Imaging the early response to chemotherapy in advanced lung cancer with diffusion-weighted magnetic resonance imaging compared to fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography. 
To evaluate the feasibility of diffusion-weighted magnetic resonance imaging (DW-MRI) for assessment of the early response to chemotherapy and outcome in patients with advanced lung cancer through comparison with fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT).  Twenty-eight lung cancer patients underwent DW-MRI, FDG-PET, and CT before and after one course of chemotherapy.  Changes in the apparent diffusion coefficient (ΔADC), the mean standardized uptake value (ΔSUV), and the maximum diameter (ΔMD) were measured and compared.  According to the response evaluation criteria, patients were divided into two groups, responders and nonresponders, and progression-free survival (PFS) and overall survival (OS) were estimated.  The relationship between ΔADC and ΔSUV had the highest correlation coefficient.  A cutoff value of ΔADC between responders and nonresponders was estimated as 21.5%.  PFS and OS between responders and nonresponders were significantly different on DW-MRI (PFS, P = 0.012; OS, P = 0.006) and on FDG-PET (PFS, P = 0.017; OS, P = 0.036), but not on CT (PFS, P = 0.105; OS, P = 0.051).  DW-MRI can be used to predict prognosis in patients with advanced lung cancer.