title: Strategies of radioiodine ablation in patients with low-risk thyroid cancer.
abstract: BACKGROUND
  It is not clear whether the administration of radioiodine provides any benefit to patients with low-risk thyroid cancer after a complete surgical resection. The administration of the smallest possible amount of radioiodine would improve care.
  
  
  METHODS
  In our randomized, phase 3 trial, we compared two thyrotropin-stimulation methods (thyroid hormone withdrawal and use of recombinant human thyrotropin) and two radioiodine ((131)I) doses (i.e., administered activities) (1.1 GBq and 3.7 GBq) in a 2-by-2 design. Inclusion criteria were an age of 18 years or older; total thyroidectomy for differentiated thyroid carcinoma; tumor-node-metastasis (TNM) stage, ascertained on pathological examination (p) of a surgical specimen, of pT1 (with tumor diameter ≤1 cm) and N1 or Nx, pT1 (with tumor diameter >1 to 2 cm) and any N stage, or pT2N0; absence of distant metastasis; and no iodine contamination. Thyroid ablation was assessed 8 months after radioiodine administration by neck ultrasonography and measurement of recombinant human thyrotropin-stimulated thyroglobulin. Comparisons were based on an equivalence framework.
  
  
  RESULTS
  There were 752 patients enrolled between 2007 and 2010; 92% had papillary cancer. There were no unexpected serious adverse events. In the 684 patients with data that could be evaluated, ultrasonography of the neck was normal in 652 (95%), and the stimulated thyroglobulin level was 1.0 ng per milliliter or less in 621 of the 652 patients (95%) without detectable thyroglobulin antibodies. Thyroid ablation was complete in 631 of the 684 patients (92%). The ablation rate was equivalent between the (131)I doses and between the thyrotropin-stimulation methods.
  
  
  CONCLUSIONS
  The use of recombinant human thyrotropin and low-dose (1.1 GBq) postoperative radioiodine ablation may be sufficient for the management of low-risk thyroid cancer. (Funded by the French National Cancer Institute [INCa] and the French Ministry of Health; ClinicalTrials.gov number, NCT00435851; INCa number, RECF0447.).
authors.affiliation: Department of Nuclear Medicine and Endocrine Oncology, Institut Gustave Roussy and University Paris-Sud, Villejuif, France. schlumbg@igr.fr
authors.forename: Martin
authors.initials: M
authors.lastname: Schlumberger
authors.forename: Bogdan
authors.initials: B
authors.lastname: Catargi
authors.forename: Isabelle
authors.initials: I
authors.lastname: Borget
authors.forename: Désirée
authors.initials: D
authors.lastname: Deandreis
authors.forename: Slimane
authors.initials: S
authors.lastname: Zerdoud
authors.forename: Boumédiène
authors.initials: B
authors.lastname: Bridji
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bardet
authors.forename: Laurence
authors.initials: L
authors.lastname: Leenhardt
authors.forename: Delphine
authors.initials: D
authors.lastname: Bastie
authors.forename: Claire
authors.initials: C
authors.lastname: Schvartz
authors.forename: Pierre
authors.initials: P
authors.lastname: Vera
authors.forename: Olivier
authors.initials: O
authors.lastname: Morel
authors.forename: Danielle
authors.initials: D
authors.lastname: Benisvy
authors.forename: Claire
authors.initials: C
authors.lastname: Bournaud
authors.forename: Françoise
authors.initials: F
authors.lastname: Bonichon
authors.forename: Catherine
authors.initials: C
authors.lastname: Dejax
authors.forename: Marie-Elisabeth
authors.initials: ME
authors.lastname: Toubert
authors.forename: Sophie
authors.initials: S
authors.lastname: Leboulleux
authors.forename: Marcel
authors.initials: M
authors.lastname: Ricard
authors.forename: Ellen
authors.initials: E
authors.lastname: Benhamou
mesh_terms: D055011:Ablation Techniques; D018263:Adenocarcinoma, Follicular / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D000328:Adult; D002291:Carcinoma, Papillary / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007037:Hypothyroidism / Q000209:etiology; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging; D011788:Quality of Life; D013963:Thyroid Hormones / Q000097:blood / Q000627:therapeutic use; D013964:Thyroid Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D013965:Thyroidectomy; D013972:Thyrotropin / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D007457:Iodine Radioisotopes; D013963:Thyroid Hormones; D013972:Thyrotropin