Feasibility of celiac axis delineation and treatment on combined magnetic resonance imaging and linear accelerator systems

Abstract

Trials have been performed on irradiating celiac plexus for pancreatic cancer pain management. Images from a combined magnetic resonance imaging and linear accelerator system (MR-linac) for ten patients were assessed for delineation of celiac ganglia, aiming for smaller target volumes and reducing treatment risks versus standard linac-based treatments. MRI-linacs showed superior soft tissue contrast, enabling increased dose to ganglia while irradiating smaller target volumes versus regular linacs (median: 0.8 cm³ vs. 32.2 cm³, p < 0.05 for ten pairs of plans). While further studies are needed, MR-linac treatments could improve targeting precision, minimize dose to organs-at-risk and enhance effectiveness in palliative care.

Keywords: Celiac plexus irradiation; Low-Field MRI; MR-Linac; Palliative care; Pancreatic cancer.

Fig. 1

Celiac ganglia. A. Diagram of the location of the celiac ganglia (IVC = inferior vena cava; Ao = aorta); B. Axial MRI images showing the celiac plexus surrogate as contoured on MR for CT-based planning (blue contour around aorta) and bilateral ganglia as contoured for MRI plans (red contour, right: posterior to IVC; left: anterior to aorta).