[I184] Benefits of MRI for radiation therapy

The treatment success of radiotherapy depends on the capability of imaging to precisely localize and delineate the tumor including its biological and functional heterogeneity. Advances of radiation therapy are therefore intrinsically and inevitably linked to advances of imaging for visualizing individual morphologic, functional and molecular tumor characteristics with high spatial and temporal resolution. In order to achieve optimized tumor control and to minimize side effects 3D/4D treatment planning, guidance, and monitoring should include morphological, functional, metabolic and targeted molecular imaging as an integrative part. Oncologic MR imaging is accordingly challenged to improve and further develop novel concepts for precise tumor delineation and characterization. Significant progress has been achieved in morphologic-functional MRI and PET/MR, which have the potential to improve the delineation of target volumes and to adapt the dose to selected subvolumes. But integration of multiparametric MR imaging data into individual radiotherapy planning, guidance and control is still challenging. Improved IT concepts for precise spatial coregistration of multimodal morphologic and functional imaging data as well as for integration of complex imaging data into the radiotherapy process including quality control are required. Concerning imaging, hardware integration of PET and MRI (PET/MR) has proved to improve spatial coregistration of morphologic and biologic/functional imaging information. For use of imaging to improve daily radiotherapy planning and guidance hardware integration of MRI and linear accelerators (MR/Linac) are currently under development. The presentation will outline the potentials, challenges and limitations of MR and PET/MR imaging for modern radiotherapy.