tailieunhanh - Báo cáo khoa học: "Impact of residual and intrafractional errors on strategy of correction for image-guided accelerated partial breast irradiation"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Impact of residual and intrafractional errors on strategy of correction for image-guided accelerated partial breast irradiation. | Cai et al. Radiation Oncology 2010 5 96 http content 5 1 96 RADIATION ONCOLOGY RESEARCH Open Access Impact of residual and intrafractional errors on strategy of correction for image-guided accelerated partial breast irradiation z z- -1t 1 t 1 w I X 1 T rx- n 1 71 71 X 1 1 Gang Cai t Wei-Gang Hu t Jia-Yi Chen Xiao-Li Yu Zi-Qiang Pan Zhao-Zhi Yang Xiao-Mao Guo Zhi-Min Shao2 Guo-Liang Jiang1 Abstract Background The cone beam CT CBCT guided radiation can reduce the systematic and random setup errors as compared to the skin-mark setup. However the residual and intrafractional RAIF errors are still unknown. The purpose of this paper is to investigate the magnitude of RAIF errors and correction action levels needed in cone beam computed tomography CBCT guided accelerated partial breast irradiation APBI . Methods Ten patients were enrolled in the prospective study of CBCT guided APBI. The postoperative tumor bed was irradiated with Gy in 10 fractions over 5 days. Two cone-beam CT data sets were obtained with one before and one after the treatment delivery. The CBCT images were registered online to the planning CT images using the automatic algorithm followed by a fine manual adjustment. An action level of 3 mm meaning that corrections were performed for translations exceeding 3 mm was implemented in clinical treatments. Based on the acquired data different correction action levels were simulated and random RAIF errors systematic RAIF errors and related margins before and after the treatments were determined for varying correction action levels. Results A total of 75 pairs of CBCT data sets were analyzed. The systematic and random setup errors based on skin-mark setup prior to treatment delivery were mm and mm in the lateral LR mm and mm in the superior-inferior SI and mm and mm in the anterior-posterior AP directions. With the 3 mm correction action level the systematic and random RAIF errors were mm and mm in the LR