Recently, NHS radiotherapy centres in England started to let men swap from standard radiotherapy that needs 20 sessions to a new high-power version that can be done in five.

Now an early-stage trial by the Oncology Institute of Southern Switzerland suggests this could be safely and effectively reduced further to just one.

The precision treatment, named stereotactic ablative radiotherapy (SABR) or stereotactic body radiotherapy (SBRT) in the US, uses higher doses of radiation and fires beams at the tumour from multiple directions.

This allows doctors to cut sessions, while reducing the risk of tumours growing or spreading and sparing healthy tissue.

The new trial examined the single dose treatment in 43 men with localised prostate cancer at five hospitals across Europe and the United States.

Analysis indicated 92.9 per cent were free of prostate cancer after three years, based on their PSA blood test results.

Publishing their findings in the medical journal JAMA Oncology, the researchers commented: This data indicates that single-dose SBRT remains a promising approach, although its definitive role will require confirmation in larger studies with longer follow-up.