Accuracy of preoperative ultrasonography in measuring tumor thickness and predicting the incidence of cervical lymph node metastasis in oral cancer

Abstract

Context: A major determinant of the prognosis of oral cancer is the risk of cervical lymph node metastasis. Several factors have been assessed preoperatively to predict the risk of lymph node metastasis; among them, tumor thickness is proved to be a significant predictor of lymph node metastasis. Ultrasonography (US) is a noninvasive, rapid, easily repeatable, and economical examination to measure tumor thickness. This study is undertaken for evaluating the usefulness of US to predict neck metastasis. Aim: To measure tumor thickness in oral cancer with preoperative US and to predict occult cervical lymph node metastasis. Materials and Methods: In all, 43 patients with biopsy-proven squamous cell carcinoma of tongue/buccal mucosa underwent preoperative US to measure tumor thickness. Statistical Analysis: Tumor thickness from histolopathology and US was analyzed using Pearson's product moment correlation. Fisher's exact test was used to assess the relationship between tumor thickness and the risk of cervical lymph node metastasis. Results: There was a significant correlation between preoperative US and histological measures of tumor thickness (correlation coefficient 0.961, P 0.05. Conclusion: Preoperative US is an accurate measure of maximal tumor thickness. Tumor thickness ≥5 mm can be considered as a risk factor for cervical lymph nodal metastasis.