基于电子射野影像系统的光栅位置和剂量验证研究  

Research on Position Verification of Multi-Leaf Collimator(MLC)and Dose Verification Based on Electronic Portal Imaging Device

作　　者：眭建锋 孙佳伟 谢凯 髙留刚[1,2,3] 林涛 倪昕晔 SUI Jianfeng;SUN Jiawei;XIE Kai;GAO Liugang;LIN Tao;NI Xinye(Radiotherapy Department,Changzhou No.2 People’s Hospital,Affiliated Hospital of Nanjing Medical University,Changzhou,213161;Center of Medical Physics,Nanjing Medical University,Changzhou,213161;Jiangsu Province Engineering Research Center of Medical Physics,Changzhou,213161)

机构地区：[1]南京医科大学附属常州第二人民医院放疗科,常州市213161 [2]南京医科大学医学物理研究中心,常州市213161 [3]江苏省医学物理工程研究中心,常州市213161

出　　处：《中国医疗器械杂志》2024年第2期150-155,共6页Chinese Journal of Medical Instrumentation

基　　金：国家自然科学基金面上项目(62371243);江苏省自然基金面上项目(BK20231190);江苏省重点研发计划社会发展项目(BE2022720);江苏省医学重点学科建设单位(肿瘤治疗学(放射治疗))(JSDW202237);江苏省卫健委面上项目(M2020006);常州市社会发展项目(CE20235063);常州市科技计划资助(CJ20220136,CJ20210128,CJ20200099)。

摘　　要：目的 使用基于电子射野影像系统(electronic portal imaging device,EPID)的质控系统,在Primus和VenusX加速器上实现光栅位置及剂量验证。方法 通过灰度值最大梯度方法计算光栅位置,评估偏差。使用剂量标定和剂量计算相结合的算法对EPID采集的图像进行剂量重建,将EPID和MapCheck/PTW得到的数据,分别与计划系统剂量进行γ通过率分析。结果 VenusX加速器光栅误差小于1 mm,Primus重新标定后误差明显减小。重建的剂量,在3%/3 mm,阈值10%和2%/2 mm,阈值10%的2种标准下,Primus加速器γ平均通过率分别为98.86%和91.39%;VenusX加速器γ平均通过率分别为98.49%和91.11%。结论 基于EPID的质控系统,可提高加速器质控效率,减轻物理师工作负担。Objective A quality control(QC)system based on the electronic portal imaging device(EPID)system was used to realize the Multi-Leaf Collimator(MLC)position verification and dose verification functions on Primus and VenusX accelerators.Methods The MLC positions were calculated by the maximum gradient method of gray values to evaluate the deviation.The dose of images acquired by EPID were reconstructed using the algorithm combining dose calibration and dose calculation.The dose data obtained by EPID and two-dimensional matrix(MapCheck/PTW)were compared with the dose calculatedγby Pinnacle/TiGRT TPS for passing rate analysis.Results The position error of VenusX MLC was less than 1 mm.The position error of Primus MLC was significantly reduced after being recalibrated under theγinstructions of EPID.For the dose reconstructed by EPID,the average passing rates of Primus were 98.86%and 91.39%under the criteria of 3%/3 mm,10%threshold and 2%/2 mm,10%threshold,γrespectively.The average passing rates of VenusX were 98.49%and 91.11%,respectively.Conclusion The EPID-based accelerator quality control system can improve the efficiency of accelerator quality control and reduce the workload of physicists.

关 键 词：电子射野影像系统 质控 光栅 剂量验证 

分 类 号：R811.1[医药卫生—放射医学] TH774[医药卫生—临床医学]