A step closer to automation: kilovoltage and Megavoltage Planar Imaging Quality Assurance, baseline, tolerance and action levels definition and exploration

Abstract

Purpose: To establish automated quality assurance (QA) procedures for the kilovoltage (kV) and the Megavoltage (MV) imagers of two linear accelerators (LINACS) using a commercial software.

Methods: SNC Machine™ phantoms and software were used and the baseline values, tolerance and action levels for various image quality parameters were defined. Scaling, spatial resolution, contrast, uniformity and noise were considered, explored and evaluated utilizing the appropriate phantoms and the accompanying software. kV and MV planar radiographic images, for 6MV and 10MV beams were obtained for each LINAC. For both kV and MV QA tasks, the baseline values for spatial resolution, contrast, uniformity and noise were defined.

Results: Subsequent measurements performed were highly reproducible and within tolerance and action levels, while noise showed variations. The calculated tolerance and action levels for noise were looser compared to the other image quality metrics.

Conclusions: An automated QA workflow of the kV and MV planar radiographic mode of LINAC imagers' was established and appears to be time effective.

Keywords: MV planar imaging; SNC Machine™; automated image quality assurance; kV planar imaging.