Low‐Cost Dual‐Dye Axillary Reverse Mapping in Locally Advanced Breast Cancer After Neoadjuvant Chemotherapy: A Phase I Feasibility and Arm‐Related Quality of Life Outcomes Study

BACKGROUND: Patients with locally advanced breast cancer (LABC) undergoing axillary lymph node dissection (ALND) after neoadjuvant chemotherapy (NACT) face substantial risk of arm morbidity and lymphedema. Axillary reverse mapping (ARM) may preserve upper-limb lymphatic drainage; however, evidence in post-NACT LABC particularly from resource-constrained settings is limited. This phase I study evaluated the feasibility of a low-cost dual-dye ARM and its impact on arm-related quality of life using LYMPH-Q. METHODS: In this prospective study, 32 patients with LABC undergoing axillary surgery after NACT were included: 16 underwent standard ALND and 16 underwent ALND with ARM. ARM was performed using fluorescein sodium injected into the ipsilateral first web space and methylene blue injected subareolarly. ARM structures were preserved when oncologically safe. LYMPH-Q Upper Extremity scores were assessed at baseline, 6 months, and 12 months. Arm circumference and lymphedema incidence were recorded. RESULTS: Baseline clinico-pathologic characteristics were comparable between groups. ARM did not significantly increase operative time (p = 0.166) or compromise nodal yield (p = 0.239). Fluorescent lymphatic channels were identified and preserved in 15/16 ARM cases. At 12 months, LYMPH-Q Symptoms scores were significantly higher in the ARM group (p = 0.039), with greater improvement from baseline p = 0.017). Lymphedema incidence was lower with ARM, though not statistically significant (p = 0.600). Increases in mid-upper arm and forearm circumference were significantly lower. CONCLUSION: Low-cost dual-dye ARM is feasible following NACT in LABC and may improve patient-reported arm symptoms while maintaining comparable operative and pathological outcomes.