Synthesis of Novel 18F-Labeled-Nitroimidazole-Based Imaging Agents for Hypoxia: Recent Advances

Hypoxia indicates the condition of low oxygen levels in tissues. In oncology, hypoxia can induce cancer progression and metastasis, as well as cause resistance to cancer therapies. The detection of hypoxia by using molecular imaging, particularly, positron emission tomography (PET) has been extensively studied due to many advantages. Nitroimidazoles, the moieties that can be trapped in hypoxic tissues due to selective reduction, have been used to design and synthesize of hypoxia-targeting radiopharmaceuticals. This review provides a summary of synthetic routes towards 18F-labeled-nitroimidazole radiotracers for PET imaging of hypoxia.