Do Hyperglycemia and Diabetes Affect the Incidence of False-Negative ¹⁸F-FDG PET/CT Studies in Patients Evaluated for Infection or Inflammation and Cancer? A Comparative Analysis

Abstract

Diabetes mellitus (DM) is a common metabolic disorder. Hyperglycemia occurs in a significant proportion of patients with uncontrolled DM but can also be found in patients without diabetes. Although the relationship between 18 F-FDG uptake in malignant tumors and blood glucose levels has been previously addressed, it has not been investigated in cases of infection and inflammation, despite the high incidence of these entities in diabetic patients. The current study assessed whether hyperglycemia and DM affect the detectability rate of disease in 18 F-FDG PET/CT studies performed for patients with suspected infectious and inflammatory processes, as compared with a group of patients with malignant tumors. Methods: 18 F-FDG PET/CT studies of 123 consecutive patients investigated for suspected infection or inflammation and 320 patients evaluated for malignancy were retrospectively analyzed. The presence of DM and the level of glucose at the time of the study were recorded. Differences between the 2 study populations in false-negative (FN) rates in patients with and without hyperglycemia and DM were compared and analyzed for statistical significance. Results: In the infection or inflammation group, 19 of 123 patients (15%) had serum glucose levels greater than 180 mg/dL and 43 of 123 (35%) had DM. There were no FN studies in patients with hyperglycemia and 4 FN studies in patients with normal glucose levels. There were 2 FN studies each in patients with and without DM. Neither glucose levels nor DM affects the detection rate of infection or inflammation with 18 F-FDG PET/CT. In the oncology group, 84 of 320 patients (26%) had serum glucose levels greater than 180 mg/dL and 183 of 320 (57%) had DM. There were 6 FN studies in cancer patients with hyperglycemia and 7 in patients with normal glucose levels. There were 8 FN studies in cancer patients with DM and 5 FN studies in patients without DM. Higher glucose levels but not DM affected the detection rate of malignancy with 18 F-FDG PET/CT. Conclusion: High glucose levels at the time of the study but not DM may reduce the sensitivity of 18 F-FDG PET/CT in the assessment of malignancy. No significant impact on the FN rate was found in patients with infection and inflammatory processes with either DM or hyperglycemia.

Fluorine-18 Fluorodeoxyglucose Uptake in Hepatocellular Carcinoma: Correlation with Glucose Transporters and p53 Expression

“…It was confirmed the absence of p53 expression by the Hep3B2. 21 It should also be noted that in both media formulations, the Hep3B2.1-7 cell line, which doesn't express p53, is one that has the highest uptake percentage of [ 18 F]FDG, and HepG2 cell line (which expresses the normal form of this protein) is always the one that has the lowest uptake percentage of this radiopharmaceutical. As mentioned previously, it appears that p53 expression can influence the [ 18 F]FDG uptake.…”

Could Different Hydration Protocols Affect the Quality of 18F-FDG PET/CT Images?

“…18 F-FDG cellular uptake in tumor tissue is related primarily to a combination of upregulation of glucose receptors (glucose transporters 1 and 3), increased glucose metabolism, and decreased glycolysis of FDG-6-phosphatase (15)(16)(17)(18) and is substantially independent of variations in the physiologic parameters and condition of the patient, except for acute hyperglycemia or uncontrolled diabetes (19,20). Therefore, the only actual possibility of increasing the target-to-background ratio is through lowering the radioactivity in normal tissues as much as possible, the denominator of this ratio.…”

EANM/SNMMI Guideline for18F-FDG Use in Inflammation and Infection

“…Diabetes and serum glucose level before 18 F-FDG administration It has been advocated that high serum glucose levels may interfere with the targeting of inflammatory and infectious sites because of competitive inhibition of 18 F-FDG uptake by D-glucose. After sporadic reports of patients with glucose levels higher than 2 g/L (10 mmol/L) who were studied successfully, it has recently been demonstrated (in a series including 123 patients with suspected infection) that neither diabetes nor hyperglycemia at the time of the study had any significant impact on the false-negative rate in this clinical scenario (123). This is different from tumor imaging, especially of pancreatic and lung cancers, for which reduced 18 F-FDG uptake has been observed at 1.4 g/L (8 mmol/L) (124).…”