54 here, sorry to welcome you to this unfortunate club but at least you are among friends!

From my understanding after talking to multiple docs in multiple disciplines, our age often prompts removal before radiation because radiation is a back-up plan. If you do radiation first then any surgery after is salvage surgery where they scrape out the gel like substance that used to be your prostate before radiation. So you can, but the way every doctor put it to me: "there are long term effects of radiation that won't necessarily manifest in a 65+ year old man but at your age you will likely see them which is why it's recommended you remove it first and go with additional treatments later if needed as a backup to the primary treatment".

I make no recommendations, only the information given to me that I took to heart. For me, I'm opting for removal because then they can fully grade the cancer and know precisely what we are dealing with and it gives me several more treatment options based on that data.