In the last 20 years, only temozolomide has obtained indication for the treatment of High-grade glioma (HGG). Temozolomide during and later radiation therapy has doubled one year survival and is the standard treatment for glioblastoma. But 30% of glioblastomas receive only a biopsy as they can't be resected and don't get benefit from this treatment. They and should be treated immediately after the biopsy to prevent neurological deterioration but in spite of this approach they often deteriorate neurologically during radiotherapy. . An effective pre-radiation treatment should improve their prognosis and allow them to complete concomitant radiotherapy and temozolomide treatment. Bevacizumab in recurrent HGG displays 63% of objective responses when combined with irinotecan. But irinotecan is not the most active treatment in this disease.

We propose a phase II, two arms, open label, randomized, multicentric study with 2 cycles of temozolomide before radiation therapy and concomitant temozolomide, in patients with glioblastoma and 'biopsy-only'. Bevacizumab will be added to one arm.

Inclusion Criteria:

1. Patients with glioblastoma, non-resectable, biopsy only. Accepting a craniotomy with resection attempted if an RMN within a period of about 72 hours to confirm that the resection was less than 25% of the tumor and fulfill criterion
2. Measurable disease and contrast uptake ≥ 3 cm in one of its diameters.
3. Stable doses of dexamethasone during the week prior to inclusion.
4. Performance Status ≤ 2.
5. Age ≤ 75 years.
6. MiniMental Status> 25/30.
7. Bartel index > 50%.
8. The surgical incision should be healed prior to randomization. The treatment can be started at 3 weeks of a simple stereotactic biopsy or 4 weeks in case of open biopsy (craniotomy).
9. Maximum baseline MRI performed 4 weeks before starting treatment (acceptance of the MRI done for neuronavegation biopsy as baseline).
10. Adequate bone marrow reserve: neutrophils>2000x109/L, platelets>100x109/L, hemoglobin≥106g/dl.
11. Not received prior treatment with chemotherapy or radiation.
12. Adequate renal function: Creatinine <1.5 ULN of the laboratory performing the analysis.
13. Adequate liver function: Serum bilirubin <1.5/ULN SGOT, SGPT<2.5ULN. Serum alkaline phosphatase<3/ULN.
14. Absence of proteinuria.
15. Effective method of contraception for patients and their partners.
16. Written informed consent
17. Collecting material for a double histological confirmation of diagnosis.

Exclusion Criteria:

1. Prior radiotherapy or chemotherapy for the treatment of glioma.
2. Less than 5 years prior to any invasive neoplasia. Accepted carcinoma in situ of cervix carcinoma or cutaneous vasocelular.
3. Cerebral hemorrhage after biopsy.
4. Pregnancy or lactation.
5. Clinically significant cardiovascular disease: - Myocardial infarction or unstable angina (≤ 6 months before randomization) - Congestive heart failure (CHF) class ≥ II NYHA, New York Heart Association. - Cardiac Arrhythmia uncontrolled despite medication (may include patients with atrial fibrillation often controlled). - Peripheral vascular disease ≥ grade 3 (ie, symptomatic and interfering with everyday activities or specifying repairs or review).
6. Continued use of aspirin> 325 mg / day, currently or recently (within the 10 days prior to randomization).
7. Currently established treatment with therapeutic doses of anticoagulants Coumarin derivatives (courmarina, warfarin) or a week before starting treatment. It allows the administration of heparin for control of Deep Vein Thrombosis (DVT)
8. Patients with PTSD and patients with inflammatory bowel disease, with risk of perforation.
9. HT with values above 150 mmHg systolic pressure of 100 mmHg and diastolic tension is not controllable with standard antihypertensive drugs.
10. Not healed scars, ulcers or recent bone fracture.
11. Bleeding diathesis or coagulopathy.