[Use of diffusion-weighted MRI in monitoring response of lymph node metastatic bladder cancer treated with chemotherary].

Diffusion-weighted MRI (DW-MRI) is a functional imaging to assess molecular diffusion. We report a case in which treatment response to lymph node metastatic bladder cancer was monitored by DW-MRI. A 67-year-old man had paraaortic lymph node metastasis from bladder cancer; the paraaortic lymph node showed high signal intensity on DW-MRI. After four course treatment of gemcitabine and cisplatin, the lesion showed reduction of signal intensity on DW-MRI and increase of the apparent diffusion coefficient value. These signal changes were consistent with the change of morphological images (CT, MRI (T1-W, T2-W)), 18F-FDG PET and tumor markers. This case suggests that DW-MRI is useful in monitoring treatment response of metastatic bladder cancer.