Study examines mismatch between breast MRI BI-RADS assessments, clinical recommendations

Breast MRI examinations assessed using BI-RADS guidelines don’t always coincide with expected clinical management recommendations, according to results of a study published online in the American Journal of Roentgenology.

Over the past 10 years, the advantages of MRI as an imaging modality have led to a rapid increase in its use for detecting and diagnosing malignant breast cancers, particularly those not easily identifiable through traditional breast imaging methods such as mammography or ultrasound.

In response to this increased utilization, the American College of Radiology expanded its BI-RADS breast imaging reporting system—which uses categories numbered 0 through 6 to assess malignancy—to include breast MRI, with the latest update occurring in 2013.

But exactly how BI-RADS assessments of breast MRI exams correlate to existing recommendations for patient management has yet to be investigated, according to Amie Lee, MD, and her colleagues from the University of California San Francisco.

“Given the relatively recent introduction of the breast MRI BI-RADS lexicon, little is known about use patterns of MRI BI-RADS assessment categories and whether they are used with concordant management recommendations in community practice,” wrote the authors. “Discordance between assessments and recommendations could have significant influence on patient care, potentially leading to unnecessary workup or to delayed cancer diagnosis.”

Lee and her team collected breast MRI data of women between the ages of 18 and 79 from four regional Breast Cancer Surveillance Consortium registries from 2005 to 2011 to compare assessments and recommendations to determine concordance with BI-RADS guidelines. Assessment category, year of examination and clinical indication were used to compare concordance.

They found that concordance was highest in examinations with a BI-RADS category 2 (benign) assessment at 93 percent, followed by examinations with category 1 (negative) at 87 percent, category 0 (incomplete) exams at 83 percent, category 5 (highly suggestive of malignancy) at 83 percent, and category 4 (suspicious) at 74 percent. The lowest concordance rates were found in breast MRI exams with categories 3 (probably benign) and 6 (known biopsy-proven malignancy), with concordance at 36 percent and 56 percent, respectively.

“Breast MRI BI-RADS management recommendations were most concordant for assessments of negative, incomplete, suspicious, and highly suggestive of malignancy,” concluded Lee et al. “Lower concordance for assessments of probably benign and known biopsy-proven malignancy and for examinations performed to assess disease extent highlight areas for interventions to improve breast MRI reporting.”