Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) want to build the world’s first prototype that tracks moving tumors with magnetic resonance imaging (MRI) in real time during proton therapy. They are combining a rotating open MRI device, designed for the LINAC-MR system from Alberta Health Services, with an actively scanned clinical-akin proton beam at OncoRay, the Dresden-based National Center for Radiation Research in Oncology. The rotating MRI device is produced by ASG Superconductors, using their helium-free superconducting magnesium diboride (MgB2) magnet. Real-time MRI would make it possible to synchronize the proton beam to tumor motion during radiation dose delivery. So far, this has been impossible and therefore was a limiting factor for treating moving tumors with this promising cancer therapy.