Synergy CBCT两种配准方式对脑肿瘤放疗摆位误差的研究

A Study on the Set-Up Errors of Brain Tumors by Two Kinds of Registration Methods of Synergy CBCT

目的:分析脑肿瘤的影像引导放射治疗中,Synergy加速器里的CBCT两种影像配准方式的摆位误差。方法:选择100例脑肿瘤患者,在治疗前进行CBCT扫描,将得到的扫描影像与计划CT影像对比,分别采用骨配准与灰度配准方式。记录这两种配准方式在X、Y、Z三个线性方向上的误差值,并采用配对t检验对数据进行两两比较,计算差别是否达到显著性水平。结果:采用骨配准在X、Y、Z方向上的误差值分别是(-0.051±0.136)cm、(-0.059±0.130)cm、(0.057±0.132)cm,灰度配准在X、Y、Z方向上的误差值分别是(-0.055±0.135)cm、(-0.065±0.129)cm、(0.065±0.129)cm。三个方向上统计学分析表明这两种配准方式的数据差异达到显著性水平。结论:初步研究显示在脑肿瘤的影像引导放疗中,CBCT的骨配准精度比灰度配准精度更高。

Purpose:To analyze the set-up errors of two kinds of image registration methods in CBCT of Synergy accelerator in the image guided radiotherapy of brain tumors.Methods:A total of 100 patients with brain tumor were enrolled for CBCT scan before first treatment,compared the obtained image with planned CT image,bone and grayscale registration were used respectively.The error values of two kinds of registration methods were recorded in X,Y and Z axes.Paired t-test was used to evaluate the differences.Results:The error values of bone registration in X,Y and Z axes were(-0.051±0.136)cm,(-0.059±0.130)cm and(0.057±0.132)cm respectively,while(-0.055±0.135)cm,(-0.065±0.129)cm and(0.065±0.129)cm with gray-scale registration.The difference between the two methods in three directions was with statistical significance.Conclusion:The accuracy of bone registration is higher than that of gray-scale registration in CBCT of brain tumors.