Multiparametric Evaluation of Breast Lesions Using PET-MRI

Abstract

The purpose of this study was to evaluate the diagnostic accuracy of multiparametric evaluation of breast lesions combining information of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), diffusion-weighted imaging (DWI), and 18F-fluoro-deoxi-glucose (18F-FDG) positron emission tomography/computed tomography (PET-CT). After approval of the institutional research ethics committee, 31 patients with suspicious breast lesions on MRI performed 18F-FDG PET-CT with a specific protocol for breast evaluation. Patients’ mean age was 47.8 years (range, 29–77 years). Positron emission tomography and magnetic resonance imaging (PET-MRI) images were fused. A lesion was considered positive on multiparametric evaluation if at least 1 of the following was present: washout/type 3 kinetic curve on DCE-MRI, restricted diffusion on DWI with minimum apparent diffusion coefficient value <1.00 × 10−3 mm2/s, and abnormal metabolism on 18F-FDG PET-CT (higher than the physiologic uptake of the normal breast parenchyma). Thirty-eight lesions with histologic correlation were evaluated on the 31 included patients, being 32 mass lesions (84.2%), and 6 nonmass lesions (15.8%). Lesions’ mean diameter was 31.1 mm (range, 8–94 mm). Multiparametric evaluation provided 100% sensitivity, 55.5% specificity, 87.9% positive predictive value, 100% negative predictive value, and 89.5% accuracy, with 29 true-positives results, 5 true-negatives, 4 false-positives, and no false-negative results. Multiparametric evaluation with PET-MRI functional data showed good diagnostic accuracy to differentiate benign from malignant breast lesions, reducing the number of unnecessary biopsies, without missing any diagnosis of cancer in our case series.

PET/MRI in Breast Cancer

“…A lesion had to meet one of three criteria: a washout curve on DCE MRI, ADC min <1.00 × 10 mm/s, or 18 F‐FDG uptake above background. The specificity in this study was 55% . In another multiparametric study, Pinker et al included four parameters: PET, DCE MRI, DWI, and 1hydrogen‐MRS, in their evaluation of 78 indeterminate or suspicious breast lesions .…”

“…DCE breast MRI has a high sensitivity, reported at up to 100%, and a positive predictive value above 35% . PET/CT is not routinely performed for breast cancer detection because is it not adequately sensitive, especially for lobular cancers and for cancers less than 1 cm . Authors have investigated whether combining DCE MRI and PET data in the breast can improve the diagnostic accuracy for breast cancer, but have found that the addition of PET often decreases the sensitivity of DCE‐MRI.…”

“…However, Bitencourt et al showed that when multiple MR parameters are included in a PET/MR evaluation, 100% sensitivity could be achieved . In that study, the authors evaluated 38 lesions, 29 of which were malignant, with DCE MRI, DWI, and 18 F‐FDG PET.…”

Assessment of Aggressiveness of Breast Cancer Using Simultaneous 18F-FDG-PET and DCE-MRI

“…Differences in patient positioning during PET/CT and MRI examinations may alter the quantitative results of these imaging modalities. Whole body PET/MRI not only facilitates quantitative tumor characterization, it also allows for confident detection of primary breast cancer, satellite lesions, and distant metastases while at the same time decreasing radiation dose to the patient compared to PET/CT [41–43]. When PET/MR was performed after PET/CT with a single injection, there were strong correlations between SUV values from PET/CT and PET/MRI in breast cancer metastases [44].…”

The Diagnostic Value of Superb Microvascular Imaging (SMI) in Detecting Blood Flow Signals of Breast Lesions

“… 2 Currently, breast tumor vascularity can be assessed by noncontrast-enhanced ultrasonography, such as color Doppler flow imaging (CDFI), and contrast-enhanced imaging techniques, such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), contrast-enhanced ultrasound (CEUS), and dynamic contrast-enhanced computed tomography. 3 – 5 CDFI can provide information on tumor vascularity associated with breast malignancy; however, it has been proven to be unreliable in differentiating benign from malignant breast lesions when compared with the invasive imaging modalities listed above. 6 , 7 The number of vessels seen with CDFI often indicates the macrovascularity of breast cancers, but not the microvasculature.…”