Squamous cell carcinoma (SCC) is the most common malignancy of the oral cavity, with the tongue most commonly affected. Depth of invasion (DOI) is a predictor of cervical metastasis, recurrence, and disease-specific survival, and is a clinical criterion for performance of elective neck dissection in early oral SCC. Post-contrast three-dimensional fast field echo (3D-FFE) imaging and Dixon T2-weighted imaging may be useful to predict pathological DOI and can contribute to successful treatment and improved prognosis. The purpose of this study was to compare post-contrast 3D-FFE imaging with Dixon T2-weighted imaging for assessing radiological DOI, in relation to pathological DOI, in oral tongue SCC.
Twenty-two patients with tongue SCC were included in this study. The Wilcoxon signed-rank test was used to compare radiological DOI with pathological DOI, using both post-contrast 3D-FFE and Dixon T2-weighted imaging.
The correlation coefficients between radiological and pathological DOIs were 0.79 (p < 0.01) using post-contrast 3D-FFE imaging and 0.72 (p < 0.01) using Dixon T2-weighted imaging. The correlation coefficient between radiological DOIs using post-contrast 3D-FFE imaging and Dixon T2-weighted imaging was 0.88 (p < 0.01). The mean difference of measured values between the radiological and pathological DOIs was 3.3 mm for post-contrast 3D-FFE imaging and 5.6 mm for Dixon T2-weighted imaging.
These data suggest that both post-contrast 3D-FFE imaging and Dixon T2-weighted imaging may be useful to provide DOI estimations in oral tongue SCC; however, post-contrast 3D-FFE imaging may be superior to Dixon T2-weighted imaging in these cases.
Key words: depth of invasion (DOI), magnetic resonance imaging (MRI), oral tongue SCC