Adrenal glands uptake patterns in ¹⁸F-Fluoroethylcholine PET/CT

Area of Science:

• Nuclear medicine
• Radiopharmacology
• Oncology imaging

Background:

• 18F-fluoroethylcholine (FEC) positron emission tomography/computed tomography (PET/CT) is used in cancer staging.
• Adrenal gland uptake of radiotracers can vary, potentially impacting diagnostic accuracy.
• Understanding factors influencing adrenal uptake is crucial for accurate interpretation of PET/CT scans.

Purpose of the Study:

• To investigate the reasons behind varying radioactive choline uptake in adrenal glands of patients with prostate or renal cancer.
• To identify correlations between adrenal gland characteristics and uptake patterns in 18F-fluoroethylcholine PET/CT.

Main Methods:

• Analysis of 49 18F-fluoroethylcholine PET/CT studies, evaluating 96 adrenal glands.
• Assessment of adrenal gland shape, uptake patterns (diffuse, focal, mixed), and maximum standardized uptake value (SUVmax).
• Correlation analysis between adrenal uptake and 15 recorded parameters, including ratios, pituitary, and liver uptake.

Main Results:

• Adrenal glands showed diverse uptake intensities (SUV range 2-7.9) and patterns.
• SUVmax in the right adrenal gland correlated positively with parenchymal thickness (p=0.000).
• Adrenal gland uptake (SUVmax and mean) significantly correlated with pituitary and liver uptake (p<0.011). Hormonal treatment and age did not show significant correlation.

Conclusions:

• Variable radiocholine uptake in adrenal glands is likely influenced by systemic metabolism and pituitary function.
• Significant correlations were observed between adrenal, pituitary, and liver uptake.
• Focal or mixed uptake patterns in morphologically normal adrenal glands on CT require careful assessment to avoid diagnostic errors.