CONICET | Buscador de Institutos y Recursos Humanos

Radiology quality assurance procedures are based on modern reliable dosimetry,which follows strict protocols for accurate determination of absorbed dose in water.Dose determinations must be referred to the absorbed dose to water at the referencedepth in a homogeneous water phantom.Ideally, the phantom material should be water equivalent having the same absorptionand scattering properties as water. However, for traditional dosimeters it becomesnecessary to use suitable conversions to link the absorbed dose in other materials or itis required to know the corresponding calibration factors. Hence, dosimetry systemsdirectly based on in-water measurements would be convenient alternatives since theycould avoid, or minimize, the uncertainties derived from the conversions of absorbeddose between different materials. In this context, gel (Fricke and polymers) dosimetersappear as the most suitable option to design and implement dosimeters capable ofperforming direct measurements of absorbed dose in aqueous media acting as sensi-tive material in the detection system.The present study focuses on theoretical and experimental studies about radiologi-cal water-equivalence of ferrous sulfate (Fricke) and polymer (N-isopropylacrylamideNIPAM, polyacrylamide, PAGAT and itaconic acid with bisacrylamide, ITABIS) geldosimeters. Relevant physical properties, such as mass and electronic densities, ef-fective atomic number, and cross sections are calculated by means of theoreticalapproaches. Additionally, irradiated and non-irradiated samples of all studied gel do-simeter types were scanned by standard computed tomography and high resolutionmicro-computed tomography assessing experimental data confirming excellent radio-logical water-equivalence of gel dosimeters.