Health security

New ultrasound treatment kills off cancer cells

Most cancer treatments involve surgery, chemical poisons or toxic radiation. Because they tend to take out healthy cells along with cancerous ones, these treatments can leave patients tired, hurting and more. So researchers are looking for new approaches that spare the healthy cells. One new idea would destroy cancer cells with ultrasound energy. Even this treatment, however, can sometimes damage healthy tissue. But a new development may help. It limits the ultrasound energy’s damage to only the cancer cells. Healthy cells should suffer little if any harm from it.

It’s exciting, says David Mittelstein of his team’s findings. Mittelstein is a biomedical engineer at the California Institute of Technology, in Pasadena. Low-intensity ultrasound, he says, “may allow physicians to target cancer cells based on their unique physical and structural properties.” Any spillover of the energy should cause little harm to healthy tissue.

The treatment sends out pulses of sound waves — energy — that have a frequency above 20,000 hertz (cycles per second). That’s too high for our ears to hear. (That’s also what makes it “ultra” sound.) Medical imaging relies on very short pulses of this low-intensity ultrasound.