Axumin depends on the amount of an amino acid (isoleucine) that gets picked up by the prostate cancer cells. All prostate cells pick it up to some degree, but prostate cancer cells pick up more of it (the amino acid transport receptors are upregulated to fuel their growth). That's why there is diffuse moderate homogeneous uptake from healthy prostate cells feeding. To distinguish cancer from benign tissue, radiologists look for the maximum "standardized uptake value" (SUVmax) they can find in the PET scans. If the SUVmax is below about
2.5, it is considered to be uptake from benign tissue. Above that, there is an equivocal range for a couple of points. But if it is, say, 6, that probably indicates cancer.
Biochemical recurrence for you is 2.44 ng/ml, so you are kind of jumping the gun, although 5 increases would make anyone anxious. The fact that it went down from 1.95 to 1.30 suggests that there are likely benign causes for it. I think that the first thing you should suspect is prostatitis - possibly a consequence of the seeds. Please read this article about
bounces - they are prognostic for success rather than failure (and your nadir of 0.44 is also a good sign).
/pcnrv.blogspot.com/2018/03/bounces-after-primary-radiation-therapy.htmlBTW - if your PSA should bounce up above 2.0, you would qualify for the free DCFPyL PET scan at NIH. It's the most accurate one reported in tests so far.