Combinations of Digital Breast Tomosynthesis and Full-field Digital Mammography for Different Density Types of Breasts

Background: The combination of FFDM and DBT can significantly improve the diagnostic efficiency of breast cancer, but with the increase of breast radiation absorbed dose.

Objectives: To compare and analyze the radiation dose and diagnostic performance of different mammography positions combinations of digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) for different density types of breasts.

Methods: This retrospective study involved 1,195 patients who underwent simultaneous breast DBT and FFDM. The mammography combinations were Group A, FFDM(CC+MLO); Group B, FDM(CC)+DBT(MLO); Group C, FFDM(MLO)+DBT(CC); Group D, DBT(CC+MLO); and Group E, FFDM(CC+MLO)+DBT(CC+MLO). An intergroup comparative analysis of radiation dose and diagnostic performance of different combinations of mammography positions for different breast density types was performed using the pathologic and 24-month follow-up results as the diagnostic basis.

Results: Overall, 2,403 mammograms indicated 477 cases of non-dense breast tissues and 1,926 cases of dense breast tissues. Differences in the mean radiation dose for each non-dense and dense breast group were statistically significant. The areas under the diagnostic receiver operating characteristic (ROC) curves for the non-dense breast group were not statistically significant. In the dense breast group, the z-values were 1.623 (p = 0.105) and 1.724 (p = 0.085) for the area under the ROC curve in Group C compared with Groups D and E, respectively, and 0.724 (p = 0.469) when comparing Group D with Group E. The differences between the remaining groups were statistically significant.

Conclusion: Group A had the lowest radiation dose and no significant difference in diagnostic performance compared with the other non-dense breast groups. Group C had high diagnostic performance in the dense breast group considering the low radiation dose.