3-D Breast Imaging May Improve Cancer Detection

3-D Breast Imaging May Improve Cancer Detection
WEDNESDAY, Nov. 28 (HealthDay News) -- A 3-D view of breasttissue may give women a more accurate method of detecting breast cancers,according to a trial of a new technology called stereoscopic digitalmammography.
False-positive results were almost cut in half with stereo mammography,said the technology's developer David Getty, a division scientist at BBNTechnologies in Cambridge, Mass.
"These are women who at the moment are getting a call back from aradiologist saying something suspicious has been found," he explained.However, after subsequent testing, "most of them are finding out there wasnothing there," Getty added.
"Being able to cut that number in half would have a dramatic impact"in reducing both patient anxieties and cost, he said.
A second dramatic benefit to the new technology lies in "findinglesions that are being missed on standard mammography. Most of them willturn out to be benign, but some additional cancers will be found," Gettysaid.
Getty was expected to present the results Wednesday at the RadiologicalSociety of North America's annual meeting in Chicago.
The five-year trial, conducted at Emory University in Atlanta andscheduled to end in December, focused on almost 1,100 women at elevatedrisk for breast cancer. According to Getty, the trial was a collaborationwith Dr. Carl D'Orsi, the director of Emory's breast imaging center.
Results so far show that that stereo mammography reducedfalse-positives by 49 percent. The stereoscopic equipment failed todetect 24 out of 109 cancerous lesions, compared to 40 out of 109 lesionsnot found through standard digital mammography, Getty said.
Another advantage of the stereoscopic digital mammography is that it"is much better at picking up cluster calcifications [that] can beassociated with malignancy," Getty added.
This technology also allows radiologists to get a picture of the entirebreast volume in a slice-by-slice view. "It certainly helps, becauseyou're seeing all of the tissue in depth," Getty explained. The capacityof mammography to detect problems in dense breasts is not an issue withthe stereoscopic digital equipment because it "doesn't look as dense,because tissue is being spread out in depth," he said.
A stereoscopic mammogram image works on principles similar to the oldViewmaster slide viewers used by children, Getty explained. Each of twoimages inserted in the Viewmaster were channeled to a different eye, andthe brain's "visual cortex -- the magician in all this -- then combinesthe two images, artificially recreating what your two eyes normally createwhen you walk around in a three-dimensional world," Getty said.Similarly, the viewing monitor for stereo mammography merges two distinctimages to create a 3-D look at tissue.
Experts say stereo mammography does show promise, but more work isneeded.
"Stereo mammography is a step in the right direction, but it is not abreakthrough," said Dr. David Bluemke, a professor of radiology andmedicine at Johns Hopkins Medical Institutions in Baltimore. "True 3-Dtomographic imaging of the breast is ultimately needed." By givingradiologist a view of slices through the breast, 3-D tomography wouldallow radiologist to see lesions that are otherwise obscured by beingsuperimposed on normal breast tissue, he explained.
Stereoscopic digital mammography "seems very promising," added Dr.Kristin Byrne, the chief of breast imaging at Lenox Hill Hospital in NewYork City. "It would make mammography that much better."
With current technology, the problem of calling back a woman whosebreasts show a suspicious area is that radiologists often can't find thatsame suspicious tissue in a second view, so the woman has to follow-upwith further monitoring in another six months or have a biopsy, shenoted.