It appears from your pathology you would be classified as "high risk". (For recurrence of cancer) The good news is your PSA post-surgery has been "undetectable" and stable. There does seem to be an upward trend in your PSA, but you had a PSMA pet scan early enough to find a small lesion. Does your Dr. plan to do a biopsy? It would be helpful to know if the Gleason grade has changed or not. It would also be useful to have the biopsy sample sent for genomic testing. This type of test can determine what type of cancer you have and guide treatment decisions with targeted therapies that might be more effective in treating the cancer.

Either way, with radiation therapy and a short course of hormone therapy (ADT for 6-12 months) there is about an 80% chance that this can result in a cure and at the very least a long remission before cancer could come back.

here is a video that I think might help.