@boki01 Biochemical recurrence since they are depending on the PSA to signal the recurrence. Clinical is when they do a PSMA Pet scan, etc. and find cancer. Also, as mentioned you want to get PSA tests every 3-6 months and have these tests done at the same lab to get a record of a continuous rising PSA vs. artifacts from different labs/measurement methods, possible inflammation, or a PSA bounce (know artifact after RT), etc. all of which can produce a higher PSA but do not cause sustained increases over multiple tests.