The fast technological development and the rapid clinical implementation of MRI in radiation therapy applications is currently one of the most exciting as well as most challenging developments in radiation oncology. We are happy to announce, that our 8th MR in RT Symposium in Heidelberg is rescheduled to 2021 as a virtual event and will take place online. With this 2.5 day science meeting we would not only like to virtually bring together specialists from all involved disciplines, but also to foster a discussion about the scientific direction of the field. The latest developments in physics and technology of MR-guided radiotherapy, clinical directions and results will be presented. It is our pleasure to cordially invite you on behalf of the organizing and scientific committees to participate in our 8th MR in RT Symposium and to submit your abstracts for posters and presentations.