Brain tumor delineation based on CT and MR imaging. Implications for radiotherapy treatment planning.

This paper deals with the impact MRI may have on radiotherapy treatment planning of brain tumors. The authors analyzed differences in size and position of treatment fields as indicated by three observers (two radiotherapists and one neuroradiologist) using CT or MR based radiotherapy planning procedures for cerebral-gliomas. Large differences in field size and position were found in non CT contrast enhancing tumors, all low grade gliomas. Small differences were found in contrast enhancing lesions including the high grade gliomas. We conclude that implementation of MRI in radiotherapy treatment planning leads to a greater precision in treatment fields for non CT contrast enhancing lesions.