Prostate cancer kills 10,000 men in the UK each year
An experimental therapy using sound waves may offer people with early stage prostate cancer an alternative treatment option, doctors believe.
The technique, called High Intensity Focused Ultrasound (HIFU), uses sound waves to heat and kill cancerous cells.
The researchers from University College and Princess Grace hospitals in London used it on 172 men with high rates of success and low levels of side effects.
But experts said long-term follow-up was needed to confirm its potential.
The men taking part in the trial were discharged on average five hours after receiving the HIFU treatment, the British Journal of Cancer reported.
Typically men with the aggressive form prostate cancer, which kills 10,000 people a year in the UK, are treated with either surgery or radiotherapy.
There is also a benign version of the disease, which is rarely life-threatening and sometimes so slow-growing it never causes any problems.
Surgery usually requires a two to three-day in-patient stay and radiotherapy requires daily treatment as an outpatient for up to one month.
Of the initial group, 159 men were followed up a year later and 92% did not have any recurrence of prostate cancer.
Both surgery and radiotherapy have similar success rates.
But the sound waves treatment showed lower levels of side effects than would be expected for the other two.
Just one man had incontinence, none had any bowel problems, while a third of the group had impotence - low in terms of prostate treatment.
Guy MacPherson, 73, from Oxfordshire, who took part in the trial, was full of praise.
"I was very happy about the treatment. I had no side effects.
"The day following the treatment I was walking the dog, washing the car and going Christmas carolling."
Dr Hashim Ahmed, who led the trial, said the results were very encouraging.
"This study suggests it's possible that HIFU may one day play a role in treating men with early prostate cancer with fewer side effects."
HIFU can target cancerous tissue down to a millimetre accuracy.
It literally boils the cells until they are destroyed.
Since this first group underwent the treatment another 800 men around the UK have also entered trials, although results are not available yet.
It has also started to be tested on other forms of cancer, such as liver and kidney.
The technique is already used in other parts of Europe and Japan.
But experts still want to see long-term results before they give it their backing for NHS use.
Professor Peter Johnson, of Cancer Research UK, said HIFU needed "careful evaluation".
And John Neate, chief executive of the Prostate Cancer Charity, added long-term data was required.
But he said: "HIFU potentially offers a 'third way' approach to the treatment of localised prostate cancer."