A Feasibility Study of MRI Guided Stereotactic Ablative Radiotherapy (MIDSECTION)

Inclusion criteria: 1. Have no MRI contra-indications. 2. Eligible for abdominal SABR in accordance with the NHSE SABR Consortium Guidelines or eligible for central lung SABR in accordance with RTOG Guidelines. 3. Be able to give informed consent. 4. Anticipated life-expectancy \> 6 months. 5. Not more than 3 oligmetastatic sites treated in total per patients. 6. Performance status ≤ 2. 7. Willing to attend follow-up and have details collected on prospective basis for a minimum of 1 year. Exclusion criteria: 1. Any contraindications to MRI identified after MRI safety screening including completion of an MRI Safety Screening Form. 2. Unable to tolerate MRI scans. 3. Any evidence of severe or uncontrolled systemic diseases which, in the view of the investigator make it undesirable for the patient to participate in the study. 4. Any evidence of significant clinical disorder or laboratory finding which, in the opinion of the investigator, make it undesirable for the patient to participate in the study. 5. Any patient known to have active hepatitis B, hepatitis C or human immunodeficiency virus (HIV).