RODRIGUES, P.S.BURIN, A.L.TALACIMON, C.F.MEDEIROS, I.M.M.A.PEREIRA, J.J.N.TEODORO, L.E.H.RIGO, M.E.Z.GESSERAME, M.M.F.TAVARES, P.V.S.MARTINS, A.C.SOUZA, C.D.ZEITUNI, C.A.RODRIGUES JUNIOR, O.ROSTELATO, M.E.C.M.2024-12-102024-12-102024RODRIGUES, P.S.; BURIN, A.L.; TALACIMON, C.F.; MEDEIROS, I.M.M.A.; PEREIRA, J.J.N.; TEODORO, L.E.H.; RIGO, M.E.Z.; GESSERAME, M.M.F.; TAVARES, P.V.S.; MARTINS, A.C.; SOUZA, C.D.; ZEITUNI, C.A.; RODRIGUES JUNIOR, O.; ROSTELATO, M.E.C.M. Investigation for Monte Carlo simulation with geometric simplification of the GammaCell 220 irradiator with experimental measurements using Fricke xylenol gel (FXG). <b>Radiation Physics and Chemistry</b>, v. 224, p. 1-6, 2024. DOI: <a href="https://dx.doi.org/10.1016/j.radphyschem.2024.112000">10.1016/j.radphyschem.2024.112000</a>. Disponível em: https://repositorio.ipen.br/handle/123456789/48744.0969-806Xhttps://repositorio.ipen.br/handle/123456789/48744Radiation therapy necessitates dosimetry using materials with densities similar to human tissue and at a lower cost. Comparisons with simulation methods will help validate new dosimeters and their measurements. To experimentally simulate radiation effects, an industrial irradiator like the GammaCell 220 can be utilized. This study aims to validate FXG dosimetry through Monte Carlo simulations using the MCNP and TOPAS codes, employing a simplified geometry model of the GammaCell 220 irradiator. The FXG dosimeter demonstrated linearity with an R2 of 0.99517. Monte Carlo simulations using both codes showed coherence, with MCNP exhibiting greater similarity to experimental results. The incorporation of simplified Monte Carlo modeling demonstrates the feasibility of obtaining satisfactory results for the GammaCell 220 irradiator geometry. Additionally, it validates the applicability of FXG dosimetry for future utilization in radiation therapy.1-6openAccessArtigo de periódico22410.1016/j.radphyschem.2024.112000http://orcid.org/0000-0003-1335-8864https://orcid.org/0000-0002-7303-6720https://orcid.org/0000-0002-6704-1910https://orcid.org/0000-0003-2943-609770.081.00