High dose rate brachytherapy in combination with external beam radiotherapy in the radical treatment of prostate cancer: initial results of a randomised phase three trial

Background and purpose:A randomised phase III trial has compared external beam radiotherapy alone with a dose escalated schedule using high dose rate brachytherapy. Patients with histologically confirmed prostate cancer, no evidence of metastases, a PSA <50, no previous TURP and fit for general anaesthetic were included.Methods:Patients were randomised to receive either standard radiotherapy 55 Gy in 20 fractions treating Monday to Friday over 4 weeks or a combined schedule comprising external beam treatment delivering 35.75 Gy in 13 fractions treating daily Monday to Friday over 2.5 weeks followed by a temporary high dose rate afterloading implant delivering 17 Gy in two fractions over 24 h.Results:A total of 220 patients were randomised, balanced for important prognostic parameters including tumour stage, presenting PSA, Gleason score and use of adjuvant anti-androgens.With a median follow up of 30 months (range 3–91) a significant improvement in actuarial biochemical relapse-free survival is seen in favour of the combined brachytherapy schedule (p = 0.03).A lower incidence of acute rectal discharge was seen in the brachytherapy group (p = 0.025) and other acute and late toxicities were equivalent. Patients randomised to brachytherapy had a significantly better FACT-P score at 12 weeks (p = 0.02).Conclusions:The use of high dose rate brachytherapy in combination with external beam radiotherapy resulted in an improved biochemical relapse-free survival compared to external beam radiotherapy alone with less acute rectal toxicity and improved quality of life in this randomised trial.