What You Need to Know: An MRI screening protocol for breast cancer that takes just 3 minutes is as good as a regular MRI that takes 21 minutes, and more accurate than digital mammography, according to a proof-of-concept study published in the August 1 issue of the Journal of Clinical Oncology.
What: The accelerated MRI was as good as regular MRI for detecting 11 invasive breast cancers that had escaped detection on regular mammography, report Christiane A. Kuhl, MD, and colleagues from the University Hospital of Aachen in Bonn, Germany.
“MRI is the technique of the future [for screening]. Ionizing radiation is not involved. Compared with digital mammography, it is highly sensitive, and overdiagnosis is less of a problem, contrary to current notions,” Dr. Kuhl told Medscape Medical News.
How: Dr. Kuhl’s team “stripped down MRI to the essential part that makes for fast acquisition,” she explained. For the 3-minute protocol, the radiologist reads the first postcontrast subtracted (FAST) and maximum-intensity projection images; for the full diagnostic protocol, all the images are read. The screening accuracy of the accelerated MRI is similar to that of a full diagnostic MRI, she added.
The accelerated protocol “is a huge step forward in breast cancer screening,” writes Elizabeth A. Morris, MD, chief of breast imaging services at the Memorial Sloan Kettering Cancer Center in New York City, in an accompanying editorial. “Data clearly demonstrate that FAST breast MRI could be the standard for breast cancer screening: it is safe, does not induce cancers, and can find more cancers than mammography,” she explains.
The study consisted of 443 asymptomatic women at mild to moderate risk for breast cancer. They had all undergone digital mammography, and the women with dense or extremely dense breasts had also undergone ultrasound screening, all with negative results. The women then underwent MRI screening, which identified 11 breast cancers — 7 invasive cancers and 4 ductal carcinoma in situ. The identification of these 11 cancers provided an additional cancer yield of 18.3 per 1000.
My Take: Though not ready for general use, fast MRI is promising. In the screening setting, the investigators achieved a high detection rate. They accomplished this without a high false-positive rate, suggesting that we may have a quality screening test. The negative predictive value (the test says no cancer, when there really is no cancer) was 99.8%. Currently, I believe that 3D (tomosynthesis) mammograms represent the best technology for screening women at average risk. If you have a high risk for breast cancer, ask about risk-reducing methods (including tamoxifen), and whether you should add MIR to your mammogram routine. I’m Dr. Michael Hunter.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
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References: http://www.medscape.com/viewarticle/830245; 2014 August 1 issue of the Journal of Clinical Oncology.