Sentinel node biopsy in head and neck squamous cell carcinoma.

PURPOSE OF REVIEW: Sentinel node biopsy (SNB) is emerging as a potential tool to evaluate neck node metastasis in head and neck cancer. The purpose of this article is to undertake a systemic review of published literature and to outline future directions for further studies. RECENT
FINDINGS: Existing data suggest that the status of the sentinel lymph node (SLN) predicts the pathologic stage of the nodal basin. It has been demonstrated that radiolabeled lymphoscintigraphy is superior to blue dye to localize the SLN in head and neck cancer. SLN biopsy should be recommended only in patients with previously untreated early stage (T1/2) oral cavity and orophparynx cancer with clinical N0 stage. The procedure is technique sensitive. The isolated SLN should be subjected to serial step sectioning at 150 microm and staining by hematoxylin and eosin and immunohistochemistry. Intraoperative frozen section and imprint cytology are not sensitive to identify small foci of micrometastasis and isolated tumor cells within the SLN. The clinical relevance of micrometastasis and isolated tumor cells needs to be established. It is necessary to develop a better method for intraoperative pathological confirmation of SLN metastasis. There exists no randomized clinical trial with adequate power that compares SNB and elective neck dissection in head and neck cancer.
SUMMARY: SNB in head and neck squamous cell carcinoma should be considered as an investigational tool pending validation by larger randomized clinical trials; therefore, it should not be recommended at present outside a clinical trial setting.