Water-equivalence of gel dosimeters for radiology medical imaging

• Published in: Applied radiation and isotopes 2018-11, Vol.141, p.193-198
• Main Authors: Valente, M., Vedelago, J., Chacón, D., Mattea, F., Velásquez, J., Pérez, P.
• Format: Article
• Language: English
• Subjects: Computed tomography; Ferrous Compounds; Gel dosimetry; Gels; Humans; Monte Carlo Method; Phantoms, Imaging; Polymers; Quality Assurance, Health Care; Radiation Dosimeters - standards; Radiation Dosimeters - statistics & numerical data; Radiometry - standards; Radiometry - statistics & numerical data; Solutions; Tomography, X-Ray Computed; Water; Water-equivalence
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2018.03.005

International dosimetry protocols are based on determinations of absorbed dose to water. Ideally, the phantom material should be water equivalent; that is, it should have the same absorption and scatter properties as water. This study presents theoretical, experimental and Monte Carlo modeling of water-equivalence of Fricke and polymer (NIPAM, PAGAT and itaconic acid ITABIS) gel dosimeters. Mass and electronic densities along with effective atomic number were calculated by means of theoretical approaches. Samples were scanned by standard computed tomography. Photon mass attenuation coefficients and electron stopping powers were examined. Theoretical, Monte Carlo and experimental results confirmed good water-equivalence for all gel dosimeters. Overall variations with respect to water in the low energy radiology range (up to 130 kVp) were found to be less than 3% in average. •Water-equivalence for radiology applications was evaluated for gel dosimeters.•Fricke and polymer (NIPAM, PAGAT and itaconic acid) gel dosimeters investigated.•Experimental, theory and Monte Carlo approaches were applied.•Variations less than 3% were found for radiology energy range (up to 130kVp).•Results suggest promising performance of gel dosimetry for radiology applications.