I think this is your second post regarding your treatment; so you’ve ruled out surgery - a big first step.
Now you and your RO can decide on what type of radiation: IMRT - multiple sessions of (20-39) low dose therapy.
SBRT - 5 sessions of high dose therapy
HDR - a boost of very high dose (via seeds, etc) followed by either IMRT or SBRT.
All of these have the same goal but some - and only in some men - have more SE’s than others; usually the higher dose. There is a test (whose name escapes me) to see how you might tolerate higher dose radiation so ask your RO.
ADT is going to give you an extra margin for success, no two ways about it. But how much that is varies from 3-10%, depending on what you read or whom you ask. At age 80, perhaps the actuarial tables would say not to bother since you are already living longer than the average adult male in the US.
But that is an average - not an indicator of YOUR current health status. You’ve indicated that you are in excellent health with no co-morbidities so you have a very good chance of living 10 more years and beyond. So ADT could prevent recurrence in your lifetime.
That said, you could drop dead tomorrow from a heart attack in excellent health…people do die.
So the decision to ‘ADT or not to ADT’ is really a coin toss and how comfortable you are with that decision.
And just to confuse matters more, side effects from ADT vary from person to person SO MUCH, that you cannot predict how you will react. But if you take Orgovyx - an oral form of ADT - you’ll know within 6 weeks or so how much you are affected by it; so you CAN stop it and recover very quickly.
Lupron (and others) is an injection and its effects ‘spike’ soon after and are usually much more pronounced. But it’s now in your system and will take months to wear off. You really don’t want that. Best,
Phil