ESTRO 2024 - Abstract Book

S3826

Physics - Image acquisition and processing

ESTRO 2024

for both MR systems. Repeatability results are shown in table 1 for 12 patients (with 19 lesions) who underwent double baseline imaging. DCE-MRI parameter wCV ranged from 4-22%.

There was overlap in the RC LOAs between MR Sim and MR Linac for all parameters, i.e, no evidence in this cohort of differences between systems. Data were subsequently combined from the two systems and response data compared to double baseline (figure 1). For the combined data, Ktrans increased from 0.14 min-1 pre-treatment to 0.18 min-1 at W2 (p < 0.001) and ve increased from 0.33 to 0.45 (p < 0.001). The overall wCV was converted to a percentage repeatability coefficient (where RC% = 2.77x wCV) and the incidence of each lesion changing beyond the parameter RC% was found to be 13/27 for Ktrans and 12/27 for ve.

Conclusion:

It is possible to acquire quantitative DCE-MRI data on the MR Linac system. Results show good repeatability and are comparable against a standard MR system. Treatment response can also be measured using DCE-MRI in HNSCC. This is a promising step towards developing treatment adaption techniques based on DCE-MRI.

Keywords: MRI, MRLinac, Neck

References:

1. Gaddikeri S et al. AJNR Am J Neuroradiol. 2016 Apr;37(4):588-95

2. Kooreman ES et al. Front Oncol. 2022;12:897130

3. Berks et al. Madym: JOSS, 6(66), 3523

1312

Proffered Paper

Can pre-treatment MRI detect head & neck cancers at greater risk of hypoxia induced radioresistance?

Alastair McCabe 1 , Stewart Martin 2 , Rafal Panek 3

1 Nottingham University Hospitals NHS Trust, Radiotherapy Department, Nottingham, United Kingdom. 2 University of Nottingham, Translational & Radiation Biology Research Group, Nottingham, United Kingdom. 3 Nottingham University Hospitals NHS Trust, Medical Physics and Clinical Engineeringtment, Nottingham, United Kingdom

Purpose/Objective: