1. Department of Medical Physics, Aarhus University/Aarhus University Hospital,
Aarhus, Denmark
2. Department of Physics and Technology, University of Bergen,
Bergen, Norway
3. Scripps Proton Radiotherapy Center,
San Diego, California, USA
4. Procure Proton Therapy Centers,
New York, New York, USA
5. Proton Therapy Center, Department of Radiation Oncology, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center,
Houston, Texas, USA
6. Department of Radiology, Oncology and Radiation Science, Uppsala University,
Uppsala, Sweden