Impact of treatment set-up errors on accuracy of post-operation radiotherapy in patients with breast cancer
- VernacularTitle:影响乳腺癌术后精确放疗的因素分析
- Author:
Jianzhou GONG
;
Ping ZHANG
;
Xiaoli YU
;
Jiayi CHEN
- Publication Type:Journal Article
- Keywords:
breast cancer;
radiotherapy;
set-up error
- From:China Oncology
2009;19(6):439-442
- CountryChina
- Language:Chinese
-
Abstract:
Background and purpose: The precise radiotherapy in patients with breast cancer consists of multiple procedures, such as simulation, treatment planning and delivery. We assessed the impact of treatment set-up errors on accuracy of post-operative radiotherapy (RT) in patients with breast cancer receiving tangential RT. Methods: Between November 2007 and August 2008, a total of 50 patients were enrolled an institutional review board-approved study. All patients received tangential RT for either right or left breast cancer. Read-out numbers of X, Y, Z directions shown on linear accelerator were recorded according to the sequence of before and after medial tangential field and after lateral tangential field.The impact of treatment set-up errors on post-operative radiotherapy (RT) in different subgroup patients was analyzed using stata 7.0 statistics software. Results:The mean set-up errors on Z, Y, X direction were 2.55, 3.96 and 0.58 cm, respectively. The largest set-up errors in all three directions were observed in the first week during treatment and the largest movement was observed in Z direction. Conclusion: The movements after medial tangential field treatment are much more than those after lateral treatment during RT.The movements in X direction arc substantially less than Y direction or Z direction intrafraction. As interfraction differences have been observed, the movements in the beginning two weeks are more than other treatment period.
