Breast density-tailored screening for breast cancer in females is of great interest. 1 Breast density is a predictor of breast cancer; it reduces the sensitivity of mammography, leading to an increased risk of interval cancer in the screening population. 2,3 Several breast imaging modalities have been used as adjuncts to screening mammography in females with dense breasts, including ultrasound (US; handheld or automated), MRI, and the more recently applied digital breast tomosynthesis (DBT). DBT is an emerging technique that allows the breast to be viewed quasi-three-dimensionally, which reduces superimposition of the breast tissue. 4,5 Previous studies showed that DBT improved the accuracy of full-field digital mammography (FFDM) in screening across all breast densities by reducing the recall rates and increasing the cancer detection rates. 6-10 In addition, a recent study including females with dense breasts reported that the addition of DBT increased the sensitivity of FFDM. 11-13 To date, the effect of breast density on the diagnostic performance of DBT was evaluated based on percentage-based classification. Breast density assessed using mammography, reflects the breast composition. High breast density can comprise various breast compositions. The tumour located in the dense breast with small amount of interposed fat tissue that overlaps individual sections may result in mammographically occult cancer and even with the use of DBT. 14 Moreover, in case of the occurrence of small tumour without noticeable calcification,