ESTRO 2024 - Abstract Book

S3950

Physics - Image acquisition and processing

ESTRO 2024

Fig. 2: Two axial slices showing the post-contrast T1-weighted MRI and the skull-stripped APTw-image of a patient with glioblastoma in the right hemisphere (study patient 5). An uneven distribution of elevated APTw signal is visible within the GTV (a,b). At the inferior part of the GTV (c,d), hyperintense APTw signal was observed to extent beyond the GTV.

Conclusion:

In this study, the distinctive GTV APT volumes in relation to the GTV and CTV underscore the potential of APTw-CEST MRI for enhanced visualization of tumor infiltration and improved target delineation, while offering further evidence in support of the hypothesis that the isotropic 15-mm CTV-margin includes substantial amounts of healthy tissue. The introduction of APTw-CEST MRI for target delineation of glioblastoma marks a first step towards personalized CTV definition, enabling more precise radiotherapy treatment and reduced risk of radiation-induced toxicity. Future work will focus on the generation of the CTV APT , its relation to the conventional CTV and pattern-of-failure analysis of the recurring tumor.

Keywords: glioblastoma, advanced MRI, precision radiotherapy