ESTRO 2024 - Abstract Book

S5036

Physics - Radiomics, functional and biological imaging and outcome prediction

ESTRO 2024

When comparing the mean dose to the entire liver, no significant differences were found (p=0.2), showing that the plans have successfully prioritised the sparing of the functional liver. Upon individual inspection, patients who saw a small reduction in functional dose were those with functional sparing volumes covering most of the liver and so the LMD dose was already as low as possible in the standard plan.

Conclusion:

The MR-Linac gives the opportunity to both adapt to functional images and to monitor liver function during treatment without additional appointments. Previous studies have used other imaging modalities or have employed contrast agents, making them unsuitable for use on the MR-Linac. This study has shown the feasibility of using Hepatica liver MR images, acquired without contrast, to reduce dose to functional areas of the liver whilst retaining clinically acceptable plans. Although there were reductions in target coverage, these were within clinical tolerances. The most benefit was seen for patients with more reduced liver function and hence smaller sparing areas. These would be the patients most at risk from RILD, for whom a 1.5 Gy reduction in mean dose could be clinically significant. Further work is needed to gather images locally of prospective patients and this will form part of future planning and imaging studies.

Keywords: liver, MR, SABR