Representation and illustration of the initial parameters in GATE 8.1 monte carlo simulation of an Elekta Versa-HD linear accelerator

The purpose of this study is to validate GATE 8.1 Radiotherapy Monte Carlo (MC) simulation of a 6 MV Elekta Versa-HD linear accelerator at King Abdulaziz University Hospital (KAUH). The simulation data using GATE 8.1 was benchmarked against measured data at KAUH. The simulation comprises treatment head, Multi-Leaf Collimators (MLCs), and homogeneous water phantom, whereas the measured data was performed using MP3 phantom and PTW 31,010, 0.125 cm(3) Semiflex Chamber. Dose depth distribution and dose profiles were carried out at three different field sizes 10x10, 20x20, and 30 x 30 cm(2). The calculated TPR20,10 for the simulated data was found to be 0.658, 1.1% less than the measured TPR20,10 which was found to be 0.666. The obtained results indicate good agreement between the simulated and measured data, where Gamma Index 3%/3 mm criteria reached values of 97% and 90% for relative dose and dose profiles, respectively.