Experimental ultrasound could refine cancer detection
Technique may reduce biopsies for breast lumps
CHICAGO -- An experimental ultrasound technique that measures how easily breast lumps compress and bounce back could enable doctors to determine instantly whether a woman has cancer without doing a biopsy.
In a small study of 80 women, the technique, called elastography, distinguished harmless lumps from malignant ones with nearly 100 percent accuracy. Cancerous tumors are firmer than benign ones.
If the results hold up in a larger study, elastography could save thousands of women from the waiting, cost, discomfort, and anxiety of a biopsy, in which cells are removed from the breast -- sometimes with a needle, sometimes with a scalpel -- and examined under a microscope.
"There's a lot of anxiety, a lot of stress, a lot of fear involved" with biopsies, said Susan Brown, manager of health education for the Susan G. Komen Breast Cancer Foundation. "And there's the cost of leaving work to make a second appointment. If this can be done instead of a biopsy, there would be a real cost reduction."
Up to 1 million biopsies are performed each year on suspicious breast tissue detected by mammograms and self-exams, but as many as 8 out of 10 of these biopsies find that the lumps are benign.
Biopsies can cost $200 to $1,000, depending on whether some fluid or an entire lump is removed, and it can take days or weeks to get the results.
The cost of elastography is not yet clear, but some specialists said the procedure might run from $100 to $200. And it can yield results in minutes.
When checked against biopsies of women's breast tissue, the ultrasound technique correctly identified 17 out of 17 cancerous tumors and 105 out of 106 harmless lesions. The findings were reported at a national radiology meeting in Chicago this week.
Scientists said the approach may also be used someday to rapidly diagnose damaged hearts and guide the treatment of prostate cancer.
The technique was pioneered during the 1990s at the University of Texas Medical School at Houston by Jonathan Ophir and his colleagues.
Ophir describes elastography as a way to measure and picture the elasticity of body tissue. In effect, it is an extension of one of the oldest tools in medicine, palpation, in which a doctor feels the shape and firmness of body tissue.
To explain elastography, Ophir likens the body to a box-spring mattress, but "a crazy mattress made out of millions of small springs and each one is a little different. Each is moving around at a different rate, depending on their individual stiffness." Cancerous tumors are like stiff springs. Normal tissue and benign lesions compress more easily.
Both traditional ultrasound and elastography use echoes from high-frequency sound waves to create pictures of what is going on inside the body, but elastography goes a step further.
In traditional ultrasound, a doctor or technician places a hand-held device on the skin that sends high-frequency sound waves into the body. Organs and tissue reflect the sound back as echoes, which are sent to a computer that turns them into a picture. Many people have seen ultrasound images of fetuses.
Elastography, however, also gauges movement. As the doctor moves the hand-held device against the breast, the device collects echoes before and after the compression or movement of the breast tissue. The resulting images show stiff tissues as dark areas and soft tissues as light areas.
Breast cancer shows up larger on an elastogram than it does on a traditional ultrasound image, perhaps because the elastogram can "see" the scar tissue around the cancer, Ophir said.
"It's like finding a marble in Jell-O," said Dr. Richard Barr, a professor of radiology at Northeastern Ohio Universities College of Medicine, who reported his findings at the annual meeting of the Radiological Society of North America. Germany-based Siemens AG provided the ultrasound equipment and software for Barr's study.
Ophir and other researchers said breast cancer diagnosis will be elastography's first real-world application.
"If it doesn't fly there, it won't fly anywhere," said Elisa Konofagou of Columbia University, who is testing elastography on animals and humans to determine the extent of damage after a heart attack. Uses in prostate cancer and thyroid cancer also are under study elsewhere.