My husband was the same age as you when he was diagnosed last year. PSA 8, Gleason 4+3, T3a N1 M1b. He was offered chemo or enzalutimide. he was reluctant to have chemo but as Peter says it doesn’t always seem to be as debilitating as some chemos for other cancers.
We got a second opinion though and after a PSMA pet scan he was downgraded from advanced to locally advanced (no bone met) still in one lymph node. He ended up having surgery and they removed his prostate and 14 lymph nodes. Post op histology changed things to Gleason 4+5, T2 N1. Not sure if the downgrade on tumour was related to him having 4 months of HT?
His 3 post op PSA tests have been <0.025, he has another one this week so a constant waiting game to see if he will need SRT.
I would definitely assume that your RT will target lymph nodes so as Andy has said you would think this will be a curative treatment.
Good luck with your decision and wishing you all the best