Optimal Detection of Sentinel Lymph Node Metastases by Intraoperative Radioactive Threshold and Molecular Analysis in Patients with

The aim of this study was to optimize a protocol for radioguided biopsy of the sentinel lymph node (SLN) in patients with melanoma. The protocol was based on a combination of ex vivo counting of the nodes detected intraoperatively and analysis of the harvested nodes by hematoxylin and eosin staining plus immunohistochemistry (conventional histopathology [PATH]) and by molecular biology (reverse-transcriptase polymerase chain reaction [RT-PCR]). Methods: A total of 124 patients with primary clinical stage I–II (according to the American Joint Committee on Cancer) cutaneous melanoma underwent successful radioguided SLN biopsy. SLNs harvested for analysis included any additional nodes whose ex vivo counting rate exceeded 20 % of the hottest node. All removed SLNs were examined by conventional PATH and with RT-PCR analysis for the expression of messenger RNA for tyrosinase and the melanoma antigens recognized b