Two-view 2D digital mammography versus one-view digital breast tomosynthesis

Introduction

In routine breast screening using 2D digital mammography (2DM), mediolateral-oblique (MLO) and craniocaudal (CC) views are performed to maximise cancer detection. Digital breast tomosynthesis (DBT) improves the visibility of lesions by eliminating the problem of superimposition of normal structures, and there is uncertainty regarding the need for two views. The purpose of this study is to compare the accuracy of two-view 2DM with one-view DBT.

Methods

Five hundred and one cases were evaluated from the DBT trial dataset of clients recalled for further workup after their initial film-screen mammography. Bilateral two-view 2DM and DBT examination were performed in all study subjects. Mammography scores (1 to 5) based on RCR Breast Group criteria were recorded and an overall score for 2DM was established based on the highest value of MLO and CC scores. Unblinded interpretation of the 2DM followed by MLO-alone DBT was carried out. Statistical analysis was done using the receiver-operative characteristic (ROC).

Results

There were 111 (22.1%) cancers. The ROC area under the curve (AUC) for two views combined 2DM was 0.915 and for MLO-alone DBT was 0.960 (difference 0.045; P = 0.009). The distribution of M-scores against the histology-proven malignant lesions is presented in Table 1.

Table 1

Conclusions

In this series, one-view (MLO-alone) DBT had superior sensitivity compared with two-view 2DM.