title: Usefulness of 201TL SPECT/CT relative to 18F-FDG PET/CT in detecting recurrent skull base nasopharyngeal carcinoma.
abstract: BACKGROUND
  This study was designed to compare (201)Tl single photon emission computed tomography (SPECT)/CT with 18-fluoro-2-deoxyglucose ((18)F-FDG) PET/CT in diagnosing recurrent skull base nasopharyngeal carcinoma (NPC).
  
  
  METHODS
  Twenty-seven patients were recruited. Both (201)Tl SPECT/CT and (18)F-FDG PET/CT for each patient were performed at least 4 months later after initial therapy.
  
  
  RESULTS
  The sensitivity and specificity for (201)Tl SPECT/CT were 66.7% and 100%, and those for (18)F-FDG PET/CT were 86.7% and 75.0%. Lesion/background ratios were obtained for the 10 lesions that were both SPECT and PET true positive. For the 8 patients with recurrences in nasopharyngeal regions, PET lesion/background ratios were all higher than SPECT lesion/background ratios. For the 2 patients with intracranial metastases, SPECT lesion/background ratios were higher than PET lesion/background ratios.
  
  
  CONCLUSIONS
  (201)Tl SPECT/CT is as effective as (18)F-FDG PET/CT in detecting recurrent NPC. For intracranial recurrence, (201)Tl SPECT, because of its high intracranial lesion/background ratio, is probably better than (18)F-FDG PET.
authors.affiliation: Department of Nuclear Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Ruoh-Fang
authors.initials: RF
authors.lastname: Yen
authors.forename: Lai-Lei
authors.initials: LL
authors.lastname: Ting
authors.forename: Mei-Fang
authors.initials: MF
authors.lastname: Cheng
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Wu
authors.forename: Kai-Yuan
authors.initials: KY
authors.lastname: Tzen
authors.forename: Ruey-Long
authors.initials: RL
authors.lastname: Hong
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011336:Probability; D011446:Prospective Studies; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D019291:Skull Base / Q000000981:diagnostic imaging* / Q000473:pathology; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18