Study Finds No Difference Between Digital Breast Tomosynthesis and Digital Mammography in Cancer Detection for BI-RADS 4 Lesions

A large retrospective study has found no difference between digital mammography and digital breast tomosynthesis when it comes to cancer detection in patients who had BI-RADS 4 breast lesions.

For the study, recently published in the European Journal of Radiology, researchers assessed 11,657 patients who were diagnosed with BI-RADS 4 breast lesions. According to the study, 6,020 patients were diagnosed with two-dimensional digital mammography (DM) and 5,637 patients were diagnosed with digital breast tomography (DBT).

While breast lesions were classified as BI-RADS 4 5.66 percent more often with DBT, the study authors noted similar cancer detection rates for DM (112.65) and DBT (120.76). In regard to biopsy results, there were 4,969 biopsies in the DM group and 4,452 biopsies in the DBT group. The study showed similar malignancy detection with 716 cases in the DM group (14.41 percent) and 712 cases in the DBT group (15.99 percent). There was also no evidence that DBT reduced unnecessary biopsies, according to the study.

The study authors acknowledge that DBT offers better imaging of masses, asymmetries, and other anomalies in contrast to DM. However, they maintained that the study revealed no significant differences between the screening modalities on a variety of measures among patients with BI-RADS 4 breast lesions.

“Our findings indicate that once the assessment is made as BI-RADS 4, biopsy outcomes were comparable for both DM and DBT as malignancy rates, cancer detection rates, and biopsy-derived positive predictive values were similar, such that differences were not statistically significant,” wrote co-author Stephen Wong, Ph.D., the John S. Dunn Presidential Distinguished Chair and chief research informatics officer with the Houston Methodist Cancer Center at the Houston Methodist Hospital, and colleagues.

While the study data was drawn from multiple hospitals, clinics and outpatient breast imaging centers, the research was done within a single health-care system, so the study authors concede a potential for bias. They also noted a possible limitation to the data due to BI-RADS 4 sub-categories not being included in hospital mammogram reports. Limitations with the data also prevented assessment of the impact of breast fibrodensity or tumor grading, according to the study authors.