I would lean heavily in the direction of surgery unless your facility does not offer a robotic surgical approach. If your biopsy shows it’s not metastasized then surgery should work. I know that many improvements have been made and complications are less likely that 10-15 years ago.
I had 40 radiation treatments that caused all kinds of issues with digestion and colon inflammation. Treatments for the damage caused by radiation were more involved than the prostate radiation. I am still not always able to work around the house or take trips without worrying about episodes.
My brother had a Davinci surgical procedure with no nerve issues and no incontinence after recovery.
Make sure you stress surgery as your primary method.
I am sorry for your condition but know that many people are still kicking after the diagnosis you have. Good luck and God Bless.