Sentinel lymph node analysis in squamous carcinoma of the oral cavity and oropharynx

The aim of our study was to evaluate the usefulness and applicability of sentinel lymph node (SLN) identification in N0 carcinomas of the oral cavity and oropharynx.

We carried out a prospective evaluation of SLN identification in 20 patients with oral cavity or oropharynx carcinomas with no clinical evidence of lymph node metastases.

Peritumoral infiltration with technetium-99-labeled nanocolloid followed by lymphoscintigraphy was carried out approximately 18 hours prior to surgery. A vital dye was injected intraoperatively and the SLN was identified with the aid of a gamma probe. All patients underwent routine neck dissection.

While multiple radioactive nodes were generally identified on lymphoscintigraphy, the number of nodes ranging from one to five with variable degrees of uptake, intraoperative gamma probe scanning allowed the identification of a single more radioactive lymph node in 19 of the 20 patients. In only one patient did this method lead to the identification of two equally highly radioactive SLNs, with no uptake in the remaining nodes. All SLNs were ipsilateral to the neoplastic lesion. In 15 cases the SLN was tumor negative and so were the remaining nodes obtained by comprehensive neck dissection. In five cases the SLN was the only lymph node containing micrometastasis among those obtained by dissection. There were no instances of node positivity not involving the SLN.

Sentinel lymph node identification in ENT surgery may indicate intraoperatively if node metastasis are present, thereby avoiding overtreatment in a substantial proportion of patients with N0 carcinomas of the oral cavity or oropharynx.