• This study aims to compare radiotherapy alone versus radiotherapy plus concomitant and adjuvant temozolomide for the treatment of glioblastoma.
• Multi-center, randomized, controlled trial.
• Patients with newly diagnosed, histologically confirmed glioblastoma were randomly divided into Radiotherapy alone, or Radiotherapy plus Temozolomide groups.
• Primary end point was overall survival. Secondary end points were progression-free survival, safety, and quality of life. 
• Radiotherapy only group: 286 patients, received 60 Gy total, divided over 6 weeks, with 2 Gy given Monday through Friday. 
• Radiotherapy plus temozolomide: 287 patients, during radiotherapy: they received temozolomide at a dose of 75 mg/m2 of body surface area, followed by a 4-week break, and post radiotherapy: received 150-200 mg/m2 of body surface area up to 6 cycles according to the standard 5-day schedule every 28 days.
• Results: For the radiotherapy-only group, median survival was 12.1 months and two year survival was 10.4%, as opposed to 14.6 months and 26.5% respectively for the radiotherapy-plus-temozolomide group. 
• Safety: 7% of patients suffered grade 3 or 4 hematologic toxic effects in the radiotherapy-plus-temozolomide group, while no patients in the radiotherapy-only group suffered grade 3 or 4 effects. Overall, at a median follow up of 2 years, there was no evidence of increase in treatment-induced late toxic effects in the radiotherapy-plus-temozolomide group. 

Reference:

NEJM

https://www.nejm.org/doi/full/10.1056/nejmoa043330