The status of the axillary nodes in breast carcinoma patients is one of the most significant prognostic factors. Although many trials in order to gain information concerning axillary status, to date there is no satisfactory procedures other than axillary lymph node dissection (ALND) which has many complications. Recently sentinel lymphadenectomy has become accepted as an alternative to ALND.

Sentinel lymphadenectomy followed by ALND was performed in 157 patients with invasive breast carcinoma between Nov. 1998 and Dec. 2000. The period from Nov. 1998 to May. 1999, which included the first 54 patients was set as a learning period. 99m Tc antimony trisulfide colloid was used in the detection of the sentinel node, with a gamma camera preoperatively and then a gamma probe in the operating room. The dissected sentinel nodes were examined by both frozen section and serial section (SS) with immunohistochemical stains (IHC).

The detection rate was 96.8%. The false negative rate was 22.6% for the frozen sections and 4.8% for the permanent sections. The detection rate and the false negative rate had improved after the learning period with statistic significance (P-value<0.05). The false negative rate for tumors less than 2 cm was significantly lower than that for tumors greater than 2 cm (P-value=0.000).

Sentinel lymphadenectomy using 99m Tc antinomy trisulfide colloid showed high detection rate and low false negative rate. The learning period is thought to be necessary for its clinical application. In the future, sentinel lymphadenectomy may replace axillary lymph node dissection in certain subgroups of breast carcinoma patients.