Expanding CAM Models: In Vivo PET/CT Imaging of Cancer Xenografts on the Ostrich CAM.

Animal models are utilized in the investigation of a variety of research questions in nuclear medicine. Radiopharmaceutics are usually tested in mouse, rat or chick chorioallantoic membrane (CAM) models and visualisation of their biodistribution is performed using dedicated small-animal PET/CT scanners. However, the limited availability of such scanners represents a significant bottleneck in preclinical imaging. To address this limitation, we explored an alternative animal model compatible with clinical imaging systems. The ostrich chorioallantoic membrane (CAM) was utilized as a platform for tumor xenografts, enabling imaging with a standard human PET/CT scanner. Growth conditions for tumor formation were established using human glioblastoma (U87) and breast cancer (MDA-MB-231) cell lines. Tumor visualization was achieved using 18F-fluorodeoxyglucose (18F-FDG), a widely used clinical PET tracer, and its pharmacodynamic behavior was assessed. Our findings demonstrate that the ostrich CAM tumor model is a feasible and efficient system for the rapid evaluation of diagnostic tracers. Importantly, tracer uptake and kinetics can be reliably assessed using a clinical PET/CT scanner. This approach highlights the potential of the ostrich embryonic model as a versatile and accessible preclinical platform for nuclear medicine research.