You want the PSA value at diagnosis - you might already know this.
Of the TNM staging, you should be able to get the TxNx staging, but not the Mx yet - that comes from a nuclear bone scan which will follow. They might want to do a CT scan for the Nx too if it wasn't clear on the mpMRI scan.
You also want to know the gleason score, and you probably want to know where it is and size in the prostate. You could ask for the prostate size too - there's an enormous variation in that - it's not related to the cancer, but can be useful for interpreting PSA values now and in the future.
I don't think they'll give you treatment options yet, because it will depend on bone scan, but they might be able to tell you some things that are ruled out. You could ask what the options are if the bone scan is clear. For a prostatectomy, I would want to know the chances of it being nerve sparing.
Write your questions in on a piece of paper, with a pen to write the answers down. Do that during or immediately after the call. It can be useful to have your partner or a friend on the call too, to catch anything you miss. My consultant actually takes my question sheet and writes the answers on it, which would be fantastic if I could read his writing. Some consultants may allow you to record the session on a phone, but you mast ask (in that case, they have to record it too and put it in your medical records). My treatment hospital will even do that for you and give you a CD (although maybe not for a phone consultation).
I had decided before I had this appointment that I had cancer, and it did help with keeping my cool because when the consultant told me, it was what I was expecting. This strategy won't necessarily work for everyone.
I wish you all the best.