Estudio computacional en Gate de la interacción de protones con tejidos biológicos y con yoduro de sodio dopado con talio

Abstract

The physics of ionizing radiation plays a fundamental role in the development of dosimetry, since it deals strictly with the measurement of the absorbed dose as a result of the interaction between ionizing radiation and matter. To carry out such dose measurement, in some cases materials with a crystalline structure are implemented, such as scintillator material (sodium iodide doped with thallium), which can be adapted as dosimeters. The scintillation counter is based on the principle that light is emitted when the scintillator material is exposed to radiation, this occurs because part of the energy deposited by the incident radiation is absorbed by the material: this implies that the molecular structure is excites by ionizing the compound, showing a change in its electronic configuration. As the material is ionized, the electrons acquire energy but after a certain time they return to their fundamental state, emitting radiation (photons). Assuming that the crystalline material to be handled is thallium-doped sodium iodide, a simulation will be implemented in a Geant4 extension called Gate; in order to determine the dose delivered to sodium iodide with thallium impurities [NaI(Tl)]. Similarly, a biological tissue (pancreas) will be irradiated with protons in the Gate computational tool, to determine its respective dose. Once these dose values ​​are obtained, they will be compared in order to establish whether sodium iodide is a material that resembles the response to radiation with respect to the response of a biological tissue such as the pancreas. The development of this work will aimed at carrying out the corresponding computational simulations in the Gate extension with the purpose of grounding the comparisons between the inorganic material [NaI(Tl)] and the organic material (pancreas), that is, to study the response of sodium iodide doped with thallium and the pancreas by exposing them to radiation from a proton beam.