PSA ups and downs

Hi everyone. My dad was diagnosed in fall 2014, initially with Gleason 9 and a PSA of 66. He had surgery which I worried was the wrong choice. It was his choice, though. After surgery they downgraded him to a Gleason 7. He had radiation basically as soon as he healed from the surgery. The surgery was November 2014, radiation April-May 2015.

His PSA went down from .9 (I believe) after surgery, to .5 soon after radiation, then .4 last October. It was bad up to .5 in January. I was so upset. His dr. said they would do one more test in April and if it continued to go up, they would discuss hormone therapy. I was pretty hopeless for his long term survival.

He just got his PSA tested again on Friday, in anticipation of meeting with his dr. this coming Wednesday. He's able to see his results online before his appointments, and his latest result became available today.

Less than .1. What?!?!?!?! Is this too good to be true? I'm scared to get excited. I know that PSA can go up a little and then down after radiation. But can it happen nearly a year after radiation? Can it really go down from .5 to less than .1 in three months, after going up to .5 from .4 in the previous three month period?

He has been eating better and taking pomegranate pills. I'm worried this affect his PSA but not the actual underlying cancer. I'm not sure go that actually works.

He and my mom are going to ask for another test very soon, to make sure it wasn't some kind of error. I'm guessing the dr would recommend that anyway. But I guess I'm just wondering if anyone has similar stories or knows whether this is actually something I should be happy about.

Thank you, InTheShop!!!

I wanted to add this info. He had positive margins after his surgery, meaning there was some tissue left. He did not have any cancer in his lymph nodes, though. The fact that he had a detectable PSA after his surgery is bad though, I know. I guess I just wish I knew exactly where the PSA is coming from. When it went up to .5 I was worried it was all over his body and rising that way. But it seems like if it went down so much, a lot of the cancer must have still been contained in the area that was radiated. Does that make sense? I know it's probably useless to try and figure this out in this much detail but I can't help but cling to the hope that they somehow got it all, even though I know that's very unlikely.