Detection of metastatic bone lesions in breast cancer patients: Fused 18F-Fluoride-PET/MDCT has higher accuracy than MDCT. Preliminary experience

Abstract Purpose So far, no studies comparing 18 F-Fluoride-PET/CT and MDCT for the detection of bone metastases are available. We compared the accuracy of 18 F-Fluoride-PET/CT (MDCT: 3.75 mm thickness-image-reconstruction), whole-body Multi-Detector-CT (MDCT: 1.25 mm thickness-image-reconstruction) and 18 F-Fluoride-PET/MDCT (MDCT: 1.25 mm thickness-image-reconstruction) in identifying bone metastases in breast cancer patients. Methods We studied 39 breast cancer patients for bone metastases. Imaging was performed on an integrated PET/MDCT-system; CT images were reconstructed at 3.75 mm and 1.25 mm thickness. Two nuclear medicine physicians and one radiologist interpreted blindly 18 F-Fluoride-PET/CT, 18 F-Fluoride-PET/MDCT and MDCT. MDCT at 12 months served as the standard of reference. Results Overall, 662 bone lesions were detected in our analysis. Of these, 542 were malignant and 120 were benign according to the standard of reference. 18 F-Fluoride-PET/CT detected 491 bone metastases, 114 (23%) of which displayed no clear morphological changes on MDCT, whereas MDCT detected 416 bone metastases, 39 (9.3%) of which showed no 18 F-Fluoride-PET uptake. Overall sensitivity and specificity were: 91% and 91%, respectively, for 18 F-Fluoride-PET/CT, and 77% and 93% for MDCT. The integrated assessment of 18 F-Fluoride-PET/MDCT yielded sensitivity and specificity values of 98% and 93%, respectively. Conclusions 18 F-Fluoride-PET/MDCT has higher diagnostic accuracy than 18 F-Fluoride-PET/CT and MDCT for the evaluation of bone metastases in breast cancer.