Comparative analysis of indocyanine green and technetium-99m for sentinel lymph node localization in breast cancer - institutional experience.

BACKGROUND

Sentinel lymph node biopsy is the gold standard for axillary staging in early breast cancer. The conventional dual-tracer technique using technetium-99m (Tc-99m) and blue dye is highly effective but limited by radiation exposure and logistical complexity. Indocyanine green (ICG) fluorescence imaging offers a radiation-free, real-time alternative. This study aimed to assess the diagnostic performance and clinical feasibility of ICG-guided SLNB compared with the standard Tc-99m-nanocolloid method.

METHODS

This prospective, open label, single center paired diagnostic comparison trial was conducted at the Department of Surgery, University of Debrecen Clinical Centre, Hungary. Eligible patients had biopsy-confirmed ductal carcinoma in situ or clinically node-negative invasive breast cancer (T1-T3) undergoing breast-conserving surgery or mastectomy. Periareolar injections of 99mTc-nanocolloid and 5 mg ICG were performed according to standardized international SLNB protocols. Lymphatic mapping was achieved with gamma-radiation detecting and near-infrared fluorescence imaging. Sentinel node detection rate, number of retrieved nodes, metastatic involvement, and adverse events were recorded and analyzed.

RESULTS

A total of 106 patients were included. ICG fluorescence achieved a sentinel node detection rate of 90,6%, compared with 97,1% for Tc-99m. A median of 2,1 lymph nodes were excised per patient. 21.7% received neoadjuvant systemic therapy and 63.2% had breast conserving surgery. The overall per-patient sentinel lymph node (SLN) detection rate was 90.6% with indocyanine green (ICG), 97.1% with technetium-99m (Tc-99m), and 98.1% with the combined technique. On a per-node basis (n = 221), detection rates were 88.2%, 83.7%, and 100%, respectively. Among patients with positive SLNs (n = 34), metastatic node detection was 94.1% using ICG, 79.4% with Tc-99m, and 100% with the combined approach. In both upfront surgery and neoadjuvant subgroups, no statistically significant differences were observed between detection methods (p > 0.05); however, interpretation of neoadjuvant results was limited by the small sample size. No ICG-related complications or adverse events were reported.

CONCLUSIONS

ICG fluorescence-guided SLNB alone is a safe, effective, and radiation-free alternative to conventional radioisotope mapping. Its high detection accuracy, simplicity, and real-time visualization support its integration into standard breast cancer surgery protocols. Further multicenter studies are warranted to validate long-term oncological outcomes.