Preoperative ultrasonography for evaluation of clinically N0 neck in oral cavity carcinoma

The aim of this study was to evaluate preoperative ultrasound criteria to detect lymph node (LN) cervical metastasis in patients with clinically node-negative neck (cN0) oral cavity squamous cell carcinoma (OCSCC). A prospective, single-center, observational study was conducted in 90 patients undergoing cancer excision with or without elective neck dissection (END) between 2005 and 2012. A surgeon and an experienced radiologist performed preoperative cervical ultrasonography in all cases. The primary objective was to obtain an a priori sensitivity of 90% and specificity >50% in cN0 OCSCC staging. The sonographic criteria for LN assessment were as follows: number; neck levels; clusters; aspect; heterogeneity; longitudinal diameter (L); transverse diameter (T); L/T ratio; and combination in series or in parallel of T and L/T ratio. The gold standard for comparison was the LN histological identification of metastasis after END or the occurrence in the follow-up at least 36 months. Statistically significant sonographic criteria in univariate analysis (P < 0.05) were as follows: multilevel lymph nodes, T diameter >6.5 mm, and the combination T > 6.5 mm or L/T < 1.3 ratio; and in multivariate logistic regression analysis were (P < 0.05): combination T > 6.5 mm and L/T < 1.3 ratio, LN in level II, and moderately-poorly differentiated OCSCC. By using selected sonographic criteria, ultrasound can be a valid preoperative diagnostic method to optimize staging cervical metastasis and to help decide about neck dissection.