Pretreatment nomogram for predicting freedom from recurrence after permanent prostate brachytherapy in prostate cancer

Objectives. To develop a prognostic nomogram to predict the freedom from re currence for patients treated with permanent prostate brachytherapy for loc alized prostate cancer. Methods. We performed a retrospective analysis of 920 patients treated with permanent prostate brachytherapy between 1992 and 2000. The clinical param eters included clinical stage, biopsy Gleason sum, pretreatment prostate-sp ecific antigen (PSA) value, and administration of external beam radiation. Patients who received neoadjuvant androgen deprivation therapy were exclude d. Failure was defined as any posttreatment administration of androgen depr ivation, clinical relapse, or biochemical failure, defined as three PSA ris es. Patients with fewer than three PSA rises were censored at the time of t he first PSA rise. Data from two outside institutions served as validation, Results. A nomogram that predicts the probability of remaining free from bi ochemical recurrence for 5 years after brachytherapy without adjuvant hormo nal therapy was developed using Cox proportional hazards regression analysi s. External validation revealed a concordance index of 0.61 to 0.64, and ca libration of the nomogram suggested confidence limits of +5% to -30%. Conclusions. The pretreatment nomogram we developed may be useful to physic ians and patients in estimating the probability of successful treatment 5 y ears after brachytherapy for clinically localized prostate cancer. UROLOGY 58: 393-399, 200 1. (C) 2001, Elsevier Science Inc.