Implementing MRI in the radiotherapy treatment position for patients with hepatobiliary malignancies: A staged feasibility evaluation.

BACKGROUND: Magnetic resonance imaging (MRI) is increasingly recommended in radiotherapy planning for patients with hepatobiliary malignancies due to its superior soft-tissue contrast. However, implementing MRI in the radiotherapy treatment position, particularly when incorporating motion-management strategies such as abdominal compression (AC) and exhale breath-hold (EBH), remains operationally challenging. This evaluation aimed to establish and evaluate a clinically deliverable MRI-in-treatment-position workflow for hepatobiliary radiotherapy. METHODS: A single-centre staged implementation and feasibility evaluation was conducted, informed by the Medical Research Council framework for complex interventions. The pathway was developed through sequential phases: (1) evaluation of MRI-compatible immobilisation and equipment, including phantom testing; (2) feasibility testing and protocol optimisation in healthy volunteers; and (3) implementation in a prospective pilot of 10 patients diagnosed with hepatobiliary malignancies. The workflow incorporated AC and EBH. Outcomes were assessed descriptively across technical feasibility, workflow integration, multidisciplinary (MDT) collaboration, and staffing requirements. RESULTS: A total of 14 healthy volunteers and 10 patients were imaged during the staged implementation. MRI-compatible immobilisation and AC equipment were safely introduced with no significant artefacts or safety issues. Combined AC and EBH imaging were feasible, enabling optimisation of MRI sequences for hepatobiliary target delineation. MDT review identified the MRI sequences most consistently used, which informed protocol refinement. Staffing requirements were reduced to a two-operator model of diagnostic and/or therapeutic radiographers (radiation therapists) as experience increased. CONCLUSION: MRI in the radiotherapy treatment position, incorporating AC and EBH, can be implemented within routine clinical pathways for hepatobiliary radiotherapy. A staged, MDT approach enabled safe development and integration of the pathway while addressing technical, workflow, and staffing requirements. These findings provide practical insight for centres seeking to introduce MRI-based radiotherapy planning in clinical practice. PLAIN LANGUAGE SUMMARY: MRI scans can improve radiotherapy planning for liver and bile duct cancers, but acquiring MRI in the radiotherapy position can be difficult to organise in practice. This evaluation developed and tested a step-by-step MRI planning process using specialist positioning equipment, breathing control, healthy volunteers, and patient volunteers with hepatobiliary cancers. This evaluation found that the workflow could be introduced safely into routine practice, produced useful images for treatment planning, and became more streamlined as staff gained experience. This matters because MRI planning pathways may help improve the accuracy of radiotherapy while supporting safe patient care.