Prospective Comparison of 99mTc-MDP Scintigraphy, Combined 18F-NaF and 18F-FDG PET/CT, and Whole-Body MRI in Patients with Breast and Prostate Cancer

We prospectively evaluated the use of combined F-18-NaF/(18)FFDG PET/CT in patients with breast and prostate cancer and compared the results with those for Tc-99m-MDP bone scintigraphy and whole-body MRI. Methods: Thirty patients (15 women with breast cancer and 15 men with prostate cancer) referred for standard-of-care bone scintigraphy were prospectively enrolled in this study. F-18-NaF/F-18-FDG PET/CT and whole-body MRI were performed after bone scintigraphy. The whole-body MRI protocol consisted of both unenhanced and contrast-enhanced sequences. Lesions detected with each test were tabulated, and the results were compared. Results: For extraskeletal lesions, F-18-NaF/F-18-FDG PET/CT and whole-body MRI had no statistically significant differences in sensitivity (92.9% vs. 92.9%, P = 1.00), positive predictive value (81.3% vs. 86.7%, P = 0.68), or accuracy (76.5% vs. 82.4%, P = 0.56). However, F-18-NaF/F-18-FDG PET/CT showed significantly higher sensitivity and accuracy than whole-body MRI (96.2% vs. 81.4%, P < 0.001, 89.8% vs. 74.7%, P = 0.01) and bone scintigraphy (96.2% vs. 64.6%, P < 0.001, 89.8% vs. 65.9%, P < 0.001) for the detection of skeletal lesions. Overall, F-18-NaF/F-18-FDG PET/CT showed higher sensitivity and accuracy than whole-body MRI (95.7% vs. 83.3%, P < 0.002, 87.6% vs. 76.0%, P < 0.02) but not statistically significantly so when compared with a combination of whole-body MRI and bone scintigraphy (95.7% vs. 91.6%, P 5 0.17, 87.6% vs. 83.0%, P = 0.53). F-18-NaF/F-18-FDG PET/CT showed no significant difference from a combination of F-18-NaF/F-18-FDG PET/CT and whole-body MRI. No statistically significant differences in positive predictive value were noted among the 3 examinations. Conclusion: F-18-NaF/F-18-FDG PET/CT is superior to whole-body MRI and Tc-99m-MDP scintigraphy for evaluation of skeletal disease extent. Further, F-18-NaF/F-18-FDG PET/CT and whole-body MRI detected extraskeletal disease that may change the management of these patients. F-18-NaF/F-18-FDG PET/CT provides diagnostic ability similar to that of a combination of whole-body MRI and bone scintigraphy in patients with breast and prostate cancer. Larger cohorts are needed to confirm these preliminary findings, ideally using the newly introduced simultaneous PET/MRI scanners.