Dye-guided sentinel node biopsy revisited; validation and observational study from a single institute.

Abstract

The aims of this study were to evaluate the feasibility and accuracy of indigocarmine dye-guided sentinel node biopsy and to apply this method to avoid further axillary node dissection in sentinel node negative cases. Sixty consecutive clinically node-negative breast cancer patients underwent sentinel node biopsy using 0.5% indigocarmine followed by standard axillary node dissection. Sentinel node biopsy was then applied to 42 clinically node-negative patients to avoid axillary node dissection with intraoperative diagnosis made by frozen section. Validation study: Sentinel nodes were successfully detected in all 60 patients. The mean number of harvested nodes was 1.7 (range 1-3). Sentinel nodes were positive in all 20 axillary node-positive patients, and therefore the false negative rate was 0% (0/20). Only sentinel nodes contained metastases in 55% (11/20) of node positive patients. Observational study: Sentinel nodes were successfully detected in all 42 patients. The mean number of harvested nodes was 1.6 (range 1-3). Sentinel nodes were positive in 12 patients by final histology, and there was one false negative case by frozen section (8%, 1/12). Only sentinel nodes contained metastases in 55% (6/11) of node positive patients. The detection rate, mean number of harvested sentinel nodes and proportion of node positive patients were similar between the validation and observational studies. Indigocarmine dye-guided sentinel node biopsy was feasible and accurate. This method can be applied to observational studies after successful validation.