ESTRO 2025 - Abstract Book

S3030

Physics - Image acquisition and processing

ESTRO 2025

the entire monitored volume. Sub-millimeter distortion is observed with frame B at both 1.5 and 3T within the treatable area of the GK platform (Fig. 2d).

Figure 2: An indicative slice of the phantom (a) without frame at 1.5T, with frame A at (b) 1.5T and (c) 3T and (d) with frame B at 1.5T. Red dashed lines are drawn to guide the eye and highlight potential increased distortion levels.

Conclusion: For the imaging protocols studied, frame A may compromise target localization or image co-registration accuracy in GK SRS if the volume of interest lies close to the frame base. Frame B significantly enhances MR image spatial accuracy and fidelity at both 1.5T and 3T.