Inclusion Criteria:

- Male and female patients with a recurrence / progression of glioblastoma either not
being eligible for tumour resection or having macroscopic residual tumour after
resection of the recurrence

- Diagnosis of glioblastoma must be proven histologically and progress must be
documented by MRI. MRI images must not be older than 2 weeks before first
dosing/start of RT

- Not more than two prior therapy regimens including one or two resections, one or two
chemotherapies of which one must have been TMZ-containing and one radiotherapy (RT)
for the brain tumour

- Previous irradiation therapy of the primary tumour with a maximal dose of 60 Gy; at
least 8 months since the end of preirradiation

- Candidate for reirradiation with recurrent tumour visible on MRI-T1 (Gd) and with the
largest diameter measuring 1 cm to 4 cm

- Informed consent

- Age at least 18 years, smoking or non-smoking, of any ethnic origin

- Karnofsky performance index (KPI) ≥ 60%

- Neutrophile counts > 1500/μl / Platelet counts > 80.000/μl / Haemoglobin > 10 g/dl /
Serum creatinine < 1.5-fold upper normal range / Bilirubin, AST or ALT < 2,5-fold
upper normal range unless attributed to anticonvulsants / Alkaline phosphatase <
2,5-fold upper normal range

- Adequate contraception

- Stable or decreasing treatment with steroids within 5 days before treatment start

Exclusion Criteria:

- More than one RT of brain, prior first radiotherapy with more than 60 Gy

- Cumulative total dose on the optical chiasm >54 Gy for 2 Gy/fraction, α/β=2

- Prior treatment with bevacizumab, iodine seeds and/or brachytherapy

- Unable to undergo MRI

- Past medical history of diseases with poor prognosis according to the judgement of
the Investigator, e.g. severe coronary heart disease, severe diabetes, immune
deficiency, residual deficits after stroke, severe mental retardation

- HIV or hepatitis infection

- Pregnancy or breast feeding

- Treatment within any other clinical trial parallel to the treatment phase of the
current study or within 30 days before inclusion

- Known active coronary artery disease, significant cardiac arrhythmias or severe
congestive heart failure (NYHA class III - IV)