Estudo da viabilidade da tomografia computadorizada na leitura do dosímetro de gel polimérico magic-f

Abstract

This work’s purpose is to analyze the applicability of the computerized tomography (CT) images as a method of reading the polymeric gel dosimeter MAGIC-f. The gel in question has the advantage of being an easy and inexpensive material to be produced and present a positive response to radiation, proven by previous studies. As it has been proven that the irradiated gel has its density changed, the idea of the use of computerized tomography comes from the probable change in the contrast of the images according to the change in the density of the samples. The advantages in the use of CT are the easy access to such equipment in radiotherapy centers, its low cost, a shorter image acquisition time and better spatial and contrast resolution. CT scans were performed on the SIEMENS / SOMATON EMOTION DUO / 46154 scanner, which is used as a tool for the treatment planning. CT scans were obtained with different acquisition parameters to evaluate the sensitivity of the gel. To analyze the images, were used the NTC, the histograms and other tools that allow the study of the contrast in the digital images. The gel reading by the contrast of the images acquired by computerized tomography did not obtain the ideal result, in other words, the contrast did not show a dependency on the difference in the density of the samples.