Dynamic Susceptibility Contrast Perfusion-Weighted Magnetic Resonance Imaging and Diffusion-Weighted Magnetic Resonance Imaging in Differentiating Recurrent Head and Neck Cancer From Postradiation Changes.

Purpose The aim of this study was to assess dynamic susceptibility contrast (DSC) perfusion-weighted magnetic resonance (MR) imaging and diffusion-weighted MR imaging in differentiating recurrent head and neck cancer from postradiation changes. Methods A prospective study was done on 41 patients with head and neck cancer after radiotherapy who underwent diffusion-weighted MR imaging, DSC perfusion-weighted MR imaging, and routine postcontrast MR imaging. The apparent diffusion coefficient (ADC) map and time signal intensity curve of the lesion were created. The ADC value, DSC percentage (DSC%), and contrast enhancement percentage of the lesion were calculated. The final diagnosis was done with biopsy. Results There was significant difference (P = 0.001) in ADC between recurrent cancer (0.94 0.16 x 10(-3)mm(2)/s) and postradiation changes (1.37 +/- 0.12 x 10(-3)mm(2)/s). There was significant difference (P = 0.001) in DSC% of recurrent cancer (30.9% +/- 5.16%) and postradiation changes (12.1% +/- 3.06%). Selection of ADC equal to or less than 1.07 x 10(-3)mm(2)/s and DSC% greater than 16.6% to predict recurrence have areas under the curve of 0.822 and 0.900 and accuracy of 92.7% and 95.1%, respectively. Combination of ADC and DSC% has are under the curve of 0.992 and accuracy of 97.6%. Conclusions Combined ADC and DSC% are noninvasive imaging parameters that can play a role in the differentiation of recurrent head and neck cancer from postradiation changes.