Avaliação da interação de feixes monoenergéticos e polienergéticos por meio de simulações em GEANT4 em fantomas diversos

Abstract

Proton therapy is present in 16 countries and by 2015 has treated more than 130,000 Patients. However, in Brazil this therapy is not yet present for several reasons, Being the main the high cost. Before performing treatments, it is necessary to do some tests to verify the energy delivery of the proton bundles. As the Microdosimetry are very expensive, the main alternative is to carry out simulations in Programs such as GEANT4 and SRIM. GEANT4 is a program that Allows you to simulate complex geometries, while SRIM performs more complex simulations. Simple and both work with the Monte Carlo method. On this work were used these twain tools to perform a proton beam simulation in phantom with three different compositions (water, bones and water, brain and bones). To perform the energy delivery analysis of the proton beams along these phantoms, has become necessary create a program denominated “Data Processing Program Proton Therapy Simulated”, which allowed to create matrices, beyond the calculations of the Bragg peaks for interaction evaluation. Besides that, it was analyzing the homogeneity of the integration of a proton beam into a detector, in which it was verified that the simulations on GEANT4 are homogeneous, not having a tendency of the beam in locating in a certain region, just as the energies deposited are equal. The value of the depth range of the Bragg peaks were also evaluated in cylindrical phantoms with three different densities: 1,03 g/cm³, 1,53g/cm³ and 2,03 g/cm³, the first being the density provided by GEANT4 for brain tissue. It has been found that the depth range distances of the Bragg peaks are the same at these three different densities.