Análise quantitativa da precisão da entrega de dose em tratamento de radioterapia com a técnica IMRT em tumores de cabeça e pescoço utilizando simulador antropomórfico

Abstract

The dose administered to the patient in treatments of radiotherapy verification has a great importance for the patient safety. In head and neck tumors, due to the number of organ at rick that are present in the region, the concern becomes even greater. Thus, in order to verify the IMRT technique validation efficiency using an anthropomorphic phantom, the end-to-end tests quality control from head and neck radiotherapy treatments, the Nasopharingeal Carcinoma were chosen, were quantitative evaluated. Verifying the dose delivery in the volume of interest and adjacent volumes, and evaluating the uncertainties associated with the absolute dose calculation in different areas. The radiotherapy treatments planning using the IMRT technique showed a relative deviation between the absolute dose calculated by TPS Eclipse and the absolute dose measured with the ionization microchamber lower than 3% at all studied regions points. In the Lung, Cervical, Marrow and PTV70 regions the relative dose deviation were 2.24%; 0.21%; 2.47% and 1.73%, respectively. Therefore, It can be concluded that, from the use of a composed by different materials anthropomorphic simulator characterizing different heterogeneities, the quality assurance verification from the absolute dose process in head and neck tumors treatments using the IMRT technique can be assessed by assuring an expanded relative uncertainty of approximately 6.6% in the absolute dose calculation with a confidence interval of 95.45% and ensuring the reliability of correct dose delivered to the patient.