title: Differentiated thyroid carcinoma after 131I-MIBG treatment for neuroblastoma during childhood: description of the first two cases.
abstract: BACKGROUND
  It is well known that the thyroid gland is sensitive to the damaging effects of irradiation (X-radiation or (131)I¯). For this reason, during exposure to (131)I- metaiodobenzylguanidine (MIBG) in children with neuroblastoma (NBL), the thyroid gland is protected against radiation damage by the administration of either potassium iodide (KI) or a combination of KI, thyroxine, and methimazole. Although hypothyroidism and benign thyroid nodules are frequently encountered during follow-up of these children, differentiated thyroid carcinoma (DTC) has never been reported after treatment with (131)I-MIBG in children who have not been given external beam irradiation. Here, we describe the first two cases of DTC after (131)I-MIBG-therapy.
  
  
  METHODS
  A 6-year-old boy, treated with (131)I-MIBG for NBL at the age of 4 months, and a 13-year-old girl, treated at the age of 9 months, were both diagnosed with DTC at 5 and 12 years after (131)I-MIBG treatment, respectively. Both children received thyroid protection during exposure to (131)I-MIBG. In each child DTC was discovered in nonpalpable nodules by thyroid ultrasound.
  
  
  CONCLUSIONS
  The first two pediatric patients with DTC after treatment with (131)I-MIBG are reported.
  
  
  CONCLUSIONS
  Both these cases of DTC after (131)I-MIBG for childhood NBL underline the importance of adequate thyroid protection against radiation exposure during treatment for NBL. Children who have been treated with (131)I-MIBG should be given life-long follow-up, not only with regard to thyroid function, but also with surveillance for the development of thyroid nodules and thyroid cancer.
authors.affiliation: Department of Pediatric Endocrinology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands. h.m.vansanten@amc.uva.nl
authors.forename: Hanneke M
authors.initials: HM
authors.lastname: van Santen
authors.forename: Godelieve A M
authors.initials: GA
authors.lastname: Tytgat
authors.forename: Marianne D
authors.initials: MD
authors.lastname: van de Wetering
authors.forename: Berthe L F
authors.initials: BL
authors.lastname: van Eck-Smit
authors.forename: Saskia M J
authors.initials: SM
authors.lastname: Hopman
authors.forename: Alida F
authors.initials: AF
authors.lastname: van der Steeg
authors.forename: Els J M
authors.initials: EJ
authors.lastname: Nieveen van Dijkum
authors.forename: A S Paul
authors.initials: AS
authors.lastname: van Trotsenburg
mesh_terms: D019797:3-Iodobenzylguanidine / Q000009:adverse effects* / Q000627:therapeutic use*; D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000532:radiotherapy*; D002277:Carcinoma; D002291:Carcinoma, Papillary; D002648:Child; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D009447:Neuroblastoma / Q000532:radiotherapy*; D013899:Thoracic Neoplasms / Q000532:radiotherapy*; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D007457:Iodine Radioisotopes; D019797:3-Iodobenzylguanidine