@vircet You can find many PCRI videos (w/Dr. Scholz, MD) on YouTube talking about this topic - what to expect with PSA following each type of radiation treatments - EBRT (SBRT, IMRT, Proton) and internal radiation (brachytherapy: HDR/LDR), and what PSA bounce is all about.
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At each of your PSA tests, it’s important to know what your testosterone levels were.
> At 3 months post-SBRT (PSA of 0.36); were you still on Orgovyx?
> At 6 months post-SBRT (PSA of 0.22) & 2 weeks off Orgovyx, how high had your testosterone levels risen?
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Typically, ADT hormone therapy will push your PSA to nearly undetectable while it’s in your system and then PSA will begin to increase as the ADT wears off. (My PSA remained at 0.008 ng/mL the entire time the ADT (Eligard) was in my system. Once the Eligard wore off, we measured my PSA at 0.198 ng/mL (as you can see in my attached PSA tracking chart). That became my nadir.)

At just 3-1/2 months off Orgovyx (PSA at 0.98), that’s too soon to for a PSA “bounce.” With Orgovyx out of your system, PSA following SBRT should remain very low (“nadir”), but begin to stabilize near your “new normal” PSA levels.

(If it were me, at that next consultation I’d request another PSA (& testosterone) test just to see if PSA is still trending up (or going down). If it’s still trending up, I’d request a PSMA PET scan to get a better view of what might be going on.)

You mentioned, “When I last saw my RO, she said that a rise in PSA will be normal if it correlates (can be explained by) a corresponding rise in my T level.” Yes, that’s true - a slight rise in PSA is normal with a rise in T level. But, that rise should optimally be capped at about 0.2 ng/mL and will be your “nadir.” Then, over time, your PSA may eventuality rise a little more and settle into a range that will be your new normal. (My “new normal” PSA is between 0.35-0.55; if it begins trending well above that range, we’ve already agreed that we’ll start looking into it.)