High-dose-rate brachytherapy without external beam irradiation for locally advanced prostate cancer.

Abstract

High-dose-rate brachytherapy (HDR-BT) had been used only in combination with external beam irradiation (EBI) until our previously reported first trial of HDR-BT alone without EBI. The purpose of the current report is to evaluate the feasibility, toxicity and efficacy of this regimen, with more patient accrual and longer follow-up. From 1995 through 2004, 111 patients with localized prostate cancer were treated with HDR-BT without EBI. Fifteen patients were considered as low-risk, 28 as intermediate-risk, and 68 as high-risk. The prescribed dose was 48 Gy/8 fractions/5 days or 54 Gy/9 fractions/5 days. Median follow-up time was 27 months (range 5-119). All the patients completed the treatment regimen. The 3- and 5-year PSA failure-free rates were 83% and 70%, and the local control rates 100% and 97%. The maximum toxicities observed were Grade 3 by CTCAE v3.0 (6 acute, 1 chronic). HDR-BT without EBI was feasible and its toxicity acceptable. Short-term tumor control was promising, even for locally advanced cases. More patient accrual and longer follow-up are needed to confirm the efficacy of this novel approach.