The .2 is just a common line in the sand that some go by. I have read .5 and I have read 1.0. Studies show that the sooner you start, once you have recurrance for sure, the better the chances are that SRT can be efffective. But even then, it depends on your pre-surgery psa velocity, and post surgery psa's as well. You would also have to factor in your Gleason/Stage into the mix.
All 3 radiation oncologists I met with agreed that SRT is definitely not too effective if you let it rise to or above 1.0.
And Mel, most of the experts agree that you need 3 consecutives rises above .10 to validate recurrance. So all the numbers below .10 are within the range of normal testing tolerances, and there can be up and down movements in that range that mean nothing at all.
In my own case, they made a lot of fuss about how quickly I got to .16, which by some people's thinking isn't all that high,, but they factored in the high PSA velocity I had pre-surgery as being very darning to my case, even post surgery.
David in SC
Age: 57, 56 dx, PSA: 7/07 5.8, 7/08 12.3, 9/08 14.5, 10/08 16.3
3rd Biopsy: 9/08 - 7/7 Positive, 40-90% Cancer, Gleason 4+3
Open RP: 11/08, Rht nerves saved, 4 days in hospt, on catheters for 63 days, 5th one out 1/09
Path Rpt: Gleason 3+4, pT2c, 42g, 20% cancer, 1 pos margin
Incontinence: 1 Month ED: Non issue at any point post surgery
Post Surgery PSA: 2/09 .05,5/09 .1, 6/09 .11. 8/09 .16
Post SRT PSA: 1/10 .12
Latest: 7/9 met 2 rad. oncl, 7/9 cath #6 - blockage, 8/9 2nd corr surgery, 8/9 cath #7 out 38 days, 9/9 - met 3rd rad. oncl., mapped 9/9, 10/1 - 3rd corr. surgery - SP cath/hard dialation, 10/5 - 11/27 IMRT SRT 39 sess/72 gys ,cath #8 33 days, Cath #9 35 days, 12/7 - Cath #10 43 days, 1/10 - Corrective Surgery #4, and Caths #11 and #12 in at the same time