Patients with progressive disease during the last year will receive treatment with everolimus 10 mg/day orally and 89Zr-bevacizumab PET imaging will be performed before start of treatment and after 2 and 12 weeks of treatment in the first three patients. If the scan after 2 weeks of treatment is already informative further patients will not undergo a scan at 12 weeks. A scan is considered already informative if both scans show at least 30% decrease in uptake in case of response, or at least 30% increase in uptake in case of disease progression.