Clinical value of [F-18]fluoro-deoxyglucose positron emission tomography for patients with fever of unknown origin

We describe the diagnostic contribution of [F-18]fluoro-deoxyglucose (FDG) positron emission tomography (PET) scan in 58 consecutive cases of fever of unknown origin (FUO) and compare this new approach with gallium scintigrap hy. This investigation was performed from March 1996 through October 1998 a t Gasthuisberg University Hospital in Leuven, Belgium. A final diagnosis wa s established for 38 patients (64%). Forty-six FDG-PET scans (79%) were abn ormal; 24 of these abnormal scans (41% of the total number of scans) were c onsidered helpful in diagnosis, and 22 (38% of the total number) were consi dered noncontributory to the diagnosis. In a subgroup of 40 patients (69%), both FDG-PET and gallium scintigraphy were performed. FDG-PET scan and gal lium scintigraphy were normal in 23% and 33% of these cases, respectively; helpful in diagnosis in 35% and 25%, respectively; and noncontributory in 4 2% each. All foci of abnormal gallium accumulation were also detected by us e of an FDG-PET scan. We conclude that FDG-PET is a valuable second-step te chnique in patients with FUO because it yielded diagnostic information in 4 1% of the patients in whom the probability of a definite diagnosis was only 64%. FDG-PET scan compares favorably with gallium scintigraphy for this in dication. Because of the quick results (within hours instead of days), FDG- PET scan may replace gallium scintigraphy as a radiopharmaceutical for the evaluation of patients with FUO.