OUTLINE: This is a randomized study. Patients are stratified according to WHO disease grade (III vs IV), center, and age (under 40 vs 40 and over). Patients are randomized to undergo stereotactic radiotherapy or no further treatment after conventional radiotherapy. Patients undergo conventional radiotherapy once or twice a day for up to 6 weeks. Patients randomized to receive additional treatment receive stereotactically guided conformal boost radiotherapy for 4 days, within 4 weeks after completion of conventional radiotherapy. Quality of life is assessed before radiotherapy, then at follow up visits. Patients are followed every 3 months for 1 year, every 6 months for 1 year, and then annually thereafter.