title: Study of cytogenetic toxicity of low-dose radioiodine therapy in hyperthyroid patients using a micronuclei assay.
abstract: OBJECTIVE
  Radioiodine, in low doses, has been used as a treatment modality for hyperthyroidism worldwide for a long time. However, there is little information available on the severity of cytotoxicity of radioiodine at these low doses. The present investigation aimed to study the cytogenetic toxicity of low-dose radioiodine in hyperthyroid patients using a cytokinesis-blocked micronuclei (MN) assay.
  
  
  METHODS
  All of the patients received radioiodine in the form of sodium iodine (oral form). Blood samples of these patients were collected before therapy and 3 months after therapy, and lymphocytes were analysed for MN assay.
  
  
  RESULTS
  Peripheral blood lymphocytes were analysed in 74 hyperthyroid patients (52 men, 22 women). The results indicated a positive relationship between age and the frequency of MN. However, there was no statistically significant difference in MN frequency at 3 months after therapy in comparison with that before therapy.
  
  
  CONCLUSIONS
  This study showed that the cytogenetic damage produced by low-dose radioiodine was transient and reversible. Thus, patients can be motivated to undergo this safe and easy procedure as a modality of treatment for hyperthyroidism.
authors.affiliation: Departments of aNuclear Medicine bAnatomy cBiostatistics, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Girish K
authors.initials: GK
authors.lastname: Parida
authors.forename: Chandrasekhar
authors.initials: C
authors.lastname: Bal
authors.forename: Rima
authors.initials: R
authors.lastname: Dada
authors.forename: Madhavi
authors.initials: M
authors.lastname: Tripathi
authors.forename: Sadanand
authors.initials: S
authors.lastname: Dwivedi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000235:genetics* / Q000532:radiotherapy*; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use*; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D048629:Micronuclei, Chromosome-Defective / Q000528:radiation effects*; D015162:Micronucleus Tests / Q000379:methods; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D012974:Sodium Iodide / Q000009:adverse effects / Q000627:therapeutic use; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D012974:Sodium Iodide