Tumor hypoxia imaging.

There is a need to measure tumor hypoxia in assessing the aggressiveness of tumor and predicting the outcome of therapy. A number of invasive and noninvasive techniques have been exploited to measure tumor hypoxia, including polarographic needle electrodes, immunohistochemical staining, radionuclide imaging (positron emission tomography [PET] and single-photon emission computed tomography [SPECT]), magnetic resonance imaging (MRI), optical imaging (bioluminescence and fluorescence), and so on. This review article summarizes and discusses the pros and cons of each currently available method for measuring tissue oxygenation. Special emphasis was placed on noninvasive imaging hypoxia with emerging new agents and new imaging technologies to detect the molecular events that are relevant to tumor hypoxia.