title: No survival difference after successful (131)I ablation between patients with initially low-risk and high-risk differentiated thyroid cancer.
abstract: OBJECTIVE
  To compare disease-specific survival and recurrence-free survival (RFS) after successful (131)I ablation in patients with differentiated thyroid carcinoma (DTC) between those defined before ablation as low-risk and those defined as high-risk according to the European Thyroid Association 2006 consensus statement.
  
  
  METHODS
  Retrospective data from three university hospitals were pooled. Of 2009 consecutive patients receiving ablation, 509 were identified as successfully ablated based on both undetectable stimulated serum thyroglobulin in the absence of antithyroglobulin antibodies and a negative diagnostic whole-body scan in a follow-up examination conducted 8.1+/-4.6 months after ablation. Of these 509 patients, 169 were defined as high-risk.
  
  
  RESULTS
  After a mean follow-up of 81+/-64 months (range 4-306 months), only three patients had died of DTC, rendering assessment of disease-specific survival differences impossible. Of the 509 patients, 12 (2.4%) developed a recurrence a mean 35 months (range 12-59 months) after ablation. RFS for the duration of follow-up was 96.6% according to the Kaplan-Meier method. RFS did not differ between high-risk and low-risk patients (p=0.68). RFS differed slightly but significantly between those with papillary and those with follicular thyroid carcinoma (p=0.03) and between those aged </=45 years those aged >45 years at diagnosis (p=0.018).
  
  
  CONCLUSIONS
  After (near) total thyroidectomy and successful (131)I ablation, RFS does not differ between patients classified as high-risk and those classified as low-risk based on TNM stage at diagnosis. Consequently, the follow-up protocol should be determined on the basis of the result of initial treatment rather than on the initial tumour classification.
authors.affiliation: Department of Nuclear Medicine, University of Würzburg, Oberdürrbacher Strasse 6, Würzburg, 97080, Germany. verburg_e@klinik.uni-wuerzburg.de
authors.forename: Frederik Anton
authors.initials: FA
authors.lastname: Verburg
authors.forename: Marcel P M
authors.initials: MP
authors.lastname: Stokkel
authors.forename: Christian
authors.initials: C
authors.lastname: Düren
authors.forename: Robbert B T
authors.initials: RB
authors.lastname: Verkooijen
authors.forename: Uwe
authors.initials: U
authors.lastname: Mäder
authors.forename: Johannes W
authors.initials: JW
authors.lastname: van Isselt
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Marlowe
authors.forename: Johannes W
authors.initials: JW
authors.lastname: Smit
authors.forename: Christoph
authors.initials: C
authors.lastname: Reiners
authors.forename: Markus
authors.initials: M
authors.lastname: Luster
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000401:mortality* / Q000532:radiotherapy*; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals