title: Combined positron emission tomography/computed tomography (PET/CT) for imaging of orbital tumours and tumours extending into the orbit.
abstract: To assess clinical and radiological performance of combined positron emission tomography/computed tomography (PET/CT) in patients with secondary and primary intraorbital tumours.
  
  
  
  14 adults with secondary and 1 child with primary orbital masses underwent combined whole-body PET/CT. Radiopharmaceutical tracers applied were (18F)-fluorodeoxyglucose, (18F)-fluoroethylcholine (FEC) and (68Ga)-DOTATATE. Histopathology and/or all conventional radiographic work-up and clinical course served as standard of reference. Descriptive statistics and Fisher's exact test were used for analysis.
  
  
  
  PET/CT detected all orbital masses. All 15 patients had malignant disease. Local osseous infiltration was correctly identified in 11 patients. Lymph node metastases were present in two of eight patients (25%) with haematogenous orbital metastases and in five of six patients (83%) with infiltrative carcinoma (p=0.05). Further distant metastases were present in all eight patients suffering from orbital metastases, but only one patient with infiltrative carcinoma (17%) presented with disseminated disease (p=0.003). In one metastasis, PET/CT excluded vital orbital tumour tissue after radiation therapy. Local recurrence was detected in another patient suffering from prostate cancer.
  
  
  
  PET/CT is a sensitive tool for the detection and localisation of orbital masses, enabling assessment of both morphology and cell metabolism. Detailed imaging of the head and neck region with a small field-of-view should be performed when suspecting lymphatic metastases. As metastatic disease to the orbit is associated with advanced disease, focus should be laid on whole-body imaging for staging of these patients. Different radiopharmaceutical tracers can be applied to distinguish the origin of orbital metastases.
authors.affiliation: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Klingenstein
authors.affiliation: Department of Radiology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Gerd-Ullrich
authors.initials: GU
authors.lastname: Mueller-Lisse
authors.affiliation: Department of Nuclear Medicine, Ludwig-Maximilians-University, Munich, Germany Division of Nuclear Medicine, Medical University Vienna, Vienna, Austria.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Haug
authors.affiliation: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Aylin
authors.initials: A
authors.lastname: Garip-Kuebler
authors.affiliation: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Christina V
authors.initials: CV
authors.lastname: Miller
authors.affiliation: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany.
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Hintschich
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D009915:Orbit / Q000000981:diagnostic imaging*; D009918:Orbital Neoplasms / Q000175:diagnosis*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D055815:Young Adult
keywords: Imaging; Neoplasia; Orbit