Hypoxia-induced tumor biological behavior changes and application of radiotracers for PET imaging of tumor hypoxia

Hypoxia exists in a wide range of advanced solid tumors and is often associated with poor prognosis. Hypoxia can enhance tumor invasion, promote tumor angiogenesis, impact genomic stability and change the tumor microenvironment by activating expression of relevant genes through hypoxia-induced factors (HIFs). Hypoxia provides favorable conditions for tumor metastasis and relapse, and it is involved in all aspects of tumor development. The study of hypoxia in tumors may provide useful information for pre-clinical evaluation, individualized treatment and clinical prognosis. Positron emission tomography (PET) is a non-invasive imaging method, which can be used for assessing and quantifying tumor hypoxic microenvironment. This article reviews the mechanisms of hypoxia-induced tumor biological behavior changes and the research progress of the application of radiotracers for PET imaging of tumor hypoxia. Key words: Cell hypoxia, neoplasms; Hypoxia-inducible factor 1, alpha subunit; Radioactive tracers