Abstract
Background: The photoelectric and pair production processes increase when high-energy photons interact with materials with high atomic number Z. The energy loss results in a dose enhancement at the target implanted with these materials. This will lead to a higher active dose to be delivered to tumor, while sparing healthy tissues around the target volume.
Objective and method: The objective of this work was to compute the radial dose enhancement, using GEANT4 based Monte Carlo simulations, at and near a 1 x 1 x 1 cm(3) brain tumor implanted with different concentrations of gadolinium nanoparticles when using Ir-192, Cs-137 and Co-60, brachytherapy sources with parallel beam geometry.
Results: Our outcomes show a dose enhancement factor of 1.45 for a concentration of 70 mg of gadolinium in the tumor when irradiated with 0.38 MeV gamma-photon from Ir-192 source. It was also observed that this dose enhancement increased with increasing gadolinium concentration in the target and with photon energy.
Conclusion: Gadolinium nanoparticles are groundbreaking agents with strong advantageous potential in cancer radiotherapy due to the fact that they enhance the radiation dose within the tumor. (C) 2016 Elsevier Ltd. All rights reserved.