Evolution of sentinel lymph node biopsy for melanoma at a National Cancer Institute - designated cancer center

Background. Sentinel lymph node biopsy (SLNB) has rapidly evolved into the standard of care for clinically node-negative melano mn. Since adopting sen tinel lymph node (SLN) technology in 1993, we have periodically reviewed ou r institution's results and made several modifications. Methods. From January 1993 to December 1998, 182 patients with clinically n ode-negative primary cutaneous melanoma underwent SLNB. Charts were retrosp ectively reviewed and assessed for the technique for the identification of the SLN, the pathologic analysis, and the use of intraoperative frozen sect ion. Results. The accuracy of SLN identification improved from 91% to 100% with the combination of isosulfan blue dye and radiolabeled colloid over isosulf an blue dye alone. Routine versus selective lymphoscintigraphy identified 7 in-transit SLNs and increased detection of dual nodal basin drainage (15%- 27%). Identification of micrometastases in the SLN increased from 14% to 24 % after a modification of pathologic evaluation. The positive SLN was the o nly involved node in most patients (80%). Intraoperative frozen section had a sensitivity of 58% and was of benefit in only 13 of 124 patients Conclusions. Several modifications to the identification of the SLNs and th e detection of metastatic melanoma have improved our outcome with SLNB. A c areful, periodic review of results to identify areas for improvement at eac h institution is crucial to the success of SLNB for melanoma.