title: Risk of Thyroid Nodules in Residents of Belarus Exposed to Chernobyl Fallout as Children and Adolescents.
abstract: Although radiation exposure is an important predictor of thyroid cancer on diagnosis of a thyroid nodule, the relationship between childhood radiation exposure and thyroid nodules has not been comprehensively evaluated.
  
  
  
  To examine the association between internal I-131 thyroid dose and thyroid nodules in young adults exposed during childhood.
  
  
  
  In this cross-sectional study, we screened residents of Belarus aged ≤18 years at the time of the Chernobyl nuclear accident for thyroid disease (median age, 21 years) with thyroid palpation, ultrasonography, blood/urine analysis, and medical follow-up when appropriate. Eligible participants (N = 11,421) had intact thyroid glands and doses based on direct individual thyroid activity measurements.
  
  
  
  Excess odds ratios per Gray (EOR/Gy, scaled at age 5 years at exposure) for any thyroid nodule and for nodules grouped by cytology/histology, diameter size, and singularity.
  
  
  
  Risk of any thyroid nodule increased significantly with I-131 dose and, for a given dose, with younger age at exposure. The EOR/Gy (95% confidence intervals) for neoplastic nodules (3.82; 0.87 to 15.52) was significantly higher than for nonneoplastic nodules (0.32; <0.03 to 0.70) and did not vary by size; whereas the EOR/Gy for nonneoplastic nodules did vary by size (P = 0.02) and was 1.55 (0.36 to 5.46) for nodules ≥10 mm and 0.02 (<-0.02 to 0.70) for nodules <10 mm. EORs/Gy for single and multiple nodules were comparable.
  
  
  
  Childhood exposure to internal I-131 is associated with increased risk of neoplastic thyroid nodules of any size and nonneoplastic nodules ≥10 mm.
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Elizabeth K
authors.initials: EK
authors.lastname: Cahoon
authors.affiliation: The Republican Research Center for Radiation Medicine and Human Ecology, Gomel 246040, Belarus.
authors.forename: Eldar A
authors.initials: EA
authors.lastname: Nadyrov
authors.affiliation: The Republican Research Center for Radiation Medicine and Human Ecology, Gomel 246040, Belarus.
authors.forename: Olga N
authors.initials: ON
authors.lastname: Polyanskaya
authors.affiliation: The Republican Research Center for Radiation Medicine and Human Ecology, Gomel 246040, Belarus.
authors.forename: Vasilina V
authors.initials: VV
authors.lastname: Yauseyenka
authors.affiliation: The Republican Research Center for Radiation Medicine and Human Ecology, Gomel 246040, Belarus.
authors.forename: Ilya V
authors.initials: IV
authors.lastname: Veyalkin
authors.affiliation: The Republican Research Center for Radiation Medicine and Human Ecology, Gomel 246040, Belarus.
authors.forename: Tamara I
authors.initials: TI
authors.lastname: Yeudachkova
authors.affiliation: The Republican Research Center for Radiation Medicine and Human Ecology, Gomel 246040, Belarus.
authors.forename: Tamara I
authors.initials: TI
authors.lastname: Maskvicheva
authors.affiliation: Belarusian Medical Academy of Post-Graduate Education, Minsk 220714, Belarus.
authors.forename: Victor F
authors.initials: VF
authors.lastname: Minenko
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Wayne
authors.initials: W
authors.lastname: Liu
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Drozdovitch
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Mabuchi
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Little
authors.affiliation: Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California 94118.
authors.forename: Lydia B
authors.initials: LB
authors.lastname: Zablotska
authors.affiliation: The Thyroid Center, Columbia University, New York, New York 10032.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: McConnell
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Maureen
authors.initials: M
authors.lastname: Hatch
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Kamau O
authors.initials: KO
authors.lastname: Peters
authors.affiliation: The Republican Research Center for Radiation Medicine and Human Ecology, Gomel 246040, Belarus.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Rozhko
authors.affiliation: Division of Cancer Epidemiology & Genetics, National Cancer Institute, Bethesda, Maryland 20892-9778.
authors.forename: Alina V
authors.initials: AV
authors.lastname: Brenner
mesh_terms: D000293:Adolescent; D047852:Chernobyl Nuclear Accident; D002648:Child; D002675:Child, Preschool; D004307:Dose-Response Relationship, Radiation; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007457:Iodine Radioisotopes / Q000009:adverse effects; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology / Q000209:etiology*; D002094:Republic of Belarus / Q000453:epidemiology; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D014463:Ultrasonography
chemical_list: D007457:Iodine Radioisotopes