Impact of Postmastectomy Radiation Therapy on Sensory Recovery Following DIEP Flap Breast Reconstruction with Superficial Neurotization

BACKGROUND: Superficial breast neurotization, involving elongation of the fourth intercostal lateral cutaneous nerve to the preserved nipple and skin, shows promise in sensory recovery. However, the impact of postmastectomy radiation therapy (PMRT), on sensory outcomes in breast neurotization is underexplored. This study evaluates PMRT's impact on sensory outcomes. MATERIALS AND METHODS: A retrospective review was conducted on patients undergoing DIEP flap breast reconstruction with neurotization from August 2019 to August 2024. Patients were categorized into PMRT and non-PMRT groups, with sensory assessments performed using Semmes-Weinstein monofilaments. Patient-reported outcomes were assessed using a questionnaire incorporating BREAST-Q domains and study-specific items addressing aesthetic and sensory outcomes. RESULTS: Among 135 patients, 27 received PMRT. Both groups exhibited reduced sensation compared to the normal breast (PMRT: 31.51 ± 81.70 vs. 0.07 ± 0.19 g, p < 0.001; non-PMRT: 14.62 ± 54.27 vs. 0.07 ± 0.17 g, p < 0.001). Preoperative thresholds were similar between groups (PMRT vs. non-PMRT: 0.10 ± 0.23 vs. 28.49 ± 85.76 g, p = 0.950). Sensory recovery improved gradually in both groups, with differences diminishing over time (PMRT vs. non-PMRT at 0-6 months: 158.27 ± 140.97 vs. 58.11 ± 98.37 g, p = 0.007; 19-24 months: 1.40 ± 2.20 vs. 2.76 ± 13.90 g, p = 0.389). Nipple sensation and sensory-related BREAST-Q domains showed no significant. PMRT group reported modestly lower psychosocial well-being (36.95 ± 9.98 vs. 41.68 ± 7.35, p = 0.042) and satisfaction with breasts (42.64 ± 9.34 vs. 48.65 ± 8.15, p = 0.036). CONCLUSIONS: While PMRT initially impedes sensory recovery after neurotization, this negative impact diminishes progressively. By 13-18 months postoperatively, patients who received PMRT achieve sensory outcomes comparable to non-irradiated cases. Furthermore, PMRT does not significantly increase complication rates or the need for secondary revision procedures in this patient population.