Subareolar injection is a better technique for sentinel lymph node biopsy

Background: Numerous techniques and materials show accuracy in localizing the sentinel lymph node (SLN). We hypothesized that subareolar injection of material would localize the SLN as effectively as peritumoral injection. Methods: Thirty-eight patients were injected with technetium-99 sulfur colloid either peritumorally or subareolarly in addition to the injection of blue dye around the tumor. Radioactive SLNs were localized using a hand-held gamma probe. Results: Nineteen patients were included in each of the two groups, peritumoral and subareolar. SLNs were found in all patients injected subareolarly and in 18 of 19 injected peritumorally. The false-negative rate was 20% for peritumoral injection and 0% for subareolar injection. Conclusions: The results suggest that subareolar injection was as accurate, if not more accurate, than peritumoral injection for localizing the SLN. This technique is simpler than peritumoral injection and does not require injection under image guidance for nonpalpable lesions.