Novel Strategy for a Cocktail 18F-Fluoride and 18F-FDG PET/CT Scan for Evaluation of Malignancy: Results of the Pilot-Phase Study

F-18-FDG PET/CT is used for detecting cancer and monitoring cancer response to therapy. However, because of the variable rates of glucose metabolism, not all cancers are identified reliably. Sodium F-18 was previously used for bone imaging and can be used as a PET/CT skeletal tracer. The combined administration of F-18 and F-18-FDG in a single PET/CT study for cancer detection has not been reported to date. Methods: This is a prospective pilot study (November 2007-November 2008) of 14 patients with proven malignancy (6 sarcoma, 3 prostate cancer, 2 breast cancer, 1 colon cancer, 1 lung cancer, and 1 malignant paraganglioma) who underwent separate F-18 PET/CT and F-18-FDG PET/CT and combined F-18/F-18-FDG PET/CT scans for the evaluation of malignancy (a total of 3 scans each). There were 11 men and 3 women (age range, 19-75 y; average, 50.4 y). Results: Interpretation of the combined F-18/F-18-FDG PET/CT scans compared favorably with that of the F-18-FDG PET/CT (no lesions missed) and the F-18 PET/CT scans (only 1 skull lesion seen on an F-18 PET/CT scan was missed on the corresponding combined scan). Through image processing, the combined F-18/F-18-FDG scan yielded results for bone radiotracer uptake comparable to those of the F-18 PET/CT scan performed separately. Conclusion: Our pilot-phase prospective trial demonstrates that the combined F-18/F-18-FDG administration followed by a single PET/CT scan is feasible for cancer detection. This combined method opens the possibility for improved patient care and reduction in health care costs.