ESTRO 2025 - Abstract Book

S3704

Physics - Quality assurance and auditing

ESTRO 2025

Keywords: Radiosurgery, Frame Slippage, Quality Assurance

References: Peach MS, Trifiletti DM, Dutta SW, Larner JM, Schlesinger DJ, Sheehan JP. Spatial shifts in frame-based Gamma Knife radiosurgery: A case for cone beam CT imaging as quality assurance using the Gamma Knife® Icon™. J Radiosurg SBRT. 2018;5(4):315-322. PMID: 30538892; PMCID: PMC6255723.

Otto K, Fallone BG. Frame slippage verification in stereotactic radiosurgery. Int J Radiat Oncol Biol Phys. 1998 Apr 1;41(1):199-205. doi: 10.1016/s0360-3016(98)00005-4. PMID: 9588934.

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Digital Poster Concordance testing of Elekta Machine QA (AQUA) daily output measurements Joe R Whitbourn Medical Physics, South Tees Hospitals NHS Foundation Trust, Middlesbrough, United Kingdom

Purpose/Objective: An important new development in the current generation of linacs is the provision of integrated manufacturer provided quality control (QC) systems (manufacturer integrated quality control - MIQC) – such as Varian’s Machine Performance Check (MPC) and Elekta’s Machine QA (EMQA, also known as AQUA). EMQA can make use of the megavoltage imaging panel to perform a variety of QC tasks in an automated way with ‘iCom’ control of the linac. In this study we have investigated the stability of the EMQA output test on two linacs during a trial period of over approximately 100 days on two linacs as well as studying the test’s concordance with existing output QC tests. Material/Methods: To minimise the impact of environmental factors on panel sensitivity the EMQA output test was run alongside daily machine run-up on two treatment units. This was alongside the existing daily output test performed using a SunNuclear QA3 device and routine Farmer chamber QA output measurements. For consistency in measures across the time series QA3 output drift has been corrected for the routine calibrations of device sensitivity performed at the routine QC.