How DBT can provide additional value during breast cancer staging

Using digital breast tomosynthesis (DBT) in addition to digital mammography (DM) can help providers identify additional lesions in patients with known breast cancers, according to a new study published in Radiology.

DBT’s ability to increase cancer detection rates and decrease recall rates is understood, the authors noted, but less research has covered its potential role in breast cancer staging.

“To date, no published studies have specifically assessed the accuracy of DM plus DBT in the identification of additional lesions by excluding the index lesion even though data on multifocality, multicentricity, and bilaterality are crucial to plan management once breast cancer has been diagnosed,” wrote author Marion Fontaine, MD, from Montpellier University Hospital in Montpellier, France, and colleagues. “This study was designed to compare the performance of DM with that of DM plus DBT in the diagnosis of multifocal, multicentric, or bilateral cancer in women with newly diagnosed breast cancer by using breast MRI and pathologic confirmation as reference standards.”

For the study, four radiologists independently reviewed DM and DM plus DBT images from 166 breast cancer patients. Breast MRI and pathologic verifications were used as reference standards. Overall, 24 women exhibited multifocal lesions, 20 exhibited multicentric lesions, 39 exhibited additional ipsilateral lesions and 18 exhibited bilateral lesions. DM plus DBT had a higher sensitivity than DM alone for diagnosing multicentric lesions (51% vs. 37%) and additional ipsilateral lesions (52% vs. 44%). The area under the ROC curve (AUC) was higher for DM plus DBT than DM alone (0.74 vs. 0.67) when diagnosing bilateral breast cancer.

There were important areas, however, where DBT did not lead to improvements when combined with DM.

“The added value of DBT in breast cancer staging was restricted to women with nondense breasts,” the authors wrote. “We did not find any increase in specificity associated with the addition of DBT.”