When I had a bone scan and a PSMA pet test I was informed that there was a metastasis on my L4. I was not told anything about a reading. I was just told that I had a metastasis.. If there is a metastasis, then SBRT radiation can frequently eliminate it. That should be your concern more than the reading. Did they find a metastasis?

If you get SBRT then because cancer has reoccurred, you want to go on ADT to try to prevent it from spreading to other parts of your body. You don’t want to let it sit there and not treat it, But just going on ADT is not enough of a solution for a bone metastasis, if you’re looking for long-term survival. ADT will probably stop a Metastasis from growing further, but that’s only for a matter of time, before it starts to grow again.

A doctor might prescribe medication at any point after -1, depending upon other risk factors.
If there is a possibility of cancer metastasis to the bone, bisphosphonates are generally prescribed. And commonly if you are on long term ADT bisphsophonates or Prolia are prescribed.
If you were on short term ADT and have quit the, likelyhood is that you would wait for testosterone to restore bone.