Combined 18F-Fluoride and 18F-FDG PET/CT Scanning for Evaluation of Malignancy: Results of an International Multicenter Trial

F-18-FDG PET/CT is used in a variety of cancers, but because of variable rates of glucose metabolism, not all cancers are reliably identified. F-18(-) PET/CT allows for the acquisition of highly sensitive and specific images of the skeleton. We prospectively evaluated combined F-18(-)/18F-FDG as a single PET/CT examination for evaluation of cancer patients and compared it with separate F-18(-) PET/CT and F-18-FDG PET/CT scans. Methods: One hundred fifteen participants with cancer were prospectively enrolled in an international multicenter trial evaluating F-18(-) PET/CT, F-18-FDG PET/CT, and combined F-18(-)/F-18-FDG PET/CT. The 3 PET/CT scans were performed sequentially within 4 wk of one another for each patient. Results: F-18(-)/F-18-FDG PET/CT allowed for accurate interpretation of radiotracer uptake outside the skeleton, with findings similar to those of F-18-FDG PET/CT. In 19 participants, skeletal disease was more extensive on F-18(-) PET/CT and F-18(-)/F-18-FDG PET/CT than on F-18-FDG PET/CT. In another 29 participants, F-18(-) PET/CT and F-18(-)/F-18-FDG PET/CT showed osseous metastases where F-18-FDG PET/CT was negative. The extent of skeletal lesions was similar in 18 participants on all 3 scans. Conclusion: This trial demonstrated that combined F-18(-)/F-18-FDG PET/CT shows promising results when compared with separate F-18(-) PET/CT and F-18-FDG PET/CT for evaluation of cancer patients. This result opens the possibility for improved patient care and reduction in health-care costs, as will be further evaluated in future trials.