Subareolar injection of ^99mTc facilitates sentinel lymph node identification

Background: Sentinel lymph node (SLN) biopsy with the standard intraparenchymal injection has been accepted as an alternative to routine axillary dissection for patients with breast cancer. However, the identification and false-negative rates with this method can vary widely from surgeon to surgeon. The subareolar location contains a rich lymphatic network and represents a potential site of injection for SLN identification. Methods: Between August 1, 1999, and December 31, 2000, we performed 159 SLN biopsy procedures on 158 patients with breast cancer. For each patient, ^99mTc-labeled sulfur colloid was injected into the subareolar location, and 1% isosulfan blue dye was given as an intraparenchymal injection. Results: In every case, at least one radioactive SLN was identified with the subareolar injection of technetium; a blue SLN was found in 97% of the cases. The blue SLN was also radioactive in 98% of the cases, indicating that the blue dye injected around the tumor and the technetium injected into the subareolar location drained to the same SLN. Conclusions: Subareolar injection of technetium can improve SLN identification rates for breast cancer. The simplicity and accuracy of this technique may also reduce the variable results reported with the standard intraparenchymal method.