Measurements of Photon Beam Flattening Filter Using an Anisotropic Analytical Algorithm and Electron Beam Employing Electron Monte Carlo

Introduction: This study aimed to report the measurement of photon and electron beams to configure the Analytical Anisotropic Algorithm and Electron Monte Carlo used in clinical treatment. Material and Methods: All measurements were performed in a large water phantom using a ۳-dimensional scanning system (PTW, Germany). For photon beams, the data were measured with a ۰.۱۲۵cc cylindrical chamber. For electron, the data were performed with a Roos chamber. Results: In photon beams, flatness and symmetry for reference field size ۱۰×۱۰cm۲ were within the tolerance intervals. Flatness were ۰.۷۹% and ۱.۵۵% for X۶MV and X۱۸MV, respectively. Symmetry were ۰.۵۷ and ۰.۲۵ for X۶MV and X۱۸MV, respectively. The output factor vary between ۰.۸۳ and ۱.۱۱ for X۶MV. Moreover, it varies between ۰.۷۴ and ۱.۰۹ for X۱۸MV. The leaf transmission factors were ۰.۹۷% for X۶MV and۱.۱۴% for X۱۸MV. The DLG were ۱.۳۱ and ۱.۳۴ for X۶MV and X۱۸MV, respectively. For electron beams, the quality index R۵۰ for applicator ۱۵×۱۵cm۲ were in the tolerance. Maximum depth dose for ۶, ۹, ۱۲, ۱۶ and ۲۰MeV were ۱.۲, ۱.۹, ۲.۷, ۲.۹۹ and ۲.۴cm, respectively. Bremsstrahlung tail were ۶MeV–۲.۸۶cm, ۹MeV–۴.۳۲cm, ۱۲MeV–۵.۹۶cm, ۱۶MeV–۷.۹۳cm, and ۲۰MeV–۱۰.۰۸cm per energy levels. Conclusion: The obtained results and international recommendations were in a good agrement

Keywords:

Linear accelerator Algorithm , Monte Carlo Method Radiotherapy