Diffusion-weighted MRI versus 18F-FDG PET/CT: performance as predictors of tumor treatment response and patient survival in patients with non-small cell lung cancer receiving chemoradiotherapy.

OBJECTIVE. The purpose of this study was to compare the predictive capabilities of diffusion-weighted MRI (DWI) and 18F-FDG PET/CT for tumor response to therapy and survival in patients with non–small cell lung cancer (NSCLC) receiving chemoradiotherapy. SUBJECTS AND METHODS. The study included 64 patients with NSCLC diagnosed as stage III who underwent pretherapeutic DWI and FDG PET/CT and were treated with chemoradiotherapy. For quantitative prediction, apparent diffusion coefficient (ADC) for DWI and maximum standardized uptake value (SUVmax) for PET/CT were measured at all targeted lesions and averaged to obtain final values for each patient. To evaluate the predictive capability of either index for distinguishing partial response and nonresponse (stable or progressive disease) groups, receiver operating characteristic analysis was performed, and sensitivity, specificity, and accuracy of the two modalities were compared using the McNemar test. Finally, overall and progression-free survival curves divi...