title: Changes in pediatric thyroid sonograms in or nearby the Kanto region before and after the accident at the Fukushima Daiichi nuclear power plant.
abstract: Following the accident at the Fukushima Daiichi Nuclear Power Station which occurred on March 11, 2011 due to the Eastern Japan Great Earthquake (the Accident), there have been concerns over elevation of the risk of thyroid cancer among children due to internal exposure to radioactive iodine. In Fukushima Prefecture, screening of children with thyroid ultrasonography has been carried out, yielding numerous findings, suggesting a possible influence from the Accident. We report thyroid ultrasonographic findings, used by similar device at Fukushima Prefecture's study, at Ito-hospital. Of the 2721 children aged 15 or less who visited our hospital between January 2005 and March 2013, 1214 children (330 boys and 884 girls; median age, 12; range of age, 4-15) were covered by evaluation of thyroid ultrasonographic findings, excluding children known in advance to have thyroid disease on the basis of disease history, palpation and blood tests. Among these 1214 children, 709 children (58.4%) were found cysts (≤ 5 mm in 665 cases) by ultrasonography, 43 children (3.5%) were found nodules (≤ 5 mm in 18 cases) and 9 children (5.2%) were found an intrathyroid ectopic thymus. Analysis of the data before and after the Accident using the same device, involving age adjustment on the basis of the standard population in 2010, showed no difference in the incidence rate of cysts or nodules. In children examined, the incidence rate of cyst formation (particularly ≤ 5 mm) was higher, and there was no difference in the incidence rate of cysts or nodules between the pre- and post-accident period.
authors.affiliation: Ito Hospital, Tokyo 150-8308, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Iwaku
authors.forename: Jaeduk Yoshimura
authors.initials: JY
authors.lastname: Noh
authors.forename: Eiji
authors.initials: E
authors.lastname: Sasaki
authors.forename: Nami
authors.initials: N
authors.lastname: Suzuki
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Kameda
authors.forename: Sakiko
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Ai
authors.initials: A
authors.lastname: Yoshihara
authors.forename: Hidemi
authors.initials: H
authors.lastname: Ohye
authors.forename: Natsuko
authors.initials: N
authors.lastname: Watanabe
authors.forename: Miho
authors.initials: M
authors.lastname: Suzuki
authors.forename: Masako
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Yo
authors.initials: Y
authors.lastname: Kunii
authors.forename: Koji
authors.initials: K
authors.lastname: Mukasa
authors.forename: Kiminori
authors.initials: K
authors.lastname: Sugino
authors.forename: Koichi
authors.initials: K
authors.lastname: Ito
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002828:Choristoma; D003560:Cysts / Q000000981:diagnostic imaging; D055866:Earthquakes; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D055848:Nuclear Power Plants; D018788:Radioactive Hazard Release; D013950:Thymus Gland; D013959:Thyroid Diseases / Q000000981:diagnostic imaging*; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging; D014463:Ultrasonography