High resolution diffusion weighted imaging for neoadjuvant chemotherapy assessment of nasopharyngeal carcinoma

Background To evaluate the feasibility of high resolution diffusion weighted imaging (DWI) for the prediction about the response of neoadjuvant chemotherapy (NAC) in patients. Methods 119 NPC patients who underwent magnetic resonance imaging (MRI) including readout-segmented diffusion weighted imaging (RESOLVE-DWI) before treatment enrolled in this study from September 2017 to December 2019, and all patients underwent follow-up MRI at 3 month after two cycles of NAC. Patients were classified into stable disease (SD), partial response (PR) or completed response (CR) based on Response Evaluation Criteria in Solid Tumors (RECIST). Apparent diffusion coefficient (ADC) values were measured from RESOLVE-DWI in the first MRI examination. The ADC values were compared between responders (CR and PR) and non-responders (SD) using Independent samples t-test, and the receiver operating characteristic curve (ROC) was calculated to assess the diagnostic efficacy. Results The ADC value of responders was significantly higher than that of non-responders (719.73 ± 100.44 × 10− 3 mm2/s and 583.28 ± 53.15 × 10− 3 mm2/s, p < 0.001, respectively). The area under the curve (AUC) was 0.879 with a sensitivity at 82.8%, and specificity at 84.6%. Conclusions The ADC value obtained by RESOLVE-DWI, with a high diagnostic accuracy for NAC assessment, could be used as a pretreatment imaging biomarker to predict the early response to NAC in NPC patients.