Preoperative evaluation of oral tongue squamous cell carcinoma with intraoral ultrasound and magnetic resonance imaging-comparison with histopathological tumour thickness and accuracy in guiding patient management.

The aim of this study was to investigate the correlation between tumour thickness (TT) on intraoral ultrasound (US) and magnetic resonance imaging (MRI) with the histologically determined TT of tongue cancers. Secondary objectives included evaluation of potential confounders that affect this association and the predictive value for simultaneous neck dissection. Eighty-eight consecutive patients referred to the study institution between January 2007 and August 2012 with the presumptive diagnosis of invasive squamous cell carcinoma (SCC) of the tongue were analyzed. Seventy-nine patients had preoperative US and 81 had MRI. Correlation between image-determined TT and histological TT was assessed by Bland-Altman plot and Pearson's correlation coefficient. Potential confounders were assessed by subgroup analysis. Preoperative TT as determined by US demonstrated high correlation and MRI moderate correlation with histological TT. With subgroup analysis, negative associations were biopsy prior to imaging and resection diagnosis other than invasive SCC. Our experience suggests that US could be considered the initial modality of choice for preoperative assessment of TT.