Results of irradiation in patients with high-grade gliomas evaluated by magnetic resonance imaging.

Evidence shows that most high-grade gliomas are a diffuse process. Prior studies reported a median survival with surgery and postoperative radiotherapy of 8.6 months for glioblastoma multiforme (GBM) and 36.2 months for anaplastic astrocytoma (AA). Since MRI delineated the glioma better than CT scan, using MRI-based radiotherapy treatment planning allows for more precise treatment volumes. We retrospectively reviewed the records of the first 36 patients with malignant glioma, who had a presurgery MRI-based radiotherapy treatment planning. These patients were diagnosed between January 1986 and February 1991. Minimum follow up was 14 months and median survival was 15.4 months for GBM (7-42 months) and 27.4 months for AA (7-53 months). We feel that the trend for increased median survival in GBM (15.4 vs 8.6 months) is partly due to better definition of the tumor volume by using MRI. Larger studies are needed to confirm this finding.