Above: Steven P. Poplack, MD, and Matthew F. Covington, MD, discuss the image findings of a contrast-enhanced digital mammogram (left monitor) against a traditional 2D mammogram.
The advent of advanced technologies has revolutionized both the quality of breast imaging and how those images may be used in screening and diagnosing patients. It’s an exciting time for breast imaging research and development worldwide, according to Catherine Appleton, MD, chief of breast imaging at Mallinckrodt Institute of Radiology. And the research being done by the section’s diagnostic radiologists is contributing to that excitement.
A Spirit of Innovation
“We have outstanding clinicians, and every one of them has a passion for clinical breast imaging,” says Appleton. “That’s what we do, day in and day out, in our clinic.”
That passion took root in August 1986, when a committed group of radiologists at Mallinckrodt established a screening mammography program, the first of its kind in the Midwest. A component of the program was a mammography van; today, the van
service is the longest running of its type in the U.S. and among the most successful.
“Throughout the ensuing years, we have focused on providing our patients with the best possible breast imaging technology. We have been active participants in landmark studies in order to achieve that level of excellence,” says Appleton.
The first major transition in breast imaging was from film screen to digital mammography. Mallinckrodt was the top recruiting site for the Digital Mammographic Imaging Screening Trial (DMIST), a pivotal landmark study published in 2006 that proved the benefits of digital mammography for certain groups of women.
“Next was the advent of digital breast tomosynthesis, and again we were a beta test site and early adopter of this technology,” says Appleton. Digital breast tomosynthesis uses multiple X-rays and computer reconstructions to produce three-dimensional images of the breast.
“Multiple studies have shown that digital breast tomosynthesis improves sensitivity which, in turn, improves our ability to detect breast cancer,” says Appleton, adding that it also improves specificity. “In other words, it reduces the false alarms that can be associated with mammograms.”
Another First: Contrast-Enhanced Digital Mammography
a traditional mammogram view shows a metallic
clip within a known breast cancer.
The enhanced mammogram image shows several additional masses not
clearly identified on the traditional view.
In February, Mallinckrodt became one of just a few sites in the U.S. to offer the latest advancement in breast imaging: contrast-enhanced digital mammography (CEDM). As with contrast-enhanced CT or MRI, patients receive a contrast agent before the imaging study begins. Software and equipment upgrades to existing mammography machines produce two sets of images: the standard 2-D digital mammogram, along with the same views enhanced by the contrast agent but with normal breast tissue removed from the images to aid in cancer detection.
“This dual-image capability is one of the advantages CEDM has over contrast-enhanced MRI of the breast,” says Matthew Covington, MD, assistant professor of radiology. “Comparing the standard images with the contrast-enhanced images can help us to better identify cancers that may not have been detected on the mammogram alone, and to better characterize those cancers.”
Another significant advantage over contrast-enhanced MRI is the comparative brevity of CEDM and its cost savings.
“CEDM takes just eight to 10 minutes and appears to be better tolerated by patients, particularly if they are claustrophobic or have certain pacemakers or other medical devices that makes MRI impossible,” says Covington. “In addition, it’s estimated that CEDM is approximately 25% of the cost of an MRI.”
Currently CEDM is being used for women with known breast cancer to evaluate the extent of their disease and determine if there are additional cancer sites within the breasts. It also is being used to evaluate how patients are responding to chemotherapy by comparing the size of the breast cancer before treatment and then while they are receiving treatment.
“It’s exciting to have this technology, not only for these two groups of patients but also for the possibilities it has for future uses,” says Covington. “For example, among women who need a biopsy, could a CEDM identify those who could safely forego that procedure if findings on the contrast-enhanced mammogram show nothing suspicious? Or could this technology be a replacement or substitute for MRI for women who have the BRCA or another high-risk mutation, who have dense breast tissue, or who have other risk factors and are unable to undergo an MRI? These are areas of study we hope to pursue in the future in order to maximize the potential of CEDM.”
The Research Continues
The breast imaging section at MIR currently has more than 35 research projects in various stages of development. Steven P. Poplack, MD, associate professor of radiology, believes this robust research program directly influences the quality of patient care provided by the section’s clinicians.
“It’s absolutely true that as researchers we are able to offer patients diagnostic modalities to which they may not otherwise have access,” he says. “But there’s a cascade effect to it. By performing research, it pushes us to be at the leading edge of the specialty, to be true experts in our field. In turn, it enhances our knowledge and helps inform our clinical practice.”
Steven P. Poplack, MD, believes a robust research
program directly influences the quality of patient care.
Several breast imaging research projects currently underway hold promise for advancing that knowledge and clinical practice. Catherine Young, MD, assistant professor of radiology, is the local principal investigator for a vendor-sponsored initial evaluation of the Brevera® breast biopsy system. Brevera combines tissue acquisition, real-time imaging, sample verification and advanced post-biopsy handling in one integrated system. Rather than having to move to another room to image and verify a patient’s tissue samples, radiologists obtain and image tissue samples in the procedure room in just a few seconds.
Poplack is the local principal investigator for ECOG-ACRIN 1141, a clinical trial studying abbreviated breast MRI vs. digital breast tomosynthesis in women with dense breasts.
“Until now, MRI has been restricted to screening women at very high risk for cancer, either because of a genetic mutation or a high lifetime risk based on family history,” says Poplack. “One of the barriers to widespread use has been the cost of and access to MRI. In this trial, the number of MR pulse sequences has been shortened so that the patient spends less than 10 minutes being imaged. If this comes to fruition, abbreviated breast MRI could change the landscape of how we screen patients, making it more affordable and widespread.”
Poplack, Appleton and Young are also collaborating with Quing Zhu, PhD, a professor at Washington University’s School of Engineering and Applied Science. They’re using a fusion of ultrasound and near-infrared imaging modalities to find out if this combination can more accurately determine a patient’s response to neoadjuvant (first step) treatment, such as chemotherapy or endocrine therapy.
“If we were able to determine earlier or more accurately whether or not a treatment is working, it would save patients from receiving additional, potentially toxic treatments, and allow oncologists to tailor individual therapies much more rapidly,” Poplack says.
Additional current and potential research studies include cryoablation, or freezing, of small invasive breast tumors, trends in the utilization of screening mammography among privately insured women in the U.S., and ultrasound to identify patients who may not need axillary surgery.
“Mallinckrodt’s breast imaging section has multiple strengths that support our research efforts,” adds Appleton. Her list includes the talented investigators, the stellar reputations of MIR and Washington University School of Medicine that attracts outside collaborations, and internal collaborations with various departments within Washington University.
“Underlying all that we do is the knowledge that in the United States 40,000 women die of breast cancer every year, and about a quarter million will be diagnosed with the disease,” she says. “We still have a big job to do, and it’s vital for us to be engaged in the research that will help improve outcomes for all women.”
Above: Contrast-enhanced digital mammography can help “better identify cancers that may not have been detected on the mammogram alone,” says Matthew Covington, MD.