(P116) Bilateral Immediate DIEP Reconstruction and Postmastectomy Radiotherapy: Experience at a Tertiary Care Institution

Melissa R. Young, MD, PhD, Stefano Fusi, MD, Monica Kaur, CMD, Sameer K. Nath, MD, MS, Suzanne B. Evans, MD, MPH, Jeffrey C. Salomon, MD, FACS, Susan A. Higgins, MD; Departments of Therapeutic Radiology and Plastic Surgery, Yale University School of Medicine

Purpose: Although autologous and immediate reconstruction has potential advantages when compared with delayed and implant-based reconstruction for patients with breast cancer (BCA), concerns exist for potential increased complications and technical difficulty in the delivery of postmastectomy radiotherapy (PMRT). Bilateral immediate reconstruction (BIR) with a deep inferior epigastric perforator (DIEP) flap offers several distinct advantages for patients with BCA: it produces a chest wall reconstruction with a robust vascular supply, eliminates the need for subsequent reconstructive surgery, and potentially decreases the overall time needed to complete cancer therapy. The purpose of this study was to report the outcomes for patients treated with bilateral mastectomy (BLM), BIR with DIEP, and PMRT at our institution.

Methods: We performed a retrospective review of patients with BCA who underwent BLM, BIR with DIEP, and PMRT at Yale–New Haven Hospital. A minimum of 6 months of follow-up since completion of PMRT was required.

Results: A total of 17 patients were identified. Median age at the time of surgery was 53 years (range: 26–60 yr). Median follow-up from completion of PMRT was 26.4 months (range: 6.3–67.2 mo). All surgeries were performed by a single surgical team (SF and JS). Three patients received neoadjuvant chemotherapy (NAC), and 14 received adjuvant chemotherapy. The stage distribution for patients who received adjuvant chemotherapy was: stage IIA (3 patients), stage IIB (3 patients), stage IIIA (6 patients), and stage IIIC (2 patients). PMRT was delivered to the ipsilateral chest wall (all patients), supraclavicular fossa (16 patients), and axilla (5 patients). No patient had internal mammary nodal radiation. Prior to PMRT, five patients required additional chest wall surgery. One of these patients had total flap loss (due to necrotizing cellulitis), and two patients had partial flap loss. No patient had flap loss after PMRT. A total of 33/34 DIEP reconstructions were maintained at the time of last follow-up. Lung dose-volume histogram information was calculated for all patients. Median ipsilateral lung (IL) V20 was 22.7% (range: 6.7%–33.5%), median bilateral lung V20 was 11.7% (range: 3%–16.8%), and median mean IL dose was 13.3 Gy (range: 5.7–15.7 Gy) There were no reported cases of radiation pneumonitis and no isolated locoregional failures. Median time from surgery to completion of RT was 7.9 months (range: 2.4–10.4 mo) for all patients and 2.8 months (range: 2.4–4.1 mo) for patients undergoing NAC (reconstruction of the nipple-areola complex).

Conclusions: Our institutional review of 17 patients who had BLM, BIR with DIEP, and PMRT demonstrates that this approach was well tolerated. Using standard PMRT treatment techniques, the IL V20, total lung V20, and mean lung dose values were within acceptable limits. Furthermore, for patients who underwent NAC, median total time from surgery to completion of RT was 2.8 months-significantly shorter than that observed in the setting of delayed reconstruction with expanders. In our experience, BIR with DIEP can be performed prior to PMRT with a relatively low incidence of surgical complications, high rate of DIEP viability at 26.4 months, no pulmonary complications, and no compromise in standard lung DVH parameters. Longer follow-up will be needed to assess delayed complication rates and disease-free and overall survival.