My dad just had his second bone scan following completion of 6 rounds of docetaxel. PSA has fallen from 2230 to 0.06. I've attached a comparison of the first (left) and second (right) scans.
He has 2 lesions that persist. The caveat is that these 2 lesions were read as appearing like Paget disease on the first scan (second scan not yet read). I'm no radiologist, but they certainly don't have the classic punched-out appearance of metastatic lesions. Initially, I don't think any of us (esp his oncologist) really thought he had coexisting Paget disease, not with PSA that high.
We are planning on going straight into another form of therapy (probably abiraterone) along with continued ADT. Would it be worthwhile to pursue a bone biopsy to see what those lesions really are? If cancer, could he potentially get radiation there? I was also thinking about a PET scan, but I've read several places that a PET wouldn't be expected to show anything at a PSA as low as his is.