18F-FHBG

**18F-FHBG** is a fluorine-18-labeled acycloguanosine derivative used as a positron emission tomography (PET) imaging agent. It acts as a specific substrate for herpes simplex virus type 1 thymidine kinase (HSV1-tk), which phosphorylates and traps the compound in cells expressing this gene. This property enables noninvasive imaging of HSV1-tk gene expression, making it valuable for monitoring gene transfer efficiency and tracking therapeutic transgenes in vivo, particularly in the context of cancer gene therapy and cell-based therapies. The tracer demonstrates favorable pharmacokinetics, rapid blood clearance, low background signal, biosafety, and acceptable radiation dosimetry in humans[2][3][4]. It does not cross the blood-brain barrier under normal conditions[4].

Other names

9-(4-(18F)Fluoro-3-(hydroxymethyl)butyl)guanine