MGMT and glioblastoma: Although radiation in combination with temozolomide is recommended over single-modality therapy for newly diagnosed GBM patients who are older than 70 years of age and have good performance status, the results of two phase III studies support the recommendation that temozolomide alone as initial therapy may be a reasonable option for elderly patients who have MGMT promoter-methylated tumors and would be initially preferred to delayed radiation treatment [37, 38].