Gamma-probe-guided Lymph Node Localization in Malignant Melanoma

The initial draining lymph node (sentinel node) has been successfully localized using intraoperative vital dye mapping and reportedly is predictive of regional nodal metastases in Clinical- Stage 1 melanoma. In an animal model, we previously established the technique of gamma-probe-guided localization of the technetium-99 sulfur colloid labelled sentinel node and found its sensitivity equal to vital dye mapping. We now report our initial experience using gamma-probe-guided localization to identify and then surgically remove the first draining lymph node(s) in 10 malignant melanoma patients. Lymphoscintigraphy was used to confirm localization. We conclude that this technique: (a) reliably localizes the sentinel node draining the site of a primary melanoma, (b) allows the lymphatic bed to be checked intraoperatively verifying complete sentinel node biopsy, and (c) is relatively simple and can be performed under local anaesthesia.