LAUSR

PURPOSE To compare the extent of disease as seen on mammography, breast MRI and final surgical pathology in all patients with non-calcified DCIS identified on stereotactic core biopsy. Can MRI provide useful diagnostic information to the surgeon when mammographically occult DCIS is present. METHOD AND MATERIALS All patients with stereotactic core biopsies performed at the University of Chicago from 2010 to 2017 were retrospectively reviewed. Patients with pathology demonstrating DCIS in non-calcified cores on stereotactic biopsy were further selected based on whether they had a subsequent breast MRI and definitive surgical treatment. A total of 76 patients met these criteria. All patients undergoing stereotactic core biopsy had at least six 9-gauge cores removed, all of which were radiographed and separated based on whether calcifications were present or absent. Select patients with documented DCIS in the non-calcified cores had a MRI. All patients with MRI underwent a routine diagnostic protocol consisting of one pre- and five post-contrast bilateral, fat suppressed T1 sequences along with a non-fat suppressed T2 sequence. Final surgical treatment was subsequently determined and performed by the breast surgeon. RESULTS 76 women met all criteria for this study. In 16/76 (21%) of the cases, MRI revealed greater extent of disease than was detected via mammography, and led to change in management in half of those cases (8/76 - 11%). In all 16 of these cases, final surgical pathology confirmed the MRI-detected extent of disease. In 52/76 (68%) of the cases, MRI confirmed the extent of disease detected on mammography and final surgical pathology. In 8/76 (11%) of the cases, MRI showed little to no abnormal enhancement at site of mammographically detected calcifications, even though final surgical pathology confirmed presence of residual disease. CONCLUSION The presence of non-calcified DCIS in stereotactic core biopsy samples raises the suspicion for the presence of mammographically occult disease. Breast MRI performed in this setting shows that in majority (82% -68/76) of the cases, MRI can either confirm or even advantageously reveal greater extent of disease than was initially detected on mammography. Furthermore, there can be a change in management due to the breast MRI findings. CLINICAL RELEVANCE/APPLICATION Breast MRI can be a useful diagnostic tool for the surgeon when non-calcified DCIS is present in stereotactic core biopsy samples. Citation Format: Sheth D, Bao J, Abe H, Jaskowiak N. Diagnostic value of breast MRI in evaluating total extent of disease when non-calcified DCIS is present in stereotactic core biopsy samples [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-05.