Apport du guidage par l'image pour le repositionnement au cours de la radiothérapie des tumeurs encéphaliques

A narrow therapeutic index and more and more patients with long survival characterize primary and second brain tumors. Image-guided radiotherapy can increase accuracy of the patient's position during a course of intracranial irradiation thanks to a direct or indirect visualization of targets volumes. Treatment reproducibility and organ at risk-sparing are the primary issues, particularly with the development of stereotactic radiotherapy and protontherapy. Regarding intracranial treatments, image-guided radiotherapy seems to be a repetitive task based on skeletal structures registration. And yet, this innovation makes possible to assess the dosimetric impact of daily positioning variations avoiding invasive immobilizations. Image-guided radiotherapy offers automated tools to limit time consumption and furthers adaptive radiotherapy opportunities. Nevertheless, medical evaluation is still necessary and image processing should be strictly defined (frequency, use, performance). The purpose of this article is to describe image-guidance in brain irradiation, as repositioning tool and to focus on its recent prospects.