The treatment of brain stem and thalamic gliomas with 78 Gy of hyperfractionated radiation therapy.

PURPOSE: To see whether increasing the dose of hyperfractionated radiation therapy from 72 to 78 Gy would increase survival time in patients with gliomas, particularly those with brain stem or thalamic tumors.
METHODS: Seventy-eight patients with a clinical and radiographic diagnosis of a brain stem or thalamic glioma were enrolled in a trial to receive 78 Gy (1.0 Gy twice a day). Six patients with disease in other sites were also treated. The initial response to therapy was determined by comparing pretreatment magnetic resonance images and neurological examinations with those obtained within 2 weeks of completing therapy; subsequent responses were determined from bimonthly follow-up images. Time-to-tumor progression was measured from the date radiation therapy began until the date of documented radiographic or clinical progression. Survival time was measured from the date radiation therapy began until the date of death. Cox proportional hazards analysis was used to estimate the effects of specific variables on survival.
RESULTS: Of 81 evaluable patients, 68 received > or = 76 Gy, 10 received between 70 and 75 Gy, and 3 received between 60 and 68 Gy. The overall response or stabilization rate was 70.4%. Tumor size decreased in 30.8% of patients; 39.5% had stable disease, and 29.6% had immediate progression. The median survival time was 12.7 months (16.1 months for adults and 10.8 months for children). The median time to tumor progression was 9.0 months (11.4 months for adults and 8.4 months for children). A duration of symptoms < or = 2 months and a diffuse lesion were each associated with shorter survival and progression times.
CONCLUSIONS: For patients with brain stem or thalamic gliomas, increasing the dose of radiation therapy from 72 to 78 Gy did not significantly improve survival. Different treatment strategies are clearly needed.