Avaliação do uso de filmes radiocrômicos ao lado de câmara de ionização e TLDs na mensuração de doses periféricas em radioterapia

Abstract

The growing number of survivors of cancer has created the need to investigate the cause of the sequelae of treatment. Measurements of peripheral radiation to the radiotherapy increment the knowledge of the subject and assist in the development of protection methods. As the periphery of the radiation field the spectrum is different from that in the beam, the energy independence supposedly provided by radiochromic films can overcome the energy dependence found on ionization chambers and thermoluminescent dosimeters, in order to discard the necessity of correction of the values if films are used. The objective of this work is to submit radiochromic films, TLDs dosimeters and ionization chamber to identical situations of irradiation, in order to assess their capabilities in measuring peripheral doses. In this work the three dosimeters were subjected to doses exposure to 6 MV beams, field 10 cm x 10 cm field and 500 UM. The dosimeters were placed at 0, 10, 17.5 and 30 cm from the central ray, always under 5 cm of water. The results showed that the values presented by the films have high standard deviation and for more conclusive results it is necessary to proceed with the radiations, employing more intense beams.