title: Hypothyroidism after head-and-neck radiotherapy in children and adolescents: preliminary results of the "Registry for the Evaluation of Side Effects After Radiotherapy in Childhood and Adolescence" (RiSK).
abstract: OBJECTIVE
  The "Registry for the Evaluation of Side Effects After Radiotherapy in Childhood and Adolescence" (RiSK) has been established to prospectively characterize dose-volume effects of radiation in terms of side effects. The aim of this analysis was to characterize the function of the thyroid gland after radiotherapy to the head-and-neck region in children and adolescents.
  
  
  METHODS
  Detailed information regarding radiation doses to at-risk organs has been collected across Germany since 2001. Thyroid function was evaluated by blood value examinations of thyroid-stimulating hormone, triiodothyronine, and thyroxine. Information regarding thyroid hormone substitution was requested from the treating physicians.
  
  
  RESULTS
  Until May 2009, 1,086 patients from 62 centers were recruited, including 404 patients (median age, 10.9 years) who had received radiotherapy to the thyroid gland and/or hypophysis. Follow-up information was available for 264 patients (60.9%; median follow-up, 40 months), with 60 patients (22.7%) showing pathologic values. In comparison to patients treated with prophylactic cranial irradiation (median dose, 12 Gy), patients with radiation doses of 15 to 25 Gy to the thyroid gland had a hazard ratio of 3.072 (p=0.002) for the development of pathologic thyroid blood values. Patients with greater than 25 Gy to the thyroid gland and patients who underwent craniospinal irradiation had hazard ratios of 3.768 (p=0.009) and 5.674 (p<0.001), respectively. The cumulative incidence of thyroid hormone substitution therapy did not differ between defined subgroups.
  
  
  CONCLUSIONS
  Radiation-induced thyroid function impairment, including damage to the thyroid gland and/or hypophysis, can frequently be observed after radiotherapy in children. A structured follow-up examination is advised.
authors.affiliation: Department of Radiotherapy, University Hospital of Münster, and Department of Medical Informatics and Biomathematics, University of Münster, Münster, Germany. Tobias.Boelling@uni-muenster.de
authors.forename: Tobias
authors.initials: T
authors.lastname: Bölling
authors.forename: Alina
authors.initials: A
authors.lastname: Geisenheiser
authors.forename: Hildegard
authors.initials: H
authors.lastname: Pape
authors.forename: Carmen
authors.initials: C
authors.lastname: Martini
authors.forename: Christian
authors.initials: C
authors.lastname: Rübe
authors.forename: Beate
authors.initials: B
authors.lastname: Timmermann
authors.forename: Karin
authors.initials: K
authors.lastname: Fischedick
authors.forename: Rolf-Dieter
authors.initials: RD
authors.lastname: Kortmann
authors.forename: Joachim
authors.initials: J
authors.lastname: Gerss
authors.forename: Raphael
authors.initials: R
authors.lastname: Koch
authors.forename: Normann
authors.initials: N
authors.lastname: Willich
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016371:Cranial Irradiation / Q000009:adverse effects; D005858:Germany; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D020249:Hormone Replacement Therapy / Q000706:statistics & numerical data; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000188:drug therapy / Q000209:etiology*; D007223:Infant; D008137:Longitudinal Studies; D058958:Organs at Risk / Q000528:radiation effects*; D010902:Pituitary Gland / Q000528:radiation effects; D011879:Radiotherapy Dosage; D012042:Registries; D012306:Risk; D013961:Thyroid Gland / Q000528:radiation effects*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D055815:Young Adult
chemical_list: D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine