Ultrasound for Prostate Cancer
Focused pulses of ultrasound can eradicate prostate cancer as effectively as cutting the tumour out with surgery, but with far fewer side effects.
This conclusion comes from the most comprehensive study of the technique to date, carried out by Jean-Yves Chapelon, of the French Institute of Health and Medical Research in Paris, and colleagues. Prostate cancer is the third most common cause of cancer death among men.
"The results are very exciting," said Gail ter Harr, who is studying ultrasound as a means of treating liver cancer at the Royal Marsden Hospital in London, UK. "It is by far the most advanced area of clinical trials."
The researchers conducted a trial involving 243 prostate cancer patients at a hospital in Lyon. They found that a few seconds of concentrated ultrasound could obliterate a tumour, but without having to cut into the body. In contrast, surgery caused much more collateral damage.
Surgery for prostate cancer involves removing the entire prostate, but impotency and incontinence are common consequences of this treatment.
Chapelon says ultrasound was 80 per cent successful at eradicating the cancer from the patients in the trials, a similar rate to surgery. But, impotence was seen in 40 per cent of cases, about half as many as with surgery. Furthermore, incontinence was seen reported in just eight per cent of patients after their treatment, a threefold decrease.
Chapelon says the ultrasound treatment leaves nerves untouched, while surgery almost always cuts through them. "If we take care to spare the nerves, we can maintain potency," he says.
The device used in the French trials delivers high-intensity focused ultrasound via an endorectal probe. The same probe uses less intense ultrasound to image the prostate gland prior to treatment. Once destroyed, the prostate tissue is naturally flushed away by the body.
Doctors hope that eventually many different kinds of cancer could be treated using ultrasound. However, ter Harr notes that some kinds of cancer - such as lung and brain cancer - may be less susceptible to treatable because ultrasound does not travel through bone well.
"There are some cancers for which it will revolutionize treatment, but it's too early to tell which," she says.