Effect of Sorafenib on ccRCC Uptake of Radiolabeled Bevacizumab or cG250

Inclusion Criteria: * Renal cell carcinoma patients planned for surgery (nephrectomy/metastasectomy) * Karnofsky \> 70 % * Laboratory values within 14 days prior to start: * White blood cells (WBC) \> 3.5 x 109/L * Platelets \> 100 x 109/L * Hemoglobin \> 6 mmol/L * Total bilirubin \< 1.5 upper limit of normal (ULN) * ASAT, ALAT \< 2.5 x ULN (\<5 x in case of liver metastases) * Lactate dehydrogenase (LDH) \> 1.5. ULN * Serum creatinine \< 2 x ULN * Amylase and Lipase \< 1.5 ULN * Negative pregnancy test in premenopausal women * Age over 18 years * Signed informed consent * Life expectancy \> 24 weeks * PT/APTT/ INR \< 1.5 ULN * No current use of coumarin derivatives Exclusion Criteria: * Known subtype other than clear cell RCC * Pre-exposure to murine/chimeric antibody therapy * Known brain metastases * Untreated hypercalcemia * Uncontrolled hypertension * Concurrent therapeutic anticoagulation * Chemotherapy, immunotherapy or radiation therapy within 4 weeks prior to start of study. Palliative limited field external radiation for fracture prevention is allowed * Cardiac arrhythmias requiring antiarrhythmics (beta-blockers, digoxin), symptomatic coronary artery disease and congestive heart failure New York Heart Association III or IV. * Previous malignancy \< 2 years prior to the study (except for cervical carcinoma in situ, basal cell carcinoma, or superficial bladder tumours (Ta, Tis, T1) * Any medical condition present that in the opinion of the investigator will affect patients' clinical status. No other concurrent malignancy except nonmetastatic nonmelanoma skin cancer or carcinoma in situ of the cervix. * Active clinically serious bacterial or fungal infections (\< grade 2 NCI-CTC version 3) * Known history of Human Immunodeficiency virus (HIV) infection or chronic hepatitis B/C. * Prior use of Raf-kinase inhibitors, MEK and Farnesyl transferase inhibitors * Prior use of Bevacizumab and all other drugs that target VEGF/ VEGF-receptors * Use of antiepileptic drugs * Pregnancy and lactation