Abstract
Over the last two decades, the computed tomography simulator became the standard of the contemporary radiotherapytreatment planning(RTP) process. Along the same time, the superb soft tissue contrast of magnetic resonance imaging(MRI) was widely incorporated into RTP through the process of image coregistration. This review summarizes the efforts of incorporation of MRI data into target definition process for RTP based on gained clinical evidence so far and opens a question whether the time is up for bringing a MRI-simulator as an additional standard imaging tool into radiationoncology departments.