Background: The standard of care for patients with newly diagnosed glioblastomas after surgical resection is radiotherapy with concomitant and adjuvant temozolomide chemotherapy. Yet, inclusion into the pivotal trial was limited to patients up to the age of 70, and subgroup analyses suggested that older patients did not gain benefit from combined modality treatment. Further, the efficacy of radiotherapy has been confirmed in a randomized trial comparing best supportive care versus radiotherapy alone. Of note, hypofractionated radiotherapy is equieffective in patients aged 65-70 years and more. Two randomized trials in elderly patients (NOA-08, Nordic Trial) indicated smilar efficacy of primary temozolomide chemotherapy alone compared with radiotherapy alone. Combined radiochemotherapy is compared with radiotherapy alone in an ongoing NCIC-CTG EORTC TROG Japanese group trial 26062-22061. Thus, radiotherapy alone is the standard of care for newly diagnosed glioblastoma of elderly patients. These clinical data justify the exploration of new, temozolomide-free first-line treatment strategies in elderly patients. Methods: The ARTE trial will therefore investigate bevacizumab when added to a short course of radiotherapy and bevacizumab maintenance therapy until progression. The translational research program shall include blood and urine biomarker analysis and FET-PET in addition to MRI for monitoring the course of the disease. This trial is an explorative randomized, non-comparative phase II trial aiming at recruiting 60 patients in Switzerland. Elderly patients (> 65) will be randomized 2:1 either to the experimental arm (bevacizumab plus radiotherapy) or the standard arm (radiotherapy). The primary endpoint is median overall survival. Secondary endpoints include overall survival at 6 months, overall survival at 12 months, median progression-free survival, progression-free survival at 6 months, median time to treatment failure.