What questions would you wish you had asked at your radiation consult?

My 75yo dad was diagnosed with a huge glioblastoma in the left parietal region, and had a "near-perfect" resection back in November '25. His only symptoms at the time of being admitted were confusion and speaking gibberish a couple of times. His cells were methylated, so instead of radiation, he did two rounds of TMZ. At his MRI follow up appointment this week, his scans show that the tumor is just about back to the size it was before surgery. We were expecting the opposite, since so many of his post-op symptoms have been improving significantly.

His chemo oncologist is getting us in with a phenomenal radiation doctor ASAP. The other options she gave were to try Avastin to manage the tumor's size, or ultimately choose quality over quantity and do nothing, which would likely be about 2 months considering how fast the tumor is growing back.

I'm taking my dad to his consult on Monday, and as I'm putting together a list of questions, I feel so incapable of covering everything. If you guys have suggestions for what I should include in my questioning, I would appreciate the input.