Abbreviated Screening MRI Protocol Is Highly Accurate in Breast Cancer Detection in Women at Increased Risk
As reported in the Journal of Clinical Oncology, Kuhl et al assessed whether an abbreviated breast magnetic resonance imaging (MRI) protocol, consisting of one pre- and one postcontrast acquisition and derived images—first postcontrast–subtracted (FAST) and maximum-intensity projection (MIP) images—was suitable for breast cancer screening. They found that an MRI acquisition time of 3 minutes and expert radiologist MIP reading time of 3 seconds were sufficient to accurately establish the absence of breast cancer in high-risk women and that, with a reading time < 30 seconds, the complete abbreviated protocol had diagnostic accuracy equivalent to a full diagnostic protocol.
Study Details
This prospective study involved 443 women with mildly to moderately increased risk of breast cancer who underwent 606 screening MRIs. The women had to have normal or benign findings on digital mammogram and those with heterogeneously or extremely dense breasts (n = 427) had to have normal or benign ultrasound findings. Expert radiologists first reviewed MIP images to identify significant enhancements and then reviewed the complete abbreviated protocol of MIP and FAST images, with the option of reviewing the nonsubtracted source images, to establish diagnosis. The full diagnostic protocol was then analyzed.
Average MRI acquisition time was 17 minutes for the full protocol vs 3 minutes for the abbreviated protocol; the average reading times were 2.8 seconds for single MIPs and 28 seconds for complete abbreviated protocols.
Diagnostic Yield
A total of 11 breast cancers were diagnosed, representing an increased diagnostic yield of 18.2 per 1,000 screening rounds and a breast cancer incidence of 2.5%. Cancers consisted of four ductal carcinomas in situ and seven invasive cancers, all of which were T1N0 intermediate or high grade.
Accuracy
Sensitivities were 90.9% for MIP rating and 100% for both the complete abbreviated protocol and the full diagnostic protocol (P = .317). Negative predictive values were 99.8%, 100%, and 100%. Specificities were 94.3% for the abbreviated protocol and 93.9% for the full protocol (P = .563), and positive predictive values were 24.4% and 23.4%.
The investigators concluded, “[O]ur study suggests that with the abbreviated breast MRI approach…, screening breast MRI is feasible without compromising sensitivity or specificity compared with the regular full diagnostic MRI protocol. Abbreviated breast MRI screening could thus open up the opportunity for batch MRI screening according to the model of mammographic screening. If confirmed by future trials, this could increase access to breast MRI and decrease the cost of existing MRI screening programs.”
Christiane K. Kuhl, MD, of University of Aachen, Germany, is the corresponding author for the Journal of Clinical Oncology article.
The authors indicated no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
