Do benign-concordant breast MRI biopsy results require short interval follow-up imaging? Report of longitudinal study and review of the literature.

OBJECTIVE

The objectives of this study were to examine the frequency and outcomes of short interval imaging follow up of benign, concordant breast MRI biopsies and review the published literature on this topic.

MATERIALS AND METHODS

This was an IRB-approved, HIPAA compliant retrospective review of women undergoing MRI-guided breast biopsies between October 1, 2008 and December 31, 2014. Patients with malignant or high risk lesions with recommendation for excision, discordant cases, and those undergoing breast conservation therapy in same quadrant, chemotherapy or mastectomy were excluded. At least 2 years imaging and/or clinical follow-up without development of cancer in the same quadrant as the biopsy was set as the benchmark to confirm benign etiology. A PubMed search of similar articles through 2018 was also performed for the literature review.

RESULTS

943 consecutive MRI-guided biopsies were performed in 785 women. Of these, 378/943 (40.1%) were benign and met inclusion criteria. Eleven cases were recommended for and underwent repeat MRI-guided biopsy or excision, 2 of which were malignant. The overall false negative rate for benign concordant MRI-guided biopsy was 2/378, 0.5% (95% CI 0.02 to 2.0%). Literature search demonstrated five articles with similar methodologies yielding 628 additional cases of benign concordant breast biopsies. Nine of these cases were eventually diagnosed as malignancy with a false negative rate of 1.4%. Combined with our data, the overall false negative rate is 1.1%.

CONCLUSIONS

Short interval follow-up exams for benign concordant MRI-guided breast biopsies may not be necessary given the low malignancy rate.