Comparison of Accelerated Hyperfractionated Radiotherapy and Conventional Radiotherapy for Supratentorial Malignant Glioma

Between 1988 and 1993, 71 patients with glioblastoma or anaplastic astrocytoma were treated either with accelerated hyperfractionation radiotherapy (1.5 Gy twice daily to a total dose of 69 Gy, n = 35) or with conventional fractionation radiotherapy (1.8 Gy daily to 64.8 Gy, n = 36). Two patients in each group did not complete radiotherapy, leaving 67 evaluable. All patients received the chemotherapeutic regime ACNU intraarterially (50 mg/m2) or intravenously (100 mg/m2) prior to and after radiotherapy. Between 1990 and 1992, 19 patients also received intravenous interferon-β (3 × 106 U, three times weekly) during radiotherapy. The median survival time was 14.5 months for the accelerated hyperfractionation group and 14 months for the conventional fractionation group. The median time to progression was 12 months for the accelerated hyperfractionation group and 9.5 months for the conventional fractionation group. There was no significant difference in either survival (P = 0.89) or progression-free survival (P = 0.25) between the accelerated hyperfractionation and conventional fractionation groups. Interferon therapy was associated with poorer survival. Brain necrosis developed in four out of 10 patients receiving accelerated hyperfractionation radiotherapy plus interferon-β, but in none of nine patients receiving conventional fractionation radiotherapy plus interferon (P = 0.033). In conclusion, our study failed to demonstrate any possible benefit of accelerated hyperfractionation radiotherapy for malignant glioma. The incidence of brain necrosis may be increased by combining accelerated hyperfractionation radiotherapy and interferonβ.