timber, there is a newer contrast agent pylarify https://www.pylarify.com/
It might be that you want to listen to the urologist and basically not treat the cancer. And that may be what your dad prefers (at this point). Quality of life is very important. And these decisions are quite personal.
With hormone treatment, it is considered that treatment has begun and it gives you time to get other opinions, which I think you need.
I can't think that it is of any advantage to wait to radiate the bones until the bones crumble before having radiation.
Your dad could have hormone resistant cancer. So, he could suffer all the effects of ADT (not our best quality of life control) without any advantage.
This diagnosis is usually unnerving. Your dad's initial response may turn into something more receptive. And , of course, it is his choice. If he saw the spectrum, he might not choose to treat with hormone alone.
You might gather his records and send them for a second opinion and ask for a referral to a radiation oncologist and a surgical oncologist.
When cancer invades the bones you end up with fractures. They are painful and will obviate any thoughts of "quality of life." The quality concept should include treatment because untreated cancer is not a good, or fast way to die.
Bless your struggle.

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