title: Comparison of ¹³¹I whole-body imaging, ¹³¹I SPECT/CT, and ¹⁸F-FDG PET/CT in the detection of metastatic thyroid cancer.
abstract: OBJECTIVE
  The aim of this study was to compare (131)I whole-body scintigraphy (WBS), WBS with (131)I single photon emission computed tomography/computed tomography (SPECT/CT), and (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in the detection of distant metastases of differentiated thyroid cancer (DTC).
  
  
  METHODS
  A total of 140 patients with 258 foci of suspected distant metastases were evaluated. (131)I WBS, (131)I SPECT/CT, and (18)F-FDG PET/CT images were interpreted separately. The final diagnosis was obtained from histopathologic study, serum thyroglobulin level, other imaging modalities, and/or clinical follow-up.
  
  
  RESULTS
  Of the 140 patients with 258 foci, 46 patients with 166 foci were diagnosed as positive for distant metastasis. The sensitivity, specificity, and diagnostic accuracy of each imaging modality were 65, 55, and 59%, respectively, for (131)I WBS; 65, 95, and 85% for (131)I SPECT/CT, respectively; and 61, 98, and 86%, respectively, for (18)F-FDG PET/CT in patient-based analyses. Lesion-based analyses demonstrated that both SPECT/CT and PET/CT were superior to WBS (p<0.001) in all patient groups. SPECT/CT was superior to WBS and PET/CT (p<0.001) in patients who received a single challenge of radioiodine therapy, whereas PET/CT was superior to WBS (p=0.005) and SPECT/CT (p=0.013) in patients who received multiple challenges.
  
  
  CONCLUSIONS
  Both SPECT/CT and PET/CT demonstrated high diagnostic performance in detecting metastatic thyroid cancer. SPECT/CT was highly accurate in patients who underwent a single challenge of radioiodine therapy. In contrast, (18)F-FDG PET/CT presented the highest diagnostic performance in patients who underwent multiple challenges of radioiodine therapy.
authors.affiliation: Department of Nuclear Medicine, Clinical Medicine Research Center, Chonnam National University Hospital, 671 Jebongno, Gwangju 501-757, Republic of Korea.
authors.forename: Jong-Ryool
authors.initials: JR
authors.lastname: Oh
authors.forename: Byung-Hyun
authors.initials: BH
authors.lastname: Byun
authors.forename: Sun-Pyo
authors.initials: SP
authors.lastname: Hong
authors.forename: Ari
authors.initials: A
authors.lastname: Chong
authors.forename: Jahae
authors.initials: J
authors.lastname: Kim
authors.forename: Su-Woong
authors.initials: SW
authors.lastname: Yoo
authors.forename: Sae-Ryung
authors.initials: SR
authors.lastname: Kang
authors.forename: Dong-Yeon
authors.initials: DY
authors.lastname: Kim
authors.forename: Ho-Chun
authors.initials: HC
authors.lastname: Song
authors.forename: Hee-Seung
authors.initials: HS
authors.lastname: Bom
authors.forename: Jung-Joon
authors.initials: JJ
authors.lastname: Min
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000532:radiotherapy; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods*; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D019788:Fluorodeoxyglucose F18