Iodine-125 brachytherapy for prostate cancer: First published Australian experience

Ten-year outcomes using low dose rate brachytherapy for localised prostate cancer: An update to the first Australian experience

INTRODUCTION

To report long-term prostate-specific antigen (PSA) and toxicity outcomes for patients with localised prostate cancer treated with Iodine-125 permanent implantation at a single Australian centre.

METHODS

Between September 1994 and November 2007, 207 patients at Sir Charles Gairdner Hospital with localised prostate cancer were consecutively treated with Iodine-125 permanent interstitial implantation. Post-therapy assessment was performed three times a month and included clinical review and biochemical (PSA) evaluation. PSA progression was evaluated using the Phoenix (nadir + 2.0) definition. Treatment-related morbidity was assessed using the Common Terminology Criteria for Adverse Events (CTCAE) version 3.0 guidelines. The rate of biochemical failure was calculated by Kaplan-Meier plots. Univariate and multivariate analyses were performed to evaluate outcomes by pre-treatment clinical prognostic factors and radiation dosimetry.

RESULTS

Median follow-up was 7.8 years. The 10-year biochemical disease-free survival (bDFS) for the entire cohort was 89%. Ten-year bDFS estimates by pre-treatment risk group were 96% for low-risk, 83% for intermediate-risk and 50% for high-risk disease. On multivariate analysis, pre-treatment PSA was an independent predictor of bDFS. D90 dose did not show a statistically significant effect on bDFS. The peak incidences of late grade 3 or higher urinary and rectal toxicities were 10.7% and 1.1% respectively.

CONCLUSION

Excellent long-term biochemical control was demonstrated with Iodine-125 permanent interstitial implantation in appropriately selected patients with prostate cancer. The results of our single centre experience are comparable with those of other single institutions.

Estimating the risk of long-term erectile, urinary and bowel symptoms resulting from prostate cancer treatment

Reports on long-term complications resulting from treatment for localized prostate cancer are very inconsistent. In order to estimate the risks of long-term erectile dysfunction, urine symptoms and bowel symptoms following prostatectomy (RP), external conventional or conformal beam radiation (ERT or CRT) and brachytherapy (BRT), 98 papers from the PubMed and Cochrane Clinical Trial databases were selected, reviewed and critically evaluated. The majority of papers were institution-based retrospective and prospective follow-up studies; only two of these studies measured the risk of developing more than one treatment complication. Due to differences in study designs and populations, it is difficult to directly compare studies and not meaningful to calculate summary estimates. In addition to focusing on randomized clinical trials and well-designed population based studies, future research should adopt standardized methodologies and should measure the risk of developing more than one treatment complication.