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.
Abstract
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 calculated by Pinnacle/TiGRT TPS for γ 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 the instructions of EPID.For the dose reconstructed by EPID,the average γ 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,respectively.The average γ 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.
基金项目
国家自然科学基金面上项目(62371243)
江苏省自然科学基金面上项目(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项目(JSDW202237)
江苏省卫生健康委面上项目(M2020006)
常州市社会发展项目(CE20235063)
常州市科技计划(CJ20220136)
常州市科技计划(CJ20210128)
常州市科技计划(CJ20200099)
维普
万方数据