New gantry angle-dependent beam control optimization with Elekta linear accelerator for VMAT delivery.

Introduction: This paper describes a method to improve gantry-dependent beam steering for Elekta traveling wave linear accelerators by applying the measured and filtered beam servo corrections to the existing lookup table (LUT). Beam steering has a direct influence on the treatment accuracy by affecting the beam symmetry and position. The presented method provides an improved LUT with respect to the default Elekta method to reduce treatment delivery interruptions.

Gantry angle dependent beam control optimization of a traveling wave linear accelerator to improve VMAT delivery.

Introduction: Increased modulation and dynamical delivery of external beam radiotherapy (EBRT), such as volumetric modulated arc therapy (VMAT) with dynamic gantry rotation, continuously variable dose rate (CVDR) and field shapes that change during the beam, place greater demands on the performance of linear accelerators (linac). In this study, the accuracy of the linac beam steering is improved by the application of a new method to determine the gantry-dependent lookup table.

Methods: An improved method of lookup table creation based on service graphing information from the linac is investigated.