The proposed trial involves the prospective collection of imaging data at standard clinical time points before and during treatment with TTFields. All patients who are offered treatment with TTFields will also be offered enrollment in this non-randomized, observational study. Imaging data will include the standard battery of MRI sequences, which includes DWI and ADC reconstruction. These data will be collected at standard time points and the proposed study will not rely on any additional imaging or tests outside of the clinical standard of care.