Impact of Plasma Glucose Level at the Time of Fluorodeoxyglucose Administration on the Accuracy of FDG-PET/CT in the Diagnosis of Pancreatic Lesions

Background: High fasting plasma glucose (FPG) levels before fluorodeoxyglucose (FDG) administration for positron emission tomography/computed tomography (PET/CT) might affect the accuracy of 18-fluoro-deoxy-glucose-positron emission tomography-computed tomography (FDG-PET/CT) in diagnosis of pancreatic lesions. Current guidelines require FPG levels of < 200 mg/dL before FDG administration; however, the literature on the effect of FPG levels of < 200 mg/dL on the accuracy of FDG-PET/CT is scarce. Objectives: The aim of this study was to evaluate the effect of FPG levels of < 200 mg/dL on the accuracy of FDG-PET/CT in diagnosis of pancreatic lesions. Patients and Methods: In this retrospective study, 161 patients who had FDG-PET/CT for initial diagnosis of pancreatic lesions were included. Fasting plasma glucose levels before FDG administration were recorded. Accuracy of FDG-PET/CT in diagnosis of pancreatic lesions was compared between patients who were non diabetic (FPG < 126 mg/dL) and hyperglycemic (126 ≤ FPG < 200 mg/dL). Results: Thirty-four patients were hyperglycemic and 127 non diabetic. Sensitivity, specificity, positive predictive value and negative predictive value of FDG-PET/CT were 90%, 88%, 87% and 91% in non diabetic and 82%, 92%, 95% and 73% in hyperglycemic patients, respectively. Overall, the accuracy was higher in non diabetic than hyperglycemic patients (89% vs. 85%). Conclusions: Accuracy of FDG-PET/CT for primary diagnosis of pancreatic lesions is higher in patients with FPG levels < 126 mg/dL than in patients with FPG levels between 126 and 200 mg/dL.