I had a talk with my oncologist (also in Ontario) about this yesterday at our quarterly appointment. He was a resident at Harvard Medical School before returning to Canada, so he's quite familiar with PSMA PET, even though it became available in Canada only in 2022 when the makers of the radioactive agent finally bothered to get it approved here.

He knows he can talk frankly with me — which I appreciate — and he said the biggest challenge with PSMA PET is that the field doesn't know yet exactly what to do with the results. By that, he doesn't mean that they're ignorant of the latest treatment options, but (I think) that the body of research isn't there yet to establish whether they're over-/under-treating based on the more-sensitive results that PSMA PET provides over CT, MRI, and/or bone scan.

That makes sense to me. It's the same problem they faced a few decades ago when PSA screening first became available, and they were way overtreating people based on small PSA rises "just to be safe," because they didn't have other risk-assessment tools and best-practices established yet.

PSMA PET scans are available at my Cancer Centre, but his advice is to wait until my PSA starts rising above 0 before getting one, because then the treatment options will be clearer if the scan shows some potential tiny positive results. As long as my PSA is 0 on the ultrasensitive test, nothing's growing, so leave well enough alone. YMMV.