光学体表监测系统在乳腺癌术后放疗颈胸膜固定中的应用  

Application of optical surface monitoring system(OSMS)during postoperative radiotherapy for breast cancer patients immobilized with neck and thorax thermoplastic mask

作　　者：李俊禹 于松茂 周舜 吴昊[1] 弓健[1] 杨敬贤[1] 岳海振[1] 李廷廷 杜乙 Li Junyu;Yu Songmao;Zhou Shun;Wu Hao;Gong Jian;Yang Jingxian;Yue Haizhen;Li Tingting;Du Yi(Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing),Department of Radiation Oncology,Peking University Cancer Hospital&Institute,Beijing 100142,China;The Fifth Medical Center of PLA General Hospital,Beijing 100039,China)

机构地区：[1]北京大学肿瘤医院暨北京市肿瘤防治研究所放疗科恶性肿瘤发病机制及转化研究教育部重点实验室,100142 [2]解放军总医院第五医学中心,北京100039

出　　处：《中华放射医学与防护杂志》2020年第7期524-528,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：北京市自然科学基金(1202009,1184014,7172048)。

摘　　要：目的建立光学体表监测系统(OSMS)在乳腺癌术后患者放疗颈胸膜固定中的摆位流程,与传统体表标记线摆位方式的摆位精度及其计划靶区体积(PTV)外放边界进行比较。方法回顾性分析2019年3月至2019年8月于北京大学肿瘤医院行乳腺癌放疗的20例患者摆位数据,根据摆位方式分为OSMS摆位组和传统体表标记线摆位组,每组10例。通过锥形束CT(CBCT)刚性配准靶区微调后获取床左右(x轴向)、升降(y轴向)、进出(z轴向)、床旋转(Rtn)、进出倾斜(Pitch)、左右转动(Roll)配准误差;采用独立样本t检验和χ^2检验分别统计误差绝对值和误差分布;最后由PTV外扩公式计算CTV-PTV外扩范围。结果OSMS组和传统体表标记线组6维度配准误差取绝对值后平均值依次为0.18和0.18 cm、0.12和0.13 cm、0.13和0.23 cm、0.55°和0.74°、0.63°和0.99°、0.67°和0.68°;标准差依次为0.13和0.12 cm、0.09和0.09 cm、0.11和0.16 cm、0.37°和0.55°、0.53°和0.65°、0.42°和0.55°。两组病例摆位误差在z和Pitch方向差异均具有统计学意义(t=3.53、2.98,P<0.05),两组z方向误差分布差异具有统计学意义(χ^2=11.090,P<0.05)。OSMS组和传统体表标记线组x、y、z轴向CTV-PTV外放边界分别为0.28和0.26 cm、0.21和0.20 cm、0.24和0.35 cm。结论建立和应用OSMS引导乳腺癌术后患者摆位流程,其摆位精度整体优于传统体表标记线摆位方式,且在z、Pitch方向摆位精度提升显著,z方向PTV外扩边界明显缩小,具有临床应用价值。Objective To build patient setup workflow based on the optical surface monitoring system(OSMS)in postoperative radiotherapy for breast cancer,and compare the setup accuracy and PTV margin between OSMS based setup and conventional skin marker based method.Methods The setup data of 20 cases of postoperative radiotherapy for breast cancer were retrospectively analyzed and divided into two groups:OSMS setup group and conventional skin marker setup group with 10 patients in each group.All CBCT rigid registration values in six dimensions(x,y,z,Rtn,Pitch,Roll)were obtained,and the absolute value and distribution of errors were statistically analyzed by single sample t-test andχ^2-test respectively.Finally,the CTV-PTV margins were compared using the extension formula.Results The mean values in OSMS setup group and conventional skin marker setup group in sixdirections were 0.18 and 0.18 cm,0.12 and 0.13 cm,0.13 and 0.23 cm,0.55°and 0.74°,0.63°and 0.99°,0.67°and 0.68°,respectively,while the standard deviations were 0.13 and 0.12 cm,0.09 and 0.09 cm,0.11 and 0.16 cm,0.37°and 0.55°,0.53°and 0.65°,0.42°and 0.55°,respectively.The setup error differed in both z and Pitch directions(t=3.53,2.98,P<0.05),while the error distribution rate difference was statistically significant between two groups in z direction(χ^2=11.090,P<0.05).The CTV-PTV margins in OSMS setup group and conventional skin marker setup group were 0.28 and 0.26 cm,0.21 and 0.20 cm,0.24 and 0.35 cm,respectively.Conclusions The proposed OSMS-based patient setup work flow is better than the conventional skin marker based method in setup accuracy,with significant setup error differences in z and Pitch directions.The proposed OSMS workflow is of potential clinical benefit.

关 键 词：乳腺肿瘤 光学体表监测系统 摆位流程 摆位误差 外放边界 

分 类 号：R737.9[医药卫生—肿瘤]