title: The role of single-photon emission computed tomography/computed tomography for precise localization of metastases in patients with differentiated thyroid cancer.
abstract: OBJECTIVE
  It is very important in the management of patients with differentiated thyroid cancer (DTC) to precisely localize the foci of I-131 uptake, but it is difficult because of a lack of anatomic landmarks. The purpose of this study was to investigate the added value of I-131 single-photon emission computed tomography (SPECT)/computed tomography (CT) fusion imaging using a hybrid system in patients with DTC.
  
  
  METHODS
  Ninety-four patients with DTC underwent I-131 SPECT/CT using a hybrid tomography consisting of a dual-head variable-angle gamma camera and a low-dose X-ray tube. Results were compared with I-131 whole-body scan (WBS). SPECT/CT was performed 5-7 days after administration of a therapeutic dose of I-131. Fusion images were constructed by combining the digital CT and SPECT images on a computer workstation.
  
  
  RESULTS
  Compared with I-131 WBS, SPECT/CT imaging had improved the precise localization in 21% (20/94) of patients. In addition, SPECT/CT provided additional clinical data in 12 of the patients examined (12/94) and also caused physicians to reconsider the (131)I therapeutic approach in 22 patients.
  
  
  CONCLUSIONS
  The results of the current study indicate that the addition of I-131 SPECT/CT to WBS can improve the localization of metastases in patients with DTC. It may also detect metastases missed by WBS and adjust the therapy plan.
authors.affiliation: Department of Nuclear Medicine, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China. wangh13@hotmail.com
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Hong-Liang
authors.initials: HL
authors.lastname: Fu
authors.forename: Jia-Ning
authors.initials: JN
authors.lastname: Li
authors.forename: Ren-Jian
authors.initials: RJ
authors.lastname: Zou
authors.forename: Zhen-Hui
authors.initials: ZH
authors.lastname: Gu
authors.forename: Jing-Chuan
authors.initials: JC
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals