Adding Tomosynthesis to Contrast Mammography Cuts False Positives Without Sacrificing Sensitivity

As contrast-enhanced mammography (CEM) gains traction as a powerful screening tool for breast cancer, new research suggests that pairing it with digital breast tomosynthesis (DBT) can reduce false positives—without undermining CEM’s high sensitivity. The findings, presented Tuesday, could help shape how radiology departments implement CEM in practice.

“We have been using DBT routinely for screening since 2011, and we know that it improves performance compared to 2D mammography—both for detecting cancers and reducing false alarms,” said Wendie A. Berg, MD, PhD, professor of radiology at the University of Pittsburgh School of Medicine and UPMC Magee-Women’s Hospital. “When we started doing CEM, we did not want to lose those benefits.”

While CEM’s ability to detect small invasive cancers is well established, it's been less clear whether adding DBT meaningfully improves outcomes. In real-world settings, radiologists typically view all image types together, making it difficult to isolate the contribution of each. To address this, Dr. Berg’s team designed a controlled reader study using software that guided five breast imagers through a locked-step interpretation: first low-energy (LE) images, then recombined contrast-enhanced (RC) images, and finally DBT.

The study included 403 enriched screening cases. The addition of RC images significantly boosted sensitivity—from 44% on LE alone to 79% with CEM. “The cancers that we find because of contrast are mostly small invasive cancers, averaging 6–7 millimeters, and mostly found before they spread to lymph nodes,” Dr. Berg said. “These are exactly the cancers we want to find.”

However, adding DBT did not further increase sensitivity. That outcome was expected, according to Dr. Berg, since most noncalcified invasive cancers already enhance with contrast, while ductal carcinoma in situ (DCIS), which might not enhance, often shows up via calcifications on LE images.

Instead, DBT’s value came in reducing false positives. Viewing RC images increased the false recall rate, but DBT helped lower it by 5%, allowing radiologists to dismiss benign findings more confidently. “False alarms cause stress for patients and add cost, and it is always desirable to minimize them, as long as we don’t sacrifice cancer detection,” Dr. Berg noted. She added that in clinical practice, the benefit might be even greater due to the availability of prior DBT exams showing stable benign findings.

Beyond numbers, DBT still offers anatomical clarity that complements the vascular insights from contrast imaging. “DBT can help us recognize (and dismiss) normal lymph nodes, bends in blood vessels and skin lesions that can enhance on CEM,” Dr. Berg said. “DBT also shows mass margins better than we can see them on CEM.”

Still, radiation dose remains a consideration. Adding DBT nearly doubles the dose compared to CEM alone, though levels remain within accepted limits. Dr. Berg cautioned that special attention is needed when imaging younger patients or those with radiation-sensitive genetic mutations such as BRCA or TP53.

For practices considering CEM, the takeaway is clear: adding DBT offers a meaningful reduction in false positives and improves interpretive confidence. “When considering implementation strategies to add CEM to one’s practice, it is useful to know that there is a benefit to including DBT as part of the CEM examination,” Dr. Berg said.