The Royal National Throat, Nose and Ear Hospital, London 1 article published in JoVE Bioengineering Patient-Specific Polyvinyl Alcohol Phantom Fabrication with Ultrasound and X-Ray Contrast for Brain Tumor Surgery Planning Eleanor C. Mackle*1,2, Jonathan Shapey*1,2,3,4, Efthymios Maneas1,2, Shakeel R. Saeed3,5,6, Robert Bradford3, Sebastien Ourselin4, Tom Vercauteren4, Adrien E. Desjardins1,2 1Wellcome / EPSRC Centre for Interventional and Surgical Sciences, University College London, 2Department of Medical Physics and Biomedical Engineering, University College London, 3Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, 4 This protocol describes the fabrication of a patient specific skull, brain and tumor phantom. It uses 3D printing to create molds, and polyvinyl alcohol (PVA-c) is used as the tissue mimicking material.