title: Influence of prior carbimazole on the outcome of radioiodine therapy in pediatric and adolescent Graves' disease.
abstract: OBJECTIVE
  Therapeutic options for pediatric Graves' disease (PGD) include antithyroid drug therapy (ATD) as the first line and radioiodine (I-131) therapy as the second line of treatment. To date, controversies persist regarding the true effect of prior ATD in the outcome of I-131 therapy in PGD. This study evaluated the effect of prior carbimazole treatment on the outcome of I-131 therapy in PGD.
  
  
  METHODS
  This is a retrospective study covering the years 1995-2012, with a median follow-up of 75 months. Records of 114 children (84 girls and 30 boys, age range: 5-20 years, mean 24-h radioiodine uptake, 58%) who had clinically and biochemically proven Graves' disease irrespective of prior ATD therapy were included. All patients were treated with fixed doses of 5 mCi (185 MBq) I-131 for Graves' disease; 74 had undergone prior carbimazole treatment (group 1) and 40 were drug naive (group 2). The endpoint of follow-up was stable euthyroid or hypothyroid in patients. The effect of prior carbimazole treatment on the outcome of I-131 therapy in PGD patients was evaluated. The success of radioiodine therapy was defined as the cure of hyperthyroidism. Variables were analyzed to identify the potential predictive factors for euthyroidism/hypothyroidism after treatment.
  
  
  RESULTS
  The cure rate was 70% in group 1 and 83% in group 2 with a single dose of radioiodine (P=0.299). The success rate achieved at the end of 1-year follow-up in group 1 and group 2 was 81 and 87%, respectively (P=0.401). No independent predictor was associated with success or failure of treatment. At the median follow-up of 75 months (range: 12-216 months), 76% of patients were hypothyroid on replacement doses of levothyroxine and 24% still continued to be euthyroid.
  
  
  CONCLUSIONS
  Prior carbimazole treatment does not alter the outcome of radioiodine therapy in PGD.
authors.affiliation: Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Sanjana
authors.initials: S
authors.lastname: Ballal
authors.forename: Ramya
authors.initials: R
authors.lastname: Soundararajan
authors.forename: Harmandeep
authors.initials: H
authors.lastname: Singh
authors.forename: Aayushi
authors.initials: A
authors.lastname: Garg
authors.forename: Saurav
authors.initials: S
authors.lastname: Chopra
authors.forename: Chandrasekhar
authors.initials: C
authors.lastname: Bal
mesh_terms: D000293:Adolescent; D013956:Antithyroid Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002231:Carbimazole / Q000494:pharmacology* / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D005260:Female; D006111:Graves Disease / Q000188:drug therapy* / Q000378:metabolism / Q000532:radiotherapy*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D053208:Kaplan-Meier Estimate; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D013956:Antithyroid Agents; D007457:Iodine Radioisotopes; D002231:Carbimazole