Positron Emission Tomography (PET) is a non-invasive diagnostic method that provides tomographic images by measuring the three-dimensional distribution of pharmaceuticals labeled with positron-emitting radionuclides and provides some quantitative parameters about the metabolic activity or receptor expressions of target tissues. In this way, PET allows the evaluation of biochemical and functional processes. As it is known, in malignant cells, glucose metabolism increases and as a result, an increase in FDG uptake is observed.