Introduction: In response to the COVID-19 pandemic, many centres have adopted patent blue single technique for sentinel lymph node biopsy (SLNB) due to logistical challenges of accessing or administering isotope whilst minimising patient exposure to COVID. We aimed to assess the efficacy of blue dye alone in real-world practice, compared to the standard practice of Tenetium99 isotope with or without blue dye.
Methods: A retrospective analysis of 100 consecutive breast cancer patients from a single unit who had SLNB utilising patent blue dye only were compared to 261 patients who underwent Tenetium99 isotope SLNB, from a historic cohort. Numbers of sentinel and non-sentinel nodes harvested were compared.
Results: 16 (16%) patients had no SLN identified in the patent blue group, compared to 6 (0.4%) in the isotope cohort. Median number of SLN removed was 3 (range 1-4) compared to 2 (range 1-6) in the isotope cohort. The median of total nodes removed was 3 (mean=2.86, range 1-11) compared to 2 (mean= 2.16, range 1-7). 22 patients (26%) had additional non-sentinel nodes removed compared to 50 (20%) in the isotope group.
Conclusion: Although the use of single blue dye technique was a practical requirement, in current real-world practice, blue dye is associated with increased LN removal and likely greater axillary dissection. This provides evidence to support the need for improved localisation techniques.