THE TREATMENT OF BRAIN-STEM AND THALAMIC GLIOMAS WITH 78 GY OF HYPERFRACTIONATED RADIATION-THERAPY

Purpose: To see whether increasing the dose of hyperfractionated radia tion 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 diagn osis of a brain stem or thalamic glioma were enrolled in a trial to re ceive 78 Gy (1.0 Gy twice a day). Six patients with disease in other s ites 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 therap y began until the date of documented radiographic or clinical progress ion, 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 8 1 evaluable patients, 68 received greater than or equal to 76 Gy, 10 r eceived between 70 and 75 Gy, and 3 received between 60 and 68 Gy. The overall response or stabilization rate was 70.4%, Tumor size decrease d in 30.8% of patients; 39.5% had stable disease, and 29.6% had immedi ate 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 pr ogression was 9.0 months (11.4 months for adults and 8.4 months for ch ildren). A duration of symptoms less than or equal to 2 months and a d iffuse lesion were each associated with shorter survival and progressi on times. Conclusions: For patients with brain stem or thalamic glioma s, increasing the dose of radiation therapy from 72 to 78 Gy did not s ignificantly improve survival, Different treatment strategies are clea rly needed.