Development of 68 Ga‐labeled fatty acids for their potential use in cardiac metabolic imaging

• Published in: Journal of labelled compounds & radiopharmaceuticals 2014-06, Vol.57 (7), p.463-469
• Main Authors: Jindal, Akanksha, Mathur, Anupam, Pandey, Usha, Sarma, H. D., Chaudhari, Pradip, Dash, Ashutosh
• Format: Article
• Language: English
• ISSN: 0362-4803; 1099-1344
• DOI: 10.1002/jlcr.3205

While [ 11 C]palmitate continues to be a promising tracer for cardiovascular Positron Emission Tomography (PET) imaging, unfavourable logistics due to the short half‐life of 11 C (20 min) and cumbersome labeling methodologies are the major impediments that limit its widespread use. In order to circumvent such limitations, an attempt has been made to explore the potential of 68 Ga‐labeled fatty acid analogs for metabolic imaging owing to the availability of 68 Ga through a 68 Ge/ 68 Ga generator on an on‐demand basis. In this study, two fatty acid conjugates were synthesized by conjugation of p ‐SCN‐benzyl NOTA with the ω ‐amino group of 11‐amino undecanoic acid and 12‐amino dodecanoic acid, respectively, under alkaline conditions. Both derivatives were radiolabeled in high yields with 68 Ga obtained from an in‐house 68 Ge/ 68 Ga generator. Biodistribution studies in Swiss mice showed reasonable myocardial uptake at 2 min for both derivatives (7.4 ± 2.8% ID/g for 11‐carbon fatty acid‐NOTA conjugate and 6.4 ± 2.1% ID/g for 12‐carbon fatty acid‐NOTA conjugate), which cleared rapidly over 30 min. However, significant activity was found in blood for both tracers, with heart/blood ratios observed to be below 0.5 at all time points, diminishing the potential of the synthesized complexes for cardiac imaging. Copyright © 2014 John Wiley & Sons, Ltd.