Immediate breast reconstruction can impact postmastectomy irradiation

Objective: Immediate breast reconstruction is an attractive option for patients who undergo mastectomy. The purpose of this study was to qualitatively assess the effect of immediate reconstruction on the design of postmastectomy radiotherapy fields at our institution. Methods: We retrospectively reviewed the records of 152 patients treated at our institution with postmastectomy radiotherapy over a 1-year period. We identified 18 postmastectomy radiotherapy plans in the setting of prior reconstruction. By consensus, 2 board-certified radiation oncologists scored the 18 plans in terms of 4 outcomes: coverage of the chest wall breadth, coverage of the ipsilateral internal mammary chain (IMC) region, minimization of lung exposure, and avoidance of the heart. Results: Only 4 of the 18 plans resulted in optimal treatment of the chest wall breadth and IMC region while well avoiding the heart and lung. Of the remaining 14 plans, 12 compromised coverage of the chest wall breadth medially and/or laterally, and 9 provided no IMC coverage. Conclusion: Immediate breast reconstruction may impose limitations on the treatment planning of postmastectomy radiotherapy, particularly in regard to providing broad coverage of the chest wall and IMC region while avoiding excess exposure of the heart and lung.