Inclusion Criteria:

- Patients with pathologically confirmed (first presentation or relapsed) high grade
glioma (Grade III or Grade IV according WHO criteria) proposed for radical treatment
with 3D radiotherapy and temozolomide.

- Patients 18-75 years old.

- Karnofsky >= 60% and ECOG =< 2.

- Signed informed consent.

Exclusion Criteria:

- Clinical or psychological contraindications to fly (if 18F-FMISO-PET is realized in
Madrid) or to SCS-placement (only for this subset).

- Pregnant or breastfeeding women and women of fertile age who are not using a safe
contraceptive method or do not intend to use one during the trial. Safe contraceptive
methods are oral or parenteral contraceptive treatments or barrier methods: masculine
or feminine condom, diaphragm and/or intrauterine device (IUD) or withdrawal over the
course of the study.

- Serious co-existing or concurrent illness, including any of the following:
uncontrolled or severe infection, heart, liver or kidney disease

- Lung thromboembolism.

- Another malignancy in the last 5 years other than basal cell or squamous cell
carcinoma of the skin or carcinoma in situ of the cervix.

- Patients with life expectancy <3 months.

- Patients with any of the following: creatinine > 2 mg/dl, neutrophils <1.5 * 10^9/L,
platelets <100 * 10^9/L or hemoglobin <8.5 g/dL.

- Contraindications to receive radiotherapy or chemotherapy Clinical or psychological
contraindications for placement of spinal cord stimulation devices (only for that
specific subset of patients).

- Patients who are unable or unwilling to meet the protocol study.

- Patients who do not meet all the inclusion criteria.