fluorine F 18 EF5

Fluorine F 18 EF5 is an investigational radiopharmaceutical tracer used in positron emission tomography (PET) to visualize and quantify tumor hypoxia. As a 2-nitroimidazole derivative, it functions through a bioreductive mechanism: the nitro group is reduced by intracellular reductases (such as cytochrome P450 reductase) to form reactive intermediates. In the presence of adequate oxygen, these intermediates are rapidly re-oxidized and the tracer remains mobile; however, under hypoxic conditions (low oxygen tension), the intermediates form stable covalent adducts with cellular macromolecules, primarily proteins. This metabolic trapping allows the PET scanner to detect regions of hypoxia, which are frequently associated with resistance to radiation therapy and chemotherapy, as well as poor clinical outcomes. It has been studied across various solid tumors, including brain, head and neck, and cervical cancers.

Other names

2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetamide[18F]EF5F-18-2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetamide