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.

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 24h.

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).

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.