1. Charing Cross Hospital, Imperial College NHS Healthcare Trust, London, United Kingdom
2. Department of Neurosurgery, St George’s Hospital, London, United Kingdom
3. Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, United Kingdom
4. National Hospital for Neurology and Neurosurgery, University College London NHS Trust, London, United Kingdom
5. UCL Cancer Institute, London, United Kingdom