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

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.