Unification of a common biochemical failure definition for prostate cancer treated with brachytherapy or external beam radiotherapy with or without androgen deprivation

Conclusions: Biochemical failure definitions applying a PSA threshold at or after the nadir (e.g., threshold 3) demonstrated the highest association with CF, OS, and CSS for all assessed treatment modalities. Definitions incorporating a PSA increase above the nadir value (e.g., nadir + 2 ng/mL) were also superior for all modalities. In general, BF definitions have greater predictive capacity for clinical outcome with brachytherapy or neoadjuvant AD than EBRT alone, possibly because of less “noise” from production of background PSA.