Recommendations for Standardizing Thorax PET-CT in Non-Human Primates by Recent Experience from Macaque Studies.

Abstract

Simple SummaryWith computed tomography (CT) only anatomical information is obtained, but there is no information about function. Positron emission tomography (PET) only gives functional information about a target organ/tissue by the distribution of a specific contrast agent, a radiotracer. Combining the two imaging techniques provides synergy and they can amplify each other. In clinical practice, this combined PET–CT technique is already broadly used. For monkeys, it is increasingly used, with procedures and protocols mainly based on clinical practice. In this publication, we make recommendations about key steps towards standardization and optimization of non-human primate PET–CT (from study preparation to image interpretation).Despite the possibilities of routine clinical measures and assays on readily accessible bio-samples, it is not always essential in animals to investigate the dynamics of disease longitudinally. In this regard, minimally invasive imaging methods provide powerful tools in preclinical research. They can contribute to the ethical principle of gathering as much relevant information per animal as possible. Besides, with an obvious parallel to clinical diagnostic practice, such imaging platforms are potent and valuable instruments leading to a more refined use of animals from a welfare perspective. Non-human primates comprise highly relevant species for preclinical research to enhance our understanding of disease mechanisms and/or the development of improved prophylactic or therapeutic regimen for various human diseases. In this paper, we describe parameters that critically affect the quality of integrated positron emission tomography and computed tomography (PET–CT) in non-human primates. Lessons learned are exemplified by results from imaging experimental infectious respiratory disease in macaques; specifically tuberculosis, influenza, and SARS-CoV-2 infection. We focus on the thorax and use of 18F-fluorodeoxyglucose as a PET tracer. Recommendations are provided to guide various stages of PET–CT-supported research in non-human primates, from animal selection, scan preparation, and operation, to processing and analysis of imaging data.