Toxicity Outcomes for Immediate and Delayed Autologous Reconstruction in Patients Receiving Post-mastectomy Radiation Therapy: Is It Time to Reconsider Sequencing?

Abstract

Delayed autologous reconstruction is usually recommended in patients anticipating postmastectomy radiation therapy (PMRT). However, it has been suggested that immediate autologous reconstruction (AR) may be acceptable for many patients. In this study, we sought to assess toxicity outcomes in patients receiving PMRT and AR. Retrospective chart review was performed in all patients receiving PMRT and AR, both immediate and delayed, at a single institution between April 2012 and November 2016. PMRT was designed using 3D planning and included treatment of the internal mammary, supraclavicular, and un-dissected axillary nodes typically prescribing 50 Gy over 25 fractions. A mastectomy scar line boost was delivered in 48.5% of patients. Incidence of major and minor complications were assessed. Preoperative and postoperative photos were also assessed for subjective outcome. Statistical analysis was performed with Students t-tests. Of the 739 patients that underwent AR, 60 received PMRT, 33 of which had at least 3 months of follow up from either date of RT completion in immediate AR or date of surgery in delayed AR, as well as evaluable 3D planned radiotherapy. Unilateral AR occurred in 82% and bilateral in 18%. Median age was 47 years (31 to 62) and median follow up was 7 months (3 to 36 months). All patients received either neoadjuvant or adjuvant chemotherapy. A total of 11 patients underwent immediate AR at the time of mastectomy and 23 patients underwent delayed AR 10 months (median; 4-36 range) after PMRT. The time interval in weeks from surgery to start of PMRT was 3 months (range 1 to 7) in immediate AR and the interval from RT to surgery was 7 months (range 4 to 36) in delayed AR. The infection rate in the entire group was 12% (N=3 immediate; N=1 delayed, p=0.062). Fat necrosis occurred in 9.1% (N=1) in the immediate group and 26% (N=6) in the delayed group (p=0.24). Incidence of revision operations was 54.5% (N=6) in the immediate group and 35% (N=8) in the delayed group (p=0.33). Unplanned reoperation rates were 13% (N=3) and 0% (p=0.21), flap failures were encountered in 1 delayed AR patient and 0 immediate AR (p=0.48), respectively. Total operation time was 9 hours 21 minutes for immediate AR vs 7 hours 49 minutes for delayed AR (p=0.055); and 90-day readmission rates were 9.1% (N=1) vs 8.7% (N=2), (p=0.21) respectively, in immediate and delayed cases. Photo ratings were comparable between the two groups. In a more modern treatment era, immediate autologous reconstruction in the setting of PMRT appears to show acceptable toxicity results that are comparable to delayed reconstruction. Increased patient numbers to corroborate these early findings and assessment of patient reported outcomes are needed to support that a change in sequencing AR with PMRT is warranted.