title: Comparison of dual-head coincidence PET versus ring PET in tumor patients.
abstract: This study compared the multiring detector (Ring-PET) and the dual-head coincidence imaging system (DH-PET) for staging/ restaging neoplastic patients before or after surgery or radiochemotherapy.
  
  
  METHODS
  Seventy patients with suspected tumor recurrence or metastatic dissemination received an intravenous dose of 18F-fluorodeoxyglucose (FDG) under overnight fasting and were studied in sequence with a dedicated positron emission tomograph with Ring-PET and a DH-PET. Ring-PET studies were performed 45-75 min postinjection and were followed by a DH-PET scan approximately 3 h postinjection. Number and location of the hypermetabolic lesions detected on DH-PET and Ring-PET reconstructed images were blindly assessed by three independent observers.
  
  
  RESULTS
  DH-PET identified all 14 head lesions detected by Ring-PET, 53 of 63 thoracic lesions and 36 of 45 abdominal lesions. Of the 19 lesions not identified by DH-PET, 6 were smaller than 10 mm, 8 were between 10 and 15 mm and 1 was 18 mm; dimensions of 4 bone lesions were not available. A concordant restaging, based on location and number of lesions detected, was found in all 14 patients with head tumors, in 28 of 30 patients with thoracic tumors and in 24 of 26 patients with abdominal tumors.
  
  
  CONCLUSIONS
  We found a good agreement between Ring-PET and DH-PET assessment of oncologic patients in detecting hypermetabolic lesions > or = 10-15 mm.
authors.affiliation: INB-CNR, Scientific Institute H San Raffaele, University of Milano, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Landoni
authors.forename: L
authors.initials: L
authors.lastname: Gianolli
authors.forename: G
authors.initials: G
authors.lastname: Lucignani
authors.forename: P
authors.initials: P
authors.lastname: Magnani
authors.forename: A
authors.initials: A
authors.lastname: Savi
authors.forename: L
authors.initials: L
authors.lastname: Travaini
authors.forename: M C
authors.initials: MC
authors.lastname: Gilardi
authors.forename: F
authors.initials: F
authors.lastname: Fazio
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D015902:Gamma Cameras; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D019275:Radiopharmaceuticals; D013899:Thoracic Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy; D014055:Tomography, Emission-Computed / Q000191:economics / Q000379:methods*
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18