Ultrasound’s New Focus

Can it Eradicate Tumors?

Science News, April 29, 2006 by Ben Harder

Just Warming Up

Continued from Friday’s article.

In addition to scoring direct hits against cancer, HIFU may provide assists when used in combination with established drugs. Researchers at the National Institutes of Health’s Clinical Center in Bethesda, Md., showed at last year’s radiology meeting that HIFU can boost the amount of a chemotherapy drug that reaches a tumor. Sergio Dromi and his colleagues injected skin tumor-carrying mice with microscopic envelopes of fat, called liposomes, that contained the anticancer drug doxorubicin. Liposomes carry drugs and other substances into cells.

In some mice, the researchers then used a HIFU machine to deliver intermittent pulses of ultrasound energy to each tumor, elevating its temperature to 42°C and breaking down the liposomes. Examination of the tumors revealed that three times as much doxorubicin reached the target in the HIFU-treated mice as in the other mice.

Other researchers are pursuing HIFU as a method for cauterizing hemorrhaging internal wounds (SN: 1/6/01, p. 12) and breaking up blood clots and kidney stones (SN: 11/26/05, p. 346).

Suarez, the urologist who treated Reinwald in Santiago, anticipates that HIFU may treat pancreatic and kidney cancer, fix heart arrhythmias, and even improve liposuction.

Use of HIFU for cancer could dramatically reduce health care costs, argues Suarez. It requires little or no hospitalization and less recovery time than alternative treatments do. Because HIFU is associated with a low rate of permanent complications, it also decreases the cost of treating those side effects.

“I’m treating about 20 patients a month [with HIFU],” Suarez says. “We are concentrating on prostate cancer fight now. There’s a sense of urgency–it is the most common cancer in men.”