title: Usefulness of (99m)Tc-pertechnetate whole body scan with neck and chest SPECT/CT for detection of post-surgical thyroid remnant and metastasis in differentiated thyroid cancer patients.
abstract: OBJECTIVE
  The aim of the study was to evaluate the usefulness of (99m)Tc-pertechnetate whole body scan (WBS) with neck and chest SPECT/CT for detection of post-surgical thyroid remnant and metastasis in differentiated thyroid cancer (DTC) patients.
  
  
  METHODS
  Fifty-six post total thyroidectomy patients were included. All patients were prospectively imaged with (99m)Tc-pertechnetate WBS with neck and chest SPECT/CT before (131)I ablation. The post-ablative (131)I WBS with SPECT/CT was performed at 5-7 days after receiving (131)I. Both scans were directly compared to determine the concordance of sites and number of remnant and metastasis.
  
  
  RESULTS
  Overall per-patient analysis, the percentage of concordance between two scans was 96.4%. In thyroid bed, lymph node, lung and bone subgroups, the percentage of concordance between two scans was 96.4, 92.9, 98.2 and 100%, respectively. All of them show good correlation with unweighted kappa between 0.7 and 1. Overall per-lesion analysis, the percentage of concordance between two scans was 84%. In thyroid bed, lymph node, lung and bone subgroups, the percentage of concordance between two scans was 89.5, 55, 82.6 and 50%, respectively.
  
  
  CONCLUSIONS
  Pre-ablative pertechnetate WBS with neck and chest SPECT/CT has good correlation for the detection of post-surgical thyroid remnant, cervical node and discrete lung nodule metastasis as compared to (131)I WBS with SPECT/CT per-patient basis. Because (131)I therapeutic activity is desired base on metastatic site and less concerning about the number of lesions, pre-ablative (99m)Tc-pertechnetate WBS with SPECT/CT was a good alternative tool to avoid radioiodine stunning in post-surgical DTC patients.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Rd Pathum Wan, Bangkok, 10330, Thailand, aueng_tw45@hotmail.com.
authors.forename: Maythinee
authors.initials: M
authors.lastname: Chantadisai
authors.forename: Kanaungnit
authors.initials: K
authors.lastname: Kingpetch
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009333:Neck / Q000000981:diagnostic imaging; D009362:Neoplasm Metastasis; D011184:Postoperative Period; D013902:Radiography, Thoracic; D013670:Sodium Pertechnetate Tc 99m; D013909:Thorax / Q000000981:diagnostic imaging; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000601:surgery; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D051598:Whole Body Imaging; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D013670:Sodium Pertechnetate Tc 99m