MRI Prognostic Factors of Tongue Cancer (Tumor Thickness, Para-lingual Distance & DWI/ADC Values): Potential Predictors of Cervical Lymph Nodal Metastases

Abstract

Purpose: This study aimed to evaluate the efficacy of three MR imaging parameters which are tumour thickness, para-lingual distance and ADC values for prediction of cervical lymph nodal metastasis in cancer tongue patients.

Methods: Fifty patients with known cancer tongue by histopathological examination underwent MRI examination. T1 and T2- weighted MRI, Diffusion-weighted images and post-contrast T1 fat suppression sequences were used.

Results: The patients were classified according to LN involvement as seen by MRI into two groups. Significant differences between positive and negative nodal groups were observed regarding tumour thickness and para-lingual distance (p values = 0.008 and 0.003 respectively). ROC curve analyses revealed cut off values >13.8 mm and ≤ 3.3 mm for tumour thickness and para-lingual distance respectively for prediction of positive nodal spread. No significant differences between patients with and without cervical lymph nodal metastasis regarding corresponding ADC values of the tumor (p-value = 0.518).

Conclusion: Para-lingual distance and tumor thickness are significant factors that could influence pre-operative judgment and prognosis of tongue cancer patients. ADC value of the tumour itself did not seem to be a reliable index to the stage of cancer progression or prediction of the status of lymph nodal spread. 

Keywords: Tongue cancer, tumor thickness, para-lingual distance, apparent diffusion coefficient, cervical lymph node metastases.