Teste | Abstract: 78-1 | ||||
Abstract:Fricke gels are considered the only true dosimeters currently available for3D dosimetry. This dosimetric system, based on the oxidation of ferrous ions to ferric ions, has the ability to respond proportionally to the energy of radiation absorbed in its sensitive volume. They are considered one of the most recent and favorable developments in radiotherapy (RT) dosimetry. Dosimetric control in this area is necessary to ensure the clinical quality of the treatment and to protect the patient from unnecessary irradiations. Scientific advancements in this field have been working on formulations to improve the sensitivity of these devices and expand their application areas. The objective of this work was to evaluate new formulations of Fricke gel using iron oxide nanoparticles (NP-Fe), with the perspective of improving the resolution of volumetric measurements. Samples of Fricke gels traditionally produced with ferrous sulfate salts were doped with different concentrations of NP-Fe and evaluated using cone beam computed tomography. The presented results indicated advantages regarding the quality of the volumetric image. The dosimeters with NP-Fe immersed in their medium showed better contrast when compared to undoped dosimeters. Furthermore, in the dose response evaluation, the dosimeters composed of NP-Fe had a significant gain in their response, demonstrating an increase in the sensitivity of these devices. It was concluded that the change in the Fricke gel formulation allowed for improvements in its applications using nanometric materials. Despite the wide applications of NP-Fe in the field of medicine, there are still many challenges to ensure their in vivo applicability. However, significant advances in this scenario bring an optimistic perspective on new modalities to overcome these limitations. Keywords: Dosimetry, Fricke Gel, cone-beam computed tomography |