A small-scale anatomical dosimetry model of the liver

Phys Med Biol. 2014 Jul 7;59(13):3353-71. doi: 10.1088/0031-9155/59/13/3353. Epub 2014 May 30.

Abstract

Radionuclide therapy is a growing and promising approach for treating and prolonging the lives of patients with cancer. For therapies where high activities are administered, the liver can become a dose-limiting organ; often with a complex, non-uniform activity distribution and resulting non-uniform absorbed-dose distribution. This paper therefore presents a small-scale dosimetry model for various source-target combinations within the human liver microarchitecture. Using Monte Carlo simulations, Medical Internal Radiation Dose formalism-compatible specific absorbed fractions were calculated for monoenergetic electrons; photons; alpha particles; and (125)I, (90)Y, (211)At, (99m)Tc, (111)In, (177)Lu, (131)I and (18)F. S values and the ratio of local absorbed dose to the whole-organ average absorbed dose was calculated, enabling a transformation of dosimetry calculations from macro- to microstructure level. For heterogeneous activity distributions, for example uptake in Kupffer cells of radionuclides emitting low-energy electrons ((125)I) or high-LET alpha particles ((211)At) the target absorbed dose for the part of the space of Disse, closest to the source, was more than eight- and five-fold the average absorbed dose to the liver, respectively. With the increasing interest in radionuclide therapy of the liver, the presented model is an applicable tool for small-scale liver dosimetry in order to study detailed dose-effect relationships in the liver.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arteries / radiation effects
  • Humans
  • Kupffer Cells / radiation effects
  • Liver / anatomy & histology*
  • Liver / blood supply
  • Liver / cytology
  • Liver / radiation effects*
  • Models, Biological*
  • Phantoms, Imaging
  • Radiometry