Outcomes of Different Radiation Therapy Dose-splitting regimens after Radical Surgery for Early stage Breast Cancer

Abstract

Objective: To investigate the outcomes of different dose-splitting radiotherapy regimens after radical or modified radical surgery for early-stage breast cancer. Material and methods: Between 2015 and 2020, 412 patients treated with radiotherapy after radical or modified radical surgery for early-stage breast cancer were allocated into 3 groups according to different dose-splitting regimens of postoperative radiotherapy. Conventional radiotherapy group157 cases, 2Gy/ fraction, once/day, 5 times/week, DT50 Gy; Alternate-day radiotherapy group 202 cases, 3 Gy/fraction, 3 times/week, DT45Gy; Fast radiotherapy group 53 cases, Days 1 and 3, 5Gy/fraction, Days 15 and 17, 6.5 Gy/fr, DT23Gy. Overall, 318 cases were treated with chemotherapy and/or hormone therapy. For the whole group, the 5-year overall and disease-free survival rates were 87.4% and 89.6% respectively. The 5-year disease-free survival rates for the Conventional radiotherapy group, the Alternate-day radiotherapy group, and the Fast radiotherapy group were 90.8%, 86.5%, and 84.6% (P=0.13).The locoregional recurrence rates were 7.0%, 9.9 and 5.7 respectively. There was no significant difference between the three groups in terms of local control. Conclusion: With similar 5-year disease-free-survival rates, and the same efficacy, Alternate-day radiotherapy has the advantage of giving fewer fractions, which is suitable for a unit with limited resources. Fast radiotherapy shortens the duration of the treatment, and its efficacy and toxic effects deserve further study.