Following the pioneering experiences which lasted several decades, particle therapy has become a recognized way of curing cancer. 2 new European dual-ion facilities (Heidelberg, Pavia) will soon become operational, followed by several others which are today at different stages of planning and construction. Hadron therapy faces the challenge of improving treatment outcomes with tools able to provide on-line a 4 dimensional feedback of the irradiation to enhance the dose conformation to the cancer volume and improve the treatment of moving organs. ENVISION is set up by 15 leading European research organisations, and 1 leading industrial partner IBA , to respond to these challenges. CERN is project coordinator and the majority of the key European experts in this field are involved, as well as the Hadron Research Facilities (Heidelberg, Pavia) who will immediately benefit from the developments foreseen in this project. A valorisation committee with members of the industrial partners has been established to maximally exploit the results. ENVISION tackles the problems of on-line Dose Monitoring and of performing accurate Quality Assurance tests by developing novel imaging modalities related to dose deposition and allow assessing the treated volume and deriving reliable indicators of the delivered dose. It concentrates on the detection of nuclear reaction products produced by the interaction of the beam with atomic nuclei of the tissue (positron emitting nuclides for ibPET, photons or light charged particles for ibSPAT). The methods are applicable to all therapy relevant ion species. The application of TOF techniques with superior time resolution to beam delivery integrated double head ibPET scanners has the potential for improving ibPET image quality. Furthermore, the real-time observation of the dose delivery process will become feasible for the 1st time, substantially reducing intervention times in case of treatment mistakes or incidents.