Study of Possibility to Reduce Flattening Filter Volume for Increasing Energetic Photons for High Radiotherapy Efficiency

Abstract

Increasing dose for improved radiotherapy efficiency is essential for linear accelerator development and also for flattening filter geometry and material enhancement. Determination and understanding the photon beam properties using material and geometry of a beam modifier is very important in radiotherapy department and also for high patient life quality. This Monte Carlo study aims to improve the FF in a linac for increasing the photon number at the entrance of treatment volume tumor and the dose delivered inside the treatment volume as recommended by the IAEA protocols. The aim of this study was to check out the possibility to reduce the flattening filter volume for improving the clinical photons at phantom surface. We have studied photon attenuation coefficients and beam softening coefficients with FF volume reduction. The FF volume was reduced by 10, 20, and 30% of initial FF volume. The photon fluence increased with FF volume reduction near the beam central axis than the beam edge and the beam softening coefficients remained apparently invariable with FF volume reduction as a function of off-axis distance. Our work can be a basic study that will be used in research and improvement for future linac configuration in terms of photon attenuation and beam softening for a material, geometry and volume that were used for finding out good flattening and good softening to produce an optimal delivered dose as recommended by IAEA.