辐射研究与辐射工艺学报2025，Vol.43Issue(2)：50-57,8.DOI:10.11889/j.1000-3436.2024-0104
六维床在头、胸、腹部肿瘤常规直线加速器放射治疗中的摆位误差回顾性分析
Retrospective analysis of setup error with a six-degree-of-freedom couch in medical linear accelerator radiotherapy for head,thoracic,and abdominal tumors
摘要
Abstract
Cone-beam computed tomography(CBCT)images of tumor patients were retrospectively analyzed based on a six-degree-of-freedom(6-DOF)couch for accelerators,whereby patient setup error data were compared,and intra-fractional setup errors during radiotherapy were investigated for tumor patients.This study aimed to evaluate the differences in setup performance for tumors in various anatomical locations.A total of 85 tumor patients who underwent radiotherapy at the radiotherapy center between March 2020 and September 2023 were selected and categorized into four groups:brain tumors,lung cancer,rectal cancer,and breast cancer.The initial and intra-fractional setup errors for the four groups were statistically analyzed across six degrees of freedom:left-right(X),head-foot(Y),anterior-posterior(Z),and rotations(Rx,Ry,Rz).A two-sample heteroscedastic t-test was used to compare the intra-fractional setup errors in different directions among the tumor types.After corrections using the 6-DOF couch,the translational error ranges for both initial and intra-fractional setup errors were generally consistent,primarily within±1 cm.In intra-fractional setup errors,the Rx direction exhibited a slightly reduced error range.However,the rotational errors in the Ry and Rz directions were significantly larger in breast cancer cases.Regarding intra-fractional translational errors across different tumor groups,patients with brain tumor exhibited the smallest errors along translational directions.Patients with lung cancer also showed relatively small translational errors but exhibited a skew in the Z direction(anterior-posterior).Patients with rectal cancer exhibited relatively large translational errors,particularly in the Z direction.Additionally,both the initial and intra-fractional setups demonstrated that brain tumor errors were the smallest,followed by lung cancer,whereas breast and rectal cancer errors were relatively larger.There were no significant differences in the Rx direction among different tumor types(p>0.01).However,significant differences were observed between breast and brain tumor patients(p=0)and between breast and lung cancer patients(p=0).A weakly significant difference was also noted between patients with breast and rectal cancer(p=0.034).In the Rz direction,patients with rectal cancer exhibited significant differences compared to those with brain tumor(p=0.003)and lung cancer(p=0.002).A weakly significant difference was also found between rectal and breast cancer patients(p=0.033),indicating that rectal cancer cases had notably different setup errors in the Rz rotational direction compared to the other tumor types.The application of a 6-DOF couch significantly improved the translational setup precision and rotational errors.However,limitations remain in controlling rotational errors,particularly for tumor types with strong site specificity or complex surrounding organ structures,such as breast and rectal cancers.Further optimization of immobilization devices and enhanced respiratory management tailored to individual patient characteristics are recommended to improve the precision and effectiveness of radiotherapy.关键词
摆位误差/六维床/肿瘤放疗Key words
Positioning error/Six-dimensional couch/Radiotherapy分类
医药卫生引用本文复制引用
万宝,葛彦东,孙朔,赵宇,张彦新,张伟,郇福奎,梁斌,王宏凯..六维床在头、胸、腹部肿瘤常规直线加速器放射治疗中的摆位误差回顾性分析[J].辐射研究与辐射工艺学报,2025,43(2):50-57,8.基金项目
国家自然科学基金(12205374、12475314)和北京市自然科学基金(1232033)资助 Supported by National Natural Science Foundation of China(12205374,12475314)and Beijing Natural Science Foundation(1232033) （12205374、12475314）
