SELECTIVE REGIONAL LYMPHADENECTOMY IN MAL IGNANT-MELANOMA USING A GAMMA-PROBE

The accurate excision of the first tumour draining lymph node (sentine l lymph node SLN) can prevent extended surgery intervention in many pa tients with malignant melanoma. The aim of our study was to test the p racticability of the SLN dissection using a gamma probe. In a total of 52 patients, mostly with high-risk melanoma, a selective lymph node d issection was performed. We injected intracutaneously about 50 MBq Tc- 99m colloid around the tumour or scar followed by dynamic and late sta tic imaging. The site of SLN was localized with a gamma probe and mark ed on the skin. This was followed by the dissection of the SLN using t he gamma probe. In 51 of 52 patients the SLN could be found intraopera tivly using the gamma probe. The SLN contained microscopic metastases in 13 patients (24%). The rate of positive SLN was 40% in patients wit h high-risk melanoma (Breslow thickness more than 1.5 mm). In case of positive SLN a second surgical intervention with radical lymph node di ssection was followed. We conclude that dynamic lymphscintigraphy and the selective lymph node dissection using the gamma probe is a simple and minimally invasive method which can improve the survival probabili ty in patients with micrometastases.