1. 11 C-PABA as a PET Radiotracer for Functional Renal Imaging: Preclinical and First-in-Human Study.
- Author
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Ruiz-Bedoya CA, Ordonez AA, Werner RA, Plyku D, Klunk MH, Leal J, Lesniak WG, Holt DP, Dannals RF, Higuchi T, Rowe SP, and Jain SK
- Subjects
- Adult, Animals, Female, Humans, Kidney metabolism, Male, Rabbits, Radiation Dosage, Rats, Rats, Wistar, 4-Aminobenzoic Acid pharmacokinetics, Carbon Radioisotopes pharmacokinetics, Kidney diagnostic imaging, Positron-Emission Tomography methods
- Abstract
para- Aminobenzoic acid (PABA) has been previously used as an exogenous marker to verify completion of 24-h urine sampling. Therefore, we hypothesized that PABA radiolabeled with
11 C might allow high-quality dynamic PET of the kidneys with less radiation exposure than other agents because of its shorter biologic and physical half-life. We evaluated if11 C-PABA can visualize renal anatomy and quantify function in healthy rats and rabbits and in a first-in-humans study on healthy volunteers. Methods: Healthy rats and rabbits were injected with11 C-PABA intravenously. Subsequently, dynamic PET was performed, followed by postmortem tissue-biodistribution studies.11 C-PABA PET was directly compared with the current standard,99m Tc-mercaptoacetyltriglycin, in rats. Three healthy human subjects also underwent dynamic PET after intravenous injection of11 C-PABA. Results: In healthy rats and rabbits, dynamic PET demonstrated a rapid accumulation of11 C-PABA in the renal cortex, followed by rapid excretion through the pelvicalyceal system. In humans,11 C-PABA PET was safe and well tolerated. There were no adverse or clinically detectable pharmacologic effects in any subject. The cortex was delineated on PET, and the activity gradually transited to the medulla and then pelvis with high spatiotemporal resolution. Conclusion:11 C-PABA demonstrated fast renal excretion with a very low background signal in animals and humans. These results suggest that11 C-PABA might be used as a novel radiotracer for functional renal imaging, providing high-quality spatiotemporal images with low radiation exposure., (© 2020 by the Society of Nuclear Medicine and Molecular Imaging.)- Published
- 2020
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