808. Monitoring of Transgene Expression in Cancer Patients with Positron Emission Tomography (PET)

Background & Goal: Clinical development of gene therapy is hindered by the lack of tools that may help evaluating the intensity and duration of transgene expression. In animal models, PET imaging using a fluorine-18 labeled penciclovir analog (18FHBG) as a radiotracer can monitor in vivo the expression of thymidine kinase, a viral enzyme used for genetic prodrug activation therapy. We have explored this strategy in patients with liver cancer.