title: The effect of radioiodine on the intima media thickness of the carotid artery.
abstract: OBJECTIVE
  The radiation can induce vessel injury. The result of this injury can be severe and life-threatening. There are a few studies demonstrating an increase in intima-media thickness (IMT) of the common carotid artery (CCA) after radiotherapy, especially in head and neck cancers. We evaluated the effect of I-131 to the IMT of the CCA in the patients who were treated for hyperthyroidism.
  
  
  METHODS
  38 patients (25M, 13W) referred to our department for radioiodine treatment with the diagnosis of nodular goitre (25 patients) and diffuse hyperplasia (Graves disease (GD), 13 patients) were included to the prospective study. An USG was performed for all the patients before therapy, 3, 6 and 12 months after radioiodine therapy in order to measure IMT of CCA and the femoral artery (FA). The IMT was measured at the level of proximal part of bulbus anteriorly on the left and right side. The IMT of FA was measured just before the bifurcation.
  
  
  RESULTS
  There was a statistically significant increase in IMT of both CCA and FA bilaterally in nodular hyperthyroid patients. However, in the patients with Graves disease, there was only statistically significant increase in the left IMT of CCA at 0-3rd, 0-6th month measurements and in the right IMT of FA at 0-3rd month measurements.
  
  
  CONCLUSIONS
  Though the limitation of the study is the interobserver and intraobserver variability, it was seen that I-131 therapy might affect the IMT of CCA in the patients with NG. I-131 effect on the IMT of CCA in patients with nodular goitre was higher than the IMT of CCA in patients with GD. I-131 effect on the IMT of CCA might be due to administered dose and adjacency. The interesting point of our study was the increased thickness of IMT in FA. We think that the increase in IMT is due to the systemic effect of radioactivity circulating in the blood vessel. I-131 effect on the IMT of FA in patients with nodular goitre was higher than the IMT of FA in the patients with GD due to I-131 uptake of thyroid gland. Because I-131 uptake was lower in patients with nodular goitre, I-131 in systemic circulation was higher.
  
  
  BACKGROUND
  None declared.
authors.affiliation: Yüzüncü Yıl University School of Medicine, Department of Nuclear Medicine, Van, Turkey.
authors.forename: Erdem
authors.initials: E
authors.lastname: Sürücü
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Nuclear Medicine, İzmir, Turkey.
authors.forename: Recep
authors.initials: R
authors.lastname: Bekiş
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Nuclear Medicine, İzmir, Turkey.
authors.forename: Tarık
authors.initials: T
authors.lastname: Sengöz
authors.affiliation: Yüzüncü Yıl University School of Medicine, Department of Nuclear Medicine, Van, Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Demir
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Radiology, Izmir, Turkey.
authors.forename: Ahmet Orhan
authors.initials: AO
authors.lastname: Celik
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Radiology, Izmir, Turkey.
authors.forename: Ozge
authors.initials: O
authors.lastname: Orbay
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Radiology, Izmir, Turkey.
authors.forename: Bilge
authors.initials: B
authors.lastname: Birlik
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Nuclear Medicine, İzmir, Turkey.
authors.forename: Ozhan
authors.initials: O
authors.lastname: Ozdoğan
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Radiology, Izmir, Turkey.
authors.forename: Enis
authors.initials: E
authors.lastname: Iğci
authors.affiliation: Dokuz Eylül University School of Medicine, Department of Nuclear Medicine, İzmir, Turkey.
authors.forename: Hatice
authors.initials: H
authors.lastname: Durak
keywords: Hyperthyroidism; carotid intima-media thickness; iIodine radioisotopesy