Prostate is the second most deadly type of cancer in men, with lung cancer the only variant to claim more lives.
Treatment is challenging because surgery and radiation can leave men incontinent or impotent.
However, a pioneering new technique avoids the risks by using a rod-shaped device inserted into the urethra while guided by magnetic resonance to administer precise bursts of ultrasound.
The sound waves heat and destroy the tumour, leaving surrounding areas unharmed.
The new study was presented at the annual meeting of the Radiological Society of North America and involved 115 men with localised prostate cancer.
After treatment with ultrasound, clinically significant cancer was eliminated in 80 per cent of the group, with 65 per cent having no signs of cancer after one year.
Most of the men also saw reduced blood-antigen markers for prostate cancer, and overall no bowel complications were reported.
Study co-author Steven Raman, professor of radiology and urology at the University of California at Los Angeles, said: “It’s an outpatient procedure with minimal recovery time.
“We saw very good results in the patients, with a dramatic reduction of over 90 per cent in prostate volume and low rates of impotence with almost no incontinence.”
The process, called Tulsa-Pro, has been approved for clinical use in Europe.