Guys are just trying to be responsive, so please be nice(r). We are all in, or have had, treatment (tx) and I know that I misread or misinterpret posts from time to time. And it is the writer's responsibility to communicate clearly.
When tx fails; we look for additional tx.
I had RP, immediate detectable BCR @ PSA of .19; completed salvage radiation and ADT last June and actually am anxiously waiting for 1st post BCR tx uPSA results from blood test yesterday.
If, or when, I have detectable PSA, that would be a 2d BCR and I would seek additional tx.
There is a video from Jan 2023 on PCI.org that addresses rising PSA after RP or radiation, and you might find that helpful.
God luck.