  Gamma Knife Radiosurgery (GKRS) is a treatment choice in newly diagnosed AVMs
and residual AVMs following endovascular interventions. Aim of this study is to
determine if commercially available liquid embolic agents reduce the radiation
dose to the target due to the attenuation of the 60Co beam. Doses accumulated
by three different embolization materials, namely: Onyx, cyanoacrylate and
polyvinyl alcohol (PVA) were analysed. A collimator helmet size of 8mm was
employed in a Monte-Carlo simulation implemented in Geant4 simulation toolkit.
Obtained dose accumulations were evaluated and results demonstrated
statistically significant differences in the dosimetries calculated.
