Sounds like a good drop in PSA to me. I'm on chemo, click on my name, ColU_FC, and you will see how my PSA has dropped during chemo. My Onco is happy with the results and if she's happy, I'm happy. Regarding a target for how far the PSA should drop, there isn't one, everybody is different and react differently to the various treatments. The PSA is down, that's what matters, rejoice.