| Abstract: |
Purpose: To compare the diagnostic accuracy of prone 18F-FDG PET/CT with that of contrast-enhanced MRI (CE-MRI) at 3 T in suspicious breast lesions. To evaluate the influence of tumour size on diagnostic accuracy and the use of maximum standardized uptake value (SUV<inf>MAX</inf>) thresholds to differentiate malignant from benign breast lesions. Methods: A total of 172 consecutive patients with an imaging abnormality were included in this IRB-approved prospective study. All patients underwent 18F-FDG PET/CT and CE-MRI of the breast at 3 T in the prone position. Two reader teams independently evaluated the likelihood of malignancy as determined by 18F-FDG PET/CT and CE-MRI independently. 18F-FDG PET/CT data were qualitatively evaluated by visual interpretation. Quantitative assessment was performed by calculation of SUV<inf>MAX</inf>. Sensitivity, specificity, diagnostic accuracy, area under the curve and interreader agreement were calculated for all lesions and for lesions <10 mm. Histopathology was used as the standard of reference. Results: There were 132 malignant and 40 benign lesions; 23 lesions (13.4 %) were <10 mm. Both 18F-FDG PET/CT and CE-MRI achieved an overall diagnostic accuracy of 93 %. There were no significant differences in sensitivity (p = 0.125), specificity (p = 0.344) or diagnostic accuracy (p = 1). For lesions <10 mm, diagnostic accuracy deteriorated to 91 % with both 18F-FDG PET/CT and CE-MRI. Although no significant difference was found for lesions <10 mm, CE-MRI at 3 T seemed to be more sensitive but less specific than 18F-FDG PET/CT. Interreader agreement was excellent (κ = 0.85 and κ = 0.92). SUV<inf>MAX</inf> threshold was not helpful in differentiating benign from malignant lesions. Conclusion: 18F-FDG PET/CT and CE-MRI at 3 T showed equal diagnostic accuracies in breast cancer diagnosis. For lesions <10 mm, diagnostic accuracy deteriorated, but was equal for 18F-FDG PET/CT and CE-MRI at 3 T. For lesions <10 mm, CE-MRI at 3 T seemed to be more sensitive but less specific than 18F-FDG PET/CT. Quantitative assessment using an SUV<inf>MAX</inf> threshold for differentiating benign from malignant lesions was not helpful in breast cancer diagnosis. © 2015, Springer-Verlag Berlin Heidelberg. |
