At study commencement Participants are required to have had a CT scan of the thorax, abdomen and pelvis and a bone scan (bone scintigraphy with technetium-99m-methylene diphosphonate) no more than 4 weeks prior to trial entry to ensure that they have bony-only metastatic disease, as defined using standard imaging. Baseline WB-MRI scans are performed within 2 weeks of entry into the study.