Assessment of Lymphatic Drainage Patterns and Implications for the Extent of Neck Dissection in Head and Neck Melanoma Patients

Background And Objectives: The aim of this study is to evaluate lymphatic drainage with sentinel node location data in patients with head and neck cutaneous melanoma, and to determine the implications for the extent of therapeutic neck dissections.

Methods: Sixty-five patients with head and neck cutaneous melanoma without evidence of regional metastases at ultrasound guided fine needle aspiration cytology examination were included. Lymphatic drainage patterns were investigated using planar and dynamic lymphoscintigraphy, and SPECT/CT. Biopsy of sentinel nodes was guided by images and gamma probe. The incidence of discordant sentinel nodes was determined by comparing actual drainage patterns to "O'Briens map" and to the treatment guidelines of The Netherlands Cancer Institute.

Results: Sentinel node identification was successful in 98% of the patients. Fifteen patients (23%) were diagnosed with a tumor-positive sentinel node. Two sentinel node-negative patients (3%) developed a regional lymph node metastasis (false-negative ratio: 12%). Twenty-three percent of the harvested sentinel nodes were discordant according to "O'Brien's map," while 14% were discordant according to the treatment guidelines of The Netherlands Cancer Institute (P < 0.001).

Conclusions: Almost a quarter of head and neck melanomas metastasize outside clinically predicted neck levels. Neck surgery guidelines of The Netherlands Cancer Institute provide for a smaller number of discordant sentinel nodes.