Functional Imaging of Paragangliomas with an Emphasis on Von Hippel-Lindau-Associated Disease: A Mini Review.

Few reports have presented data and results on functional (i.e., nuclear medicine) imaging of paragangliomas and pheochromocytomas (PGLs/PHEOs) for von Hippel-Lindau (VHL) patients. Nuclear medicine localization modalities for chromaffin tumors can be specific or nonspecific. Specific methods make use of the expression of the human norepinephrine transporter (hNET) and vesicular monoamine transporters (VMATs) by these tumors. These permit the use of radiolabeled ligands that enter the synthesis and storage pathway of catecholamines. Nonspecific methods are not related to the synthesis, uptake, or storage of catecholamines but make use of the tumors' high glucose metabolism or expression of somatostatin receptors. Consensuses and guidelines suggest that metastatic and sporadic PHEOs/PGLs in VHL patients (as in patients with chromaffin tumors of yet unknown genotype) should be evaluated first with 18 F-dihydroxyphenylalanine (18 F-DOPA) positron emission tomography/computed tomography (PET/CT). The functional imaging of second choice is 123 I-metaiodobenzylguanidine (123 I-MIBG) for PHEOs in VHL patients. 123 I-MIBG, 68 Ga-DOTATATE/DOTATOC/DOTANOC PET/CT, or 18 F-fluorodeoxyglucose (18 F-FDG) PET/CT can be a second choice of functional imaging for PGLs in VHL patients.