Short-term outcomes and safety of radiotherapy for immediate breast reconstruction with autologous flap transfer following breast-conserving surgery

BACKGROUND: The outcomes of immediate autologous breast reconstruction (IABR) after partial mastectomy followed by postoperative radiotherapy (RT) in terms of aesthetics, treatment-related complications, and local control are unclear. In this study, we evaluated the efficacy of IABR after partial mastectomy with or without breast RT, and thus the impact of radiation on autologous flap transfer. METHOD: A retrospective cohort study involving consecutive breast cancer patients who underwent IABR after partial mastectomy between July 2011 and December 2017 at Shengjing Hospital was performed. Patients were divided into two groups based on whether or not they received RT after IABR. We compared aesthetic outcomes and changes in the flap size over the three-dimensional coordinates at various timepoints (pre-RT, 1, 6, and 12 months post-RT), as well as postoperative complications, survival, and recurrence rates between the two groups. RESULTS: In total, 84 breast cancer patients were enrolled, with 32 patients in the RT group and 52 in the non-RT group. At a median follow-up time of 33.3 months, no significant difference was found in the rate of regional recurrence between the two groups (3.13% vs. 3.85%, P = 1.00), and no local recurrences occurred in either group. At the timepoints pre-RT, 1, and 6 months post-RT (approximately 4, 7, and 12 months after IABR, respectively), 77 (91.7%), 70 (83.3%), and 83 (98.8%) patients, respectively, had achieved very good or good cosmetic outcomes, and only changes in breast skin color at 1 month after RT significantly differed between the RT and non-RT groups, with very good or good cosmetic result rates of 62.5% vs. 96.2%, respectively (P < 0.001). No significant difference in the reduction of flap size was observed at any timepoint between the two groups. There were no significant differences between the two groups in the rates of postoperative complications including necrosis of the flap, infection, hematoma, or seroma (all P > 0.05). Additionally, no grade 3 or greater RT-associated adverse events occurred during or after RT. CONCLUSION: RT following IABR provides aesthetically satisfactory results without intolerable adverse complications and may safely be performed in patients who underwent IABR after partial mastectomy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12885-021-07915-4.