We studied the effects of increased-dose radiation therapy in terms of survival 
time and improvement in the quality of life in 50 glioblastoma patients with 
minimal residual tumors. 1) Intraoperative radiotherapy ( IOR , 1,000-2,000 rad) 
was applied in 13 cases; the 2-year survival was 41.6%. However, in 9 patients 
who had undergone macroscopic total removal the 2-year survival rate was 68.6%. 
2) Wide resection with necrotomy after conventional external irradiation was 
used in 9 cases and conformation irradiation was added; their 2-year survival 
was 44.4%. 3) In 22 patients who received only conventional irradiation 
following surgery, the 2-year survival was 7.5%.