DBT detects additional lesions during breast cancer staging

Combining digital breast tomosynthesis (DBT) with digital mammography (DM) can spot additional lesions in patients with breast cancer, reported authors of a recent study published in Radiology.

In the study, four radiologists reviewed DM images and DM plus DBT images taken from 166 breast cancer patients. Twenty-four showed multifocal lesions, 20 multicentric lesions, 39 exhibited additional ipsilateral lesions and 18 showed bilateral lesions.

Using breast MRI and pathologic verification as reference standards, the researchers found DM combined with DBT achieved a 51% sensitivity compared to DM alone (37%) for diagnosing multicentric lesions and a 52% sensitivity for diagnosing additional ipsilateral lesions compared to the 44% achieved by DM. The combined method also produced a higher area under the ROC curve (AUC) than DM alone (0.74 vs. 0.67) for diagnosing bilateral breast cancer.

“Digital mammography (DM) plus digital breast tomosynthesis had higher sensitivity than DM for breast cancer staging regarding the diagnosis of multifocal or multicentric lesions and higher area under the receiver operating characteristic curve regarding the presence of bilateral lesions, without any change in specificity,” wrote Marion Fontaine, MD, of Montpellier University Hospital in Montpellier, France, and colleagues.

One limitation of the combination, according to the researchers, is that it is restricted to women with nondense breasts. Fontaine et al. noted studies on this topic have produced “conflicting results,” with European screening studies demonstrating DBT’s added value regardless of breast density. In contrast, the researchers cited a U.S. study of more than 400,000 patients, noting it did not improve cancer detection in women with extremely dense breasts.

In a related editorial, Linda Moy, MD, with New York University School of Medicine, wrote more research is needed to determine how DBT’s detection of additional cancers impacts long-term health outcomes, but maintained the results add to the growing literature on DBT. 

“The clinical application of tomosynthesis in the settings of screening, assessment, and staging of breast cancer is growing rapidly,” Moy wrote. “Although questions regarding tumor biology remain, this study contributes to our understanding of breast cancers detected with tomosynthesis.”