Early dynamic 18F-FDG PET/CT to diagnose chronic osteomyelitis following lower extremity fractures. A pilot study

The study investigates whether early dynamic PET/CT (edPET/CT) using 18F-fluorodeoxyglucose (FDG) discriminates between affected versus non-affected sites in patients with complicated, protracted fracture healing and suspected COM in the lower extremities.

In nine consecutive patients (1 woman, 8 men; age 54 ± 13 years), before standard late FDG-PET/CT, altogether 10 edFDG-PET/CT examinations were performed in list mode over 5 min starting with radiopharmaceutical injection. Eight consecutive time intervals (frames), four 15-s, then four 60-s, were reconstructed. For every patient, several volumes-of-interest were selected. To measure early FDG influx and accumulation, maximum and mean ed standardized uptake values (respectively, edSUVmax, edSUVmean) were calculated in each volume-of-interest during each frame. Results were compared between affected and non-affected (contralateral) bone.

Starting in the 31-45s frame, the affected bone area showed significantly higher edSUVmax and edSUVmean than did the healthy contralateral region. In conventional PET/CT, affected bone areas also significantly differed from non-affected contralateral regions.

This pilot study suggests that edFDG-PET may offer a less time consuming add on to standard FDG-PET/CT while being equally accurate. The results should be validated prospectively in larger trials.