Preliminary study of accurate position fixation between polyurethane styrofoam and vacuum negative pressure pad in IMRT after radical mastectomy for breast cancer
10.3760/cma.j.issn.1004-4221.2019.10.013
- VernacularTitle: 聚氨酯发泡胶与负压真空垫在乳腺癌保乳根治术后IMRT体位固定精度初步研究
- Author:
Changfeng ZHOU
1
;
Jiannan FANG
;
Xiaobo HUANG
;
Juntian SHI
;
Yujia MA
Author Information
1. Department of Radiation Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
- Publication Type:Journal Article
- Keywords:
Breast neoplasm/intensity modulated radiation therapy;
Postural immobilization;
Setup error
- From:
Chinese Journal of Radiation Oncology
2019;28(10):776-779
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To preliminarily investigate the difference of position fixation accuracy between polyurethane styrofoam and vacuum negative pressure pad in intensity-modulated radiation therapy (IMRT) after radical mastectomy for breast cancer.
Methods:Forty breast cancer patients, who received breast-conserving surgery followed by hyper-fractionated IMRT of the whole breast (42.56 Gy for 16 times) in our hospital between 2017 and 2018 were recruited and randomly divided into the polyurethane styrofoam group and vacuum negative pressure pad group. Before IMRT treatment, the anterior and lateral films of patients were taken with kilovoltage digital radiographs (KVDRs) by Varian Trilogy machine-borne OBI KV image verification system. The KVDRs images were matched with the DRR images reconstructed by the planned system to obtain the setup errors in the left and right, head and foot, and ventral and back directions between two groups. Each patient was verified for 10 times to obtain 400 sets of data. The independent sample t-test was adopted to analyze the setup errors between two groups. The external expansion value of graded setup errors from clinical target volume (CTV) and planned target volume (PTV) was calculated.
Results:The setup errors in the left and right, head and foot, ventral and back directions between the styrofoam fixation and vacuum pad groups were (1.63±1.29) mm and (1.83 ±1.61) mm (P=0.18), (1.46±1.51) mm and (2.26±2.03) mm (P=0.00), and (1.30±1.35) mm and (1.91±1.67) mm (P=0.00), respectively. The external expansion values of setup errors from CTV to PTV were 2.19 mm, 2.51 mm, 1.57 mm and 2.40 mm, 3.97 mm and 2.63 mm, respectively.
Conclusion:Both two fixation methods meet the clinical requirements. However, the setup accuracy and reproducibility in the polyurethane styrofoam group are better than those in the vacuum negative pressure pad group.
