Not necessarily it depends on velocity and doubling time a good of window of time is to not let it exceed .4
Then consider EBRT in conjunction with hormone therapy.

You are correct. PSA .20 or more x 2, after a prostatectomy, is considered a biochemical recurrance. That is exactly what happened to me 8 yrs post op. I had a PSMA PET Scan that lite up 3 areas in my lung (lymph nodes). I had a bronchoscopy/biopsy but all 3 areas were negative. Nothing else lite up, not even the prostate bed. So, don't know why my PSA is climbing or where the recurrence is. Might have to have a repeat PSMA PET Scan as my PSA get's higher. Might be able to pick up something at that point. Have appointment's with my Pulmonologist and Urologist in a week.

My info may be outdated, however my understanding is that the PSMA PET scan has a certain level of sensitivity, and will only be able to detect a certain minimum size of met, because the larger the met, the more PSMA so the stronger the signal.