Well, more clinical data could assist the forum in responding.

Pathology report
PSA results - you lost two but usually after surgery they are every three months for the first two years. That will also provide PSA doubling and velocity.

You say the PSMA PET was negative, statistically, you had a 1/3 chance of it locating any recurrence at that PSA.

Does a negative PSMA indicate no systemic activity, not necessarily, there may be, just too small to be detected.

Question is, what to do? Starting point may be the guidelines, NCCN, AUA, ASCO...those are generally the science though caveat emptor, they are population based and may lag behind data emerging from medical research, clinical trials.

You have choices, from congestive to aggressive.

You could do nothing, there is some data that says it could be up to 8 years for metastases to "appear."

Next step, SRT to the prostate bed only. This is today generally not considered a good choice.

You could do the SRT to the prostate bed, add whole pelvic lymph node and short term ADT, 6-24 months.

You could forgo radiation and do doublet or triplet therapy, an ADT + ARI, adding taxotere. The latter is generally for high, not intermediate risk.

If radiation is a decision, then hypo-fractionated may a possibility.

The good news, you have choices. The contrary to that is you have choices. Is there a "right" decision, likely not. There are good decisions though SRT to the prostate bed only might not be a good decision.

What would I do if I were you and the clinical data you describe? I would do radiation to the prostate bed, pelvic lymph nodes and six months ADT, Orgovyx.

Keep in mind I'm 11+ years into my journey. When I had BCR after surgery, I let my medical team talk me out of including the PLNs and short term, epic failure.

Again, if you have issues with radiation, then consider doublet therapy.

Do some homework, read through the guidelines, look through the literature from various sources, discuss with your medical team.

Kevin