Isotope-Only Localization for Sentinel Lymph Node Biopsy - Medium-Term Oncological Outcomes

Aims: Isotope and blue dye dual localization in sentinel lymph node biopsy (SLNB) gives localization rates of over 98% and is the recommended technique. However blue dye risks a range of adverse reactions. Since 2010, for clinically node negative disease, we have only used blue dye if there is no clear isotope signal at surgery.

Methods: Electronic records of patients who underwent isotope-only SLN localization between July 2010 and April 2012 were examined. Data were collected on localization and oncological outcomes.

Results: 426 patients were included. Isotope-only localization rate was 97.4% (415/426). The median follow-up was 63.5 months (IQR: 60.7-70.9). Median age was 57 (IQR: 48-67). Median SLN yield was 2 (range: 1-5). Axillary recurrence rate was 1.4% with median time to recurrence of 39.3 months. In-breast recurrence, distant disease and contralateral breast cancer rates were 2.8%, 7%, and 1.9% respectively and 15 (3.5%) patients died of metastatic breast cancer.

Conclusion: Isotope-only SLNB has a comparable localization rate to dual isotope/blue dye SLNB and can spare the risk of blue dye adverse reactions. The low axillary recurrence rate, maintained to more than 5 years, confirms that isotope-only SLNB is a feasible and safe alternative to dual blue dye/isotope localization.