I have just had five consecutive rises, so it won't take long. My PSA is not bouncing around at all. It is just monotonously, steadily, grinding upwards. That's why one of the docs I've seen said "it's a slam dunk" that I'm having a recurrence.
This is just my opinion based on my own experience, not medical advice. But I, like some others here, would be of a mind to wait until hitting a PSA of two or greater. Even though your PSA is climbing steadily upward, for reasons unknown, when mine hit 0.1 it stayed there for three years before it began moving again - and then at a much faster rate, doubling to 0.4 in ten months. So I'm not sure we can all project reliably ahead, especially based on the low measurements of ultra-sensitive PSA tests.
As for HRT. My RO recommended using Casodex only, which I did for three months beginning a couple of weeks before my first SRT treatment. He acknowledged that this is not a standard approach, though it is more common in Europe than in the U.S. His reasoning was that the Casodex-only treatment had fewer side effects than Lupron or Casodex plus Lupron, and nonetheless seems to improve the effectiveness of SRT only.
My results thus far, nearly four years since completion of SRT are literally perfect. My current PSA is 0.00 as of a week ago. I know I am a sample of 1, so you can't draw conclusions from my experience only. Maybe I've just been lucky.
FWIW the I've used the same nomogram linked above. Based on my numbers and pathology, which include seminal vesicle involvement and an enlarged lymph node that turned up on an x-ray at the time of my SRT, I have about
a 38 % chance of being recurrence free at 6 years, if my Cassodex-only treatment counts as HT within the nomogram's underlying logic. If the Cassodex-only treatment doesn't count, then my recurrence-free expectation is something like 13%. But at four years and counting, I've so far done well better than my own, or for the matter my RO's expectations.