Adding contrast to dedicated breast CT makes the technology a contender as a qualitative and quantitative imaging modality for breast cancer screening and diagnosis, according to a new study in Radiology.
Researchers at the University of California, Davis (UCD) Medical Center explored how contrast-enhanced dedicated breast CT visualized breast lesions compared to unenhanced breast CT and mammography (Radiology, September 2010, Volume 256:3, pp. 714-723). Using contrast with the technology helped it find malignant lesions including ductal carcinoma in situ (DCIS), according to contributing author John Boone, PhD, and colleagues.
"For dedicated breast CT to succeed as a screening modality in the early detection of breast cancer, its sensitivity and specificity, especially for the detection of DCIS, must be improved over the sensitivity and specificity of mammography," they wrote.
Between September 2006 and April 2009, 46 women with BI-RADS category 4 or 5 lesions had unenhanced breast CT and contrast-enhanced breast CT before biopsy. Fifty-four lesions, of which 25 were benign and 29 were malignant, were detected and included in the study. Of these 54 lesions, 40 were not palpable and were found at screening.
Contrast-enhanced dedicated breast CT found malignant lesions better than unenhanced breast CT or mammography, according to the researchers. The technology found malignant calcifications and DCIS better than unenhanced breast CT and comparable to mammography.
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| Negative scores correspond to better visualization with contrast-enhanced breast CT; positive scores correspond to better visualization with the comparison modality. Data courtesy of the Radiological Society of North America. | ||||||||||||||||||||||||||||||||||||||||||||
The receiver operator characteristics (ROC) curve analysis of lesion enhancement (which measures how well a test separates the group being tested into those with and without the disease in question) yielded an area under the ROC curve of 0.88 (an area of 1 represents a perfect test; an area of 0.5 represents a test of no value).
The study shows that contrast-enhanced breast CT could offer promise as a quantitative technique to predict malignancy in breast lesions, according to the group. Malignant lesions enhanced by a mean of 38 HU more than benign lesions (specifically, malignant calcifications enhanced by an average of 59.9 HU, with enhancement of DCIS lesions being significantly greater than that of benign lesions). These quantitative findings suggest improved specificity for contrast-enhanced breast CT in detecting malignant calcifications, Boone and colleagues wrote.
"The bottom line is that when we compared contrast-enhanced breast CT to mammography, we had significantly better visualization for all masses, benign or malignant, and for malignant calcifications," Boone told AuntMinnie.com. "But the technology does not visualize benign calcifications as well as mammography does, and that's actually an interesting thing, since we don't want to detect them. We want to catch cancers -- everything else reduces specificity."
In terms of disclosure, Boone is noted as a consultant to Varian Medical Systems and Artemis Medical and receives funding from Varian, Fujifilm Medical Systems USA, and Hologic.
By Kate Madden Yee
AuntMinnie.com staff writer
August 23, 2010
Related Reading
Study offers comparison of conebeam breast CT to mammo, July 27, 2010
CARS report: Novel conebeam CT cuts breast dose, improves accuracy, June 29, 2009
ECR delivers new findings on digital breast tomosynthesis, March 7, 2009
Italian study backs tomosynthesis over DR for lung pathology, February 18, 2009
New breast imaging applications show diagnostic promise, January 20, 2009
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