ESTRO 2024 - Abstract Book

S4776

Physics - Quality assurance and auditing

ESTRO 2024

ΔZ

0.30

0.17

Conclusion:

This work demonstrates a vendor-independent method using a simple phantom for validating the shift between the isocentre of the linac and the MRI scanner. The radiation isocentre was offset by 0.2-0.3 mm in the anterior direction compared to the isocentre used by the vendor for both MRI-linacs in consistency with previous findings. The work has demonstrated a new methodology for MR-to-MV calibration tests. However, there is a need for further investigations to state the uncertainties in the method.

Keywords: MRI-linac, coordinate system, MR-to-MV translation

References:

1. Bernchou U, Christiansen RL, Bertelsen A, Tilly D, Riis HL, Jensen HR, et al. End-to-end validation of the geometric dose delivery performance of MR linac adaptive radiotherapy. Phys Med Biol 2021;66(4):45034.

2. Malkov VN, Winter JD, Mateescu D, Létourneau D. MR-linac daily semi-automated end-to-end quality control verification. J Appl Clin Med Phys 2023;e13916.

3. Woodings SJ, de Vries JHW, Kok JMG, Hackett SL, van Asselen B, Bluemink JJ, et al. Acceptance procedure for the linear accelerator component of the 1.5 T MRI-linac. J Appl Clin Med Phys 2021;22(8):45–59.

4. IEC 61217, International Electrotechnical Commission (IEC), Radiotherapy equipment, Coordinates, movements and scales. Technical report IEC61217 (International Electrotechnical Commission, Geneva, Switzerland); 2011.

852

Proffered Paper

Exploring the potential of RTQA streamlining based on experience from the PATHOS trial (NCT02215265)

Konstantinos Rizos 1 , Zohal Nabi 1 , Nachi Palaniappan 2 , Richard Webster 2 , Matthew Beasley 3 , Emma Higgins 2 , Christie Heiberg 4 , Lisette Nixon 4 , Debra Howard 1 , Rikki Lad 1 , Elizabeth Miles 1 , Patricia Diez 1 , Terry Jones 5 , Mererid Evans 6 1 National Radiotherapy Trials Quality Assurance Group, Mount Vernon Cancer Centre, Radiotherapy Physics, Northwood, United Kingdom. 2 Velindre Cancer Centre, Directorate of Medicine, Cardiff, United Kingdom. 3 University Hospitals Bristol NHS Foundation Trust, Bristol Haematology and Oncology Centre, Bristol, United Kingdom. 4 Cardiff University, Centre for Trials Research, Cardiff, United Kingdom. 5 University of Liverpool, Department of Molecular and