Early Assessment of Induction Chemotherapy Response of Nasopharyngeal Carcinoma by Pretreatment Diffusion-Weighted Magnetic Resonance Imaging

Objectives This study aimed to evaluate the feasibility of pretreatment diffusion-weighted imaging in predicting response after induction chemotherapy (IC) in nasopharyngeal carcinoma (NPC). Methods Fifty-four patients with stage III and IV NPC underwent MRI examination at baseline, after 2 cycles of chemotherapy, and at the end of chemoradiotherapy. Apparent diffusion coefficient (ADC) values were compared between effective and ineffective subjects after IC. Results Mean ADC in effective groups was significantly (P < 0.05) higher than that in the ineffective group. Average and minimum ADCs demonstrated higher sensitivity than maximum ADC for predicting IC response, with 68.4%, 71.1%, and 50.0%, respectively, at an equivalent 68.7% specificity. We observed negative correlations between pretreatment ADC and tumor regression after chemotherapy (γ = − 0.425, P = 0.001) and after chemoradiotherapy (γ = − 0.418, P = 0.003). Conclusions Pretreatment ADC was a valuable biomarker for predicting IC response of NPC. Noninvasive diffusion-weighted imaging provides additional indicator in guiding optical therapeutic options for patients with NPC.