Abstract：Objective To explore whether the protective effect of breast bracket placement mode in volumetric modulated arc therapy
(VMAT) on organs at risk (OARs), especially heart and lung is better than that of body bracket positioning. Methods A total of 40 patients
who underwent adjuvant radiotherapy after breast conserving surgery from December 2021 to September 2022 in our hospital were
collected and divided into two groups: body bracket positioning group (group A) and breast bracket positioning group (group B)
according to the placement mode, with 20 patients in each group. Two radiotherapy plans were designed for each patient in
group A: group A-1 and group A-2, in which the collimator angle of group A-1 was 0, and the appropriate collimator angle of group
A-2 was set. In group B, only one radiotherapy plan was designed and the collimator angle was 0. The dose distribution of target
area and OARs in each group was compared. Results Comparing the target dose indexes of the two groups, the heterogeneity index
of group B was better than that of group A-1 and group A-2, and the treatment time was longer than that of group A-1 and group
A-2, the differences were statistically significant (P<0.05). There was no statistically significant difference in D2%, D98%, conformity
index, and the number of machine units among group B, group A-1, and group A-2 patients (P>0.05). The dosimetry differences of
patients’ OARs were mainly reflected in low-dose areas. The doses of V5 and V10 in the affected lung, V5 and Dmean in the healthy
mammary gland, and V5 in the heart of group B were lower than those of group A-1 and group A-2, the differences were statistically
significant (P<0.05). There was no significant difference in high dose areas such as V20 and V30 among group B, group A-1, and group
A-2 patients (P>0.05). There was statistically significant difference only the V5 doses of the liver in the right breast cancer patients
between A-1 and group A-2 (P<0.05), and there was no statistically significant difference in other OARs (P>0.05). Conclusion In
adjuvant VMAT after breast conserving surgery for breast cancer, the positioning mode of using breast bracket has better protection
effect for OARs than body frame placement mode.
朱斌，程冬，刘文敏，付振明. 乳腺托架在乳腺癌保乳术后容积
调强放疗中的应用[J]. 中国医疗设备, 2023, 38(8): 38-42.
ZHU Bin, CHENG Dong, LIU Wenmin, FU Zhenming. Application of Breast Bracket in Volumetric Modulated Arc Therapy
After Breast Conserving Surgery. China Medical Devices, 2023, 38(8): 38-42.
