Particle therapy is an advanced technique of cancer radiation therapy, using protons or other ions to target the cancerous mass. ENVISION aims at developing medical imaging tools to improve the dose delivery to the patient, to ensure a safer and more effective treatment. The animation covers some of these tools, including Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), motion monitoring techniques and simulation. The ENVISION project is co-funded by the European Commission under FP7 Grant Agreement N. 241851. ENVISION serves as a training platform for the Marie Curie Initial Training Programme ENTERVISION, funded by the European Commission under FP7 Grant Agreement N. 264552.