The role of digital breast tomosynthesis in diagnosis of breast cancer SUMMARY The purpose of this study is to describe some imaging findings and evaluate the role of digital breast tomosynthesis (DBT) in diagnosis of breast cancer. The study was conducted on 59 breasts of 59 patients with clinical signs or abnormal imaging findings. The malignant or benign nature of the lesions was established by histologic analysis of biopsied lesions or FNA with follow-up. Result : The common manifestations of cancer noted at DBT include ill-defined mass, speculated margins, architectural distortion and microcalcifications. DBT improved diagnostic sensitivity for patients with mass and architectural distortion, and allows a reclassification of the degree of BI-RADS. There was slight to fair agreement for lesion type (k= 0 - 0.25) and BI-RADS final assessment (k = 0.285 - 0.396). DBT improved diagnostic performance compared to MMG, with Se = 94.9%, Sp = 75%, PPV = 88.1%, NPV = 88.2%, Vg = 88.1%. Conclusion: Our study showed fair agreement in lesion detection and characterization between MMG and DBT images. Our findings also demonstrated that DBT is a novel technique that superior in detecting and diagnosing breast cancer compared to MMG, especially in mass and architectural distortion. Keywords : Digital breast tomosynthesis (DBT), mammography (MMG), breast cancer.