title: Sensitive immunodetection of radiotoxicity after iodine-131 therapy for thyroid cancer using γ-H2AX foci of DNA damage in lymphocytes.
abstract: OBJECTIVE
  The purpose of our study was to evaluate the degree of radiotoxicity to lymphocytes in thyroid cancer after iodine-131(I-131) therapy using γ-H2AX foci immunodetection.
  
  
  METHODS
  This study focused on 15 patients who underwent I-131 therapy for differentiated thyroid cancer after surgery. All patients received 3.7 GBq of I-131. Venous blood samples were collected from each patient before therapy and 4 days thereafter. Lymphocytes were isolated from the blood samples and subjected to γ-H2AX immunofluorescence staining.
  
  
  RESULTS
  The number (mean ± SD) of foci per lymphocyte nucleus was 0.41 ± 0.51 before and 6.19 ± 1.80 after radioiodine therapy, and this difference was statistically significant (P = 0.001 < 0.05). Absorbed doses estimated for the 15 patients were 0.77 ± 0.31 Gy applying standard line in vitro external radiation doses.
  
  
  CONCLUSIONS
  γ-H2AX foci immunodetection in lymphocytes may detect radiation-induced DNA damage associated with I-131 therapy for thyroid cancer, and may facilitate estimation of the radiation doses absorbed with this therapy.
authors.affiliation: Department of Radiology, Kanazawa Medical University, Daigaku 1-1, Uchinada, Kahoku, Ishikawa 920-0293, Japan. doaimari@kanazawa-med.ac.jp
authors.forename: Mariko
authors.initials: M
authors.lastname: Doai
authors.forename: Naoto
authors.initials: N
authors.lastname: Watanabe
authors.forename: Tomoko
authors.initials: T
authors.lastname: Takahashi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Hisao
authors.initials: H
authors.lastname: Tonami
authors.forename: Kuniyoshi
authors.initials: K
authors.lastname: Iwabuchi
authors.forename: Daiki
authors.initials: D
authors.lastname: Kayano
authors.forename: Makoto
authors.initials: M
authors.lastname: Fukuoka
authors.forename: Seigo
authors.initials: S
authors.lastname: Kinuya
mesh_terms: D000328:Adult; D004249:DNA Damage; D005260:Female; D006657:Histones / Q000235:genetics*; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use; D008214:Lymphocytes / Q000378:metabolism* / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000532:radiotherapy*
chemical_list: C468783:H2AX protein, human; D006657:Histones; D007457:Iodine Radioisotopes