title: Modeling the time dependent biodistribution of Samarium-153 ethylenediamine tetramethylene phosphonate using compartmental analysis.
abstract: OBJECTIVE
  The main purpose of this work was to develop a pharmacokinetic model for the bone pain palliation agent Samarium-153 ethylenediamine tetramethylene phosphonate ([(153)Sm]-EDTMP) in normal rats to analyze the behavior of the complex.
  
  
  BACKGROUND
  The use of compartmental analysis allows a mathematical separation of tissues and organs to determine the concentration of activity in each fraction of interest. Biodistribution studies are expensive and difficult to carry out in humans, but such data can be obtained easily in rodents.
  
  
  METHODS
  We have developed a physiologically based pharmacokinetic model for scaling up activity concentration in each organ versus time. The mathematical model uses physiological parameters including organ volumes, blood flow rates, and vascular permabilities; the compartments (organs) are connected anatomically. This allows the use of scale-up techniques to predict new complex distribution in humans in each organ.
  
  
  RESULTS
  The concentration of the radiopharmaceutical in various organs was measured at different times. The temporal behavior of biodistribution of (153)Sm-EDTMP was modeled and drawn as a function of time.
  
  
  CONCLUSIONS
  The variation of pharmaceutical concentration in all organs is described with summation of 6-10 exponential terms and it approximates our experimental data with precision better than 2%.
authors.affiliation: Health Physics and Dosimetry Laboratory, Department of Energy Engineering and Physics, Amir Kabir University of Technology, Tehran, Iran.
authors.forename: Parandoush
authors.initials: P
authors.lastname: Abbasian
authors.affiliation: Department of Nuclear Engineering, Science and Research Branch, Islamic Azad University, P.O. Box 14515-775, Tehran, Iran.
authors.forename: Monika
authors.initials: M
authors.lastname: Foroghy
authors.affiliation: Nuclear Science Research School, Nuclear Science and Technology Research Institute, Tehran 11365-3486, Iran.
authors.forename: Amir Reza
authors.initials: AR
authors.lastname: Jalilian
authors.affiliation: Health Physics and Dosimetry Laboratory, Department of Energy Engineering and Physics, Amir Kabir University of Technology, Tehran, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Hakimi
authors.affiliation: Nuclear Science Research School, Nuclear Science and Technology Research Institute, Tehran 11365-3486, Iran.
authors.forename: Simindokht
authors.initials: S
authors.lastname: Shirvani-Arani
keywords: Biodistribution modeling; Compartmental analysis; [153Sm]-EDTMP