An analysis of the National UK HDR Prostate Brachytherapy Database suggests single dose high-dose rate (HDR) brachytherapy (BT) monotherapy is suboptimal in treating localised prostate cancer.
Seven centres across the UK collaborated on a study of single dose HDR brachytherapy (19 Gy) for the treatment of localised prostate cancer. Planning target volume (PTV) was defined by the prostate capsule and a 3 mm expansion with clearly defined planning constraints for the urethra and rectum. Entry criteria allowed all risk groups provided PSA ≤40 µg/L and staging investigations were negative for metastases.
A total of 441 patients were entered into the trial. Of these, 10% were low risk, 65% were intermediate risk, and 25% were high risk.
ADT was received by 37.6% overall and 90% of high-risk patients for a median period of 6 months.
Three-year biochemical relapse free survival (bRFS) 88% overall. bRFS was 100% in low risk, 86% in intermediate risk and 75% in high risk.
Relapse in 25 patients was assessed radiologically and occurred in the prostate in 15 of these, 11 of whom had localised prostate relapse only.
The authors said the current study is limited by the short follow-up period and the long-term outcomes of this single dose HDR approach remains uncertain.