Radiation therapy of malignant glioma

A retrospective study of 34 cases irradiated for malignant glioma was undertaken to determine the optimal technique of radiation therapy. The 2-year overall survival rates of 14 patients with anaplastic astrocytoma and 20 patients with glioblastoma were 50% and 16.9%, respectively. Patients survival time was influenced by factors such as age, Karnofsky performance status, extent of surgery, and irradiated fields. Among these factors, Karnofsky score was important in the patients with both anaplastic astrocytoma and glioblastoma (p<0.05). Extent of surgery was also important in the patients with glioblastoma (p<0.05). No difference was observed in survival time among those patients treated with limited brain irradiation fields or whole brain irradiation fields. Tumor recurrence occurred within the radiotherapy fields in 9 patients with anaplastic astrocytoma and in 15 patients with glioblastoma. Our results suggested irradiation should be administered through limited brain irradiation fields according to the extent of the tumor and that we should attempt to give a high dose of more than 60 Gy to the tumor, especially in the patients with glioblastoma, taking into account the patients' performance status. (author)