The usefulness of intraoral ultrasonography in the evaluation of oral cancer

Many studies focused on the tumour thickness in oral squamous cell carcinom as, suggesting a relationship with the occurrence of cervical metastasis. A ccurate preoperative assessment of the tumour thickness of oral cancer woul d provide useful information for targeting those patients who need elective treatment of the neck. Some useful diagnostic aids to evaluate oral cancer are computed tomography (CT), magnetic resonance imaging (MRI), and intrao ral ultrasonography. The purpose of the present study is to compare intraor al ultrasonography with CT and MRI in delineating the disease extent and in measuring the tumour thickness of oral carcinoma. Thirty-nine patients wit h oral cancer were preoperatively evaluated with intraoral ultrasonography, and CT, and in 26 of them MRI was carried out. High-quality ultrasonograph ic images were obtained and the tumour thickness was measured within I mm. However, in most tumours less than 5.0 mm in thickness, CT and MRI could no t detect a sufficient density difference from the normal tissue to accurate ly delineate the extent of the tumour. There was a significant correlation between measurements by intraoral ultrasonography and the histological sect ions. The present study shows that ultrasonography is superior to CT and MR I in assessment of the primary lesion of oral carcinoma.