Methylene blue dye as an alternative to isosulfan blue dye for sentinel lymph node localization

Our study describes the use of methylene blue dye as an alternative to isosulfan blue dye to identify the sentinel lymph node (SLN). A retrospective analysis was performed of 112 breast cancer patients (113 axillae) who underwent SLN biopsy (SLNB) with methylene blue dye and (99m)Tc-labeled sulfur colloid for SLN identification. All SLNs were submitted for intraoperative frozen section analysis, hematoxylin and eosin stain, and immunohistochemical evaluation. Patients with a pathologically negative SLN did not undergo further axillary lymph node dissection. Of 112 patients who underwent SLNB, the SLN was identified in 107 (95.5%); 104 (92.8%) were identified by methylene blue dye. In a subset of 99 patients with recorded isotope status in relation to blue nodes, concordant identification with both dye and isotope was observed in 94 (94.9%). Of patients with identified SLNs, 32 (29.9%) of 107 contained metastatic disease, with 31 (96.9%) of 32 identified by methylene blue dye. The SLN was the only positive node in 18 (60.0%) of 30 patients. SLNB with methylene blue dye is an effective alternative to isosulfan blue dye for accurately identifying SLNs in breast cancer patients.