64 and recently diagnosed with prostate cancer, options?

Gleason 9 is pretty advanced, and you have no idea from the biopsy alone, how extensive the cancer pathology really is. The only way to know that is to have the radical prostatectomy to see if you have Extraprostatic Extension ("EPE"), Surgical Margins meaning cancerous tissue was left behind despite the entire prostate being removed; seminal vesicle invasion; Cribriform glands; lymph node involvement, etc. All of that is quite ominous and is completely unknown to you with just a Gleason Score. I would react right away and schedule the surgery. You have the highest chance of having any/all of that pathology by being an advanced Gleason 9. But...you might not. I was a low/moderate Gleason 3+4=7 with just 6-10% of my cells being "4". I was actually very close to being a 3+3=6, BUT...upon removal of my prostate, I had all of the above except lymph node invasion. You could also have a chance of being a Gleason 9 where the cancer has not yet broken through the membranous capsule tissue that surround the prostate. THAT is the key event that takes you to more serious levels of disease. But...without the surgery, there is no way to know. BTW...when I asked about Perineural Invasion (PI), my urologist said, "don't worry about it...everyone with a positive biopsy almost always has PI...that is the least of your worries." So...as a Gleason 9 with the greater probability leaning toward a lot of pathology that is as yet unknown, I would have the RP surgery. Good luck to you.

I would move quickly to get a PET scan and an MRI to find out as much info as you can. I was diagnosed 7 years ago, at age 63 with low grade cancer, then over time, it progressed into mid grade, Gleason 6/7. Had surgery 18 months ago at Mass General in Boston. No issues at all thus far. (I looked at Dana Farber for radiation, but eventually choose surgery, as I was a good candidate based on diagnosis and body profile)
My surgeon and his team have done the robotic procedure for over 30 years, and he was one of the first in NE to do it. If you choose surgery, only go with an MD who has done the procedure thousands of times!