To compare radiologists’ confidence in assessing breast cancer using combined digital mammography (DM) and digital breast tomosynthesis (DBT) compared with DM alone as a function of previous experience with DBT.
Materials and Methods
Institutional ethics approval was obtained. Twenty-three experienced breast radiologists reviewed 50 cases in two modes, DM alone and DM+DBT. Twenty-seven cases presented with breast cancer. Each radiologist was asked to detect breast lesions and give a confidence score of 1-5 (1- Normal, 2- Benign, 3- Equivocal, 4- Suspicious, 5- Malignant). Radiologists were divided into three sub-groups according to their prior experience with DBT (none, workshop experience, and clinical experience). Confidence scores using DM+DBT were compared with DM alone for all readers combined and for each DBT experience subgroup. Statistical analyses, using GraphPad Prism 5, were carried out using the Wilcoxon signed-rank test with statistical significance set at p< 0.05.
Confidence scores were higher for true positive cancer cases using DM+DBT compared with DM alone for all readers (p < 0.0001). Confidence scores for normal cases were lower (indicating greater confidence in the non-cancer diagnosis) with DM+DBT compared with DM alone for all readers (p= 0.018) and readers with no prior DBT experience (p= 0.035).
Addition of DBT to DM increases the confidence level of radiologists in scoring cancer and normal/benign cases. This finding appears to apply across radiologists with varying levels of DBT experience, however further work involving greater numbers of radiologists is required.