Value of dynamic contrast enhanced magnetic resonance imaging in the differentiation between post-treatment changes and recurrent salivary gland tumors

Purpose: The purpose of this study was to investigate the diagnostic value of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in the differentiation between post-treatment changes and recurrent salivary gland tumors. Patients and methods: A prospectively designed study was conducted on 37 patients having salivary gland malignant tumors treated by surgery or chemo/radiotherapy or both. All patients underwent conventional MRI and DCE-MRI. The obtained DCE-MRI data were interpreted semi quantitatively (using time intensity curves, TIC and time to peak TTP) and quantitatively (using wash in and washout rates). The obtained TICs were classified into four types (A, B, C, and D). Results: There was a significant statistical difference as regards TICs, wash in and washout rates of recurrent salivary gland tumors and that of post treatment changes, whereas there was no significant difference as regards TTP. Receiver Operating Characteristic (ROC) analysis revealed cutoff points of >10.25, and >6.25 for the wash in and washout rates used to differentiate recurrent tumors from post-treatment changes, respectively. Conclusion: We concluded that DCE MRI has a valuable diagnostic value in the differentiation of recurrent malignant salivary gland tumors from post-treatment changes, especially, for cases that remain unsolved by conventional MR imaging techniques.