Avaliação dosimétrica experimental de efeitos de inomogeneidade causados por vértebras torácicas

Authors

  • André Lima Souza Castro Departamento de Engenharia Nuclear, Universidade Federal de Minas Geras
  • Larissa Thompson Departamento de Engenharia Nuclear, Universidade Federal de Minas Geras
  • Tarcísio Passos Ribeiro Campos Departamento de Engenharia Nuclear, Universidade Federal de Minas Geras

DOI:

https://doi.org/10.29384/rbfm.2017.v11.n1.p28-34

Keywords:

Radioterapia, Efeitos de inomogeneidade, Vértebras, Filmes radiocrômicos

Abstract

A presença de inomogeneidades de tecido produz alterações na distribuição da dose absorvida, cuja magnitude depende das propriedades físicas desses tecidos e da qualidade da radiação. A avaliação incorreta da distribuição de dose pode afetar o controle local do tumor ou aumentar as probabilidades de complicações dos tecidos normais. O trabalho teve como objetivo investigar a influência dos efeitos de inomogeneidade de vértebras torácicas sobre a dose absorvida pelo tecido mole circundante. Os valores preditos pelo sistema de planejamento de tratamento (TPS) foram comparados às medidas experimentais com filmes radiocrômicos EBT-2 posicionados em um objeto simulador constituído somente de água e inseridos axialmente em um phantom simplificado de coluna vertebral e água. Observou-se significativa alteração do padrão de distribuição de dose, aumento da dose absorvida na interface osso-tecido mole e doses pontuais altas adjacentes ao osso em comparação com os resultados obtidos para os filmes em meio homogêneo e TPS. As medidas experimentais na água concordaram com o TPS em 1,0% no que se refere à dose modal enquanto que a maior diferença encontrada para o meio contendo as vértebras foi de 4,6%, no entanto, ambos os valores se encontram dentro da incerteza experimental.  

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Author Biography

André Lima Souza Castro, Departamento de Engenharia Nuclear, Universidade Federal de Minas Geras

Departamento de Engenharia Nuclear - Física Médica

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Published

2017-10-16

How to Cite

Castro, A. L. S., Thompson, L., & Campos, T. P. R. (2017). Avaliação dosimétrica experimental de efeitos de inomogeneidade causados por vértebras torácicas. Brazilian Journal of Medical Physics, 11(1), 28–34. https://doi.org/10.29384/rbfm.2017.v11.n1.p28-34

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Artigo Original

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