Post-Mastectomy Radiation Therapy after Prepectoral Breast Reconstruction Is Associated with A Low Early Explantation Rate

Abstract

Immediate breast reconstruction with a prepectoral tissue expander (TE) in women who require mastectomy is associated with reduced postoperative pain due to avoidance of muscle dissection and elimination of breast animation deformity. Outcomes of patients with immediate prepectoral breast reconstruction who undergo post-mastectomy radiation therapy (PMRT) are not well studied. We report on cellulitis and explantation rates for breast cancer patients receiving mastectomy with immediate prepectoral breast reconstruction followed by PMRT at a single institution. Patients with breast cancer who underwent mastectomy with immediate prepectoral breast reconstruction and PMRT at our institution with at least 6 months of follow up were included. Demographic data, disease and treatment characteristics, and outcomes were collected. Sixteen patients met inclusion criteria. Median age was 49 years (IQR 41.2-54.9) and median follow up after PMRT was 14.8 months (range 5.7–36.6). All patients except 1 received chemotherapy. Surgical incisions included periareolar (38%), inframammary (31%), transverse (25%), and Wise pattern (6%). All patients underwent acellular dermal matrix placement during surgery. Median time to PMRT from surgery was 88 days (IQR 68-187). All patients received 50Gy in 25 fractions, except 1 received 42.56Gy in 16 fractions on a prospective clinical trial. Ten patients were treated with 3D conformal plans and 6 with intensity modulated radiation therapy plans. Thirteen (81%) patients had no acute complications. Three patients developed cellulitis during PMRT; 2 (13%) of these patients had a history of cellulitis prior to PMRT and developed recurrent cellulitis during treatment, requiring admission with intravenous antibiotics for 2 and 4 days, respectively, and oral antibiotics for the duration of PMRT. One required TE explantation 5 months later and the others had no further complications. Seven (44%) patients underwent TE removal with permanent silicone implant placement at a median of 7.2 months (range 4.9-8.8) after PMRT. Four (25 %) patients elected to undergo autologous reconstructions subsequent to PMRT and 2 (13%) patients elected for TE removal without reconstruction. Two (13%) patients have completed PMRT but have not yet had reconstruction. No patients experienced loss of their permanent implant at time of last follow up. In this small single institution series, we found that patients who undergo PMRT after prepectoral breast reconstruction do not appear to be at higher risk for infection. Grade 3 skin infection only occurred in patients with previous history of infection prior to radiation and those patients should be monitored closely during PMRT. The majority of patients with prepectoral breast reconstructions appear to be able to proceed to second stage permanent implant. The overall loss of implant rate was 6% in this small series though longer follow-up is needed.