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

作　　者：万宝 葛彦东 孙朔 赵宇 张彦新 张伟 郇福奎 梁斌 王宏凯 WAN Bao;GE Yandong;SUN Shuo;ZHAO Yu;ZHANG Yanxin;ZHANG Wei;HUAN Fukui;LIANG Bin;WANG Hongkai(Department of Radiation Oncology,National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital,Chinese Academy of Medical Sciences,Peking Union Medical College,Beijing 100021,China)

机构地区：[1]国家癌症中心/国家肿瘤临床医学研究中心/中国医学科学院北京协和医学院肿瘤医院放疗科,北京100021

出　　处：《辐射研究与辐射工艺学报》2025年第2期50-57,共8页Journal of Radiation Research and Radiation Processing

基　　金：国家自然科学基金(12205374、12475314);北京市自然科学基金(1232033)资助。

摘　　要：回顾性分析基于加速器六维床摆位的肿瘤患者的CBCT(Cone-Beam CT,CBCT)图像,比较患者的摆位误差数据,分析肿瘤患者六维床放射治疗中分次内摆位误差的数据,研究六维床对不同位置肿瘤产生的摆位效果差异。选取2020年3月至2023年9月于本中心接受放疗的肿瘤患者85例,分成脑瘤、肺癌、直肠癌和乳腺癌。统计4组患者在左右、头脚、腹背6个自由度(X、Y、Z和Rx、Ry、Rz)的首次和分次内摆位误差。采用双样本异方差t检验对比分析不同瘤种在各个方向上的分次内摆位误差。对于首次摆位与分次内摆位误差两种情况,经六维床校正后在平移方向的误差范围基本一致,均集中在±1 cm范围内。分次内摆位误差中Rx方向的误差范围略微缩小。然而,在旋转自由度Ry和Rz方向上乳腺部位误差显著增大。从不同类型肿瘤组的分次内平移方向误差来看,脑瘤组在平移方向的误差最小。肺癌组的平移方向误差较小,但在Z方向(腹背方向)出现了一定的偏态。直肠癌组的平移方向误差相对较大,尤其在Z方向。此外,无论是首次摆位还是分次内摆位均显示脑部误差最小,肺部次之,乳腺和直肠相对较大。不同肿瘤类型之间的Rx方向没有显著性差异(p值均大于0.01)。乳腺癌患者与脑瘤患者(p=0)、肺癌患者(p=0)之间有显著性差异。乳腺癌患者与直肠癌患者存在弱显著性差异(p=0.034)。在Rz方向上,直肠癌病例与脑瘤(p=0.003)、肺癌(p=0.002)之间具有显著性差异,同时,直肠癌与乳腺癌病例之间也具有一定程度的弱显著性差异(p=0.033),说明在Rz旋转方向上,直肠癌组的摆位误差显著不同于其他肿瘤类型。六维床的应用显著提升了摆位的平移方向精度,旋转误差也有所改善。然而,在旋转方向上的误差控制仍存在一定局限性,尤其是在肿瘤部位特异性较强或周边器官情况较为复杂(如乳腺和直肠)的情况。应当进�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 intrafractional 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

关 键 词：摆位误差 六维床 肿瘤放疗 

分 类 号：R815.6[医药卫生—放射医学] R73[医药卫生—临床医学]