Radionuclide Imaging of Pheochromocytoma and Paraganglioma in the Era of Multi-omics

Abstract

Pheochromocytomas and paragangliomas (PPGLs) are highly variable with respect to clinical presentation, endocrine phenotype, growth rate, and metatastatic potential. This relates to a large genetic diversity and related pathways of tumorigenesis. By applying a multi-omics approach, profound abnormalities in tumor cell metabolism related to mitochondrial defects in a subset of PPGLs have been identified. Besides tumor localization, radionuclide imaging has been shown to be very useful for the functional characterization of PPGL and can be regarded as a tool for noninvasive and immediate in vivo metabolomics. Different genotypes underlying these tumors can be distinguished by 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and other PET tracers. This is achieved by quantitation of 18 F-FDG uptake and kinetics, identifying succinate dehydrogenase (SDH)-deficient PPGLs that are prone to malignant tumor behavior. Thereby radionuclide imaging facilitates the stratification of these tumors and can guide tailor-made and individualized diagnostic and therapeutic strategies.