Background: Despite an expanding role of adjuvant radiotherapy and the popularity of two-stage prosthesis-based reconstruction in the treatment of breast cancer, there is no consensus on the proper timing of postmastectomy radiotherapy (PMRT) in relation to the two stages of the reconstruction procedure. The present meta-analysis investigated the optimum timing of PMRT by comparing the outcomes of the following two sequences: radiation on tissue expander followed by the exchange, and radiation on the permanent implant after the exchange.
Methods: The Medline, Ovid, and Google Scholar databases were searched to identify relevant studies presenting complication rates of the two sequencings. The relative risks of the adverse outcomes between the groups were calculated.
Results: A total of eight studies were analyzed, representing 899 cases. There were no prospective randomized controlled trials, and all but one were retrospective cohorts in nature. The risks for reconstruction failure and major complication requiring reoperation tended to be higher in the group with PMRT to tissue expanders compared to that with PMRT to implants; however, the differences were not significant. The group with PMRT to tissue expanders had a significantly lower risk of severe capsular contracture (relative risk, 0.44; P < 0.001).
Conclusions: Delivering PMRT to tissue expanders can reduce the risk of severe capsular contracture compared to delivering to implants. No significant differences in the risks of other complications, including reconstruction failure between the two sequencings, were detected; however, as a result of low level of evidence and insufficient sample sizes, further studies are needed to support evidence-based decision making.