title: Efficacy of radioiodine therapy in the treatment of elevated serum thyroglobulin in patients with differentiated thyroid carcinoma and negative whole-body iodine scan.
abstract: BACKGROUND
  In the management of patients with differentiated thyroid carcinoma, serum thyroglobulin levels are often well correlated with whole-body radioiodine scanning (WBS) results. However, occasionally, a mismatched result - increased thyroglobulin with negative WBS - is observed. Radioiodine therapy has been suggested as a therapeutic choice with controversial results.
  
  
  METHODS
  We studied 32 differentiated thyroid carcinoma patients with elevated thyroglobulin level and negative WBS who had been treated with high-dose radioiodine. With a mean follow-up of 25.6 months (all follow-ups >11 months), thyroglobulin and thyroid-stimulating hormone levels, WBS, clinical, radiographic and pathological findings following treatment were recorded.
  
  
  RESULTS
  The mean pre-therapy off-treatment thyroglobulin was 152 +/- 119.0 ng.ml(-1). Although there was a mild trend towards an increase in thyroglobulin in the first post-treatment year, the difference was not significant. At the end of the follow-ups, 22 patients (68.7%) were categorized as non-responders to radioiodine therapy (any change or elevation of thyroglobulin or radiological and pathological evidences of progression), four patients (12.5%) as partial responders (transient reduction but not a normalization of thyroglobulin) and six patients (18.7%) as responders (normalization of thyroglobulin with no evidence of remnant disease). In nine of 10 partial and complete responders, reduction or normalization of thyroglobulin had occurred in the first post-treatment year.
  
  
  CONCLUSIONS
  We recommend that in differentiated thyroid carcinoma patients with elevated thyroglobulin and negative WBS, at least one course of radioiodine therapy should be undertaken and if reduction or normalization of serum thyroglobulin is not achieved, repeated courses of radioiodine therapy are not logical and other therapeutic methods should be applied.
authors.affiliation: Research Institute of Nuclear Medicine, Tehran University of Medical Sciences, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Saghari
authors.forename: Ali
authors.initials: A
authors.lastname: Gholamrezanezhad
authors.forename: Sahar
authors.initials: S
authors.lastname: Mirpour
authors.forename: Mohammad
authors.initials: M
authors.lastname: Eftekhari
authors.forename: Abbas
authors.initials: A
authors.lastname: Takavar
authors.forename: Armaghan
authors.initials: A
authors.lastname: Fard-Esfahani
authors.forename: Babak
authors.initials: B
authors.lastname: Fallahi
authors.forename: Davood
authors.initials: D
authors.lastname: Beiki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002648:Child; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D016896:Treatment Outcome; D051598:Whole Body Imaging; D014915:Whole-Body Counting
chemical_list: D014408:Biomarkers, Tumor; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D013954:Thyroglobulin