ExacTrac图像引导系统用于肿瘤骨转移病灶放疗中配准范围对配准结果的影响  

Impact of different regions on image registration results with ExacTrac image-guided system in radiotherapy of bone metastasis lesions

作　　者：罗灿 周军 张琰 李寒旭 张力维 LUO Can;ZHOU Jun;ZHANG Yan;LI Han-xu;ZHANG Li-wei(Oncology Therapy Center,the Second Affiliated Hospital of Army Medical University,Chongqing 400037,China)

机构地区：[1]陆军军医大学第二附属医院肿瘤科放疗中心

出　　处：《医疗卫生装备》2019年第6期44-47,共4页Chinese Medical Equipment Journal

摘　　要：目的:探讨ExacTrac图像引导系统用于肿瘤骨转移灶放疗中不同配准范围对配准结果的影响。方法:选取20例肿瘤骨转移患者,放疗前通过ExacTrac图像引导系统进行位置验证,同时获取锥形束CT(conebeamCT,CBCT)图像。离线模式下使用3种不同的配准范围对得到的ExacTrac图像进行配准,分别为仅包含靶区所在骨相关结构(A组)、A组基础上外扩3cm(B组)、整幅图像(C组),计算其与CBCT在AP(前后)、SI(头脚)、LR(左右)、Yaw(绕AP旋转)、Roll(绕SI旋转)、Pitch(绕LR旋转)6个方向上的偏差。组间差异使用Friedman检验,不同配准范围下与CBCT的一致性采用Bland-Altman图评估。结果:3组在AP、SI、LR、Yaw、Roll方向上的偏差差异有统计学意义,P值分别为0.021、<0.001、<0.001、<0.001、0.032;Pitch方向差异无统计学意义,P=0.23。A组在6个方向上与CBCT的一致性均好于B、C组,具有更小的一致性界限。结论:ExacTrac图像引导系统用于骨转移病灶放疗中,配准范围仅包含骨性结构时具有更好的配准结果。Objective To investigate the impact of different regions on image registration with ExacTrac image-guided system in the radiotherapy of bone metastasis lesions. Methods A total of 20 patients with bone metastases were enrolled for this study. ExacTrac image-guided system was used to perform the positioning verification, while the CBCT was also implemented at the same time. Three different registration regions were conducted, which were bone related structures only (Group A), the region extended for 3 cm on the basis of Group A (Group B) as well as the full screen image (Group C). The shifts were proposed according to the alignment offline, and the deviation of ExacTrac and CBCT in all 6 directions (AP, SI, LR, Yaw, Roll, Pitch) were calculated. Difference of setup errors between three groups was analyzed by Friedman test, while the consistency of CBCT and ExacTrac in different registration regions was estimated by Bland-Altman (B-A) plot. Results Significant results were proposed in AP, SI, LR, Yaw and Roll, and the P values were 0.02,<0.001,<0.001,<0.001, 0.032, respectively, not in Pitch (P=0.23). For the consistency of ExacTrac and CBCT, group A was superior to group B and group C, with smaller limitation of agreement emerged according to the B-A plot. Conclusion Certain impacts of different regions on image registration are shown in the radiotherapy of bone metastasis lesions with ExacTrac system, and higher accuracy is able to be achieved while the registration region contains bony related structures only.

关 键 词：ExacTrac 图像引导 配准范围 骨转移 骨性结构 

分 类 号：R318[医药卫生—生物医学工程] R730.55[医药卫生—基础医学]