Prospective evaluation of selective lymph node biopsy for cutaneous malignant melanoma

Some patients presenting with cutaneous malignant melanoma without palpable adenopathy have regional metastatic disease. We have applied the technique of gamma probe-directed selective lymph node biopsy and used the results to direct further therapy. The results of a prospective nonrandomized clinical study are presented. Between November 1993 and December 1996, 63 patients with a diagnosis of primary cutaneous malignant melanoma underwent lymphoscintigraphy with technetium sulfur colloid followed by gamma probe-guided lymph node biopsy. There were 32 (51%) women and 31 (49%) men with a mean age of 51.1 years (median, 50; range, 13-87). Mean Breslow thickness was 2.13 mm (range, 0.5-15.0 mm; median, 1.56 mm). Primary locations were head and neck in 8 (13%), trunk in 24 (38%), upper extremity in 13 (21%), and lower extremity in 18 (29%). Selective lymph node biopsy was done on an outpatient basis with local anesthesia in 49 cases (78%) and in the operating room with general anesthetic in 14 patients (22%). One lymph node site was biopsied in 46 patients (73%), two sites in 16 (25%), and three in 1 (2%), for a total of 81 selective lymph node biopsy sites, mean 1.29 per patient. The mean number of labeled lymph nodes removed per site per patient was 1.64 (range, 1-5). Seroma or infection occurred in 6 patients (10%). Micrometastatic disease was identified in nine selective lymph node biopsy sites in eight patients. Of eight patients undergoing lymph node dissection, 5 (63%) had no additional pathological lymph node involvement. With a mean follow-up of 579 days from selective lymph node biopsy (median, 594; range, 36-1157), 59 (94%) have no evidence of disease. Three patients have died, 2 with systemic disease (475 and 1149 days) and 1 from a myocardial infarction (380 days). No patient has failed with regional-only recurrence. Gamma probe-directed selective lymph node biopsy is a straightforward procedure that can be done in the outpatient setting and facilitates management of patients with cutaneous malignant melanoma.