When it comes to tumors, Squishy is better
Cancer detection: Experimental ultrasound technique could mean
fewer biopsies for women with breast lumps.
Technique could diagnose breast cancer immediately
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 having to do 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 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 eight 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 experts said the procedure might
run $100 to $200. And it could 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 this week at a national radiology
meeting in Chicago.
Scientists said the approach may also be used someday to diagnose damaged
hearts rapidly and guide the treatment of prostate cancer.
The technique was pioneered during the 1990s at the University of Texas
Medical School at Houston by radiology professor 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 in the
womb.
Elastography, though, 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.
“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 Radiological Society of North America annual meeting.
Germany-based Siemens AG provided the ultrasound equipment and software for
Barr's study.
Ophir and other researchers said breast cancer diagnosis would 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 are under study elsewhere.
Dr. Constantine Godellas, a cancer surgeon at Rush University Medical Center,
said some patients and doctors would have trouble giving up biopsies, even if
further research confirmed elastography's accuracy. Doctors might fear lawsuits
if they do not order biopsies, he said.
“With the medical legal climate the way it is, that's a tough call to make,”
Godellas said. “It won't be until a lot more research has been done that people
will really buy into it.”
Dr. Ellen Mendelson, chief of breast imaging at Northwestern Memorial
Hospital in Chicago, predicted the technique would be used, though may not
supplant biopsies, which are becoming less invasive.
“The goal of reducing unnecessary biopsies is laudable,” Mendelson said, “but
you don't want to miss a cancer.”