[18F]FDG-PET scan in patients with fasting hyperglycemia

Area of Science:

• Nuclear Medicine
• Oncology Imaging
• Diabetology

Background:

• Fasting is generally accepted to improve [18F]FDG-PET quality.
• The impact of elevated fasting blood glucose on PET scan quality remains debated.
• Clarifying this issue is crucial for managing hyperglycemic patients undergoing PET scans.

Purpose of the Study:

• To investigate the influence of fasting hyperglycemia on [18F]FDG-PET diagnostic quality.
• To provide evidence for optimizing PET imaging protocols in diabetic patients.
• To assess the impact of varying glucose levels on standardized uptake values (SUV) and PET findings.

Main Methods:

• Retrospective analysis of 116 hyperglycemic (>11 mmol/L), 116 slightly elevated glycemia (5.6-7.0 mmol/L), and 116 normoglycemic (<4.7 mmol/L) patients.
• Comparison of muscle and liver SUV, tumor SUV, and positive PET finding frequency across groups.
• Analysis included muscle-to-liver SUV ratio.

Main Results:

• No significant differences in muscle SUV or positive PET findings were observed among the three groups.
• Hyperglycemic patients showed approximately 10% higher liver SUV compared to normoglycemic and slightly elevated glycemia groups.
• A positive correlation between liver SUV and blood glucose levels was noted (r=0.2849), but tumor SUV was significantly higher in the slightly elevated glycemia group.

Conclusions:

• Fasting hyperglycemia does not appear to negatively influence the diagnostic quality of [18F]FDG-PET.
• The observed correlation between liver SUV and glucose is clinically insignificant, possibly due to increased hepatic gluconeogenesis in diabetics.
• PET imaging can be performed under fasting conditions irrespective of mild to moderate elevations in fasting blood glucose.