Assessment of error in the MV radiation isocenter position calculated with the Elekta XVI software.

Assessment of error in the MV radiation isocenter position calculated with the Elekta XVI software.
J Appl Clin Med Phys. 2020 Apr 02;:
Authors: Chojnowski JM, Warr GB, Sykes JR, Thwaites DI
Abstract
The assessment of the coincidence of imaging and radiation isocenters is an important task of regular quality assurance of medical linear accelerators (linacs) as recommended in national and international quality assurance guidelines. A previously reported investigation of the accuracy of the Elekta XVI software to localize the linac radiation isocenter, by comparing statistically with other independent software, has shown some discrepancies at the sub-mm level. A further investigation is carried out here using a set of reference images and mathematical operations to observe how the Elekta XVI software analyses them. Symmetric mathematical operations on reference images should result in symmetrical outcomes. Three different rotation functions are used in increasing degree of complexity to characterize the Elekta XVI software error in the linac radiation isocenter position. No independent algorithms or phantoms are used in this methodology. The magnitude and direction of the radiation isocenter localization error has been determined to be consistently 0.13 mm or 0.14 mm in the longitudinal direction towards the target depending on the case. The radiation isocenter localization error comprises two separated errors of the Ball Bearing Cen...

Source: Journal of Applied Clinical Medical Physics - April 1, 2020 Category: Physics Authors: Chojnowski JM, Warr GB, Sykes JR, Thwaites DI Tags: J Appl Clin Med Phys Source Type: research