Abstract : Radiation Therapy has been a key clinical application scenario for image guidance, image processing and motion compensation. It remains one of the most prominent clinical application fields for new imaging and image processing methods and it is highly computerized. Recent advances in fast and integrated imaging lead to image guided setup and inter-fractional plan adaptation. Current trends point to real-time image guidance and compensation of intra-fractional motion and deformation as well as continuous monitoring of macro- and microscopic changes in the tumor environment.This workshop will present novel and state-of-the-art approaches for medical image processing in image-guided radiotherapy (IGRT), including segmentation and registration, treatment planning and plan adaptation, image guidance and motion compensation, and imaging and visualisation. It will also provide an exciting venue for exchanging experiences and ideas on clinical and technical challenges, and for discussing recent trends in research and clinical application. The 20 papers accepted for presentation at this workshop are included in these proceedings.