OBJECTIVE: This study focuses on the biochemical response of the following variables: prostate volume, prostate-specific antigen (PSA) value, Gleason scores, staging, the risk of the disease, and hormonotherapy. MATERIALS AND METHODS: In the period between February of 1998 and July of 2001, 46 patients with prostate cancer were treated with radiotherapy, in a combination of teletherapy and high-dose rate brachytherapy (HDR). The age ranged from 51 to 79 years (averaging 66.4 years). T1c stage was the most frequent one: 30 (65%). The Gleason score was below 7 in 78% of the patients. PSA ranged from 3.4 to 33.3, being below 10 in 39% of the cases. The average prostatic volume was 32.3cc. Twenty-eight percent of the patients received hormonotherapy. Teletherapy dose ranged from 45 to 50.4 Gy, associated to four fractions of 4 Gy of HDR. RESULTS: The follow-up period varied from 6 to 43 months. Four patients missed the follow-up and four died (one due to the disease). Out of the 39 patients that were analyzed, 76% presented a less than 1.5 PSA. None of the analyzed variables were found to be of statistical significance (p>0.05) regarding biochemical control. CONCLUSION: The use of HDR brachytherapy was found to be effective in the treatment of prostate cancer and, in this study, the variables considered as prognostic factors did not interfere in the biochemical control.

Keywords: Prostate cancer, Brachytherapy, Interstitial radiotherapy