Methodological aspects on hypoxia PET acquisition and image processing.

Tumor hypoxia is one of the main factors compromising the effectiveness of radiotherapy. As a consequence, non-invasive hypoxia imaging with positron emission tomography (PET) is very promising with regard to its potential to provide a functional basis for patient stratification or therapy modification. This review article aims at providing a comprehensive overview of different methodologies for hypoxia PET image acquisition protocols as well as data processing and analysis as used in recent studies and clinical trials. Furthermore, different physical and also technical aspects that may induce ambiguities and limitations into hypoxia PET image acquisition and interpretation are discussed in the context of this article. In the future, dedicated hypoxia PET image acquisition protocols and methodologies for processing, analysis and interpretation of hypoxia PET data are necessary to allow for comparison of hypoxia PET image data acquired in different study centers and enable for the definition of multicenter trials on hypoxia PET imaging and hypoxia-based treatment interventions.