Distant and local recurrence in patients with biochemical failure after prostate brachytherapy

Purpose: To analyze the patterns of failure after the brachytherapy management of localized prostate cancer. Methods and materials: From 1990 to 2008, 2869 patients underwent prostate brachytherapy and 213 experienced a prostate-specific antigen (PSA) failure by the Phoenix definition. Of these 213 patients, 33.5% were low, 18.5% intermediate, and 58% high risk. Results: Of the 119 patients biopsied, 36 (30%) had a least one positive posttreatment biopsy. In univariate and multivariate analyses, PSA doubling time was the most predictive of a positive biopsy. Patients with doubling times ≤3, >3-6, ≥6-10, and >10 months had positive biopsy rates of 9%, 18%, 36%, and 42%, respectively (p = 0.01). The actuarial rate of remaining free from distant metastases at 10 years was 73%. Patients with PSA doubling times of ≤3, >3-6, >6-10, and >10 months had freedom from distant metastases rates of 0%, 74%, 78%, and 94.5% at 10 years, respectively (p < 0.0001). In multivariate analysis, PSA doubling time and time to PSA failure were the most significant predictors of developing distant metastases. Conclusions: About one third of patients harbor a component of local failure and one fourth demonstrate clinical metastases. PSA doubling time can be used to help predict the source of a rising PSA.