title: High management impact of Ga-68 DOTATATE (GaTate) PET/CT for imaging neuroendocrine and other somatostatin expressing tumours.
abstract: BACKGROUND
  Ga-68 DOTATATE (Ga-octreotate, GaTate) positron emission tomography (PET)/CT has multiple advantages compared with conventional and In-111 octreotide imaging for neuroendocrine tumours and other somatostatin-receptor expressing tumours. This study assesses the management impact of incremental diagnostic information obtained from this technique compared with conventional staging.
  
  
  METHODS
  Fifty-nine GaTate PET/CT studies were performed over an 18-month period (52 proven or suspected gastro-entero-pancreatic or bronchial neuroendocrine tumours and seven neural crest/mesenchymal tumours). A retrospective blinded review was performed on the number of abnormalities (1, 2-5 or >5) within defined regions with comparison to conventional imaging to assess incremental diagnostic information. Subsequent management impact (high, moderate or low) was determined by clinical review and follow up to assess pre-PET stage, treatment intent and post-PET management change.
  
  
  RESULTS
  Eighty-eight percent of GaTate studies were abnormal. Compared with conventional and In-111 octreotide imaging, additional information was provided by GaTate PET/CT in 68 and 83% of patients, respectively. Management impact was high (inter-modality change) in 47%, moderate (intra-modality change) in 10% and low in 41% (not assessable in 2%). High management impact included directing patients to curative surgery by identifying a primary site and directing patients with multiple metastases to systemic therapy.
  
  
  CONCLUSIONS
  GaTate PET/CT imaging provides additional diagnostic information in a high proportion of patients with consequent high management impact. GaTate PET/CT could replace (1)In-111 octreotide scintigraphy at centres where it is available given its superior accuracy, faster acquisition and lower radiation exposure. Rapid implementation could be achieved by allowing substitutional funding in the Medicare Benefit Schedule.
authors.affiliation: Centre for Cancer Imaging, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, VIC, Australia. michael.hofman@petermac.org
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hofman
authors.forename: Grace
authors.initials: G
authors.lastname: Kong
authors.forename: Oliver C
authors.initials: OC
authors.lastname: Neels
authors.forename: Peter
authors.initials: P
authors.lastname: Eu
authors.forename: Emily
authors.initials: E
authors.lastname: Hong
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Hicks
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography; D017481:Receptors, Somatostatin / Q000378:metabolism*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D009942:Organometallic Compounds; D017481:Receptors, Somatostatin; C513399:gallium Ga 68 dotatate