How do you approach imaging in the treatment planning of resected high grade gliomas/glioblastoma?

We typically obtain an MRI on the same day as the planning CT (whether or not the patient had a post-operative MRI). We are biased as we operate a dedicated MRI. If this were not the case, we would probably assess on a case-by-case basis (how long has it been since the last MRI, how visible is tumor...