title: Predictive value of recombinant human TSH stimulation and neck ultrasonography in differentiated thyroid cancer patients.
abstract: BACKGROUND
  Serum thyroglobulin (Tg) stimulation by recombinant human TSH (rhTSH), in combination with neck ultrasonography (US), is an important tool in the first follow-up of differentiated epithelial cell thyroid carcinoma (DTC) patients. The objective of this study was to investigate if a second rhTSH stimulation, performed 2-3 years later, is of clinical utility in the follow-up of these patients.
  
  
  METHODS
  One hundred and one consecutive ambulatory DTC patients were studied. The great majority of them (89/101) were low-risk patients, being stage I or II at tumor node metastasis (TNM) staging classification. All study patients had been treated by surgery and radioiodine ablation, and exhibited, at first rhTSH follow-up, either undetectable Tg (<or=1 ng/mL) (rhTSH1-Tg-, n = 89 patients considered as free of disease) or low Tg (>1-5 ng/mL) (rhTSH1-Tg+, n = 12 patients considered with uncertain prognosis), with no US evidence of residual disease. In all patients, serum Tg measurement after a second rhTSH stimulation and neck US were performed.
  
  
  RESULTS
  At the second follow-up, all 89 rhTSH1-Tg-patients showed a negative US, and Tg became low positive only in one case, whereas it remained undetectable in the other patients. The overall negative predictive value of rhTSH1-Tg- was, then, 98.9%. Out of the remaining 12 patients (i.e., rhTSH1-Tg+ patients), 2 showed disease persistence/recurrence (with a positive predictive value of rhTSH1-Tg+ of 16.7%) and 6 became Tg-.
  
  
  CONCLUSIONS
  A second rhTSH stimulation is useless in DTC patients who were rhTSH-Tg and imaging negative at first follow-up, while it is suggested in patients with detectable, although low, rhTSH-Tg levels at first follow-up: in the absence of clinical or US evidence of disease persistence, these patients should not be retreated by radioiodine, but simply scheduled for a later rhTSH stimulation.
authors.affiliation: Unit of Endocrinology, Scientific Institute Casa Sollievo della Sofferenza, S Giovanni Rotondo, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Crocetti
authors.forename: Cosimo
authors.initials: C
authors.lastname: Durante
authors.forename: Marco
authors.initials: M
authors.lastname: Attard
authors.forename: Adele
authors.initials: A
authors.lastname: Maniglia
authors.forename: Salvatore
authors.initials: S
authors.lastname: Tumino
authors.forename: Rocco
authors.initials: R
authors.lastname: Bruno
authors.forename: Nazario
authors.initials: N
authors.lastname: Bonfitto
authors.forename: Franca
authors.initials: F
authors.lastname: Dicembrino
authors.forename: Antonio
authors.initials: A
authors.lastname: Varraso
authors.forename: Domenico
authors.initials: D
authors.lastname: Meringolo
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Filetti
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Trischitta
authors.forename: Massimo
authors.initials: M
authors.lastname: Torlontano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011994:Recombinant Proteins; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D013972:Thyrotropin; D014463:Ultrasonography
chemical_list: D011994:Recombinant Proteins; D013972:Thyrotropin