Dynamic Total-Body PET Imaging Unfolds [¹¹C]Choline Kinetics and Dosimetry in Primary Hyperparathyroidism

Area of Science:

• Nuclear Medicine
• Radiopharmacology
• Medical Imaging

Background:

• Primary hyperparathyroidism (pHPT) diagnosis relies on accurate localization of parathyroid adenomas.
• [11C]choline is a promising radiotracer, but its biodistribution and kinetics in pHPT require detailed investigation.
• Total-body dynamic PET (dPET) offers enhanced sensitivity and quantitative capabilities for radiotracer studies.

Purpose of the Study:

• To characterize the biodistribution, kinetics, and dosimetry of [11C]choline in patients with pHPT using total-body dPET.
• To establish a baseline and reference standard for clinical [11C]choline dPET imaging in pHPT.
• To evaluate the potential for presurgical localization of parathyroid adenomas.

Main Methods:

• Six patients with pHPT underwent a 50-min dynamic and a 20-min static total-body PET scan after [11C]choline injection.
• Quantitative analysis included SUV, tissue uptake, organ-absorbed doses, and kinetic modeling.
• Comparison of kinetic parameters between parathyroid adenomas and thyroid tissue.

Main Results:

• Rapid [11C]choline uptake was observed, enabling adenoma visualization from 5 minutes post-injection.
• Liver and bowel showed higher uptake than kidneys, suggesting non-renal excretion pathways.
• Parathyroid adenomas demonstrated significantly higher uptake rates (k3, Ki) and distribution volume compared to thyroid tissue.

Conclusions:

• [11C]choline total-body dPET provides swift and effective presurgical localization of parathyroid adenomas in pHPT.
• The study highlights the importance of liver metabolism and non-renal clearance for [11C]choline.
• These findings establish crucial reference data for future clinical applications of [11C]choline dPET in pHPT.