The use of indocyanine green and technetium-99 for dual-tracer sentinel lymph node biopsy in breast cancer.

Abstract

Purpose: The aim of this study was to determine if indocyanine green (ICG) is a suitable replacement for blue dye for dual-tracer sentinel lymph node biopsy (SLNB).

Methods: A single-center retrospective review of female breast cancer patients aged ≥ 18 years who underwent SLNB with technetium-99 (Tc⁹⁹) and ICG was performed from November 2022 to April 2024. Operative reports were reviewed to determine sentinel lymph node (SLN) identification rates with ICG (fluorescent) and Tc⁹⁹ (radioactive). Pathology reports were reviewed to determine the pathology of excised SLNs.

Results: One hundred and nineteen SLNBs were performed on 117 patients. At least one radioactive or fluorescent SLN was identified in 93.2% of all patients. The mean number of SLNs retrieved per SLNB was 1.6 (fluorescent, 1.5; radioactive, 1.5). Of all excised SLNs, 89.4% were fluorescent, 88.4% were radioactive, and 81.9% were both fluorescent and radioactive. SLN metastases were present in 26 patients (22.2%); of SLNs identified with metastases on pathologic examination, 87.2% were fluorescent, 74.4% were radioactive, and 71.8% were both radioactive and fluorescent. Two patients (1.7%) experienced skin flap necrosis and one patient (0.9%) experienced prolonged skin discoloration. No patients experienced allergic reactions.

Conclusion: This study demonstrates that SLN identification rates using ICG and Tc⁹⁹ are comparable to those using blue dye and Tc⁹⁹. Thus, ICG is a suitable alternative for blue dye. Future work should assess if ICG is a suitable tracer for SLNB in low-resource settings where Tc⁹⁹ is not available.