Feasibility of brachytherapy as monotherapy for high-volume, low-risk prostate cancer.

Abstract

We sought to determine whether patients with high-volume, low-risk prostate cancer are suitable candidates for ultrasound-guided brachytherapy, monotherapy alone, without supplemental external beam radiation. The study cohort comprised 200 consecutive patients who received ultrasound.guided monotherapy from November 02, 1998 to March 26, 2010. Real.time intraoperative treatment planning was performed for all patients. 145. Gy with I125 was prescribed to the prostate with no margin. The primary endpoint was time to prostate-specific antigen. (PSA) failure using the phoenix definition. Cox multivariable regression analysis was used to determine the factors significantly associated with time to PSA failure. Median follow-up was 59 months (range 1.2-146.8 months). The median PSA was 5.0 ng/ml. For the overall cohort, both 5- and 8-year PSA failure-free survival was 92.3% (95% confidence interval [95% CI]: 86.5-95.7%). Low-risk patients per the NCCN criteria had 5- and 8-year PSA failure-free survival of 93.6%. On cox multivariable analysis, only baseline PSA (adjusted hazard ratio: 1.29 [95% CI: 1.02-1.65], P = 0.036) was associated with outcome. Among patients with Conclusions: Our analysis indicates that patients with a high number of cores positive for cancer can be adequately treated with modern brachytherapy as monotherapy and be spared the additional morbidity and cost of supplemental external beam radiation or androgen deprivation therapy.