Ultrashort-acting insulin may improve on 18F-FDG PET/CT image quality in patients with uncontrolled diabetic mellitus.

Objective: It is known that the poor image quality of (18)F-fluorodeoxyglucose ((18)F-FDG) PET scans leads to interpretation difficulty in patients with uncontrolled diabetes mellitus (DM). We usually delay (18)F-FDG PET examination when patients show high glucose levels. This study was performed to evaluate the usefulness and effects of ultrashort-acting insulin on (18)F-FDG PET/computed tomography (CT) imaging in DM patients.
Materials and Methods: A total of 105 DM patients (68 men and 37 women) were included. Ultrashort-acting insulin was intravenously injected when patients showed high glucose levels (>190 mg/dl). (18)F-FDG was injected 60 min after ultrashort-acting insulin injection, and PET/CT images were acquired. Image quality was graded by consensus using the following scale: 1, good; 2, moderate; and 3, poor. The mean standardized uptake value (SUV(mean)) of the liver, gluteal muscle, and brain was assessed to evaluate the effects of ultrashort-acting insulin.
Results: The group administered ultrashort-acting insulin (n=52, blood glucose level: 243.7 ± 46.2 mg/dl) showed a significantly higher glucose level compared with the group not administered ultrashort-acting insulin (n=53, 177.1 ± 5.2 mg/dl). Nevertheless, the image quality of the group with ultrashort-acting insulin was not significantly different from that of the group without ultrashort-acting insulin (χ(2) -test, P=0.47). No significant differences were seen in SUV(mean) in the liver (P=0.13), gluteal muscle (P=0.71), and brain (P=0.16) between groups.
Conclusion: Ultrashort-acting insulin can be used to improve the image quality of F-FDG PET/CT in uncontrolled DM patients without significant differences in SUV.