System Aids Breast Cancer Detection in Women with Dense Breasts
A unique risk-assessment imaging system and model presented on Sunday at RSNA 2013 accurately assesses the likelihood of breast cancer, especially in women with dense breasts. The metabolic imaging and risk assessment (MIRA) model works as an adjunct to mammography in enabling early detection of breast cancer.
"One of the main issues with mammography is that it is very difficult to get an accurate reading for women with dense breasts," said presenter vice-president of research and development at Real Imaging, Ltd., a medical imaging company based in Israel's Airport City. "You cannot replace mammography, but you can add an additional modality to aid the physician, particularly for women with dense breasts," he said.
Dense breast tissue appears as a solid white area on mammograms, while the non-dense (fatty) tissue appears as dark areas. Tumors are also dense tissues. Because X-rays don't penetrate dense tissue as well as they do fatty tissue, relying on mammograms alone to help detect tumors can become troublesome.
"What you get in the mammogram of a woman with dense breast tissue is the same contrast you would get for the tumor," Dr. Izhaky said. "It's very difficult for the physician to see the difference in the contrast in the image between the tumor and the healthy tissue."
Another drawback of mammography is that results are based on human interpretation, which can lead to error such as missed diagnoses of breast cancer. And the current risk assessment models for breast cancer rely on genetic susceptibility and family history, in addition to mammographic breast density.
Dr. Izhaky and his team targeted those issues in developing the computerized, noninvasive imaging modality used in the study, which comprised 3D breast vascular maps of 339 women. Of those women, 209 were healthy, 36 had benign lesions and 94 had biopsy-proven breast cancer. Researchers used receiver-operating characteristic (ROC) analysis and bootstrapping to assess the diagnostic accuracy of the breast cancer likelihood. They found an overall 84.1 percent area under the ROC curve, which increased to 86.5 percent when looking at dense-breast examples.
"We believe we have the first risk-assessment tool purely based on imaging biomarkers," Dr. Izhaky said.
The tool would be essential in early detection and prevention strategies, which depend on the ability to accurately identify individuals with significantly increased breast cancer risk. "Our technology attempts to provide a dynamic assessment analyzing the chances that a woman harbors a breast cancer at a specific time, based on objective metabolic signatures," Dr. Izhaky said. "If assessed as high risk, such a woman would need immediate further workup to detect and localize the cancer."
Researchers plan to initiate the clinical trial phase in the U.S., which Dr. Izhaky estimated could start in February 2014. "In 10 years, most imaging modalities will provide risk assessment for the presence of pathology," he said. "Providing the risk is by no means intended to exclude physicians from the clinical decision process, rather to provide them with a non-biased objective assessment in order for the physician to decide on the most appropriate workup for the patient, adopting a personalized, tailored approach."
More sessions throughout the week address the hot topic of breast density. Learn more.