze and study the dose differences among them, and explore the feasibility that phase space file from instrument company was used as input source of program. Methods: The phase space files of Truebeam and IX machine types that were provided by Varian were used to simulate the dose distributions of 4 cm×4 cm radiation field and 10 cm×10 cm radiation field. And then, the simulated dose distribution was used to compare with the measured dose distribution in installing machine and the dose data that were provided by authority, respectively. Results: Under two radiation fields, the differences of the errors of percentage depth doses among the three kinds of dose data were negligible but there were obvious differences in built-up area. At the depth of 5 cm and 10 cm, the conformity of dose between the central region of radiation field and axis was favorable, and there was a certain difference of the dose between penumbra field and axis. Conclusion: For the obtained percentage depth dose and the dose distribution by different method, there is a certain error between different depths and between the different distance off-axis. When the two kinds of dose distribution are studied, the accurate research results can be obtained according to the content of project.更多还原