A specialist in using ultrasound to treat prostate cancer yesterday said a judgment by the NHS guiding body not to recommend it risked "putting back research by many years".

The technique of High Intensity Focused Ultrasound (Hifu) has shown success in clinical trials but it is not yet available on the NHS in Scotland or elsewhere in Britain.

Yesterday, there was criticism of a draft guideline from the National Institute for Health and Clinical Excellence (Nice), issued over the summer, which said radical therapies such as Hifu "are not recommended for men with localised or locally advanced prostate cancer other than in controlled clinical trials".

A final judgment is due in February but yesterday Mark Emberton, a consultant urologist at University College Hospital, London, warned that the ruling could be used as a "rationing mechanism" to "stifle potentially useful innovation".

More than 30,000 men in the UK are diagnosed with prostate cancer every year.

Hifu is a non-invasive procedure which uses ultrasound energy to kill cancer cells in the prostate, with minimal damage to surrounding tissue.

It was approved as safe to use in the NHS in March 2005 but, in comparison with other treatments, less is known about its long-term effects and effectiveness.

Other possible treatments include surgery and radiation therapy or, where the disease is more advanced, hormone therapy and chemotherapy.

A spokeswoman for Nice said the Hifu procedure was "not cost-effective".

She said: "It's not about affordability, it's about value for money. It's better to spend the money on treatments that you know are clinically effective, that are best value for money and give the best improvement in the patient."

She said that Nice wanted to see further evidence of the efficacy of the treatment, and if it was judged to be worthwhile the final decision in February "could be different".

But Mr Emberton said: "The cost-effective argument is ludicrous, the economic argument is completely fallacious.

"We've turned a five-day hospital stay into a five-hour hospital stay. All you're doing is investing in a bit of software and ultrasound kit."

He said the equipment cost £300,000 and lasted about five years. There were no running costs, a hospital bed was not necessary, and his own machine was being used to treat five or six patients every week.

"While I'm not saying it should replace standard treatments, it should be used to compliment existing therapies. There's no one treatment superior to another," he said.

"My worry is that in a system of finite resources, this (guidance) will be used as a rationing mechanism, rather than open doors to a potentially very useful technology for the future.

"It has the potential to transform the way we treat prostate cancer."