July 29, 2008 -- Women who avoid mammograms for fear that they may be painful could one day have a comforting alternative: A scan that never touches the breast.
John M. Boone, PhD, of the University of California Davis Medical Center discussed a novel technique called dedicated breast computed tomography (CT) at the American Association of Physicists in Medicine 50th meeting today in Houston.
Traditional mammography squeezes breast tissue between cold, metal plates. Some women find the exam uncomfortable, even painful, causing them to delay or even avoid breast cancer screening -- an action that can have dire consequences.
(Have you avoided mammograms because they are just too uncomfortable? Share your experiences on WebMD's Women’s Health: Friends Talking board.)
Dedicated breast CT offers a gentler approach: The woman lies face down on a special table and suspends one breast through a hole. A unique scanner circles the breast -- no painful compression involved -- snapping virtual "slices" of breast tissue. The scans take only a few seconds. A computer reconstructs the information into a highly detailed, 3-D image.
CT scanners have long been used to peer into the brain, lungs, and belly area. Yet experts had dismissed the notion of breast CT for fear that standard CT machines would expose women to excessive radiation. The specialized cone beam breast CT (CBBCT) scanner, developed by Boone and colleagues, uses the same amount of radiation as a conventional mammogram.
So far, researchers at the university have used the machine to scan 160 women.
The team's initial tests show that the scanner delivers high-resolution images that clearly demonstrate breast lesions. Boone, a medical physicist, predicts the method could be available to women within the next 3-4 years.
Dedicated breast CT "is better [than] mammography for mass detection," Boone says in a news release. [The technique offers] "improved comfort to the patient and a better three-dimensional understanding of pathological lesions when they are present."
The method does have its drawbacks. It can miss tiny areas (microcalcifications) that can sometimes signal early breast cancer. Mammography is better at spotting such changes.
"We're not making the claim that breast CT is better than mammography -- yet," Boone says.
Early this year, Boone's team started experiments with a combined CT/PET breast scanner, which allows clinicians to track a tumor's metabolic activity. Cancer cells have higher metabolic rates than healthy cells and look different on a PET (positron emission tomography) scan. The combined device would be used to monitor cancer and plan treatment in patients already diagnosed with the disease.
"PET/CT would not be used for screening because PET is too expensive and the radiation levels of both procedures would be too high for annual testing," Boone tells WebMD. "The PET/CT studies would be more useful for follow-up imaging after mammography, before or after treatment.'"