Comparison of the performance of two methods to determine set-up errors for DIBH patients with left sided breast cancer in radiotherapy
10.3760/cma.j.cn113030-20190423-00006
- VernacularTitle:光学表面监测系统与CBCT确定左侧乳腺癌深吸气屏气放疗误差的比较
- Author:
Tantan LI
1
;
Jianghu ZHANG
;
Yongwen SONG
;
Yu TANG
;
Shunan QI
;
Fengyu LU
;
Wei ZHANG
;
Zengzhou WANG
;
Xin FENG
;
Shirui QIN
;
Bin CHENG
;
Bofei LIU
;
Guishan FU
;
Shulian WANG
;
Jianrong DAI
Author Information
1. 国家癌症中心/国家肿瘤临床研究中心/中国医学科学院北京协和医学院肿瘤医院放疗科 100021
- From:
Chinese Journal of Radiation Oncology
2020;29(4):278-282
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To establish the basic procedures of the application of optical surface monitoring system (OSMS) in the deep inspiration breath hold (DIBH) radiotherapy for patients with left sided breast cancer and compare the performance of OSMS and cone-beam CT (CBCT) in the determination of the set-up errors of DIBH radiotherapy for patients with left sided breast cancer.Methods:Twenty patients with left sided breast cancer received DIBH radiotherapy. Through the registration of CBCT images with the planning CT images, and the registration of OSMS radiography images with the outer contour of the body surface, translational set-up errors and rotational errors were determined along the lateral-medial ( Rx), superior-inferior ( Ry) and anterior-posterior ( Rz) directions. Pearson correlation analysis was performed to evaluate the correlation of the set-up errors determined by two methods, and Bland- Altman plot analysis was used to assess the coincidence of these two methods. Results:Two methods were positively correlated. The Rz volume was 0.84, 0.74 and 0.84 in the x, y and z directions, and 0.65, 0.41 and 0.54 in the Rx, Ry and Rz directions, respectively (all P<0.01). The 95% CI of agreement were within preset 5 mm tolerance (-0.37-0.42cm, -0.39-0.41cm, -0.29-0.49cm ) in x, y and z directions for two methods. The 95% CI of agreement were within preset 3 ° tolerance -2.9°-1.4°, -2.6°-1.4°, -2.4°-2.5°in Rx, Ry and Rz directions for two methods. The system errors of 20 patients with left sided breast cancer receiving DIBH radiotherapy were <0.18cm and the random errors were <0.24cm. Conclusions:OSMS is equivalent to CBCT in the determination and stimulation of set-up errors for patients with left sided breast cancer receiving DIBH radiotherapy. The combination of CBCT and OSMS is a safe and reliable method.
