The role of single-photon emission computed tomography/computed tomography for precise localization of metastases in patients with differentiated thyroid cancer

Clin Imaging. Jan-Feb 2009;33(1):49-54. doi: 10.1016/j.clinimag.2008.06.024.


Purpose: 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.

Conclusion: 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.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Female
  • Humans
  • Iodine Radioisotopes*
  • Male
  • Middle Aged
  • Radiopharmaceuticals
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Thyroid Neoplasms / diagnosis*
  • Thyroid Neoplasms / secondary*
  • Tomography, Emission-Computed, Single-Photon / methods*
  • Tomography, X-Ray Computed / methods*
  • Young Adult


  • Iodine Radioisotopes
  • Radiopharmaceuticals