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

Abstract 

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.

Keywords: Patterns of failure, Prostate brachytherapy, Prostate cancer, PSA doubling time