Performance de la ¹⁸FDG-TEP dans le dépistage de paragangliome chez des patients porteurs d'une mutation SDHx

Objective: To evaluate the performance of ¹⁸FDG-PET/CT for detecting infra-clinic paraganglioma (PGL) in SDHx mutation carriers (relatives). Patients and methods: Sixty-six patients, from 13distinct families underwent a genetic testing on the SHD genes between 2003and 2012. Among the 45patients with a mutation, 30with a ¹⁸FDG-PET performed at initial work-up were included in this retrospective study. A gadolinium-enhanced magnetic resonance angiography of the neck (angio-MR) was performed in all cases, a thoracoabdominal-pelvic contrast-enhanced computed tomography (TAP-CT) in 25cases, a TAP-MR in 20cases, a ¹²³I-metaiodo-benzylguanidine scintigraphy (¹²³I-MIBG) in 20cases and a somatostatin receptor scintigraphy (SRS) in 20cases. Gold standard was histologic or composite (confirmation by another imaging method and follow-up). Results: A tumor was found in five subjects: 2abdominal PGL, 1pheochromocytoma and 2PGL of the neck. The sensitivity of ¹⁸FDG-PET was 100%, of SRS was 80%, of ¹²³I-MIBG was 60% and of anatomical imaging (association between angio-MR of the neck and TAP-CT and/or TAP-MR) was 100%. Three false positive lesions were described: 2with the ¹⁸FDG-PET imaging and 1with the TAP-MR technique. Conclusion: ¹⁸FDG-PET/CT is an excellent tool for screening SDHx relatives and should be completed by an angio-MR of the neck if suspicion of abnormality. Association of angio-MR of the neck and TAP-MR has the advantage of being a non-irradiating imaging method but with limited access in some countries.