Examination of sentinel node navigation surgery for cutaneous malignant melanoma in Fujita Health University

In the duration from May, 2002 to June, 2005, we performed sentinel node navigation surgery (SNNS) to a total of 13 cases with malignant melanoma at our university hospital. The average observation period was 19.5 months. After the SNNS, two patients showed metastatic disease. One had liver metastasis, the other had in-transit metastasis. The average number of SN was 2.3, and positive rate of the SN metastasis was 8%. Sentinel nodes (SN) were identified in 100% of the cases with a combination method of patent blue dye method, preoperative lymphoscintigraphy and an intraoperative hand-held gamma probe. According to our and previous reports on Japanese patients, increasing tumor thickness was presumed to be associated with SN positive rate. Especially, SN positive rate was 0% for melanoma with tumor thickness less than 1mm. We suggest that SNNS has the best indication for melanoma thicker than 1mm. When we aim to predict patient's prognosis and reduce surgical stress, SNNS is very useful. However, there were not enough number of the cases, this approach needs further investigation in a larger series of patients.