Evidence Hub

A first-in-man PET study of 2-amino-[3-11C] isobutyric acid for the amino acid transport System A: biodistribution and dosimetry in healthy volunteers

Tamura K, Tsuji AB, Nishii R, Tani K, Hashimoto H, Kawamura K, Zhang MR, Maeda T et al.

Annals of nuclear medicine, 2025

Abstract

PURPOSE: This first-in-human study aimed to assess the biodistribution, radiation dosimetry, and safety of the novel PET tracer [3-11C]AIB, a putative System A amino acid transport probe, in healthy volunteers.

METHODS: Six healthy male participants underwent whole-body PET/CT scans following a rapid intravenous bolus of [3-11C]AIB (injected dose: 366.9 ± 17.9 MBq). Dynamic imaging of the upper abdomen was performed for 4 min post-injection, followed by static whole-body scans up to 90 min. The volumes of interest were drawn on major organs to derive time activity curves for dosimetry calculations. Safety was assessed through vital signs and laboratory tests before and after imaging.

RESULTS: High tracer uptake was observed in the salivary glands, pancreas, kidneys, and liver, whereas uptake in the brain and skeletal muscles remained low. The principal route of excretion was via the urinary tract. The effective dose was 5.1 µSv/MBq, corresponding to 1.9 mSv for 370 MBq injection comparable to other 11C-labeled amino acid tracers. No adverse events or significant changes in clinical assessments were noted.

CONCLUSIONS: This first-in-man evaluation of [3-11C]AIB demonstrated its safety and acceptable radiation dosimetry profile comparable to other 11C-labeled amino acid tracers. The distinct biodistribution pattern with minimal uptake in the brain and skeletal muscles creates high contrast conditions for potential tumor imaging in these regions. The rapid kinetics suggest…

How strong is the evidence?

Evidence Hub reads this as a clinical trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free