Role of novel risk classification method, Prostate Cancer Risk Index (PRIX) for clinically localized prostate cancer after high-dose-rate interstitial brachytherapy as monotherapy

To examine the role of the new grading system Prostate Cancer Risk Index (PRIX) with existing risk-grouping after high-dose-rate interstitial brachytherapy (HDR-ISBT) as monotherapy for localized prostate cancer.We analyzed outcome in 100 patients treated by HDR-ISBT as monotherapy using PRIX and compared this with D'Amico, the National Comprehensive Cancer Network (NCCN), and Seattle classifications. The median follow-up was 74 (range=48-109) months.Five-year prostate-specific antigen control and overall survival rates were 94% and 98%, respectively. PRIX separated the risks statistically significantly (p=0.004), while D'Amico (p=0.319), NCCN 2002 (p=0.126), NCCN 2012 (p=0.052) and Seattle (p=0.112) classifications failed to show a statistically significant separation.PRIX is a more useful risk classification system in high-risk patient selection than existing risk classification system in clinically localized prostate cancer after HDR-ISBT as monotherapy.