The Addition of Low-Dose-Rate Brachytherapy and Androgen-Deprivation Therapy Decreases Biochemical Failure and Prostate Cancer Death Compared With Dose-Escalated External-Beam Radiation Therapy for High-Risk Prostate Cancer

BACKGROUND: The objective of this study was to determine whether the addition of low-dose-rate brachytherapy or androgen-de-privation therapy (ADT) improves clinical outcome in patients with high-risk prostate cancer (HiRPCa) who received dose-escalated radiotherapy (RT). METHODS: Between 1995 and 2010, 958 patients with HiRPCa were treated at Schiffler Cancer Center (n484) or at the University of Michigan (n474) by receiving either dose-escalated external-beam RT (EBRT) (n510; minimum prescription dose, 75 grays [Gy]; median dose, 78 Gy) or combined-modality RT (CMRT) consisting of 103Pd implants (n369) or 125I implants (n79) both with pelvic irradiation (median prescription dose, 45 Gy). The cumulative incidences of biochemical failure (BF) and prostate cancer-specific mortality (PCSM) were estimated by using the Kaplan-Meier method and Fine and Gray regression analysis. RESULTS: The median follow-up was 63.2 months (interquartile range, 35.4-99.0 months), and 250 patients were followed for>8 years. Compared with CMRT, patients who received EBRT had higher prostate-specific antigen levels, higher tumor classification, lower Gleason sum, and more frequent receipt of ADT for a longer duration. The 8-year incidence BF and PCSM among patients wh