ESTRO 2025 - Abstract Book

S3663

Physics - Quality assurance and auditing

ESTRO 2025

Regarding gantry rotation a similar behaviour was observed across Halcyon-type LINACs (Halcyon and Ethos), with comparable trends also noted for TrueBeam systems. TrueBeam LINACs exhibited a lower deviation from the isocenter when compared to Halcyons. Additionally, two distinct regions with minimal isocenter deviation were identified, around 60º and 300º respectively. The magnitude of this deviation was more pronounced in Halcyon systems, resulting in greater variability than TrueBeams in their performance across gantry rotation angles.