Hologic, Inc. just received approval from the Food and Drug Administration for the first ever 3-D digital mammography system for screening breast cancer.
Current mammograms – with 2-D X-ray breast pictures – are limited because tissues overlapping tissues could be hiding lesions or, on the other hand, make benign areas look suspect. (About 10% of women undergo additional testing for abnormalities that are later determined to be noncancerous.)
In studies where radiologists viewed 300 mammography exams, the 3-D system “could significantly enhance existing diagnosis and treatment approaches,”says FDA’s Jeffrey Shuren. The system had better accuracy and detection, visibility and sensitivity – a 7% improvement over 2-D.
The breast is briefly compressed during the exam, which combines 3-D and 2-D imaging – resulting in a stack of thin high-resolution image slices that provide a clear rendition of the structures within the breast and the surrounding tissue.
The combination of 2-D and 3-D images about doubled the radiation dose the patient received. However, the increase in cancer risk from having both a 2-D and 3-D exam is expected to be less than 1.5% compared to natural cancer incidence, and less than 1% compared to the risk from conventional 2-D imaging, according to the FDA.
Nearly 40 million mammograms are performed each year in the US. In 2009, there were 192,370 new cases of invasive breast cancer diagnosed, and over 40,000 American women died from it in that same year. If detected early, the 5-year survival rate is 98%, according to the American Cancer Society.
“We believe tomosynthesis has the potential to change how screening and diagnostic mammography is performed, and over time will prove invaluable to the earliest possible detection of breast cancer and in the reduction of unnecessary diagnostic interventions,” says Hologic president and CEO, Rob Cascella.
Dimensions 3-D, which is an add-on to Hologic’s 2-D system, has already been commercially available in more than 40 countries. The National Cancer Institute recommends women ages 40 and older have a mammogram every one to two years.