【摘要】 目的:通过与锥形束计算机断层扫描(CBCT)参照对比,探讨光学表面监测系统(OSMS)在腹部肿瘤放疗中摆位的作用,探讨OSMS的摆位精度及其应用价值。方法:选取4名腹部肿瘤患者,应用体表"+"标记与激光灯进行治疗前摆位,行CBCT同时进行OSMS运行前的验证,分别记录OSMS和CBCT提供的配准信息,记录X(左右)、Y(头脚)与Z(前后)方向的平移误差。应用Pearson方法分析摆位误差的相关性、系统误差与随机误差,并用Bland-Altman方法评估OSMS的置信空间。计算常规方法摆位以及经过OSMS摆位后95%的剂量偏移靶区体积的k值。结果:研究发现OSMS与CBCT的摆位精度具有很好的相关性,X、Y与Z方向的相关系数分别为0.628、0.858、0.682。OSMS摆位在X、Y与Z方向的系统误差±随机误差分别为(0.01±0.33)、(-0.14±0.64)、(0.13±0.41)mm,k值为(0.801 9±0.704 4)%。结论:OSMS在实际应用中体现出与CBCT配准数据的一致性,可以摆脱CBCT的引导独立使用,精度较高。更多还原

【Abstract】 Objective To investigate the role of optical surface monitoring system(OSMS) in the positioning for abdominal tumor radiotherapy by comparing with CBCT-based positioning, and to explore the positioning accuracy of OSMS and its application value. Methods Four patients with abdominal tumor were enrolled. The "+" mark on the body surface and laser lamp were used to realize pre-treatment positioning. During CBCT examination, OSMS was verified before operation. The registration information provided by OSMS and CBCT was recorded separately, and translational errors in X(left-right), Y(head-foot) and Z(front-back) directions were recorded. Pearson method was used for analyzing positioning errors,systematic errors and random errors, and Bland-Altman method for evaluating the confidence interval of OSMS. The k value of 95% dose-shifted target volume after positioning by the conventional method or OSMS was calculated. Results There was a good correlation between the positioning accuracy of CBCT and that of OSMS, and the correlation coefficients were 0.628, 0.858 and 0.682 in X, Y and Z directions, respectively. The systemic error ± random error of OSMS positioning were(0.01±0.33),(-0.14±0.64) and(0.13±0.41) mm in X, Y and Z directions, respectively, and the k value was(0.801 9±0.704 4)%. Conclusion OSMS in the actual application has a high consistency with CBCT registration data.OSMS which has a high accuracy in positioning can be used independently without the guidance of CBCT.更多还原