[PSA recurrence following radical prostatectomy and radiotherapy].

Relapses after curative therapy for localised prostate cancer using radiotherapy or radical prostatectomy occur in a significant percentage of cases, even in times of continually improving patient selection. The definition of a biochemical relapse after surgery is a PSA value of >or=0.4 ng/ml. After radiotherapy with maintenance of the organ and residual PSA production the definition is more complicated. The current algorithm is based on the ASTRO consensus of 1996 and defines a relapse as three consecutive increases in PSA above the post-therapeutic low. A biochemical relapse can indicate a local relapse, systemic metastasising of the disease or a combination of both. The differentiation of these two possibilities can be made, apart from imaging modalities, primarily on the basis of variation in PSA kinetics, whereby a short PSA doubling time and early PSA increase after primary therapy indicate a systemic problem.