Postmastectomy Radiation Therapy and Two-Stage Implant-Based Breast Reconstruction: Is There a Better Time to Irradiate?

BACKGROUND: The ideal timing of postmastectomy radiation therapy (PMRT) in the setting of two-stage implant-based breast reconstruction remains unclear. In this cohort study, the authors sought to determine whether complication rates differed between patients who received PMRT following tissue expander placement (TE-XRT) and those who received PMRT after exchange for permanent implants (Implant-XRT) utilizing using prospective, multicenter data.
METHODS: Eligible patients in the Mastectomy Reconstruction Outcomes Consortium study from 11 institutions across North America were included in the analysis. All patients had at least 6-month follow-up after their last intervention (i.e., implant exchange for TE-XRT patients, and radiation for Implant-XRT patients). Complications including seroma, hematoma, infection, wound dehiscence, capsular contracture, and implant loss were recorded.
RESULTS: The authors identified a total of 150 patients who underwent immediate, two-stage implant-based breast reconstruction and received PMRT. Of these, there were TE-XRT 104 patients (69.3 percent) and 46 (30.7 percent) Implant-XRT patients. There were no differences in the incidence of any complications or complications leading to reconstructive failure between the two cohorts. After adjusting for patient characteristics and site effect, the timing of PMRT (i.e., TE-XRT versus Implant-XRT) was not a significant predictor in the development of any complication, a major complication, or reconstructive failure.
CONCLUSION: In the setting of PMRT and two-stage implant-based reconstruction, patients who received PMRT after expander placement (TE-XRT) did not have a higher incidence or increased odds of developing complications than those who received PMRT after exchange for a permanent implant (Implant-XRT). CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.