ESTRO 2024 - Abstract Book

S5105

Physics - Radiomics, functional and biological imaging and outcome prediction

ESTRO 2024

in training (HR: 1.93, p=0.005 for DFS; 2.08, p=0.044 for OS; 3.09, p=0.002 for DMFS, and 1.86, p=0.041 for RFS) and 2 4 times greater in eternal validation (HR: 3.76, p=0.003 for DFS; 5.00, p=0.010 for OS; 4.30, p=0.008 for DMFS, and 2.67, p=0.037 for RFS).

Conclusion:

We have successfully constructed a plan quality index from dosiomic analysis of GTVn driven by DFS for NPC patients with high cross-institutional generalizability. Survivals can be improved by at least two times if a high index is achieved for low-plan-quality patients. A refined index considering patient anatomy will be developed with larger cohort sizes and validated in a clinical scenario.

Keywords: Dosiomics, RT-plan quality index, Survival

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Digital Poster

The prognostic value of diffusion MRI is superior to clinical information in pancreatic cancer

Anne Louise Højmark Bisgaard 1,2 , Carsten Brink 1,2 , Tine Schytte 3,2 , Rana Bahij 3 , Mathilde Weisz Ejlsmark 3 , Uffe Bernchou 1,2 , Anders S Bertelsen 1 , Per Pfeiffer 3,2 , Faisal Mahmood 1,2 1 Odense University Hospital, Laboratory of Radiation Physics, Department of Oncology, Odense, Denmark. 2 University of Southern Denmark, Department of Clinical Research, Odense, Denmark. 3 Odense University Hospital, Department of Oncology, Odense, Denmark

Purpose/Objective:

Patients with pancreatic cancer generally have a poor prognosis. Identifying which patients will benefit from specific treatments is crucial to personalize care and enhance overall outcomes. Biomarkers derived from diffusion-weighted MRI (DWI) acquired at multiple time-points (longitudinal DWI) during the course of radiotherapy (RT) are promising candidates for this purpose, as they may allow prediction of RT response of the individual patients. Potentially, longitudinal DWI could guide treatment decisions during RT, or aid decisions regarding other treatment types after RT. This study investigated how longitudinal DWI as well as standard clinical parameters perform in prediction of overall survival (OS) in patients with locally advanced pancreatic cancer (LAPC) treated with stereotactic body radiotherapy (SBRT) on an MRI-Linac.

Material/Methods:

The study prospectively enrolled 45 patients with LAPC or local recurrence of pancreatic cancer in the MOMENTUM study (clinicaltrials.gov NCT04075305) [1]). All patients received 5x10 Gy on a 1.5 T MRI-Linac (patient demographics in Table 1). DWIs were acquired before irradiation at each fraction. DWI parameters were calculated within the gross