调强放射治疗计划中子野跳数输出误差分析  

Errors of monitor units in step-and-shoot intensity-modulated radiotherapy plan

作　　者：李小波[1,2] 陈丽芳 张建平 黄妙云 陈远贵[1] 徐本华[1,2] LI Xiaobo;CHEN Lifang;ZHANG Jianping;HUANG Miaoyun;CHEN Yuangui;XU Benhua(Department of Radiation Oncology,Fujian Medical University Union Hospital,Fuzhou 350001,China;Department of Medical Imaging Technology,School of Medical Technology and Engineering,Fujian Medical University,Fuzhou 350001,China;Department of Radiology,Fujian Medical University Union Hospital,Fuzhou 350001,China)

机构地区：[1]福建医科大学附属协和医院放疗科,福建福州350001 [2]福建医科大学医学技术与工程学院医学影像技术学系,福建福州350001 [3]福建医科大学附属协和医院放射科,福建福州350001

出　　处：《中国医学物理学杂志》2018年第8期885-888,共4页Chinese Journal of Medical Physics

基　　金：福建省科技厅引导性项目(2016Y0044)

摘　　要：目的:探讨三维静态调强放射治疗计划的子野机器跳数(MU)与加速器实际输出的MU存在的误差,为计划设计时最小跳数的设置提供参考。方法:选择50例调强放射治疗计划,子野数共4 842个。对治疗计划每个子野输出的MU(PDM)与实际加速器出束时每个子野的MU(ADM)进行统计学分析,判断两者的误差情况。结果:计划PDM与ADM的平均值存在显著差异(P<0.05);当PDM值较小时,PDM与ADM的相对误差概率大大增加,最高达16.33%。结论:PDM与ADM之间存在的误差临床上不可忽视。在不影响计划剂量分布的前提下,当误差可接受在5%内时,建议PDM应该大于8.49 MU;当可接受误差在3%内时,建议PDM应大于14.46 MU。Objective To discuss the errors between planned delivered monitor units（PDM） and actual delivered monitor units（ADM） in three-dimensional step-and-shoot intensity-modulated radiotherapy（IMRT） plans and provide a reference for setting the minimum monitor units. Methods A total of 50 step-and-shoot IMRT plans with 4 842 segments were selected. For each segment, statistical analysis was performed on PDM and ADM, and the errors between PDM and ADM were determined. Results Significant differences were found between PDM average and ADM average（P〈0.05）. When PDM was relatively smaller, the relative errors between PDM and ADM were remarkably increased, and the maximum relative error reached 16.33%. Conclusion The error between PDM and ADM can＇t be ignored in clinic. Under the premise of without affecting the planned dose distribution,when the error was within the acceptable limit of 5%, PDM should be greater than 8.49 MU; and when the error was within the acceptable limit of 3%, PDM should be greater than 14.46 MU.

关 键 词：调强放射治疗 子野 机器跳数 计划系统 

分 类 号：R811.1[医药卫生—放射医学]