CHARLOTTESVILLE, Va. – Perhaps no one can appreciate the importance of early cancer detection as much as Izora Armstrong. That’s because UVA 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 UVA, that they gave me the chance to be a part of this study,” says Armstrong, 53, a school bus driver in southern 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 UVA.”
The unique device, the dual modality tomographic (DMT) breast scanner, developed by UVA researchers, has shown in its pilot study the ability to pinpoint to a much finer degree the exact location of breast masses – and, even more important, to more accurately distinguish between cancerous and harmless lesions.
The pilot clinical study, led by Mark B. Williams, PhD, associate professor of radiology, biomedical engineering and physics at the University of Virginia, appears in the April 2010 issue of 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,” says Williams. “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 UVA pilot study testing the unique DMT scanning device developed by Williams and his team.
And 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,” says Williams. “This is why our research is so important for patients.”
But, as Williams points 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,” says Williams. “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 says.
To read the full study results, see Dual Modality Breast Tomosynthesis, Radiology April 2010 255:191–198 or send an email request for a copy of the paper to Dr. Williams at firstname.lastname@example.org.
For more information about the University of Virginia Cancer Center’s breast care services or to make an appointment, go to UVA Breast Care Center.
Imaging results from Armstrong’s case (courtesy of Radiological Society of North America, Inc.). Figure A is the 3-D anatomical image and shows regions of radiodense breast tissue (the white areas). Figure B is the 3-D functional image and contains a dark region that signifies above average accumulation of the tracer. Figure C is a fusion of Figures A and B. Note that the region of high tracer accumulation, corresponding to the location of the cancer (marked with a red arrow), is in the center of the most radiodense part of the breast. The circle indicates the region in which biopsy was performed based on the traditional clinical examination results. Results of that biopsy were negative.