What age were you hoping to die? I think you should be aiming for 85. So will PCa kill you in the next thirteen years? I would guess if left untreated it would.
RT is not too troublesome, so I would go for that, even if it doesn't cure you, your cancer is pretty slow and RT will probably buy you a decade before you need to even think about anything else.
If you don't have RT you might get a few more years before HT is needed, and it may work for several years, so either way I reckon you would get to about 85 but perhaps a decade of HT wouldn't be a great way to enjoy the last few years of your life.