Revision Surgeries After Proton vs Photon Postmastectomy Radiation Therapy in Prepectoral Implant-Based Breast Reconstruction.

Abstract

Background: Postmastectomy radiation therapy (PMRT) improves disease-free survival in breast cancer but reduces aesthetic satisfaction. Proton PMRT has gained popularity due to fewer systemic complications. There is a lack of data regarding revision surgeries for pre-pectoral implant-based breast reconstruction (PP-IBBR) following radiation.

Objectives: To compare the revision surgeries in PP-IBBR with photon versus proton PMRT.

Methods: A single-institution retrospective cohort study included breast cancer patients undergoing mastectomy and PP-IBBR with PMRT (January 2020-October 2022) The mean follow-up duration for the cohort was 1056.4 days (2.89 years). Revision surgeries evaluated were fat grafting, conversion to autologous flaps, implant replacement, implant removal, capsulectomy, and scar revision.

Results: 116 PP-IBBR were divided into two cohorts: photon (75, 64.66%) and proton (41, 35.34%) radiation cohorts. Overall corrective surgeries were higher with photon (27.5% overall; 32.4% photon vs 19.5% proton, p=0.132). The odds of any revision surgery were nearly double with photon (OR=1.98), and the conversion to an autologous flap was significantly more likely with photon (OR=4.55, p=0.025). Multivariable analysis showed an increased tendency for photon therapy patients to require any revision surgeries (OR=1.62, p=0.359), autologous flaps (OR=5.97, p=0.049), fat grafting (OR=1.52, p=0.664) and scar revision (OR=4.51, p=0.273).

Conclusions: Compared to proton therapy, traditional photon therapy has a higher conversion rate to autologous flaps with PP-IBBR. Photon therapy had higher rates of overall revision surgeries, however not statistically significant. Proton therapy is safer, with fewer revision surgeries, warranting larger studies and broader utilization.