Breast bracket combined with polyurethane foam improves the accuracy of immobilization in breast cancer radiotherapy
10.3760/cma.j.cn113030-20210812-00301
- VernacularTitle:乳腺托架加发泡胶提升乳腺癌放疗体位固定精度的研究
- Author:
Wenyan YAO
1
;
Biaoshui LIU
;
Jianlan FANG
;
Yongwen FANG
;
Liangjie XIAO
;
Yuliu WANG
;
Chengguang LIN
;
Jianhua WU
;
Huanxin LIN
;
Chuyan LIN
;
Senkui XU
Author Information
1. 华南肿瘤学国家重点实验室/中山大学肿瘤防治中心，广州 510060
- Keywords:
Breast neoplasms;
Radiotherapy;
Cone-beam CT;
Set-up error;
Margin of the planning target volume
- From:
Chinese Journal of Radiation Oncology
2022;31(10):916-921
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the difference between breast bracket combined with polyurethane foam and single polyurethane foam in the accuracy of immobilization, providing a better immobilization for breast cancer radiotherapy.Methods:Fifty breast cancer patients who received radiotherapy in Sun Yat-sen University Cancer Center from March 2021 to July 2021 were selected. Among them, 25 patients were immobilized with polyurethane foam (foam group), and the other 25 patients were immobilized with polyurethane foam combined with breast bracket (combination group). All patients were scanned by CBCT once a week to obtain setup errors in the SI, LR and AP directions for t-test. The formula M PTV=2.5 Σ+0.7 σ was used to calculate the margin of the planning target volume(M PTV). Results:The setup errors in the foam group were SI (2.0±3.26) mm, LR (0.88±2.76) mm, AP (1.22±3.55) mm, Rtn -0.24°±0.85°, Pitch 0.16°±1.11°, Roll -0.32°±1.05°, and the M PTV were 6.75 mm, 8.46 mm and 8.73 mm, respectively. The setup errors in the combination group were SI (1.0±3.01) mm, LR (0.62±2.74) mm, AP (1.82±3.21) mm, Rtn 0.64°±0.59°, Pitch 0.71°±1.22°, Roll 0.29°±0.73°, and the M PTV were 6.35 mm, 7.47 mm, and 7.61 mm, respectively. After comparing the setup errors in the three-dimensional directions between two groups, the t value of LR, SI, AP and Rtn, Pitch, Roll was -4.304, -2.681, 1.384, and -9.457, -3.683, -5.323, respectively. And the differences in the LR, SI, Rtn, Pitch and Roll directions were statistically significant (all P<0.05). Conclusions:The immobilization effect of polyurethane foam combined with breast bracket is better and the M PTV is also smaller than those of polyurethane foam alone. Therefore, it is recommended to use polyurethane foam combined with breast bracket for immobilization in breast cancer radiotherapy.
