Does the addition of fentanyl premedication impact brown fat uptake in children undergoing a warming protocol for FDG...

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Pediatric Oncology

Background:

• 18F-fluorodeoxyglucose (18F-FDG) Positron Emission Tomography/Computed Tomography (PET/CT) is a crucial diagnostic tool in pediatric care.
• Brown adipose tissue (BAT) uptake of 18F-FDG can be a confounding factor in interpreting PET/CT scans.
• Fentanyl is sometimes used to suppress 18F-FDG uptake in brown fat.

Purpose of the Study:

• To evaluate the effectiveness of fentanyl premedication in suppressing 18F-FDG uptake in brown fat in pediatric patients.
• To analyze the frequency, intensity, and distribution of brown fat uptake in children undergoing 18F-FDG PET/CT.
• To compare outcomes between children who received fentanyl premedication and those who did not.

Main Methods:

• Retrospective analysis of 873 pediatric 18F-FDG-PET/CT scans performed between 2014 and 2024.
• Patients were routinely warmed, with some receiving intravenous fentanyl premedication.
• Three radiologists assessed brown fat uptake presence, intensity, and location; statistical comparisons were made using Chi-square and two-sample t-tests.

Main Results:

• Brown fat uptake was observed in 5.3% of scans (46/873), with no significant difference between the fentanyl premedicated group (5.4%) and the warming-alone group (5.0%).
• Fentanyl premedication did not influence the intensity or distribution of brown fat uptake.
• Higher age and Body Mass Index (BMI) were significantly associated with increased brown fat uptake.

Conclusions:

• Fentanyl premedication does not significantly alter the frequency, intensity, or location of brown fat 18F-FDG uptake in warmed pediatric patients.
• Warming protocols alone appear sufficient for managing brown fat uptake in many pediatric cases.
• Factors like patient age and BMI are more strongly associated with brown fat uptake than fentanyl use.