Measurements of radiotherapy dosimetric parameters using Fricke gel dosimeter

Abstract

Radiation therapy is an important modality for cancer treatment. Treatment machines are divided into two types: (1) Radioactive sources (e.g. cobalt-60 machine) which deliver gamma rays; and, (2) Electrical sources such as linear accelerator machines (linacs), which produce electron beams and x-rays containing various energies. To calculate the treatment dose or to set up a radiotherapy plan for a patient with a suitable energy, some parameters must be measured to monitor the quality and the quantity of such energy. In this work, the Fricke gel dosimeter was used to determine output factors and to check beam uniformity for 6 and 15 MV photon energies and 6 and 15 MeV electron beam energies. The measurements were compared with other dosimeters such as ionization chambers and daily quality assurance (QA) devices. The aim of this work is to evaluate the Fricke gel as a more economical dosimeter for developing countries and to study its use for daily or monthly QA checks. The results showed that this dosimeter represented a sufficient tool for measuring radiotherapy dosimetric parameters with high precision and accuracy.