Breast CT imaging system marches forward as pain-free tool to aid mammograms

While questions persist about the best ways to detect breast cancer early, a CT imaging system developed at the University of Rochester Medical Center and first unveiled five years ago is in a better position today to enter the fray - at least in a supporting role to conventional mammography.

URMC radiologist Avice O'Connell, M.D., was invited to summarize the studies conducted thus far on the Cone Beam Computed Tomography (CBCT) scanner, at the Radiological Society of North America Annual Scientific Assembly in Chicago at 8:30 a.m. (EST) on Friday, December 3, 2010.

O'Connell is optimistic about the progress: The CBCT provides high-quality images and, importantly, is easier on women because it allows accurate breast scans without having to pull, flatten and compress the tissue.

In addition, preliminary research shows that breast coverage and radiation dose is comparable to mammography. Yet at this point researchers do not believe the CBCT is likely to replace mammography as a frontline screening tool. More studies are needed to verify its best usage in the clinic.

"The CBCT imaging system has some significant advantages over current imaging modalities however its greatest potential may be as an additional tool for diagnosing difficult cases. It could be extremely useful in locating tumors that are obscured by dense breast tissue, or distinguishing between benign and malignant lesions," said O'Connell, associate professor in Imaging Sciences and director of women's imaging for the Comprehensive Breast Care Center at the James P. Wilmot Cancer at URMC.

A team of URMC researchers introduced the CBCT system at the 2006 RSNA meeting. Dozens of women sought information about enrollment in clinical trials to test the new device, saying they were eager to participate in research that could lead to more comfortable, accurate, annual mammograms.

The CBCT scanner produces three-dimensional images while the breasts are in a more natural state. (Tomosynthesis is another new technology being developed for breast screening. It constructs a 3D picture of the breast using multiple x-rays, whereas the CBCT is an actual 3D image, O'Connell said.) The patient undergoing a CBCT scan lies on her stomach on a cushioned exam table – the design of which is still being improved – as one breast at a time is suspended through an opening in the table. The radiation source is positioned so that exposure to the chest or other areas of the torso can be avoided.

The scanner takes 300 high-resolution images while circling the breasts for about 10 seconds, emitting a radiation dose that's comparable to a diagnostic mammogram and within the limits set by the Food and Drug Administration. Radiologists will also be able to use the CBCT images and related software to perform biopsies directly on the table, O'Connell said.

Following is a summary of the data O'Connell will present at RSNA: