Screening in asymptomatic SDHx mutation carriers: added value of ¹⁸F-FDG PET/CT at initial diagnosis and 1-year follow-up

Eur J Nucl Med Mol Imaging. 2015 May;42(6):868-76. doi: 10.1007/s00259-015-3003-z. Epub 2015 Feb 13.


Purpose: Specific recommendations on screening modalities for paraganglioma (PGL) and phaeochromocytoma (PCC) in asymptomatic SDHx mutation carriers (relatives) are still lacking. We evaluated the added value of (18)F-FDG PET/CT in comparison with morphological imaging at initial diagnosis and 1 year of follow-up in this population.

Methods: The study included 30 consecutive relatives with a proven SDHx mutation who were investigated by (18)F-FDG PET/CT, gadolinium-enhanced magnetic resonance angiography of the head and neck, thoracic/abdominal/pelvic (TAP) contrast-enhanced CT and/or TAP MRI. (123)I-MIBG scintigraphy was performed in 20 subjects and somatostatin receptor scintigraphy (SRS) in 20 subjects. The gold standard was based on pathology or a composite endpoint as defined by any other positive imaging method and persistent tumour on follow-up. Images were considered as false-positive when the lesions were not detected by another imaging method or not confirmed at 1 year.

Results: At initial work-up, an imaging abnormality was found in eight subjects (27%). The final diagnosis was true-positive in five subjects (two with abdominal PGL, one with PCC and two with neck PGL) and false-positives in the other three subjects (detected with (18)F-FDG PET/CT in two and TAP MRI in one). At 1 year, an imaging abnormality was found in three subjects of which one was an 8-mm carotid body PGL in a patient with SDHD mutaion and two were considered false-positive. The tumour detection rate was 100% for (18)F-FDG PET/CT and conventional imaging, 80% for SRS and 60% for (123)I-MIBG scintigraphy. Overall, disease was detected in 4% of the subjects at the 1-year follow-up.

Conclusion: (18)F-FDG PET/CT demonstrated excellent sensitivity but intermediate specificity justifying combined modality imaging in these patients. Given the slow progression of the disease, if (18)F-FDG PET/CT and MRI are normal at baseline, the second imaging work-up should be delayed and an examination that does not expose the patient to radiation should be used.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Iodobenzylguanidine
  • Adolescent
  • Adrenal Gland Neoplasms / diagnostic imaging*
  • Adrenal Gland Neoplasms / genetics
  • Adrenal Gland Neoplasms / pathology
  • Adult
  • Aged
  • Asymptomatic Diseases
  • Female
  • Fluorodeoxyglucose F18*
  • Heterozygote*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Multimodal Imaging
  • Mutation
  • Pedigree
  • Pheochromocytoma / diagnostic imaging*
  • Pheochromocytoma / genetics
  • Pheochromocytoma / pathology
  • Positron-Emission Tomography*
  • Radiopharmaceuticals*
  • Succinate Dehydrogenase / genetics*
  • Tomography, X-Ray Computed


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • 3-Iodobenzylguanidine
  • Succinate Dehydrogenase