Pheochromocytoma and paraganglioma : Importance of diagnostic imaging

• Published in: Radiologe 2019-11, Vol.59 (11), p.975-981
• Main Authors: Kunz, W G, Auernhammer, C J, Nölting, S, Pfluger, T, Ricke, J, Cyran, C C
• Format: Article
• Language: ger
• Subjects: Adrenal Gland Neoplasms - diagnostic imaging; Diagnosis, Differential; Humans; Paraganglioma - diagnostic imaging; Pheochromocytoma - diagnostic imaging; Positron Emission Tomography Computed Tomography - methods; Positron-Emission Tomography - methods
• ISSN: 1432-2102
• DOI: 10.1007/s00117-019-0569-7

If pheochromocytoma (PC) or paraganglioma (PGL) is diagnosed based on serologic studies, imaging is required to locate the adrenal mass for further management. Besides pathognomonic hormonal findings, PC/PGL can exhibit typical imaging features. However, PC/PGL can also show morphological overlap with other pathologies. The modality of choice for evaluation of PC is CT. In case of extra-adrenal location, MRI is superior to CT. Imaging with PET-CT provides complementary information in the differentiation of PC/PGL and is recommended as the imaging modality of choice for malignant PC/PGL. Ga-DOTATATE (or Ga-DOTATOC/ Ga-DOTANOC) PET-CT has high sensitivity for SDHx-mutated PC/PGL and serves for planning of radioreceptor therapy with somatostatin analogues. In contrast, I-metaiodobenzylguanidine (MIBG) scintigraphy is important in assessing the potential efficacy of radioreceptor therapy with MIBG. The CT protocol for PC evaluation should include non-enhanced, arterial, portal-venous and late phases; the latter for the evaluation of wash-out. Recent studies indicate non-enhanced CT alone may be sufficient to rule out PC. For MRI, in- and opposed-phase sequences should be additionally acquired. A relevant proportion of PC is diagnosed incidentally. Therefore, imaging of PC will gain further importance. Recent studies show better response rates of PC/PGL after radioreceptor therapy with somatostatin analogues ( Lu-DOTATATE) than with MIBG. Therefore, Ga-DOTATATE PET-CT gains further importance-for diagnostic imaging and therapy planning.