Factors associated with set-up errors in intensity-modulated radiotherapy after breast conserving surgery
10.3760/cma.j.issn.0254-5098.2019.06.006
- VernacularTitle:乳腺癌保乳术后调强放疗摆位误差相关因素分析
- Author:
Xiao XU
1
;
Minna ZHANG
;
Bin WANG
;
Kan WU
;
Jiahao WANG
;
Lixia XU
;
Xiadong LI
;
Jian LIU
;
Bing XIA
Author Information
1. 杭州市肿瘤医院放疗科 310002
- Keywords:
Breast cancer;
Radiotherapy;
Thermoplastic mask;
Set-up error
- From:
Chinese Journal of Radiological Medicine and Protection
2019;39(6):434-438
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the difference of set-up errors between thermoplastic mask and breast bracket in patients receiving intensity-modulated radiotherapy after breast conserving surgery,and the impact of clinical factors associated with set-up errors.Methods A total of 34 patients treated with intensity-modulated radiotherapy after breast conserving surgery from January 2016 to June 2018 were reviewed.Eighteen patients were fixed with thermoplastic mask,and sixteen were with breast bracket.Weekly CBCT scan records were used to analyze set-up errors,and group systematic and random errors were computed.The influence of clinical factors on set-up errors was also analyzed.Results The immobilization technique with thermoplastic mask showed great superior in comparison with breast bracket;however,only in the Ty(translation) and Ry(rotation),the differences had significance.Based on group systematic and random errors,PTV margins in Tx,Ty and Tzwere 2.65,4.36 and 2.87 mm in thermoplastic mask group,as well as 5.71,6.07 and 4.20 mm in breast bracket group,respectively.Multi-factor regression analysis showed that BMI was independent factors affecting set-up errors.Conclusions Compared with breast bracket,the immobilization technique with thermoplastic mask has the potential of reducing set-up errors and PTV margins in patients receiving intensity-modulated radiotherapy after breast conserving surgery,especially in patients with high BMI.
