Background: Dual localization methods with blue dye and radioisotope represents the standard method for SLN identification. Side effects of blue dye and problems with access to radioisotope has prompted assessment of alternative tracers. This study has evaluated a combination of indocyanine green (ICG) fluorescence with radioisotope for SLN biopsy in early breast cancer.
Methods: In a prospective observational study 79 patients scheduled for SLN biopsy underwent dual localization with radioisotope nanocolloid and ICG (0.5%). The primary goal was to assess noninferiority of ICG compared with standard radioisotopic localization. Statistical analysis was performed using Stata (version 15.1).
Results: A total of 162 nodes were retrieved from 79 patients with an average nodal count of 2.04 (range 1-4) and an overall identification rate of 98.7% (78/79). Nodal detection rates for ICG alone or combined with radioisotope were 98.1% (151/154) and 73.4% (113/154) respectively. Metastasis were present in 13 nodes, all of which were both fluorescent and radioactive and distributed amongst 13 patients each with a single positive node containing macrometastases (n = 5), micrometastases (n = 6), or isolated tumor cells (n = 2). ICG was noninferior to radioisotope with the lower confidence interval not crossing within the predefined limit. No serious adverse reactions were recorded.
Conclusions: These results confirm comparable performance parameters for ICG to the "gold standard" using radioisotope. ICG can reliably be employed as a sole tracer that avoids potential drawbacks of standard tracer agents, including availability and costs of radioisotope.
© 2022. Society of Surgical Oncology.