Usefulness of preoperative lymphoscintigraphy for the identification of sentinel lymph nodes in melanoma

Background: The exact role of lymphoscintigraphy (LS) in the evaluation of sentinel lymph nodes (SLNs) in melanoma is controversial. Methods: We reviewed our experience with preoperative LS for the determination of the lymph node drainage pattern of clinically node negative primary melanomas, with attention to the rate of ambiguous drainage and the effect of previous wide local excision (WLE). Results: The scans of 87 patients who underwent LS at our institution for evaluation of their primary melanomas from 1995 to the present were reviewed. Fourteen of the primary tumor sites were in the head and neck region, 41 were truncal, and 32 were in the extremities. The average tumor thickness was 2.6 mm. Nine of 14 (64%) head/neck lesions and 12 of 41 (29%) truncal lesions displayed ambiguous drainage, as compared with only 2 of 32 (6%) extremity lesions (P <0.05). Forty-one of the 87 patients (47%) had undergone previous WLE of their primary lesion prior to their LS. The number of draining basins for the WLE and the non-WLE groups were not significantly different, and at least one SLN was found for all WLE cases. Conclusions: Preoperative LS is important for the treatment planning of SLN biopsy for head/neck and truncal melanomas, but adds little additional information for extremity lesions. Lymph node drainage scans and subsequent SLN biopsies are not contraindicated in the presence of a prior WLE.