Amy Chudgar MD, Presenter: Nothing to Disclose

Elizabeth McDonald MD, PhD, Abstract Co-Author: Nothing to Disclose

Susan Weinstein MD, Abstract Co-Author: Nothing to Disclose

Phillip Andrew Yamartino BS, Abstract Co-Author: Nothing to Disclose

Marie Synnestvedt, Abstract Co-Author: Nothing to Disclose

Emily F. Conant MD, Abstract Co-Author: Scientific Advisory Board, Hologic, Inc

To compare the utility of breast MRI in patients with newly diagnosed breast cancer detected on screening mammography in a digital breast tomosynthesis (DBT) screened population versus a digital mammography (DM) screened population.

Retrospective IRB approved review of 24,563 DBT screened patients (10/1/2011-11/20/2013) and 10,751 DM screened patients (9/1/2010 - 8/30/2011) was performed. 235 of the DBT patients had a subsequent MRI. 83 of the MRIs were obtained for staging of DBT detected newly diagnosed breast cancer. In the DM cohort, 83 patients had a subsequent MRI, 26 of which were for staging of DM detected newly diagnosed breast cancer. Three MRI exams were excluded from the DM group due to lack of sufficient follow-up leaving 23 studies. These two staging groups constituted our study population. Additional disease detected by MRI was defined as malignancy in the contralateral breast or greater than 2 cm away from the index malignancy. Differences between groups were compared using Wilcoxon Rank Sum test.

In the DBT cohort, MRI detected additional disease in 8/83 (10%). There were 12/84 (14%) false positives and in 63/83 (76%) cases, MRI did not add any additional information. In the DM cohort, 23 staging MRIs were reviewed. 7 cases were true positives (30%), 3 were false positives (13%), and 13 offered no additional information (57%). The DBT cohort had significantly less true positive staging MR exams than the DM cohort (p=0.012). There was no significant difference in the incidence of false positive findings or no additional information between the two cohorts (p=0.87 and 0.70, respectively).

In both DM and DBT screened populations with new cancer diagnoses, MRI is able to detect additional cancer. However, with the implementation of DBT, the positive impact of MRI for this indication is diminished.

With improved cancer detection by DBT, the role of MRI in screening for additional disease should be reevaluated.

Chudgar, A, McDonald, E, Weinstein, S, Yamartino, P, Synnestvedt, M, Conant, E, Digital Breast Tomosynthesis versus Digital Mammography Detected Cancers: Assessment of Disease Extent on MRI.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014818.html