A prospective comparative study to assess the contribution of radioisotope tracer method to dye-only method in the detection of sentinel lymph node in breast cancer

BACKGROUND Metastasis in the axillary lymph nodes is the most important known prognostic factor for breast cancer. We aimed to investigate the contribution of the radioisotope tracer method to the dye-only method by performing sentinel lymph node biopsy on the same patient group during a single surgical session. METHODS Forty-two patients who underwent operations in our clinic from February 2010 to October 2011 and with masses of <5 cm and clinically and radiologicallly negative axilla (T1-2 N0) were prospectively included in this study. After paraffin examination results were obtained, the numbers and metastatic states of the lymph nodes that were unidentifiable during surgery (although they were stained) but were detected by a gamma probe, lymph nodes that were only stained, lymph nodes that were only radioactive (hot), and lymph nodes that were both stained and radioactive (stained-hot) were determined in all patients. In patients who underwent axillary lymph node dissection, the total numbers of lymph nodes removed and their metastatic states were determined separately. RESULTS At least one blue-stained sentinel lymph node was identified in all patients during the blue-stained lymph node detection stage. The average number of sentinel nodes removed at this stage was 2.1 ± 1.1. In the second surgical stage (the stage in which nodes with axillary counts were investigated with the gamma probe) in these 41 patients, at least one additional hot node was removed, or at least one of the nodes that was removed because it was blue was also hot. In addition to the lymph nodes removed in the dye stage, 34 hot lymph nodes were excised from 21 patients. Overall, the average number of hot lymph nodes removed was 2.9 ± 1.5. In all patients, subsequent frozen sections and histopathological examinations were 100% concordant with the sentinel lymph nodes that were removed; the stained sentinel lymph nodes that were removed first did not affect the decision to perform axillary dissection. CONCLUSION The results of our study indicate that performing sentinel lymph node biopsy with dye only is sufficient and as effective as the combined method.