title: PRE-ABLATION THYROGLOBULIN AND THYROGLOBULIN TO THYROID-STIMULATING HORMONE RATIO MAY BE ASSOCIATED WITH PULMONARY METASTASES IN CHILDREN WITH DIFFERENTIATED THYROID CANCER.
abstract: OBJECTIVE
  Pediatric differentiated thyroid cancer (DTC) frequently presents with extensive disease. We studied the value of pre-ablation thyroglobulin (Tg) and Tg normalized to thyroid-stimulating hormone (TSH) levels in predicting distant metastases in pediatric patients with DTC.
  
  
  METHODS
  This is a retrospective cohort study of patients <21 years old who underwent thyroidectomy followed by131I ablation for DTC at 3 university hospitals over 20 years. Tg levels and the Tg/TSH ratio following surgery but prior to131I ablation were assessed. The presence of distant metastatic disease was determined from the postablation whole-body scan.
  
  
  RESULTS
  We studied 44 patients with a mean age of 15.2 years (range 7 to 21 years) and mean tumor size of 2.8 cm. Eight patients had distant metastases and had a higher mean pre-ablation Tg value compared to patients without distant metastases (1,037 μg/L versus 93.5 μg/L, P<.01). The pre-ablation Tg/TSH ratio was also associated with the presence of distant metastases: 12.5 ± 18.8 μg/mU in patients with distant metastases versus 0.7 ± 1.8 μg/mU in patients without (P<.01). A nomogram to predict distant metastases yielded areas under the receiver operating characteristic curve of 0.85 for Tg and 0.83 for Tg/TSH ratio.
  
  
  CONCLUSIONS
  After initial thyroidectomy, elevated preablation Tg and Tg/TSH ratio are associated with distant metastatic disease in pediatric DTC. This may inform the decision to ablate with131I, as well as the dosage.
  
  
  BACKGROUND
  ATA = American Thyroid Association CI = confidence interval DTC = differentiated thyroid cancer OR = odds ratio ROC = receiver operating characteristic Tg = thyroglobulin.
authors.forename: Masha J
authors.initials: MJ
authors.lastname: Livhits
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Pasternak
authors.forename: Maggie
authors.initials: M
authors.lastname: Xiong
authors.forename: Ning
authors.initials: N
authors.lastname: Li
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Gosnell
authors.forename: Michael W
authors.initials: MW
authors.lastname: Yeh
authors.forename: Harvey K
authors.initials: HK
authors.lastname: Chiu
mesh_terms: D055011:Ablation Techniques; D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008175:Lung Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging* / Q000556:secondary; D008297:Male; D009362:Neoplasm Metastasis; D011379:Prognosis; D012189:Retrospective Studies; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods*; D013972:Thyrotropin / Q000097:blood*; D051598:Whole Body Imaging; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D013972:Thyrotropin; D013954:Thyroglobulin