title: Radioidine therapy temporarily increases circulating endothelial cells and decreases endothelial progenitor cells.
abstract: BACKGROUND
  Radiotherapy can cause vascular injury. No data on radioiodine therapy and vascular damage are available.
  
  
  METHODS
  We examined the number of circulating endothelial cells (CEC) and circulating endothelial progenitor cells (CEPC) before therapy 1, 2, 3 and 5 days as well as 1, 2, 3, 4, 6, 8, 10, and 12 weeks after therapy with (131)I at doses ranging from 5-200 mCi. The individual number of CEC and CEPC is associated with the presence of risk factors.
  
  
  RESULTS
  Irrespective of prevalues, CEC exhibited a significant dose-dependent temporary increase reaching the maximum in weeks 1 and 2. In contrast, CEPC show a decrease at the same time.
  
  
  CONCLUSIONS
  These results indicate that (131)I-therapy induces a dose-dependent radiation injury at the vascular wall level enhancing endothelial desquamation and reducing reendothelialization and thereby a proatherogenic stage. The clinical consequence of these findings still needs to be assessed.
authors.affiliation: The Institute of Nuclear Medicine, University of Perugia, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Palumbo
authors.forename: Renato
authors.initials: R
authors.lastname: Palumbo
authors.forename: Helmut
authors.initials: H
authors.lastname: Sinzinger
mesh_terms: D004307:Dose-Response Relationship, Radiation; D042783:Endothelial Cells / Q000528:radiation effects*; D006801:Humans; D006980:Hyperthyroidism / Q000532:radiotherapy; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D011832:Radiation Injuries / Q000097:blood* / Q000209:etiology*; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use; D013234:Stem Cells / Q000528:radiation effects*; D013964:Thyroid Neoplasms / Q000532:radiotherapy; D014652:Vascular Diseases / Q000097:blood* / Q000209:etiology*
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals