颅内肿瘤碳离子放射治疗中新型体位固定系统的应用  

Application of a new body position fixation system in carbon ion radiotherapy for intracranial tumors

作　　者：李万国 祁英 张雁山 朱芳芳 张一贺 叶延程 李小军 王开平 杨晓东 鲁会祥 LI Wanguo;QI Ying;ZHANG Yanshan;ZHU Fangfang;ZHANG Yihe;YE Yancheng;LI Xiaojun;WANG Kaiping;YANG Xiaodong;LU Huixiang(Wuwei Heavy Ion Radiotherapy Center,Wuwei Tumor Hospital,Wuwei 733000,China)

机构地区：[1]甘肃省武威肿瘤医院重离子中心,甘肃武威733000

出　　处：《中华肿瘤防治杂志》2023年第5期275-281,共7页Chinese Journal of Cancer Prevention and Treatment

基　　金：甘肃省陇原青年创新创业人才(2021LQTD14);武威市市列科技计划(WW2002006,WW2002067)。

摘　　要：目的评估一种新的颅内固定系统,确定患者摆位误差及分次内靶区位移与治疗时长的依赖性关系,提高碳离子束放射治疗的精度。方法选取2020-03-26-2022-11-26甘肃省武威肿瘤医院重离子中心收治的碳离子束治疗患者30例,按入组时间随机分为试验组(A组)和对照组(B组),每组15例。A组采用trUpoint ARCH定位系统(CIVCO,美国)固定,B组采用传统热塑膜配合船型枕固定。2组患者在治疗前、后分别进行碳离子图像配准(ciGPS),行自动配准与手动微调。统计六维摆位误差[左右方向(X)、进出方向(Y)、升降方向(Z)、左右滚动(RX)、头尾旋转(RY)、俯仰方向(RZ)]及治疗时长数据,评估分次内靶区器官位移与治疗时长的依赖性关系。此外,对A组患者额外进行治疗后鼻根组件图像配准,评估垂直束流方向射野条件下鼻根组件对治疗的影响。结果治疗前A组六维摆位误差的旋转摆位误差较小,与B组比较差异有统计学意义(RX:t=4.481,P<0.001;RY:t=2.637,P=0.016;RZ:t=2.327,P=0.031);治疗后2组X(t=2.159,P=0.043)、Y(t=-2.419,P=0.025)、Z(t=2.176,P=0.042)及RY(t=2.305,P=0.032)方向误差比较差异有统计学意义。线性回归结果显示,2组患者靶区位移与治疗时长的依赖性关系相似(斜率k=0.06),但A组分次内靶区位移的稳定性更强(A组:R^(2)=0.246,P<0.001;B组:R^(2)=0.114,P<0.001),且A组无任何系统漂移。A组和B组计划靶区外扩边界(PTVmargin)在X、Y、Z三维线性方向的外扩分别为:4.02、2.72、2.66和4.97、3.28、3.30 mm,使用trUpoint ARCH定位系统的A组三维线性方向的PTVmargin更低。结论trUpoint ARCH定位系统用于碳离子束放射治疗六维方向摆位误差小,尤其是对旋转误差的可控性强;可提供更小的PTV外扩边界,从而保护正常组织;分次内靶区位移随治疗时长的变化小,较传统定位方式稳定性好,可用于高精度放射治疗。但受其鼻根组件不确定性的影响,为保证剂量的精确性,Objective To evaluate a new intracranial fixation system,determine the dependence of patient positioning error and fractional target displacement on treatment duration,and improve the accuracy of carbon ion beam radiotherapy.Methods Totally 30 patients treated with carbon ion beam from the Heavy Ion Center of Wuwei Cancer Hospital,Gansu Province were selected from March 26,2020 to November 26,2022 and randomly divide them into test group(group A)and control group(group B)according to the time of enrollment,with 15 patients in each group.Group A was fixed with trUppoint ARCH positioning system(CIVCO,USA),while group B was fixed with traditional thermoplastic film and ship type pillow.The two groups of patients underwent carbon ion image registration(ciGPS),automatic registration and manual fine adjustment before and after treatment.The six-dimensional positioning errors[left and right directions(X),in and out directions(Y),up and down directions(Z),left and right rolling(RX),head and tail rotation(RY),pitch direction(RZ)]and treatment duration data were counted,and the dependence of organ displacement in the target area on the treatment duration was evaluated.In addition,patients in group A were additionally registered with the image of the nasal root assembly after treatment to evaluate the effect of the nasal root assembly on treatment under the condition of vertical beam direction.Results Before treatment,the rotational positioning error of six-dimensional positioning error in group A was small,and the difference was statistically significant compared with that in group B(RX:t=4.481,P<0.001;RY:t=2.637,P=0.016;RZ:t=2.327,P=0.031);After treatment,there was statistically significant difference between the two groups in the direction error of X(t=2.159,P=0.043),Y(t=-2.419,P=0.025),Z(t=2.176,P=0.042)and RY(t=2.305,P=0.032).The linear regression results showed that the dependence of target displacement on treatment duration was similar in two groups(slope k=0.06),but the stability of target displacement in group A wa

关 键 词：颅内恶性肿瘤 碳离子放射治疗 头部固定系统 摆位误差 分次内靶区位移 计划靶区外扩边界 

分 类 号：R739.41[医药卫生—肿瘤] R730.55[医药卫生—临床医学]