For breast screening programs with limited access to MR imaging, or for patients who prefer to not undergo MR screening, contrast-enhanced mammography (CEM) could offer a low-cost alternative with similar cancer detection rates.
Berg
There is increasing interest in personalized screening based on breast density and risk, said Wendie A. Berg, MD, PhD, who serves as Distinguished Professor of Radiology and The Bernard F. Fisher Chair for Breast Cancer Clinical Science at the University of Pittsburgh School of Medicine and Magee-Womens Hospital in Pennsylvania. She presented results from her team's study, "Screening Contrast-Enhanced Mammography as an Alternative to MRI (SCEMAM)," in a Monday scientific session.
By September 2024, all women in U.S. screening programs are to receive communications telling them whether their breasts are dense or not dense. "Twenty states, including Pennsylvania, currently have laws requiring insurance coverage for supplemental MR screening in women with dense breasts—usually with other risk factors," Dr. Berg explained. "But there is limited capacity for screening MR imaging."
As part of the SCEMAM study, funded by the Pennsylvania Breast Cancer Coalition, Dr. Berg and her team examined the feasibility of adding screening CEM to tomosynthesis in women who would qualify for MR screening.
"Our study showed added detection of six cancers in 601 women," Dr. Berg said. "This is very similar to the added cancer detection rate of abbreviated MR imaging found in the ECOG-ACRIN 1141 trial."
The cancers they found were mostly small, invasive cancers with a median size of 0.7 cm, all node-negative, and three were invasive lobular cancer.
False-positive recalls from CEM occurred in 13% of the participants—a rather high rate, Dr. Berg noted, that is likely attributable to the technique's additional background enhancement. Two women had DCIS-related calcifications that were seen only on low-energy images, but the researchers found no false negatives from CEM alone—with no interval cancers reported.
Recommendations for Implementing CEM Screening
Considering the high potential for false-positive recalls, as well as the added considerations of potential contrast reactions and radiation dose, Dr. Berg offered recommendations for imaging centers looking to employ CEM in their screening programs.
"The good sides to CEM include use of current equipment, familiar positioning, the low cost of the contrast, and excellent cancer detection that is similar to that of MR imaging," Dr. Berg said. "We and others have found strong patient preference for CEM over MR." She noted that, for example, during the American College of Radiology Imaging Network (ACRIN) 6666 study, among women who were offered MR imaging at no cost, nearly 42% declined it for various reasons—the most prominent being claustrophobia.
CEM does warrant its own consideration for workflow and communication issues, Dr. Berg said, including training needed to set up an intravenous line and manage contrast reactions, as well as ensuring a physician is available to manage adverse reactions.
Dr. Berg further recommended that centers looking to implement CEM screening should have direct CEM-guided biopsy capability, since MR imaging-guided biopsy is not a good option for women who can't tolerate MR.
"We developed a case set to train our radiologists in CEM interpretation, but there is still a learning curve and need for more widespread standardized training," Dr. Berg said.
Access the presentation, "Screening Contrast-Enhanced Mammography as an Alternative to MRI (SCEMAM)," (M1-SSBR04-04) on demand at Meeting.RSNA.org.
