<qa>  What is the PSA?- Patients must have a rising PSA 2.0 following a nadir after local curative therapy either radical prostatectomy andor pelvic radiation with no clinical or radiographic evidence of metastatic disease; PSA 2.0 elevation must be confirmed by two consecutive increases, each measured at least 2 weeks apart; only patients with a biochemical PSA recurrence with no physical exam or radiographic evidence of local or distant relapse are eligible 