A few questions that might help provide answers:
> did you use a rectal spacer with your initial radiation treatment? (Did they overshoot your prostate?)

> with your initial 3+4, was there any mention of cribriform pattern, perineural invasion, Intraductal carcinoma, extracapsular extension, or seminal vesicle invasion in the MRI of biopsy reports?

> did you have a biomarker (genomic) test? What did that test show?

> did you have a genetic (germline) test? What did that test show?

Your PSA of 0.10 would’ve been your nadir. Certainly, as your PSA passed 1.0 and approached 2.0, they would’ve suspected biochemical recurrence.

> along with your salvage SBRT, did you also do hormone therapy?

Yes, these side-effects could be inflating your PSA. However, the PSMA PET results were definitive - the fact that the PSMA PET scan showed several spots, indicates that it is recurrence.

Have they diagnosed specifically what’s causing the side effects (constipation, difficulties urinating) in order to recommend treatments? (Urinary issues are a common side-effect with brachytherapy, especially if the seeds are near the urethra. Constipation wouid be from the radiation overshooting your prostate and hitting your intestines.)

(If the PSMA PET scan lights up, there is prostate cancer.)

Next steps would depend on the PSMA PET scan results (and the other test results mentioned earlier).