Contrast enhanced MRI and Diffusion Weighted Imaging for evaluation of depth of invasion of tongue carcinoma: radiological–pathological correlation

Abstract Background Tongue cancer is regarded as a major concern due to abundant vascular and lymphatic supply of the tongue that promote nodal metastases. The depth of invasion of the primary tumor has been demonstrated to be a prognostic factor for high-risk tumors, with the potential to inform treatment decisions and predict a favorable outcome and disease prognosis. Our study aimed to review and emphasize the accuracy of MRI in loco-regional staging of tongue carcinoma as regards depth of invasion (DOI), which is an important predictor of lymph node (LN) dissemination. Results A total of 30 patients with tongue squamous cell carcinoma were enrolled in this prospective study. Biopsy and conventional MRI in combination with diffusion weighted imaging and contrast enhanced MRI were performed as pre-operative local and nodal disease staging. The extent of the primary tumor (T) and metastasis to regional lymph nodes (N) were initially evaluated by MR imaging. Almost perfect agreement (k = 0.83) was noted for T staging between MRI and histopathological staging assessments. Also, almost perfect agreement was revealed for N stage between MRI and histopathological assessments (k = 0.89). The relation between DWI MRI and histopathology measured values for the mucosal epithelium depth of invasion of tongue squamous cell carcinoma was r = 0.818 ( P < 0.001). The cutoff values for the DWI MRI-measured DOI and pathological DOI that indicated nodal metastasis were 7.5 mm and 8.7 mm, respectively. Conclusion MRI with DWI and CE-MRI is the imaging modality of choice for evaluation of tongue cancer as a strong positive correlation between MRI and histopathology measured values for the mucosal epithelium depth of invasion of tongue squamous cell carcinoma. It accurately estimates cervical nodal metastasis before surgery.