title: Biokinetics of ¹³¹I after endogenous and exogenous stimulation of TSH in patients with DTC.
abstract: BACKGROUND
  The effective radioiodine treatment of patients with DTC is possible only after raising the TSH value over 30 μUI/ml. This effect might be obtained by either endogenous or exogenous stimulation. The aim of this study was to evaluate differences in (131)I biokinetics of selected regions of interest (ROIs) in cases of endogenous and exogenous stimulation.
  
  
  METHODS
  Two groups of 50 patients were enrolled in the study. All patients were treated with 3.7 GBq of ¹³¹I; the first group after thyroid hormone withdrawal (THW), the second group after rhTSH administration (rhTSH). On the basis of post-treatment images, the uptake ratios over selected ROIs (thyroid remnants, mediastinum, liver, stomach, abdomen, and whole-body) were compared between groups.
  
  
  RESULTS
  In the case of uptake over the whole-body and the liver, statistically significant higher values were received for the THW group. For the remaining regions, the differences between groups were statistically insignificant, but uptake ratios in the rhTSH group were generally numerically lower compared to the THW group.
  
  
  CONCLUSIONS
  The revealed difference in radioiodine biokinetics after thyroid hormone withdrawal or administration of recombinant human TSH may influence many important aspects of patients with DTC treatment, such as the choice of proper therapeutic scheme, the cost of therapy, and the dose assessment.
authors: Nuclear Medicine Unit, Endocrinology Department, Jagiellonian University Medical College, Krakow, Poland.
authors: Monika
authors: M
authors: Buziak-Bereza
authors: Monika
authors: M
authors: Tomaszuk
authors: Dorota
authors: D
authors: Pach
authors: Anna
authors: A
authors: Sowa-Staszczak
authors: Agata
authors: A
authors: Bałdys-Waligórska
authors: Bogusław
authors: B
authors: Głowa
authors: Maciej
authors: M
authors: Kołodziej
authors: Alicja B
authors: AB
authors: Hubalewska-Dydejczyk