April 1, 2010 — Perhaps no one can appreciate the importance of early cancer detection as much as Izora Armstrong. That's because University of Virginia Cancer Center researchers, using a first-of-its-kind hybrid breast-imaging device, found what mammography, ultrasound, MRI and even a needle biopsy couldn't.
 
"I feel truly blessed that I came to U.Va., that they gave me the chance to be a part of this study," said Armstrong, 53, a school bus driver in Fauquier County. "I went through all the regular tests and did what women are supposed to do and I still wouldn't have known I had breast cancer if it wasn't for U.Va."
 
U.Va. researchers developed the unique device, a dual modality tomographic, or DMT, breast scanner. It has shown in its pilot study the ability to pinpoint to a much finer degree the exact location of breast masses – and, even more importantly, to more accurately distinguish between cancerous and harmless lesions.
 
The results of the pilot clinical study, led by Mark B. Williams, associate professor of radiology, biomedical engineering and physics, appear in the April issue of the journal Radiology.
 
The DMT breast scanner works by marrying two cutting-edge imaging methods, one that obtains 3-D anatomical (structural) imaging and another that obtains 3-D biological (functional) imaging, into one integrated device. The machine runs the scans sequentially, obtaining both types of images with the breast in the same, immobilized position.
 
"Using the most current breast-imaging methods, only about one in four of all biopsied breast lesions are actually malignant – that is, the positive predictive value is about 25 percent – so there's a great deal of room for improved imaging diagnostic capabilities," Williams said. "Our pilot study indicates promising results toward reducing the number of false positive imaging diagnoses, which would therefore eliminate many unnecessary biopsies."
 
The scanner also is particularly useful in revealing the so-called "wolf in sheep's clothing" for women with radiographically dense breasts. The millions of women with thicker-than-average breast tissue or fibrous breasts continue to present a daunting diagnostic challenge for current breast-imaging methods.
 
Such was the case with Armstrong, who has fibrocystic disease and who several years ago had undergone two needle biopsies (with normal results). Most recently, her physician had found yet another suspicious spot on her mammogram and scheduled her for a breast biopsy, which came back normal – negative for cancer.
 
Fortunately for Armstrong, she had agreed prior to her biopsy to participate in the U.Va. pilot study testing the DMT scanning device.
 
The results of these new, unique images told a different story: Armstrong had very early-stage breast cancer.
 
The hybrid scanner used to detect her cancer combines 3-D digital x-ray breast tomosynthesis together with 3-D molecular breast-imaging tomosynthesis, a recently developed technique that uses intravenously injected compounds (tracers) that are absorbed to a much greater degree by malignant lesions than benign ones. A special camera positioned in close proximity to the breast then performs functional imaging of the entire breast, while the digital x-ray tomosynthesis obtains co-registered structural images.
 
In Armstrong's case, the tracers targeted exactly where the tiny, malignant mass was hidden, in the midst of a particularly radiodense region of her breast.

"Despite using the latest clinically available imaging technologies and the most expert radiologists, breast cancers are still missed, especially in women with radiodense breasts," Williams said. "This is why our research is so important for patients."
 
But, as Williams pointed out, this pilot clinical study of the 17 women tested could have far greater implications.
 
"Our early results show that the DMT scanner is a feasible and accurate method for detecting and diagnosing breast cancer," Williams said. "In our study, we not only were able to detect a missed cancerous lesion, but we also corroborated every single benign diagnosis from biopsy results."
 
"These findings demonstrate an obvious need for larger studies to further prove the efficacy of this new device," Williams said.
 
To read the full study results, see "Dual Modality Breast Tomosynthesis," Radiology, April 2010 255:191-198 or e-mail a request for a copy of the paper to mbwilliams@virginia.edu.

For information about the U.Va. Cancer Center's breast care services or to make an appointment, click here.