Investigation of the berrylium oxide (BEO) optical stimulated luminance (OSL) for quality control in high energy photon dosimetry used in radiotherapy

The aim of radiotherapy treatment is defined as increasing the probability of tumor control and reducing the possibility of complications in the surrounding normal tissue, and it is a complex process. In a radiotherapy clinic, it is necessary to establish quality assurance (QA) and quality control (QC) programs in accordance with international standards in order to increase the success of treatment and to protect from radiation. Today, it is recommended to use a parallel plate or cylindrical ion chambers calibrated by a secondary standard dosimetry laboratory in international standards in periodic quality control tests. In this study, it was investigated whether BeO OSL could be complementary to the ion chamber in the dosimetric quality control measurements that should be routinely performed in the radiotherapy clinic, in addition to the general use of in-vivo, and personal dosimeters. It is aimed to carry out all the tests recommended in AAPM TG 191 of BeO OSLs, to reveal all the factors and to expand the usage area. With the protocol created at the end of the study, it was aimed to reach the easy and cheap dosimetric quality control system for medical linear accelerators. In this thesis, the usability of the BeO OSL dosimeter system in dosimetric quality controls, pre-treatment patient-specific quality-control tests, and in-vivo dose measurements has been demonstrated. With the factors and functions obtained at the end of the study, a linear accelerator dosimetry quality control system was achieved with an easier and cheaper system.