COMBINATION THERAPY: Patients receive oral tipifarnib twice daily on days 1-21. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Within 5-9 days after beginning tipifarnib, patients receive oral temozolomide once daily for 6 weeks and concurrently undergo partial brain radiotherapy daily 5 days a week for 6 weeks. After completion of radiotherapy, patients proceed to adjuvant therapy.