title: Radioactive iodine for thyrotoxicosis in childhood and adolescence: treatment and outcomes.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the outcome of radioiodine treatment in thyrotoxicosis in childhood and adolescence.
  
  
  METHODS
  This was a retrospective study of 27 patients (ages 7.2- 19.8 years) with a diagnosis of thyrotoxicosis who received iodine-131 (I-131) treatment from January 2007 to December 2011 in the Nuclear Medicine Division, Department of Radiology, Faculty of Medicine, Chiang Mai University. Gender, duration of antithyroid drug (ATD) treatment, 24-hour I-131 uptake, thyroid weight, total dose and number of treatments with I-131, and thyroid status at 6 months after treatment were recorded.
  
  
  RESULTS
  The outcomes of 27 patients (85.2% female, 14.8% male) treated with radioactive iodine were analyzed to assess the effectiveness of therapy as related to dose and gland size. All children and adolescents received 150 µCi of I-131/g of thyroid tissue (n=27). Six 6 months after treatment, 44.5% of the patients were hyperthyroid, 14.8% were euthyroid, and 40.7% were hypothyroid. Of the 12 cases with hyperthyroidism, 2 cases needed a second dose of I-131 treatment, and they finally reached a hypothyroid state. The patients were classified into 2 groups according to treatment success (euthyroid and hypothyroid) and treatment failure (hyperthyroid). There were no significant differences in age, gender, duration of ATD treatment, 2- and 24-hour I-131 uptake, thyroid weight, and total I-131 dose between these two groups.
  
  
  CONCLUSIONS
  Radioiodine treatment is safe and effective for thyrotoxicosis in childhood and adolescence. It is suitable as a good second-line therapy for patients with severe complications, those who show poor compliance, and those who fail to respond to ATD treatment.
authors.affiliation: Chiang Mai University, Faculty of Medicine, Department of Radiology, Chiang Mai, Thailand. snamwong@med.cmu.ac.th
authors.forename: Sirianong
authors.initials: S
authors.lastname: Namwongprom
authors.forename: Kevalee
authors.initials: K
authors.lastname: Unachak
authors.forename: Prapai
authors.initials: P
authors.lastname: Dejkhamron
authors.forename: Supoj
authors.initials: S
authors.lastname: Ua-apisitwong
authors.forename: Molrudee
authors.initials: M
authors.lastname: Ekmahachai
mesh_terms: D000293:Adolescent; D013956:Antithyroid Agents / Q000627:therapeutic use; D002648:Child; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013961:Thyroid Gland / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects*; D013971:Thyrotoxicosis / Q000188:drug therapy / Q000532:radiotherapy*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D013956:Antithyroid Agents; D007457:Iodine Radioisotopes