Pretargeted PET Imaging Using a Bioorthogonal 18 F-Labeled trans-Cyclooctene in an Ovarian Carcinoma Model.

In cancer research, pretargeted positron emission tomography (PET) imaging has emerged as an effective two-step approach that combines the excellent target affinity and selectivity of antibodies with the advantages of using short-lived radionuclides such as fluorine-18. One possible approach is based on the bioorthogonal inverse-electron-demand Diels-Alder (IEDDA) reaction between tetrazines and trans-cyclo-octene (TCO) derivatives. Here, we report the first successful use of an F-18-labeled small TCO compound, [F-18] 1 recently developed in our laboratory, to perform pretargeted immuno-PET imaging. The study was performed in an ovarian carcinoma mouse model, using a trastuzumab-tetrazine conjugate.