P.C.R.I. interviewed two of the brachytherapists who are with Western Radiation Oncology in a video entitled Brachytherapy for Prostate Cancer. They only do LDR, i.e. low dose rate brachytherapy that is done with permanently implanted "seeds". They claim to do more than 1000 cases per year, 8000 to date.

At around 1 hour 20 minutes into the podcast, in a section "How do I measure results" they discuss the PSA bounce phenomenon @brianjarvis mentioned in a comment here.

They say they observe it in 20 to 30 percent of their patients. The discussion mentions a case where a post treatment PSA of 0.5 goes to 1.2 then three months later comes back down. It appears they don't observe the PSA going right back down in every case, yet they claim the main thing is if the PSA stabilizes. A typical case is said to be a full point bounce. They say their experience shows that jumping in and doing a biopsy is not indicated as the tissue can be difficult for a pathologist to classify, as it resembles cancer, but it is typically not, at this stage. They say that "for us for up to two years a biopsy for those guys is worthless".