Clinical Study on Dose Optimization and Toxicity Evaluation of Post-Lumpectomy Breast Cancer Based on Intensity-Modulated Radiation Therapy

Huang Qian; Xia Chunjun; Jin Xiangyue

doi:10.3969/j.issn.1004-5775.2025.15.009

Abstract：Objective:To compare the effects of intensity-modulated radiation therapy(IMRT)and three-dimensional conformal radiation therapy(3D-CRT)on dose optimization and toxicity in post-lumpectomy breast cancer treatment,so as to provide a more precise and safer therapeutic option for breast cancer patients.Methods:70 patients who underwent breast-conserving surgery for breast cancer in Jianhu County People's Hospital from January 2021 to August 2023 were enrolled.Patients were divided sequentially into study group(35 cases,receiving IMRT)and control group(35 cases,receiving 3D-CRT).The total radiation dose was 60 Gy,including 50 Gy for whole-breast irradiation and 10 Gy tumor bed boost.Target volume dose,organ-at-risk(OAR)doses,and both acute and late toxicities of two groups were compared.Results:The V95％of the study group was significantly higher than that of the control group,while V107％,V110％and dose homogeneity index(HI)were lower in the study group,with statistically significant differences(t=9.484,15.882,16.353,31.317;P＜0.05).The V5％and V20％doses of the ipsilateral lung and both lungs were lower in the study group compared to the control group,with statistically significant differences(t=9.841,11.189,5.685,9.871;P＜0.05).However,when comparing the V5％and V20％doses of the heart and the healthy breast,there was no statistically significant difference(t=0.269,0.080;P＞0.05).There was statistically significant difference in grade Ⅰtoxic reactions of breast fibrosis between the two groups(x2=0.031,P＜0.05),while there were no statistically significant differences in skin reactions,breast tissue inflammation,local edema,pulmonary toxicity,and cardiac toxicity(x2=0.921,0.516,0.324,0.729,1.061;P＞0.05).Conclusion:Compared to 3D-CRT,IMRT can significantly improve target volume dose coverage,reduce radiation doses to organs at risk,and decrease late toxicities such as breast fibrosis,demonstrating superior therapeutic efficacy and safety.