The RADICALS RT trial addresses the question of the optimum timing of postoperative radiotherapy after radical prostatectomy. Until now there have been two schools of thought – some people have advocated adjuvant radiotherapy for all men at risk of recurrence and others have recommended salvage radiotherapy later on if the disease recurs. So the RADICALS trial was designed to address that question.

The trial recruited 1,400 men who had recently had a radical prostatectomy and who had risk features for recurrence. They were randomised either to adjuvant radiotherapy or an observation policy keeping salvage radiotherapy in reserve. The results that I presented yesterday focus on biochemical progression free survival, so basically a PSA endpoint. What we found is that there was not any significant difference between these two approaches. So adjuvant radiotherapy was not found to be any better than a policy of observation and keeping salvage radiotherapy in reserve.

Using the salvage policy, two-thirds of men avoid the need for radiotherapy altogether and so there are fewer side effects. So our conclusion is that the standard approach now after radical prostatectomy should be an observation policy, keeping salvage radiotherapy in reserve in the case of PSA failure.

The results I have presented now are an early analysis focussing on the biochemical endpoints. We do want to continue follow-up to report on the main outcome measure which is freedom from distant metastases. That will take a few more years.