Calibración dosimétrica de haces de electrones de baja energía de uso clínico con cámara de ionización cilíndrica utilizando el protocolo de dosimetría TRS398 modificado, en el Instituto del Cáncer SOLCA Núcleo de Cuenca, período Agosto 2022 - Diciembre 2022

Abstract

The main protocol for physical dosimetry used to characterize medical linear accelerators is that of the International Atomic Energy Agency (IAEA) [1]. This protocol presents the use of plane-parallel ionization chambers for electron beams featuring R50 ≤ 4.0 g /cm2. Muir’s studies [3] suggest a modified formalism for electron beam reference dosimetry of the IAEA procedure. For this, updated correlation factors are used and calculated through Monte Carlo methods. To determine low-energy electron beam reference dosimetry in a linear accelerator with a cylindrical ionization chamber according to Muir’s modified TRS398 dosimetry protocol [3]. This is a descriptive – prospective study. Therefore, data collection was based on information obtained using Mephysto software and devices to measure pressure, temperature, and a clinical dosimetry system to measure charges in an electron-beam linear accelerator. After reference dosimetry was determined using the TRS398 protocol, Muir’s absolute dosimetry is carried out. The differences between the two are less than 1.2%. It is possible to use Muir’s electron-beam absolute dosimetry in an accelerator since the percentage difference is less than 1.2% in regard to the standard system.