Comparison of radiation dose between 2D digital stereotactic versus digital breast tomosynthesis-guided breast biopsies

Rationale and Objective: Use of digital breast tomosynthesis (DBT) in breast imaging has necessitated DBT-guided biopsy, however, a single DBT acquisition may result in a greater radiation dose than a single DM acquisition. Our objective was to compare the number of images acquired and the resulting radiation dose of DBT versus DM-guided breast biopsies. Method: All biopsies performed on our DM unit from 8/2016 to 1/2017 and on our DM-DBT unit from 8/2017 to 1/2018 were retrospectively reviewed. The number of image acquisitions, average glandular dose (AGD) per acquisition and per procedure were computed and stratified by guidance modality and lesion type. Results: 25 DM-guided biopsies were performed on the DM-only unit, 58 biopsies were performed with DM guidance on the dual unit (DM-DU) and 29 were performed with DBT. The average number of images acquisitions was 10.9 for DM-only unit biopsies, 9.3 images for DM-DU biopsies and 4.3 images for DBT-guided biopsies. Mean procedure AGD for DM-only unit biopsies was 28.77 mGy, versus 22.06 mGy for DM-DU and 10.18 mGy for DBT biopsies. Mean procedure AGD for biopsied calcification-only lesions was 22.3 mGy for DM-DU versus 10.7 mGy for DBT guidance (p < 0.001), with an average of 8.1 images per procedure for DM-DU versus 4.2 for DBT. Conclusion: Fewer image acquisitions were obtained with DBT compared with DM guidance, therefore, the overall dose of DBT-guided procedures was less. The dose reduction obtained with DBT is possible across all lesion types, even for calcification-only lesions.