Since its introduction in the mid-1990s, sentinel lymph node biopsy has been rapidly and widely adopted for the axillary staging of clinically node-negative breast cancer patients. However, there is some controversy in the clinical application because of its various identification rates and its false negative rates. The objective of this study was to assess the usefulness of endoscopic sentinel lymph node biopsy (ESNB) and to compare the value of two methods for identification of ESNB using blue dye only or a combination of blue dye and radioisotope.

This study was carried out in 137 breast cancer patients (bilateral breast cancer, 3 cases) who underwent ESBN, at the Department of Surgery in Soonchunhyang University from May of 2007 to August of 2008. The technique involved the injection of 5 mL of 0.5% indigocarmine or Tc-99m tin colloid into subareolar plexus. The Visiport docked with a telescope was inserted through a low transverse axillary incison (1.0 cm in size) lateral to the pectoralis major. During the dissection, we identified sentinel nodes by following blue-stained lymphatic duct directly into blue-stained lymph nodes. We compared the value of two methods for identification of ESNB using blue dye only or a combination of blue dye and radioactive tracer.

The mean number of sentinel nodes was 1.27 (range, 1-4). The identification rate and false negative rate of the sentinel node were 94.3% (132/140) and 6.9% (3/43), respectively. We compared ESNB with using blue dye only (n=77) vs. a combination of blue dye and radioactive tracer (n=63). Sentinel lymph node identification rate were 90.9% (70/77) vs. 98.4% (62/63) (p=0.043).

The endoscopic technique of sentinel node biopsy can keep better operative visual fields and is less invasive. The combination of blue dye and radioactive tracer was superior to blue dye only for identification rates.