As others have pointed out, one test alone doesn't prove anything, I guess further tests/scans etc may be needed.
I see like me you had radiotherapy some years ago, I guess you were told at the time that you could only ever have one bout of radiotherapy. If it worked it worked, if not then it was hormone therapy for the rest of your life?
That has changed, if you check my profile there are all the details of salvage HDR brachytherapy. 'Fingers crossed' it is working for me, and even if it is not it is buying me a lot of time with my PSA bumping along at currently a mere 0.5
So hopefully you don't have a reoccurrence, but if you do please be aware that science has moved on and new treatments are available.