64Cu-NODAGA-c(RGDyK) Is a Promising New Angiogenesis PET Tracer : Correlation between Tumor Uptake and Integrin αVβ3 Expression in Human Neuroendocrine Tumor Xenografts

Purpose. The purpose of this paper is to evaluate a new PET tracer 64Cu-NODAGA-c(RGDyK) for imaging of tumor angiogenesis using gene expression of angiogenesis markers as reference and to estimate radiation dosimetry for humans. Procedures. Nude mice with human neuroendocrine tumor xenografts (H727) were administered 64Cu-NODAGA-c(RGDyK) i.v. for study of biodistribution as well as for dynamic PET. Gene expression of angiogenesis markers integrin αV, integrin β3, and VEGF-A were analyzed using QPCR and correlated to the tracer uptake in the tumors (%ID/g). From biodistribution data human radiation-absorbed doses were estimated using OLINDA/EXM. Results. Tumor uptake was 1.2%ID/g with strong correlations between gene expression and tracer uptake, for integrin αV R=0.76, integrin β3 R=0.75 and VEGF-A R=0.81 (all P