Combination imaging can distinguish malignant and benign breast tumors
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Imaging breast tumors using four approaches together can better distinguish between malignant breast tumors and those that are benign, compared with imaging using fewer approaches and may help avoid repeat breast biopsies. The new imaging technique, called multiparametric (MP)18FDG PET-MRI, allows tumor imaging by four parameters: DCE-MRI, DWI, 3D1H-MRSI, and18FDG-PET.
MP18FDG PET-MRI was 96% accurate in distinguishing malignant breast tumors from those that were benign. In addition, the researchers compared the results of two and three approaches, and found that better results were had with the four approaches than with combinations of two or three imaging approaches. The study estimates that this technique can reduce unnecessary breast biopsies recommended by the commonly used imaging method, the DCE-MRI, by 50%. This study was published in Clinical Cancer Research (2014; doi:10.1158/1078-0432.CCR-13-2810).
“DCE-MRI is a very sensitive test for the detection of breast tumors, but is limited in visualizing the functional properties cancer cells acquire during development. Therefore, there is still room for improvement,” explained Katja Pinker, MD, associate professor of radiology in the Department of Biomedical Imaging and Image-guided Therapy at the Medical University of Vienna in Austria. “PET-MRI mirrors cancer biology and allows accurate diagnosis of breast cancer without a biopsy. Additionally, the more accurately we understand a tumor's biology, the better we can tailor therapy to each breast cancer patient's individual needs.
The study involved 76 patients with suspicious or inconclusive findings from a mammography or a breast ultrasonography. The researchers performed a MP18FDG PET-MRI on all the patients. In addition, all patients' breast tumor biopsies were evaluated by histopathology.
By combining the imaging data from two parameters, three parameters, and all four parameters, Pinker and colleagues were able to determine the combination of imaging parameters that yielded the most accurate results. All two-parameter and three-parameter evaluations included DCE-MRI. The results were compared with histopathology diagnosis—which diagnosed 53 as malignant and 23 as benign—to evaluate which combination was most efficient in making an accurate diagnosis.
The researchers found that none of the two- or three-parameter combinations reached the same level of sensitivity and specificity as the four-parameter method, which had an AUC of 0.935. (An AUC of 0.9 to 1 means the method is excellent, and an AUC of 0.5 means the method is worthless.)
This study was funded by the Austrian Society of Senology Scientific Funding Award, the Austrian National Bank “Jubiliaemsfond” Project, and the Medical Scientific Fund of the Mayor of Vienna Project. Pinker declares no conflicts of interest.