Imaging before radiotherapy: For each patient, active stimulation and resting fMRI examinations will be performed in addition to standard anatomic MRI for brain radiotherapy. Activation maps of regions involved in visual, language and working memory functions will be generated from the fMRI scans and the patient's responses on of the working memory task (i.e., the N-Back task) will be recorded during the fMRI studies. The MRI and fMRI will, combined, take approximately 90 minutes - 60 minutes for the standard MRI and 30 minutes for the fMRI. The activation maps will be overlaid onto the FLAIR MRI images, imported into the radiotherapy treatment planning system and co-registered with the simulation CT scan.