Axillary Reverse Mapping Using Indocyanine Green in Breast Cancer: Standardization of the Technique.

Abstract

Purpose: To validate the Axillary Reverse Mapping (ARM) technique with indocyanine green (ICG), focusing on the detection rate and the procedure's feasibility. The predictive factors for metastatic involvement of ARM nodes are also analyzed to define the target population for ARM indication.

Methods: This prospective, observational, non-randomized study of patients with breast cancer included patients with an indication for axillary lymph node dissection (ALND) performed between June 2021 and June 2023. Participants were divided into two cohorts based on pattern of ICG migration: standard technique (all ARM nodes) and targeted technique (in contact with axillary vein). The feasibility of identifying and preserving ARM nodes during ALND was assessed. Multivariate logistic regression was used to analyze predictive factors (eg, tumor size, molecular surrogate subtype, multifocality, and neoadjuvant therapy) for metastatic ARM nodes.

Results: Of the 41 patients in whom we performed the ARM technique, ARM nodes were identified and preserved after ALND in 36 patients (87.8%). Of these, 17 (89.5%) underwent the standard technique and 19 (86.4%) underwent the targeted technique. ARM metastases were identified in 12 patients: 9 (47.1%) with the standard technique and 3 (15.7%) with the targeted technique (P = .026). The ARM technique was the only risk factor for ARM involvement (odds ratio, 15.9; 95% confidence interval, 1.1-218.6).

Conclusions: ICG facilitates the successful completion of ARM in almost 90% of patients undergoing ALND. In addition, by selecting the ARM nodes closest to the axillary vein, the number of cross metastases can be significantly reduced.