The effect of the amount of peritumoral adipose tissue in the detection of additional tumors with digital breast tomosynthesis and ultrasound.

Background Digital breast tomosynthesis (DBT) and ultrasound (US) can detect additional cancers after negative mammography. However, not all cancers are visible by both techniques. Purpose To study the role of the amount of peritumoral fat in the detection of additional cancers with DBT or US. Material and Methods One reader retrospectively reviewed 142 breast cancers in 109 women who underwent mammography, DBT, US, and magnetic resonance imaging (MRI). Two readers in consensus evaluated the additional cancers detected by US, DBT, or MRI, and classified them into four groups according to the amount of peritumoral adipose tissue: group I, >75% of peritumoral fat; group II, 50-74%; group III, 25-49%, and group IV, 0-24%. The detection of additional cancers by US and DBT with respect to the other imaging techniques was evaluated. Results Seventy-eight cancers were detected by mammography and the remaining 64 cancers were detected by DBT, US, or MRI. US and DBT detected 46 (71.8%) and 25 (39.06%) additional tumors, respectively. Statistical significance was only found in group IV ( P < 0.01). Conclusion US detected more tumors than DBT in lesions surrounded by a small amount of fat. No significant differences were found between US and DBT in the detection of additional cancers in the other groups.