Intraoperative lymphatic mapping for early-stage melanoma of the head and neck

Abstract

We previously reported dye-directed intraoperative lymphatic mapping and selective sentinel lymphadenectomy for primary cutaneous melanomas draining to the neck lymph nodes. In this study we determined whether combining the dye with a radiopharmaceutical agent would enhance our rate of sentinel node detection. One hundred seventeen patients with primary cutaneous melanomas of the upper chest and head and neck underwent preoperative cutaneous lymphoscintigraphy to confirm lymphatic drainage to neck nodes, followed by intraoperative lymphatic mapping and sentinel lymphadenectomy. In 94 cases, isosulfan blue dye was injected at the primary site; in the remaining 23 cases, a 1:3 mixture of radiopharmaceutical and dye was injected, and a hand-held probe was used to determine the radioactive counts. Preoperative cutaneous lymphoscintigraphy identified 129 drainage basins; 12 patients (10%) had dual-basin drainage. During intraoperative lymphatic mapping and sentinel lymphadenectomy, 183 sentinel nodes were identified and excised from 120 basins (1.5 nodes/basin). The blue dye alone identified sentinel nodes in 93 of 101 basins (92%). The probe identified sentinel nodes in 28 of 28 basins, only one of which failed to reveal blue-staining sentinel nodes; thus, the probe plus dye identified sentinel nodes in 27 of 28 basins (96%). Histopathologic analysis revealed metastasis in sentinel nodes from 11 patients (12%) who underwent sentinel lymphadenectomy with blue dye alone and in 3 patients (13%) who underwent sentinel lymphadenectomy with dye plus probe. There were no same-basin recurrences over a mean follow-up of 46 months (range 1 to 125). Selective sentinel lymphadenectomy is a highly accurate method of staging the regional nodes in patients with primary tumors of the head and neck. Although we initially demonstrated the utility of this technique with blue dye alone, our results now suggest that the combination of dye and radiopharmaceutical may be a more sensitive method to detect sentinel nodes.