Digital Mammography, Tomosynthesis, and Contrast-Enhanced Mammography: Intraindividual Comparison of Mean Glandular Dose for Screening Examinations.

BACKGROUND. Contrast-enhanced mammography (CEM) is growing in clinical use due to its increased sensitivity and specificity compared with full-field digital mammography (FFDM) and/or digital breast tomosynthesis (DBT), particularly in patients with dense breasts. OBJECTIVE. The purpose of this study was to perform an intraindividual comparison of mean glandular dose (MGD) with FFDM, DBT, a combination protocol using both FFDM and DBT (hereafter, combined FFDM-DBT), and CEM in patients undergoing breast cancer screening. METHODS. This retrospective study included 389 women (median age, 57.4 years) with an elevated risk of breast cancer who, as part of participation in an earlier prospective clinical trial, underwent breast cancer screening with combined FFDM-DBT and CEM between February 2019 and April 2021. A total of 764 breasts (383 left, 381 right) were evaluated. One craniocaudal (CC) view and one mediolateral oblique (MLO) view were evaluated per breast for each of FFDM, DBT, and CEM. MGD values were extracted from DICOM metadata. BI-RADS breast density categories were extracted from clinical radiology reports. Data were summarized descriptively, including determination of corresponding effective doses. RESULTS. The breast density category was A in zero patients, B in 44 patients (88 breasts), C in 306 patients (599 breasts), and D in 39 patients (77 breasts). The median MGD per breast (CC and MLO views combined) was 4.07 mGy for FFDM alone, 4.97 mGy for DBT alone, 9.38 mGy for combined FFDM-DBT, 3.96 mGy for low-energy CEM, 1.90 mGy for high-energy CEM, and 5.87 for CEM overall. Corresponding effective dose values were 0.49, 0.60, 1.13, 0.48, 0.23, and 0.70 mSv, respectively. The median MGD for density categories B, C, and D, respectively, was 4.01, 4.22, and 2.70 mGy for FFDM; 5.93, 4.93, and 3.17 mGy for DBT; and 5.90, 6.02, and 4.52 mGy for CEM. CONCLUSION. In this intraindividual comparative study of screening examinations, the MGD per breast was higher for CEM than for FFDM or DBT alone. However, these differences were small, and MGD was lower for CEM than for combined FFDM-DBT. CLINICAL IMPACT. These findings are relevant to ongoing considerations of the role of CEM in breast cancer screening pathways.