title: Comparison of 68Ga-DOTATOC PET and 111In-DTPAOC (Octreoscan) SPECT in patients with neuroendocrine tumours.
abstract: OBJECTIVE
  Neuroendocrine tumours (NETs) can be imaged with scintigraphy using radiolabelled somatostatin analogues. The aim of our study was to compare the value of (68)Ga-DOTATOC PET and (111)In-DTPAOC SPECT (Octreoscan) in the detection of NET manifestations.
  
  
  METHODS
  Twenty-seven NET patients were prospectively examined. (68)Ga-DOTATOC PET and (111)In-DTPAOC SPECT were performed using standard techniques. Treatment was not applied in between. Mean and maximum standardised uptake values (SUVs) were calculated for PET findings. Tumour/non-tumour ratios were calculated for SPECT findings. Findings were compared by a region-by-region analysis and verified with histopathology, CT and MRI within 21 days.
  
  
  RESULTS
  SUVs of positive lesions on (68)Ga-DOTATOC PET ranged from 0.7 to 29.3 (mean SUV) and from 0.9 to 34.4 (maximum SUV). Tumour/non-tumour ratios on (111)In-DTPAOC SPECT ranged from 1.8 to 7.3. In imaging lung and skeletal manifestations, (68)Ga-DOTATOC PET was more efficient than (111)In-DTPAOC SPECT. All discrepant lung findings and 77.8% of discrepant osseous findings were verified as true positive PET interpretations. In regional comparison of liver and brain, (68)Ga-DOTATOC PET and (111)In-DTPAOC SPECT were identical. In lymph nodes, the pancreas and the gastro-intestinal system, different values of the two techniques were not indicated in regional analyses. In a single patient, surgical interventions were changed on the basis of (68)Ga-DOTATOC PET findings.
  
  
  CONCLUSIONS
  (68)Ga-DOTATOC PET is superior to (111)In-DTPAOC SPECT in the detection of NET manifestations in the lung and skeleton and similar for the detection of NET manifestations in the liver and brain. (68)Ga-DOTATOC PET is advantageous in guiding the clinical management.
authors.affiliation: Department of Nuclear Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. inga.buchmann@med.uni-heidelberg.de
authors.forename: I
authors.initials: I
authors.lastname: Buchmann
authors.forename: M
authors.initials: M
authors.lastname: Henze
authors.forename: S
authors.initials: S
authors.lastname: Engelbrecht
authors.forename: M
authors.initials: M
authors.lastname: Eisenhut
authors.forename: A
authors.initials: A
authors.lastname: Runz
authors.forename: M
authors.initials: M
authors.lastname: Schäfer
authors.forename: T
authors.initials: T
authors.lastname: Schilling
authors.forename: S
authors.initials: S
authors.lastname: Haufe
authors.forename: T
authors.initials: T
authors.lastname: Herrmann
authors.forename: U
authors.initials: U
authors.lastname: Haberkorn
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging*; D015282:Octreotide / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013004:Somatostatin / Q000031:analogs & derivatives*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: C499142:Ga(III)-DOTATOC; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D013004:Somatostatin; C081788:pentetreotide; D015282:Octreotide