Sentinel lymph node (SLN) biopsy has been widely used in the management of melanoma and breast cancer. The aims of this study were (1) to compare the results obtained with the different injection, intraoperative sentinel node evaluation, and postoperative evaluation; and (2) to determine the reliability of SLN to predict the regional lymph node status.

We prospectively studied selected 162 female primary breast cancer patients from Jun. 1999 to Apr. 2003. For identification of sentinel lymph node, Tc99m-antimony trisulfate was used as a tracer with two injection methods and SLN biopsy using a gamma-detection probe was done after breast lymphoscintigraphy. Frozen section biopsy or touch-print cytology was done for intraoperative evaluation. If a SLN biopsy was free of metastasis by permanent hematoxylin and eosin (H&E) staning, Immunohistochemical staning using pan-cytokeartin was done to detect micrometastasis.

SLN was detected 96.2% with lymphoscintigraphy, 100% with gamma-probe. The mean number of resected SLN was 1.83±0.95 and all SLN located in axilla. The false-negative rate of SLN biopsy was 5.6%, and there was no statistical difference in intraoperative frozen biopsy vs touch-print cytology, injection methods, tumor size, number of examined SLN (P>0.1). But a significant differences exist in preoperative ultrasonography for axillary lymph node status (P=0.014). Adding the ultrasonographic findings to the patient-selection criteria, the false-negative rates decreased to 2.9%.

We suggest that ultrasonography should be included into the patient selection criteria to reduce the false-negative rate in sentinel node biopsy of breast cancer.