The Boston Globe
February 11, 2011
by Deborah Kotz
Mammograms, those imperfect screening tests for breast cancer, may become a little bit better. The Food and Drug Administration on Friday approved the first mammography device that provides 3-D images of the breast for both general screening and diagnosis of breast lumps.
The agency said that in studies where radiologists were asked to review more than 300 mammography exams, they obtained a 7 percent improvement in their ability to distinguish between cancerous and non-cancerous abnormalities as compared with viewing traditional two-dimensional X-ray scans.
About 10 percent of women who get mammography screening undergo additional testing for findings that later turn out to be benign. So a 7 percent improvement would lower that rate down to 9.3 percent — not bad but still not significantly lowering the rate of biopsies for nonmalignant lumps.
Hologic, the Bedford-based manufacturer of the 3-D technology, says the cost for the new scan and whether it’s covered by insurers remains unknown at this point. The company “is working closely with a team of reimbursement professionals to achieve reimbursement … as soon as possible,” a statement from Hologic reads. “It is not possible to predict how long this will take at this point.”
Radiologists can purchase the 3-D software as an add-on to Hologic’s 2-D Selenia Dimension system. And it can be used along with the 2-D scan as a first-line screening test that could be particularly useful, Hologic said, “to reveal the inner architecture of the breast, free from the distortion typically caused by tissue shadowing or density.”
The one major drawback beyond the added cost for the 3-D image is the increased radiation: The FDA said the combination of the 2-D and 3-D images “approximately doubled the radiation dose the patient received” and “there is uncertainty for radiation risk estimates.”
That said, the FDA determined that the reduced risk of extra mammogram screenings and biopsies to investigate abnormalities that turn out to be benign outweighs the added risk of radiation from the 3-D scan.