title: Imaging of Prostate-Specific Membrane Antigen Expression in Metastatic Differentiated Thyroid Cancer Using 68Ga-HBED-CC-PSMA PET/CT.
abstract: OBJECTIVE
  The prostate-specific membrane antigen (PSMA) was shown to be overexpressed on the neovasculature of several malignancies. Here, the role of Ga-HBED-CC-PSMA PET/CT for the detection of PSMA expression in patients with metastasized differentiated thyroid cancer (DTC) was evaluated.
  
  
  METHODS
  Six patients with iodine-negative and F-FDG-positive metastasized DTC (mean TG, 1616 ng/mL) received 71-93 MBq of the Ga-labeled PSMA ligand and underwent PET/CT at 62 ± 7 minutes p.i.. Tumor accumulation capacity of the tracer and the detection rate of local recurrences and metastases were compared with F-FDG. Tracer uptake was quantified in terms of the SUVmax.
  
  
  RESULTS
  In 5 of 6 patients, sites of putative metastatic disease could be identified using Ga-HBED-CC-PSMA PET/CT. All lesions detected with Ga-HBED-CC-PSMA PET/CT (n = 42) were confirmed by F-FDG PET/CT or conventional CT imaging. Using Ga-HBED-CC-PSMA PET/CT, all tumor lesions identified with F-FDG PET/CT imaging could be visualized in 3 of 5 patients. In 2 patients, only the most prominent lesions detected with F-FDG PET/CT imaging were visualized by Ga-HBED-CC-PSMA PET/CT. Ga-HBED-CC-PSMA uptake ranged from low in 1 patient (mean SUVmax 3.3) to intermediate (1 patient; mean SUVmax, 6.1) to intense (3 patients; mean SUVmax, 12.8, 16.2, and 18.3). The highest SUVmax values were observed for a bone lesion, reaching 39.7.
  
  
  CONCLUSIONS
  These preliminary results indicate that Ga-HBED-CC-PSMA PET/CT might be suitable for staging of patients with metastasized DTC. Ga-HBED-CC-PSMA PET/CT could be useful for the identification of patients who might qualify for PSMA-targeted radionuclide therapy because of high PSMA uptake.
authors.affiliation: From the *Clinic for Nuclear Medicine, University Hospital Essen, Essen, Germany; †Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, the Netherlands; and ‡Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Lütje
authors.forename: Benedikt
authors.initials: B
authors.lastname: Gomez
authors.forename: Joseph
authors.initials: J
authors.lastname: Cohnen
authors.forename: Lale
authors.initials: L
authors.lastname: Umutlu
authors.forename: Martin
authors.initials: M
authors.lastname: Gotthardt
authors.forename: Thorsten D
authors.initials: TD
authors.lastname: Poeppel
authors.forename: Andreas
authors.initials: A
authors.lastname: Bockisch
authors.forename: Sandra
authors.initials: S
authors.lastname: Rosenbaum-Krumme
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004492:Edetic Acid / Q000031:analogs & derivatives; D005260:Female; D005709:Gallium Isotopes; D005710:Gallium Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009842:Oligopeptides; D009942:Organometallic Compounds; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology
chemical_list: D005709:Gallium Isotopes; D005710:Gallium Radioisotopes; D009842:Oligopeptides; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; C000718244:gallium 68 PSMA-11; D004492:Edetic Acid