Hi Scott,
Sorry to hear the news. I recently had IMRT therapy after recurrence following failed RRP. In my case, with positive margins, my doctors advised adjuvant RT, but I held off until my PSA at least rose above undetectable. It went well, even though I elected for whole-pelvic radiation to hit the pelvic lymph nodes as well.
I had hoped the Sloan-Kettering SRT nomogram would be of some help for my decision-making
nomograms.mskcc.org/Prostate/SalvageRadiationTherapy.aspx, but it isn't calibrated for numbers under .1, so I couldn't hope for anything but wild guesses. Plus, I had insufficient data to calculate PSA doubling time. Since your PSA has topped .1, perhaps you will find it useful, although I'm not sure many doctors would be happy calculating doubling time from any values below .1.
I hope you find great doctors who can help find the best treatment path for you.
Nellie