HyperArc立体定向放射治疗颅内肿瘤分次内及分次间摆位误差分析  

Analysis of positioning error of within batch and between batches of HyperArc stereotactic radiotherapy for intracranial tumors

作　　者：李楠[1] 于浪[1] 孙显松 曲慧颖 王忆君 杨波[1] 连欣[1] Li Nan;Yu Lang;Sun Xiansong;Qu Huiying;Wang Yijun;Yang Bo;Lian Xin(Department of Radiotherapy,Peking Union Medical College Hospital,Chinese Academy of Medical Sciences,Beijing 100730,China)

机构地区：[1]中国医学科学院北京协和医院放疗科,北京100730

出　　处：《中国医学装备》2025年第2期15-19,共5页China Medical Equipment

摘　　要：目的:基于超弧(HyperArc)立体定向放射治疗(SRT)技术,利用六维自由床联合双面膜固定方式治疗颅内肿瘤,分析其分次内及分次间的摆位误差,为该技术的临床精准治疗提供依据。方法:回顾性选取2023年3月至7月北京协和医院进行放疗的13例颅内肿瘤患者,均采用HyperArc SRT技术进行治疗。对治疗中分次内及分次间采集的锥形束CT(CBCT)验证图像进行分析,分析左右(x)、头脚(y)和腹背(z)方向的3个平移方向和旋转方向的摆位误差。设每次初始摆位误差为A组、经六维自由床修正摆位误差后的剩余误差为B组,治疗结束后的误差为C组。B组和C组差异均为分次内变化。根据边界(Margin)外放公式,利用分次内摆位误差计算所需的外放边界范围。结果:在六维自由床修正联合双面膜固定方式下,共进行59次头部的HyperArc SRT,在A、B和C组六维方向的平均误差比较中,A组x、y方向的误差分别为(0.119±0.039)、(-0.133±0.047)cm,与B组的误差(0.004±0.002)、(0.018±0.005)cm相比,差异均有统计学意义(t=2.890、-3.224,P<0.05),其余方向差异均无统计学意义(P>0.05)。B组旋转方向的俯仰(RX)方向误差为(0.033±0.021)°,与C组的(0.122±0.045)°比较,差异有统计学意义(t=-2.306,P<0.05),其余方向差异均无统计学意义(P>0.05)。在颅内肿瘤计划设计外放边界中,x、y和z方向分别为0.6、0.9和0.4 mm。结论:在HyperArc SRT技术进行颅内肿瘤放疗中,采用六维自由床联合双面膜治疗方式,能够显著缩小边界外放,在保证对肿瘤体积(GTV)精确照射的同时,减少周围正常组织的照射体积和剂量。Objective:Based on HyperArc stereotactic radiotherapy(SRT)technique,six-dimensional free bed combined with double mask fixation was used to treat intracranial tumors,and the positioning errors of within batch and between batches were analyzed,so as to provide basis for the accuracy of clinical treatment of this technique.Methods:A total of 13 patients with intracranial tumors who admitted to Peking Union Medical College Hospital from March to July 2023 were retrospectively selected,and they were treated by using HyperArc SRT technique.The validation images of cone-beam computed tomography(CBCT)of within batch and between batches during treatment were analyzed.The positioning errors of three translational direction[left and right(x),head and foot(y)and abdominal and dorsal(z)]and rotational direction were analyzed.The each positioning error was set as group A,and the remaining error after the positioning error was corrected through six-dimensional free bed was set as group B,and the error post treatment was set as group C.The difference between group B and group C was defined as the change of within batch.According to the margin formula,the positioning error of within batch was used to calculate the required range of margin.Results:Under the mode of six-dimensional free bed correction combined with double mask fixation,a total of 59 times of HyperArc SRT on head were performed.In the comparison of the average errors on the six-dimensional direction among groups A,B and C,the errors of group A on x direction and y direction were respectively(0.119±0.039)and(-0.133±0.047)cm,and the differences of them between group A and group B[(0.004±0.002)and(0.018±0.005)cm]were significant(t=2.890,-3.224,P<0.05).There were no significant differences on other directions between the two groups(P>0.05).The error of RX direction of group B was(0.033±0.021)°,and the difference of that between group B and group C[(0.122±0.045)°]was significant(t=-2.306,P<0.05),while there were no significant differences on other directions(P>0

关 键 词：摆位误差 立体定向放射治疗(SRT) 六维自由床 颅内肿瘤 

分 类 号：R816.1[医药卫生—放射医学]