The learning curve for sentinel node biopsy in malignant melanoma

Sentinel node biopsy (SNB) has emerged as an accurate means of identifying nodal micrometastasis incutaneous melanoma. In order to assess our learning curve, we compared our first 30 cases with our subsequent 30 cases. A total of 60 patients underwent SNB for cutaneous melanoma, using preoperative lymphoscintigraphy together with the intraoperative use of a Neoprobe and Patent Blue V dye. At least one sentinel node was identified in 93% of patients (90% in our first 30 cases; 97% in our subsequent 30 cases). Sentinel nodes contained tumour in 21% of cases. Of the sentinel nodes that contained tumour in the first 30 cases, 87% were identified by Neoprobe examination and 60% using blue dye. In the second 30 cases, the tumour-containing sentinel nodes were identified in all cases by both the Neoprobe and the blue dye. The sentinel node appeared to be the only involved node in 71% of patients. In the first 30 patients, one patient with a negative sentinel node developed nodal recurrence. These data confirm the feasibility of the sentinel-node technique in cutaneous melanoma. However, there is a learning curve, and the technique should be performed only by limited numbers of people with suitable training.