Lymphatic mapping and sentinel lymphadenectomy for 106 head and neck lesions: contrasts between oral cavity and cutaneous malignancy.

OBJECTIVES: The objectives of this prospective series were to present our results in 106 sequential cases of lymphatic mapping and sentinel lymph node biopsy (SLNB) in the head and neck region and contrast the experience in oral cancer with that for cutaneous lesions. HYPOTHESES: SLNB has an acceptably low complication rate in the head and neck. Lymphatic mapping and gamma probe-guided lymphadenectomy can improve the management of malignancies of the head and neck by more accurate identification of the nodal basins at risk and more accurate staging of the lymphatics. For appropriately selected patients, radionuclide lymphatic mapping may safely allow for minimally invasive sentinel lymphadenectomy without formal completion selective lymphadenectomy.
METHODS: One hundred six patients underwent intralesional radionuclide injection and radiologic lymphoscintigraphy (LS) on Institutional Review Board-approved protocols and 103 of these underwent successful SLNB. These included 35 patients with malignant melanoma, 10 cutaneous squamous cell carcinomas, four lip cancers, eight Merkel cell carcinomas, two rare cutaneous lesions, and 43 oral cancers. Mean follow up was 24 months. Patients with oral cavity malignancy underwent concurrent selective neck dissection after narrow-exposure sentinel lymph node excision. In this group, the SLNB histopathology could be correlated with the completion neck specimen histopathology. Patients with cutaneous malignancy underwent SLNB alone and only received regional lymphadenectomy based on positive histology or clinical indications. Data were tabulated for anatomic drainage patterns, complications, histopathology, and patterns of cancer recurrence.
RESULTS: Surgical complications were rare. No temporary or permanent dysfunction of facial or spinal accessory nerves occurred with sentinel node biopsy. Lymphatic drainage to areas dramatically outside of the expected lymphatic basins occurred in 13.6%. Predictive value of a negative sentinel node was 98.2% for cutaneous malignancies (based on regional recurrence) and 92% with oral cancer (based on pathologic correlation). Gross tumor replacement of lymph nodes and redirection of lymphatic flow represented a significant technical issue in oral squamous cell carcinoma. Sixteen percent of patients with oral cancer were upstaged from N0 to N1 after extended sectioning and immunohistochemistry of the sentinel node.
CONCLUSIONS: LS and SLNB can be performed with technical success in the head and neck region. Complications are minimal. More accurate staging and mapping of lymphatic drainage may improve the quality of standard lymphadenectomy. The potential for minimally invasive surgery based on this technology exists, but there is a small risk of missing positive disease. Whether the failure rate is greater than that of standard lymphadenectomy without gamma probe guidance is not known. New studies need to focus on refinements of technique and validation of accuracy as well as biologic correlates for the prediction of metastases.