Using virtual reality to prepare patients for radiotherapy: A systematic review of interventional studies with educational sessions

•Radiotherapy educational sessions are essential for patient engagement related to RT treatment.•VR technology as an educational tool can help patients to understand complex information and procedures.•This is the first systematic review of VR educational sessions' effect on adult patients’ psychological and cognitive variables related to RT.•Educational sessions with VR seem to enhance patients' knowledge about RT and decrease patients' anxiety, although with a less homogeneous impact.•More research is needed to clarify the effect of VR on psychological variables, to understand for which patients VR sessions are most effective.