两种检测医用电子直线加速器多叶准直器叶片到位精度的方法  

Two Methods for Testing Leaf Positioning Accuracy of Multi-Leaf Collimator of Medical Electron Linear Accelerator

作　　者：孔伟[1] 王永东 杨万福 丁伟[1] 余文军[1] 尚钧[1] Kong Wei;Wang Yongdong;Yang Wanfu;Ding Wei;Yu Wenjun;Shang Jun(General Hospital of Ningxia Medical University,Yinchuan Ningxia 750001,China;Ningxia Comprehensive Health Service Center,Yinchuan Ningxia 750001,China)

机构地区：[1]宁夏医科大学总医院,宁夏银川750001 [2]宁夏卫生健康综合服务中心,宁夏银川750001

出　　处：《医疗装备》2022年第10期14-17,共4页Medical Equipment

基　　金：宁夏医科大学校级项目(XM2018108)。

摘　　要：目的使用胶片法和电子射野影像软件分析法检测医用电子直线加速器多叶准直器的叶片到位精度,并比较两种方法的差异。方法使用医科达Precise医用电子直线加速器中内置的5组已知叶片位置的射野,在同光路条件下对胶片和电子射野影像装置(EPID)进行照射,得到胶片和电子射野影像,并分析影像得到40对叶片的位置数据,且采用配对t检验比较两种方法数据的差异。结果两种方法得到5组射野的叶片位置数据结果均在误差允许范围内,其中胶片法得到的3组数据优于电子射野影像软件分析法,分别为第4组射野Y1方向(P=0.010)、第5组射野Y1方向(P=0.002)和Y2方向(P=0.010);两种方法得到的其他数据比较,差异均无统计学意义(P>0.05)。结论EPID影像在AutoCalTM分析软件中获得的量化数据精度更高,且可直接将数据导入加速器进行叶片位置修正;但胶片影像数据更便于作为质量控制文件存档,为设备治疗保证工作提供循证依据;两种方法的测量数据差异较小且可互相验证,能够提高医用电子直线加速器多叶准直器叶片到位精度质量控制结果的可靠性。Objective The film method and electronic field imaging software analysis method were used to measure the leaf positioning accuracy of multi-leaf collimator of medical electron linear accelerator and then the differences between the two methods were compared.Methods The film and electronic portal imaging device(EPID)were irradiated under the same light path with five groups of radiation fields whose leaf position were known in Elekta Precise medical electron linear accelerator,and the film and electronic field images were obtained.The position data of 40 pairs of leaves were obtained by analyzing the images,and the differences of data between the two groups were compared by paired t-test.Results The leaf position data of five groups of radiation fields obtained by the two methods were all within the allowable error range.Among them,three groups of data film method were better than electronic field imaging software analysis method,which were Y1 direction of the fourth group of radiation fields(P=0.010),Y1 and Y2 directions of the fifth group of radiation fields(P=0.002,0.010);When the other data acquired by the two methods was compared,the differences were not statistically significant(P>0.05).Conclusion The quantitative data obtained from EPID images in AutoCalTM analysis software are more accurate,and the data can be directly imported to the accelerator for leaf position correction;but the film image data are more convenient to be archived as quality control documents,which provide evidence-based basis for assuring equipment treatment;the differences between the measurement data of the two methods are small and can be verified with each other,which can improve the reliability of quality control results of leaf positioning accuracy of multi-leaf collimator of medical electron linear accelerator.

关 键 词：多叶准直器 胶片 电子射野影像装置 AutoCalTM软件 质量控制 

分 类 号：R73[医药卫生—肿瘤]