两种固定方式在乳腺癌保乳术后调强放疗中的剂量学分析

Objective To investigate the dosimetric differences between two body membrane immobilization methods in intensity modulated radiotherapy(IMRT) for breast cancer after breast-conserving surgery. Methods 160 breast cancer patients who underwent breast-conserving surgery and receive IMRT from July 2023 to July 2025 at Hezhou People's Hospital were randomly divided into an observation group(n=80) and a control group(n=80) using a random number table method. The observation group adopted windowed body membrane immobilization, while the control group used traditional non-windowed body membrane immobilization. The radiotherapy dosimetric indicators of the two groups were compared, including PCTV-V100, PCTV-V95, conformity index(CI), homogeneity index(HI), and doses to important organs at risk. Results Compared with the control group, the observation group showed statistically significant differences in PCTVboost-V100, CIboost, PCTVb-V100, and CIb(P<0.05). There were also statistically significant differences between the two groups in the affected lung(V5, V20, V30, Dmean) and the heart of left breast cancer patients(V20, Dmean)(P<0.05). There were no statistically significant differences between the two groups in PCTVboost-V95, HIboost, PCTVb-V95, HIb, spinal cord Dmean, opposite lung Dmean, opposite breast Dmean, the heart of left breast cancer patients(V5, V30, V40), and the heart of right breast cancer patients(V5, V20, Dmean)(P>0.05). Conclusion Windowed body membrane immobilization in IMRT after breast conserving surgery for breast cancer cannot only improve the tumor target dose and the conformity of the irradiated target area but also reduce the irradiation dose to the affected lung and the heart of left breast cancer patients. It has better efficacy and safety, with obvious advantages in dosimetry.