ESTRO 2024 - Abstract Book

S3978

Physics - Inter-fraction motion management and offline adaptive radiotherapy

ESTRO 2024

The residual shifts were within ±0.5 cm for translational parameters and within ±1 degree for rotational parameters for 75% of the fractions for both setup strategies. Figure 1 shows the residual shifts required from imaging to reach the treatment isocentre for all fractions.

SGRT pre-positioning had less repeat imaging procedures for some treatment sites and more for others. In total, SGRT patients were re-imaged slightly less than laser/tattoo patients (9.1% of the time for SGRT vs 9.5% for laser/tattoo). Figure 2 show the percentage of fractions that needed repeat IGRT procedures after prepositioning with both SGRT and laser/tattoo methods across sites.