Radiation dose affected by mammographic composition and breast size: First application of a radiation dose management system for full-field digital mammography in Korean women

Background: Relative to Western women, Korean women show several differences in breast-related characteristics, including higher rates of dense breasts and small breasts. We investigated how mammographic composition and breast size affect the glandular dose during full-field digital mammography (FFDM) in Korean women using a radiation dose management system. Methods: From June 1 to June 30, 2015, 2120 FFDM images from 560 patients were acquired and mammographic breast composition and breast size were assessed. We analyzed the correlations of patient age, peak kilovoltage (kVp), current (mAs), compressed breast thickness, compression force, mammographic breast composition, and mammographic breast size with the mean glandular dose (MGD) of the breast using a radiation dose management system. The causes of increased radiation were investigated, among patients with radiation doses above the diagnostic reference level (4th quartile, ≥75%). Results: The MGD per view of 2120 images was 1.81±0.70mGy. In multivariate linear regression analysis, age was negatively associated with MGD (p<0.05). The mAs, kVp, compressed breast thickness, and mammographic breast size were positively associated with MGD (p<0.05). The "dense" group had a significantly higher MGD than the "non-dense" group (p<0.05). Patients with radiation dose values above the diagnostic reference value had large breasts of dense composition. Conclusions: Among Korean women, patients with large and dense breasts should be more carefully managed to ensure that a constant radiation dose is maintained.