18F-FDOPA PET/CT imaging of MAX-related pheochromocytoma.

18F-FDOPA PET/CT imaging of MAX-related pheochromocytoma.

J Clin Endocrinol Metab. 2018 Mar 08;:

Authors: Taïeb D, Jha A, Guerin C, Pang Y, Adams KT, Chen CC, Romanet P, Roche P, Essamet W, Ling A, Quezado MM, Castinetti F, Sebag F, Pacak K

Abstract
Context: MYC associated factor X (MAX) has been recently described as a new susceptibility pheochromocytoma (PHEO) gene with a total of approximately 40 reported cases. At present, no study has specifically described the functional imaging phenotype of MAX-related PHEO.
Objective, Patients, and Design: The objective of this study was to present our experience with contrast-enhanced CT and 18F-FDOPA PET/CT imaging in 6 consecutive patients (4 at initial diagnosis and 2 at follow-up evaluation) with rare but clinically important MAX-related PHEOs. In 5 patients, 18F-FDOPA was also compared to other radiopharmaceuticals.
Results: Patients had 5 different mutations in the MAX gene that caused disruption of Max/Myc interaction and/or abolished interaction with DNA based on in-silico analyses. All but one patient developed bilateral PHEOs during their lifetime. In all cases, 18F-FDOPA PET/CT accurately visualized PHEOs that were often multiple within the same gland or bilateral and detected more adrenal and extradrenal lesions than CT (per lesion sensitivity 90.5% vs 52.4% for CT/MRI). The 2 missed PHEO on 18F-FDOPA PET/CT were <1cm, corresponding to nodular adrenomedullary hyperplasia. 68Ga-DOTATATE PET/CT detected fewer lesions than 18F-FDOPA PET/CT in 1/3 patients and 18F-FDG PET/CT was only faintly positive in 2/4 patients with underestimation of extraadrenal lesions in 1 patient.
Conclusions: MAX-related PHEO exihibit a marked 18F-FDOPA uptake, a finding that illustrates the common well-differentiated chromaffin pattern of PHEO associated with activation of kinase signaling pathways. 18F-FDOPA PET/CT should be considered as the first-line functional imaging modality for diagnostic or follow-up evaluation in these patients.

PMID: 29534198 [PubMed - as supplied by publisher]

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