I'm sorry about
the disappointing PSA results. I hope you are under the care of a medical oncologist with whom you can explore options.
High risk men who are getting salvage radiation usually have hormone therapy starting several months before and finishing up to a couple of years after the radiation because that improves outcomes. Did you have that?
One option worth contemplating is letting your PSA rise to at least 2 and then getting a C-11 PET scan to try to locate any mets. If there are between 1 and 5 mets, they can be treated with SBRT.
A recent study showed no survival advantage for deferring hormone therapy for 2 or more years after relapse following treatment when there are no other signs of progression. It's something you can discuss with your oncologist.Immediate versus deferred initiation of androgen deprivation therapy in prostate cancer patients with PSA-only relapse.