A Review of Hypoxia Imaging Using 18F-Fluoromisonidazole Positron Emission Tomography

Tumor hypoxia is an essential factor related to malignancy, prognosis, and resistance to treatment. Positron emission tomography (PET) is a modality that visualizes the distribution of radiopharmaceuticals administered into the body. PET imaging with [¹⁸F]fluoromisonidazole ([¹⁸F]FMISO) identifies hypoxic tissues. Unlike [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG)-PET, fasting is not necessary for [¹⁸F]FMISO-PET, but the waiting time from injection to image acquisition needs to be relatively long (e.g., 2-4 h). [¹⁸F]FMISO-PET images can be displayed on an ordinary commercial viewer on a personal computer (PC). While visual assessment is fundamental, various quantitative indices such as tumor-to-muscle ratio have also been proposed. Several novel hypoxia tracers have been invented to compensate for the limitations of [¹⁸F]FMISO.