Melissa, I am in a similar situation to your hubby, but have not had SRT.
At the current low levels, the PSA number will jump around a bit so you shouldn't read too much into a rise from 0.04 to 0.09. However, it seems that whatever the doubling time, the PSA is rising so you will be faced with HT at some time in the future.
Opinions are divided at just when that should be -- my uro suggested waiting until my PSA is 10, but also there is a school of thought that suggests hit it early and hard.
Statistics indicate we have a 13-year life expectancy after recurrence -- see John T's post in this thread www.healingwell.com/community/default.aspx?f=35&m=2072465
As for the scared side of things -- I take this view: I have always been going to die of something, someday. All that has happened is that I now have some inkling of what and when, and still by no means certain. But in the meantime, I will enjoy my remaining 10 years or whatever.
No symptoms; PSA 5.7; Gleason 4+5=9; cancer in 4/12 cores
Non-nerve-sparing RRP 7 March 2008 age 63
Organ confined, neg margins. Gleason downgrade 4+4=8
Bimix worked well; now using just VED
PSA undetectable at first but now 0.4, doubling time 7 months
No radiation but ADT coming unless I can slow down the rise...