Sandra Brennan MBBCh, MSc, Presenter: Nothing to Disclose

Janice Sung MD, Abstract Co-Author: Nothing to Disclose

D. David Dershaw MD, Abstract Co-Author: Nothing to Disclose

Laura Liberman MD, Abstract Co-Author: Nothing to Disclose

Elizabeth A. Morris MD, Abstract Co-Author: Nothing to Disclose

The purpose of our study was to determine the rate of cancelled MRI-guided breast biopsies due to lesion non-visualization and to assess associated features and outcome data for these canceled cases.

With IRB approval, a retrospective review was performed of the records of 844 patients scheduled for MRI-guided breast biopsy from 2004-2008. In 71 patients, biopsy was canceled due to lesion non-visualization. Medical records and imaging studies in these cases were reviewed to determine hormonal status and background parenchymal features. Fifty-six (79%) of these 71 patients had follow-up MRI examinations at a median of 16 months, including 33 patients who had >12 month MRI follow-up. Follow-up MRI examinations were reviewed to determine outcome data. Statistical analysis was performed with the Fisher exact test.

Cancellation of MRI biopsy occurred in 71/ 844 (8%) patients. The cancellation rate was 14/102 (14%) in 2004, 9/144 (6%) in 2005, 12/146 (8%) in 2006, 17/230 (7%) in 2007, and 19/222 (9%) in 2009. A higher cancellation rate occurred in the first year as compared to subsequent years (14/102=14% vs. 57/742=8%, p=0.06). Among the 71 patients, hormonal status was premenopausal in 41 (58%) and post-menopausal in 30 (42%). Breast parenchymal density was extremely dense in 29 (41%), heterogeneously dense in 35 (49%), and scattered fibroglandular densities or fatty in 7 (10%). Background enhancement was marked or moderate in 39/71 (55%) and mild in 32/71 (45%). Lesions were characterized as mass (39/71) or non-mass (clumped 14/71 or linear 18/71). Of 56 patients with follow-up MRIs, the original lesion was seen on subsequent imaging in 20 patients. Four of these 20 patients underwent biopsy yielding benign results, including one high-risk lesion (intraductal papilloma).

Our rate of cancellation of MRI-guided biopsies due to lesion non-visualization was 8%. Failure to see the original suspicious lesion at the time of MRI biopsy does not appear to be related to hormonal status in most cases. Although we found no cancers among canceled MRI biopsies, short-term MRI follow-up may be prudent pending further studies.

Non-visualization of the MRI target at biopsy may occur due to hormonal and non-hormonal factors. Although we found no cancers among canceled cases, short-term MRI follow-up may be prudent.

Brennan, S, Sung, J, Dershaw, D, Liberman, L, Morris, E, Cancellation of MRI Biopsy due to Breast Lesion Disappearance: Frequency and Follow-up.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8012506.html