(18)F-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 (18)F was previously used for bone imaging and can be used as a PET/CT skeletal tracer. The combined administration of (18)F and (18)F-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 (18)F PET/CT and (18)F-FDG PET/CT and combined (18)F/(18)F-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 (18)F/(18)F-FDG PET/CT scans compared favorably with that of the (18)F-FDG PET/CT (no lesions missed) and the (18)F PET/CT scans (only 1 skull lesion seen on an (18)F PET/CT scan was missed on the corresponding combined scan). Through image processing, the combined (18)F/(18)F-FDG scan yielded results for bone radiotracer uptake comparable to those of the (18)F PET/CT scan performed separately.
Conclusion: Our pilot-phase prospective trial demonstrates that the combined (18)F/(18)F-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.