Your PSA may be high enough to be detectable on some of the newer PET scans. You can get the FDA-approved Axumin (fluciclovine/FACBC) PET scan at UF Jacksonville (contact details in link below). It should be covered by Medicare, but check first. If no distant mets are discovered, you may still be a good candidate for salvage radiation. /clinicaltrials.gov/ct2/show/NCT02680041
You should definitely see a radiation oncologist on your own to discuss this. Your urologist (who should have referred you when your PSA was 0.1) has no way of knowing if your spread is distant or if it is still localized and curable.