中文摘要：

目的明确利用容积旋转调强放疗（volumetricmodulatedarctherapy，VMAT）加速器的日志文件验证放疗计划技术的可行性。方法加速器（ElektaSynergy）日志文件以二进制格式记录了加速器执行计划时每个控制点对应的机架角度、多叶准直器叶片位置、累积机器跳数（MU）等信息，利用Matlab7．1编写内部程序从加速器日志文件中读取这些信息，然后将原计划文件中各控制点的机架角度、多叶准直器叶片位置、累积MU替换为日志中对应信息，从而生成-个新的计划。将新计划导入到计划系统（PhilipsPinnacle^3）中重新计算剂量。对比两者的剂量体积直方图（dosevolumehistogram，DVH）与剂量分布，判断加速器执行计划的准确性。结果新计划与原计划相比，12个弧中有4个弧机架角度差别大于±1°的控制点，占整个弧控制点数目的比例约35％。对于所有弧，约95％控制点的叶片误差为±0．5mm。单个控制点的MU误差较大，但每个弧的累积MU相差很小，所选12个弧的累积MU为-0．09％-0．11％。靶区最大剂量、最小剂量、平均剂量差别分别为-0．07％-0．42％、-0．38％-0．40％、0．03％-0．08％，危及器官最大剂量和平均剂量差别分别为-1．16％-2．51％、-1．21％-3．12％。结论利用加速器日志文件验证VMAT计划的方法可作为实验测量方法的补充。

英文摘要：

Objective To verify the dose delivery accuracy of volumetric-modulated arc therapy plan by log-file analysis of linear accelerator that can be created when a dynamic delivery occurs. Methods Accelerator log file in binary format recorded the accelerator execution plan for each control point corresponding to the gantry angle, multi-leaf collimator leave position, cumulative machine monitor units （MU）. These information were read from the accelerator log file with Matlab7.1, then the original control points in the plan file replaced the corresponding information for the log, which generated a new plan. New plan was exported into the planning system to recalculate the dose. The volume dose histogram （DVH） and dose distribution was contrasted to determine the accuracy of the accelerator plan of implementation between two plans. Results Compared with the original plan, antry angle difference over ± 1°accounted for about 35% of the entire arc of control points in 4 of 12 arcs and the percentage of the leave error of ±0. 5 mm was about 95%. MU error of a single control point was larger, but the cumulative MU for each arc was small which was located between -0.09% to 0. 11% in the selected 12 arcs. Between the targets, the maximum dose, minimum dose, the mean dose differences were from -0. 07% to 0. 42% , -0.38% to 0. 40% , 0.03% to 0.08% , respectively. The maximum dose and mean dose differences of organs at risks were located from -1.16% to 2.51%, -1.21% to 3.12% , respectively. Conclusions Accelerator log-file analysis to verify the VMAT plan can be supplyed to the experimental method supplement.