How do you evaluate PSA decline after EBRT for low-and intermediate risk prostate cancer not treated with ADT?  

This is not an answer that comes with any hard data, although both NCCN and AUA offer guidelines on PSA monitoring after therapy. First, I check a PSA at treatment completion. This is not so important when ADT is used, as PSA pretty much universally will decline (at least initially) on ADT. However...