I went with surgery. I also had Gleeson 7 (4+3) and I'm 60 years old.
I looked at surgery vs radiation & among other things, it seems that surgery can cause bladder incontinence but radiation could cause bladder AND bowel incontinence.
Bowel incontinence was a hard No for me.

Also, I've read that if you go for radiation & they don't get all of the cancerous cells, surgery later becomes salvage surgery.
My understanding is that the radiation may cause parts of the prostate to turn to mush & the later surgery will then involve scraping the mush from the prostate cavity.
That's probably as accurate & successful as it sounds.

I also wasn't keen on multiple days off work for numerous radiation sessions.

That's my uneducated understanding, anyway.
What do I know... I'm just sitting here peeing myself.

Good luck.
You've come to the right place for guys who understand what you're going through.