Room: Exhibit Hall | Forum 1
Purpose: Recently, targeting radiotherapy has become a hot topic. It has been discovered that the gold nanoparticles (GNPs) can be a potential radiation sensitizer. In our group, a biological study has shown that GNPs can induce ROS. In addition, a TEPC measurement also showed that GNPs can increase the LET of low-energy photons in the biological target. However, the physical evidence is still lack. In this study, we perform a Mote Carlo simulation to simulate the secondary particle generated from GNPs and how it increase the DNA DSB.
Methods: For this study, a Geant4 10.04.p02 Monte Carlo kernel was used. In addition, Geant4 DNA add-on was included for the DNA damage calculation. Microdosimetric simulation was used to simulate the energy spectra of secondary electrons generated from tissue with and without GNP under kV photon radiation. Then, the spectra are imported into the DNA-level simulation to calculate the DSB rate.
Results: For the number of secondary generated from tissue GNPs under irradiation with kV photons, this is 2-3 times the normal tissue. The energies of the secondary particles are mainly in a few hundred eV, which have a fairly large DNA DSB cross section. When these electrons are imported to calculate the DSB rate, the ratio to normal tissue can be hundreds of times higher when using 250 kVp photon which mean energy close to K edge of Gold.
Conclusion: In this study, we have found the physical evidence that GNPs has the potential to become a radiation sensitizer that can be used in radiotherapy.