Sentinel lymph-node biopsy for melanoma of the trunk and extremities: the McGill experience

Objective: To determine the effectiveness of sentinel lymph-node (SLN) biop sy for melanoma of the trunk and extremities. Design: Case series review. S etting: Royal Victoria Hospital, a Canadian university hospital. Patients: Thirty-six patients (18 women and 18 men) seen between October 1996 and Dec ember 1998 with melanoma 1 mm or more in thickness with clinically negative lymph-node basins. Followup was 396 days. Interventions: SLN biopsy. Techn etium-99m filtered Sulfur colloid (0.5 mCi) was injected intradermally arou nd the melanoma or the excision scar 10 to 15 minutes before the surgical s kin preparation. The identification of the SLN(s) was done with a hand-held gamma probe. Local anesthesia was used mostly for inguinal SLN biopsy wher eas general anesthesia was usually required for axillary SLN biopsy. Preope rative lymphoscintigraphy was used only for trunk melanomas. Outcome measur es: Morbidity, successful identification of the sentinel node and locoregio nal recurrence. Results: The mean age of patients at diagnosis was 53.4 yea rs (range from 22-76 yr). The melanomas were distributed between the lower extremities (20 patients), upper extremities (8 patients) and trunk (8 pati ents). The mean Breslow thickness was 2.35 mm (range from 1-8 mm). Lymphosc intigraphy accurately localized the lymph-node drainage basin for trunk mel anomas. In I patient the SLN could not be identified because the radiocollo id failed to migrate (failure rate 2.8%). The average number of SLNs remove d was 1.97. Eight patients (22%) had sentinel nodes positive for malignant disease. The postoperative complication rate was 8.5%. Seven of 8 patients with positive SLNs underwent a complete node dissection (1 patient refused) . Of the completion dissections only 2 patients had positive non-SLNs. All patients vith positive nodes received interferon alpha-2b as adjuvant treat ment. At follow-up, 34 patients are alive with no evidence of disease, 1 pa tient with a positive SLN is alive with distant metastatic disease and 1 pa tient with a negative SLN is dead of disseminated disease. Conclusion: SLN biopsy is a feasible technique With an acceptable failure rate and is thus a useful tool in the surgical management of melanoma.