Implementação de um Controle de Qualidade de DMLC utilizando um EPID (Portal Dosimetry)
DOI:
https://doi.org/10.29384/rbfm.2017.v11.n1.p21-27Keywords:
Radioterapia, Física MédicaAbstract
Um Controle de Qualidade (CQ) que garanta o desempenho esperado de um sistema de colimador multi-lâminas (MLC) é essencial para uma entrega de dose segura e adequada no tratamento dos pacientes. O tempo necessário para a realização da dosimetria e do controle dos equipamentos pode ser reduzido quando realizado com o uso do sistema de detecção Eletronic Portal Image Device (EPID). O trabalho consistiu em verificar os limites de resolução desse sistema de detecção para seu uso na modalidade IMRT (radioterapia de intensidade modulada) em modo dinâmico, e na proposta de um conjunto de testes que possam fornecer análises de posicionamento de um sistema de múltiplas lâminas. Os testes foram realizados no Clinac Varian iX equipado com o MLC Millenium 80 e com um detector de silício amorfo EPID (aS1000, Varian). O EPID se mostrou eficiente quando usado no controle do MLC, sendo capaz de detectar desvios de posicionamento de até 0,5 mm. Os testes propostos forneceram resultados relevantes sobre o posicionamento das lâminas, e revelaram que o sistema MLC se encontra dentro dos limites aceitáveis encontrados em literatura.
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