The purpose of this study is the evaluation of dynamic contrast-enhanced CT (Perfusion-CT) for therapeutic response predicition in patients with metastasized renal carcinoma (mRCC) undergoing antiangiogenetic therapy (AAT) with multikinase inhibitors.

In this study patients with mRCC under AAT will be examined with 3 serial Perfusion - CT scans - partially intergrated in their regular staging CT scheme - at baseline (before AAT start), 1 week after AAT as well as 8 weeks after AAT initialization. Thereby selected intrabdomial or intrathoracic metastases will be monitored longitudinally with perfusion CT. Pretreament and post-treament perfusion characteristics of the assessed metastatic lesions will be quantified and correlated with patient outcome.

Inclusion Criteria:

• patients with metastasized renal cell carcinoma treated at the Department of Urology (University of Munich - Grosshadern Campus)

  1. with either - Sunitinib (Sutent®), Pazopanib (Votrient ®) bzw. Sorafenib (Nexavar®) as first-line therapy
  2. with Sunitinib (Sutent®), Pazopanib (Votrient ®) bzw. Sorafenib (Nexavar®) as second-line therapy after failed first-line therapy, who are off therapy for at least 2 weeks

• no contraindications against contrast-enhanced CT

• obtained informed consent to participate in the study

Exclusion Criteria:

Patients who have:

• not given informed consent
• known iodine allergy
• high grade renal insuffiency (eGFR < 30ml/min) not on dialysis
• overt hyperthyreoidism
• singular metastases <1cm in diameter
• an increase of their baseline creatine levels of >20% between CT examinations

Patients with metastatic renal cell cancer eligible for AAT (antiangiogenic therapy) with either Sunitinib (Sutent®), Pazopanib (Votrient ®), Sorafenib (Nexavar®) presenting at the Departement of Urology. LMU, meeting the inclusion/exclusion criteria