The procedures of ART and SRT are the same. The difference is in the decision point. For ART the decision to radiate is made immediately after surgery based on what was found at the time of surgery. The radiation can take place months later, but the decision is made shortly after surgery. SRT is based upon a rising psa after surgery which could occur months or years after surgery. Either SRT or ART may be to the prostate bed only or expanded to the pelvic area .
If some cells are still in the prostate bed it could take months or years for them to get large enough to create a psa at the level that can be detected. It is recommended to have SRT before psa reaches .2 because if left alone the cancer could go systemic. In the majority of cases you are correct in that the cancer has already escaped, but SRT is still the only chance to have a complete cure, which happens about
30% of the time so it's worth the risk of having radiation.
Post Edited (John T) : 9/2/2014 7:38:40 PM (GMT-6)