Ultrasound’s New Focus

Can it Eradicate Tumors?

Science News, April 29, 2006 by Ben Harder

The Dominican Republic is known among tourists for its white sands, magnificent waterfalls, and unusual wildlife. But none of those was the attraction that drew Charles A. Reinwald. He came for a rendezvous with an ultrasound device. Reinwald had aggressive prostate cancer, and he didn’t care for the treatment options available in the United States. So, one day in late June 2004, Reinwald traveled from his home in Tequesta, Fla., to a hospital in the Dominican city of Santiago. There, a Miami-based urologist directed ultrasonic waves at the patient’s cancerous prostate gland.

The Dominican Republic and various other countries, including Canada, England, and Mexico, permit doctors to treat prostate cancer with a technique called high-intensity focused ultrasound, or HIFU. It often avoids the irreversible side effects, including impotence, that can arise during surgery, radiation, and the other treatments available in the United States.

In the Santiago hospital, urologist George Suarez and his assistants inserted a transducer emitting ultrasonic waves into Reinwald’s rectum. The curved transducer put the waves on converging paths in the same way that a magnifying glass focuses sunlight. Where the streams of energy intersected at the prostate, the temperature soared to more than 80°C, cooking small batches of tumor cells in seconds.

For about 2 hours, the transducer steadily shifted its aim across rows of space. Its progress resembled that of a dot matrix printer applying ink to paper. Tissue just millimeters away from the HIFU target zone remained unharmed.

Reinwald’s cancer isn’t cured, but he hasn’t required medical intervention since the operation. At age 80, he works full-time as president of the Cancer Cure Coalition, a nonprofit organization that he founded in 2000 after his wife’s diagnosis of cancer.

He expresses no regrets about his HIFU treatment. “Why do [surgery] when I have available to me a less toxic treatment?” he asks.

HIFU, however, is not generally available in the United States. It has been approved for only one use: treating uterine fibroids. Suarez and other urologists who treat U.S. men who have prostate cancer do so abroad and charge about $20,000 per case. Patients also need to pay their own way to Santiago, Toronto, or another foreign city, to undergo the procedure.

A handful of companies market HIFU devices. Although they vary in design and therapeutic purpose, all the machines rely on the same underlying principle. They focus ultrasound energy at a point several centimeters away from the transducer and destroy tissue there.

The companies, including US HIFU of Charlotte, N.C., which Suarez partially owns, have funded research to test whether the new approach is safer and more effective for a variety of cancers than standard therapies are. Breast, bone, brain, and liver tumors are among those cancers being treated experimentally with HIFU. Investigators also continue to study the efficacy of the technique in women with fibroids. In each case, physicians must place the transducer within a few centimeters of the target.

While HIFU appears to sidestep some typical side effects of surgery and radiation, it’s not yet clear whether the novel approach is as successful at curing cancers as those standard treatments are. So far, no study has directly compared the ultrasound procedure to an established cancer treatment.

A British government body, the National Institute for Clinical Excellence, maintains that the evidence “appears adequate to support the use of this procedure for prostate cancer.” But it also states in a document that offers guidance to the National Health Service, “The effects of HIFU for prostate cancer on quality of life and long-term survival remain uncertain.”

Please come back on Wednesday to continue the article.