Studying the Angular Sensitivity of the MatriXX Detector Array for the Dosimetric Verification of Treatment Plans with Intensity Modulation

• Published in: Moscow University physics bulletin 2021-09, Vol.76 (5), p.384-391
• Main Authors: Loginova, A. A., Tovmasian, D. A., Kokoncev, D. A., Varzar, S. M., Chernyaev, A. P.
• Format: Article
• Language: English
• Subjects: Mathematical and Computational Physics; Physics; Physics and Astronomy; Theoretical
• ISSN: 0027-1349; 1934-8460
• DOI: 10.3103/S0027134921050118

In this study, the angular sensitivity of the MatriXX detector array (IBA Dosimetry) was investigated for the purpose of applying corrections to the measured dose distribution to increase the precision of plan verification with intensity modulation. The MatriXX detector in combination with the MultiCube phantom was irradiated on a medical linear accelerator with different gantry positions. The measured dose distribution for each irradiated angle was processed in Python 3 and compared with the reference dose. The reference dose distribution in corresponding geometry was determined by calculation in the Monaco 5.10 planning system (Elekta). The sets of correction coefficients as functions of the accelerator gantry angle were created for the angular coefficients of the MatriXX detectors array. The angular MatriXX dependence was statistically analyzed; it was decided to use a universal correction coefficient for each row of detectors, except the angles within the ranges and , where a unique coefficient was applied for each detector. The application of the developed correction factors taking into account the angular sensitivity of the detectors provided the ability to improve the precision of measurements and thereby obtain better results in the verification of dosimetric plans compared to the measurements, where the angular sensitivity of detectors was neglected.