四川大学学报（自然科学版）2025，Vol.62Issue(3)：669-677,9.DOI:10.19907/j.0490-6756.240235
XHA600D医用电子直线加速器无均整模式实现类均整模式剂量学参数研究
The study of XHA600D medical electron linear accelerator in flattening filter free mode achieve similar dosimetric parameters of flattening filter mode
摘要
Abstract
This study investigates the implementation of flattening filter-free(FFF)mode in medical linear accelerators to achieve off-axis dose(OAR)curves resembling those of flattening filter(FF)mode.Using physical structure data of a real accelerator,the FF and FFF head models were established by using BEAM-nrc software,and then the water model was established by using DOSXYZnrc program.Different electron in-cident angles were set,the source to surface distance(SSD)was 100 cm,and the depth dose and off-axis dose were obtained in different fields.An optimization algorithm is used to optimize the irradiation weights at different incident angles to achieve the required flatness of the off-axis ratio at the reference depth.The results show that the optimized beams significantly improved flatness and increases the central axis dose under differ-ent fields,especially for large field of 30 cm×30 cm,the source to surface distance is 100 cm,the depth is 10 cm,and the central axis dose of the optimized beams is 1.344 times that of FF beams.The flatness of the optimized beams and FFF beams is 5.00%and 16.85%,respectively,which is an improvement of 70.33%.The expected flat off-axis ratio can be produced in FFF mode,which provides an enhanced applica-tion prospect for medical linear accelerators.关键词
均整模式/非均整模式/蒙特卡罗模拟/离轴剂量Key words
Flattening filter/Flattening filter free/Monte Carlo simulation/Off-axis dose分类
核科学引用本文复制引用
刘伟,李天航,王诗露,吴章文,勾成俊..XHA600D医用电子直线加速器无均整模式实现类均整模式剂量学参数研究[J].四川大学学报（自然科学版）,2025,62(3):669-677,9.基金项目
国家重点研发计划项目(2016YFC0105103) （2016YFC0105103）
辐射物理及技术教育部重点实验室开放课题(2023SCURPT06) （2023SCURPT06）
