Fig. 1

The MR-PROTECT MRI-only study workflow divided into the following five categories: 1. Imaging, 2. Post imaging, 3. Treatment plan creation, 4. Quality assurance and 5. Treatment delivery. Included patients underwent the workflow from category 1 to 5, following the tasks within each category as indicated by the white arrows. White boxes within each category indicate tasks inherited from the conventional dual-modality workflow. Grey boxes are new tasks specific to MRI-only. Black boxes are tasks incorporated in the study workflow for QA-purposes during the implementation procedure, but will probably not be needed in future clinical routine of MRI-only. No image registration between CT and MR was needed in this MRI-only workflow to facilitate treatment planning. In a future clinical routine MRI-only workflow, the black boxes can be excluded and replaced by appropriate QA-routines not including CT-imaging. Along some tasks in category 1–3, there are green check marks, which indicate the use of an electronic questionnaire. The electronic questionnaire items are shown below each of the corresponding check marks. Definitions: magnetic resonance (MR), computed tomography (CT), large field of view (L-FoV), treatment planning system (TPS), gold fiducial marker (GFM), clinical target volume (CTV), digitally reconstructed radiograph (DRR), Hounsfield Unit (HU), quality assurance (QA)