May as well chime in...
Here's how I understand it: for those of us who have had our prostates removed, the only things that generate detectable PSA in our blood are either prostate cells or prostate CANCER cells. Without a prostate, we shouldn't have prostate cells, so detectable PSA post-op is an indicator that there are cancer cells SOMEWHERE in our systems. Its either - residual disease (they didn't get it all), or a local recurence (which means the cancer is growing back at the surgical site) or the cancer has spread into other parts of our bodies --- which is not a good thing.
My post-op PSA have bounced between .04 and .09 (not in a linear upward trend).... my doc said not to get too worked up unless it started pushing .2. IF that happens, and you suspect local recurrence or residual diseae in the prostate bed, radiation appears to be the next step in mainstream medicine.
We want to keep an eye on this because if the PSA starts to rise, the "second chance" for a cure is best when you do additional therepy BEFORE the PSA rises to 1.
We're "lucky" that we have one of the few cancers with such a strong marker. THis saves us from jumping into unneeded treatments, and also tells us when to really get up on things.
Congrats on the .1 reading--- keep it up --- or I guess I should say DOWN!