Room: ePoster Forums
Purpose: To provide energy spectra for the Varian TrueBeam linac and have greater understanding of the radiation physics involved.
Methods: We created a TrueBeam Monte Carlo model powered by Geant4 10.3 patch-01, Gate v8.0 and the phase-space files from TrueBeam Monte Carlo Data Package v2 released by Varian. Simulations of 6 and 15 MV beams were performed both in air and in a 60x60x60 cm water phantom at 100 cm source-to-surface distance. Model verification was completed with percent depth dose (PDD) and dose profile simulations. Photon energy spectra in a cylinder with a radius of 1.5 cm and height of 1 cm along the central-axis for various field sizes were collected at the isocenter in air and 1.5, 10 and 20 cm in the water phantom.
Results: Analysis of the PDDs and profiles showed that simulations agreed well with experimental values. The average energies (
Conclusion: Energy spectra of the 6 and 15 MV beams in air and water from Varian Truebeam linac were simulated. The energy spectrum of Varian Truebeam linac can be very differet from that of other Varian linac machines.