摘要
提出了一种基于标定和计算的电子射野影像系统(EPID)剂量重建算法。首先,对连续采集模式的EPID原始数据进行暗场校正和增益校正,然后通过亮场灰度特征确定射野边界。其次,对EPID数据进行MU标定、离轴标定和射野大小标定,并根据标定后的叠加通量和加速器机头蒙特卡罗模型进行剂量重建。最后,选取9例IMRT计划,分别使用EPID和MapCheck对计划进行验证测量,并在不同γ标准下比较两种验证工具的通过率。针对选取的1例计划病例,两种标准下使用MapCheck对多个病例验证的通过率分别为99.02%±1.28%、90.84%±4.49%;使用EPID重建模型的平均通过率分别为98.86%±1.19%、91.39%±4.80%。本文提出的标定和剂量计算相结合的EPID重建算法,与主流剂量验证软件MapCheck相比,对IMRT计划的验证通过率没有统计学差异(P>0.05),符合剂量验证的临床要求。
A dose reconstruction algorithm for electrionic portal imaging device(EPID)based on calibration and calculation is developed.The raw data of EPID in continuous acquisition mode are corrected for dark field and gain,and the gray level features of bright field are used to determine the field boundary.Subsequently,MU calibration,off-axis calibration and field size calibration are performed on the EPID data,and dose reconstruction is carried out based on the calibrated superimposed flux and the Monte Carlo model of the linac head.Nine cases of IMRT plans are selected for verification and measurement using EPID and MapCheck separately,and the passing rates between the two tools are compared under different gamma criteria(3%/3 mm and 2%/2 mm).For a planned case,the average passing rates of multiple cases verified by MapCheck under the two criteria were 99.02%±1.28% and 90.84%±4.49%,and the average passing rates of the EPID reconstruction models were 98.86%±1.19% and 91.39%±4.80%.Compared with MapCheck,the EPID reconstruction algorithm based on calibration and calculation has no significant difference in the passing rate of IMRT plan verification(P>0.05),which meets the clinical requirements of dose verification.
作者
眭建锋
孙佳伟
谢凯
高留刚
林涛
倪昕晔
SUI Jianfeng;SUN Jiawei;XIE Kai;GAO Liugang;LIN Tao;NI Xinye(Department of Radiotherapy,the Affiliated Changzhou No.2 People's Hospital of Nanjing Medical University,Changzhou 213161,China;Center of Medical Physics,Nanjing Medical University,Changzhou 213161,China;Jiangsu Province Engineering Research Center of Medical Physics,Changzhou 213161,China)
出处
《中国医学物理学杂志》
CSCD
2024年第1期54-59,共6页
Chinese Journal of Medical Physics
基金
国家自然科学基金(62371243)
江苏省重点研发计划社会发展项目(BE2022720)
江苏省自然科学基金(BK20231190)
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(CJ20220136,CJ20210128)
江苏省医学重点学科建设单位(SDW202237)。
关键词
剂量标定
剂量计算
电子射野影像系统
重建
验证
dose calibration
dose calculation
electrionic portal imaging device
reconstruction
verification
