title: The significance of incidental brain uptake on 68Ga-DOTATATE PET-CT in neuroendocrine tumour patients.
abstract: OBJECTIVE
  Radiolabelled somatostatin analogues detect neuroendocrine tumours (NETs), but may reveal other tumour types. We examined the prevalence of possible meningioma in patients with known or suspected NETs imaged with Ga-DOTATATE PET-computed tomography (CT) on the basis of central nervous system uptake and compared with findings on magnetic resonance and contrast-enhanced CT imaging.
  
  
  METHODS
  Retrospective imaging reports from 313 patients who had undergone Ga-DOTATATE PET imaging for primary or repeat NET staging were searched to identify suspected meningiomas on PET. Images were then compared with findings on subsequent complementary MRI or contrast-enhanced CT scanning (performed within mean±112 days of PET-CT) if available.
  
  
  RESULTS
  Of 313 patients, 22 had regions of uptake suggestive of meningioma. MRI was available for 12 patients and contrast-enhanced CT was available for one patient. Of these, one patient with known von Hippel-Lindau syndrome had probable cerebellar NET metastasis. Six patient scans indicated lesions consistent with PET. Two of these reported initially did not comment on meningioma. No obvious lesion was found in the remaining six patients; however, five showed a possible correlation to venous structures. The mean maximum standardized uptake value±SEM for lesions in all 21 probable meningioma patients was 4.90±0.45.
  
  
  CONCLUSIONS
  Ga-DOTATATE is a sensitive marker of probable meningioma and may identify small lesions not reported on subsequent MRI. Lesions clearly observed on PET were identified on review in half of patients where complementary MR or CT imaging was available. Haemangioblastoma and metastatic NETs may have focal peripheral uptake similar to meningioma on Ga-DOTATATE PET and should be considered in the differential.
authors.affiliation: Departments of aNuclear Medicine bRadiology, Royal Free London NHS Foundation Trust, London, UK cMelbourne Brain Centre Imaging Unit, Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia.
authors.forename: Jon O
authors.initials: JO
authors.lastname: Cleary
authors.forename: Jason
authors.initials: J
authors.lastname: Yeung
authors.forename: Helena
authors.initials: H
authors.lastname: McMeekin
authors.forename: Thomas
authors.initials: T
authors.lastname: Wilhelm
authors.forename: Thomas
authors.initials: T
authors.lastname: Wagner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000378:metabolism; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D008579:Meningioma / Q000000981:diagnostic imaging / Q000378:metabolism; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000378:metabolism; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; C513399:gallium Ga 68 dotatate