Rising PSA post treatment can be a really scary thing. There are lots of factors to take into consideration when looking at this. There is a lot of controversy about what to do if the PSA is rising. No, there are many different assays around. We use the Hybritech assay.
Some institutions have different undetectable levels.
Our institution just recently changed from an undetectable level of less than 0.5 to less than 0.1 I like the lower level since it is more sensitive. I'm 16 months post tx. Thank god, PSA is stable. Redhog, I'm glad for you that your PSA is undetectable. Night, it really depends on a lot of things.