Comparison of the diagnostic performance of digital breast tomosynthesis and magnetic resonance imaging added to digital mammography in women with known breast cancers.

OBJECTIVES: To compare the diagnostic performance of digital breast tomosynthesis (DBT) and magnetic resonance imaging (MRI) added to mammography in women with known breast cancers.

METHODS: Three radiologists independently reviewed image sets of 172 patients with 184 cancers; mammography alone, DBT plus mammography and MRI plus mammography, and scored for cancer probability using the Breast Imaging Reporting and Data System (BI-RADS). Jack-knife alternative free-response receiver-operating characteristic (JAFROC), which allows diagnostic performance estimation using single lesion as a statistical unit in a cancer-only population, was used. Sensitivity and positive predictive value (PPV) were compared using the McNemar and Fisher-exact tests.

RESULTS: The JAFROC figures of merit (FOMs) was lower in DBT plus mammography (0.937) than MRI plus mammography (0.978, P = 0.0006) but higher than mammography alone (0.900, P = 0 .0013). The sensitivity was lower in DBT plus mammography (88.2 %) than MRI plus mammography (97.8 %) but higher than mammography alone (78.3 %, both P < 0 .0001). The PPV was significantly higher in DBT plus mammography (93.3 %) than MRI plus mammography (89.6 %, P = 0 .0282).

CONCLUSIONS: DBT provided lower diagnostic performance than MRI as an adjunctive imaging to mammography. However, DBT had higher diagnostic performance than mammography and higher PPV than MRI.

KEY POINTS: • Digital breast tomosynthesis (DBT) plus mammography was compared with MRI plus mammography. • DBT had lower sensitivity and higher PPV than MRI. • DBT had higher diagnostic performance than mammography.