Cuantificación de la dosis en superficie en radioterapia: Simulación Monte Carlo y medidas con cámara de extrapolación

During a radiotherapy treatment, skin of the patient is always exposed to the radiation; as a consequence late effects can be appear. Therefore, dose values in this region may be of interest for clinical evaluation and investigation of those undesirable effects. However, surface dose is not intuitiv...

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Detalhes bibliográficos
Autor: Valencia Lozano, Ingrid Isabel
Formato: tesis de maestría
Fecha de publicación:2013
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2099.1/26198
Acesso em linha:https://hdl.handle.net/2099.1/26198
Access Level:acceso abierto
Palavra-chave:Radiation -- Dosimetry
Radiation -- Dosage -- Simulation methods
Radiotherapy
Monte Carlo method
Radiació -- Dosimetria
Radiació -- Dosificació -- Mètodes de simulació
Radioteràpia
Montecarlo, Mètode de
Àrees temàtiques de la UPC::Ciències de la salut::Medicina
Àrees temàtiques de la UPC::Física::Electromagnetisme::Radioones i microones
Àrees temàtiques de la UPC::Matemàtiques i estadística::Investigació operativa::Simulació
Descrição
Resumo:During a radiotherapy treatment, skin of the patient is always exposed to the radiation; as a consequence late effects can be appear. Therefore, dose values in this region may be of interest for clinical evaluation and investigation of those undesirable effects. However, surface dose is not intuitive and is difficult to measure and calculate; the parameters, which modify it are not always the same and each one are dependent to the others. The aim of this project is to quantify absorbed dose in the build-up region and near to the skin approximately between 0 mm - 1 mm using two methods. One of them, an analytical calculation using Monte Carlo simulations; and the other an experimental approach using an extrapolation chamber. Monte Carlo simulations are performed with the PENELOPE package of subroutines for 6MV and 15MV photon beams. Experimental setup consists in the use of an extrapolation chamber (PTW model 23392), considered the most suitable instrument to measure absorbed dose in the build-up region, but its not commonly available in the hospitals because its use is not practical. The chamber was adapted for its use in clinical environments in a previous work, then for this work the measurement process is easier and results with high level of accuracy can be obtained. In this way, EC (extrapolation chamber) measurements served as the gold standard in our study to validate the Monte Carlo simulations and also with results reported by previous studies. As a result, we found that simulation outcomes are in good agreement with experimental data.