In this study the investigators want to investigate the incidence of brain metastasis in a selected high-risk group of patients with metastatic colorectal cancer. Possible prognostic biological aspects will be investigated by translational analysis of biological samples. The study population consists of patients with metastatic rectal cancer and presence of lung metastasis. The patients will undergo a standard MRI scan of the brain including injection of intravenous contrast. If positive finding, images will be evaluated at the multidisciplinary tumor board for potential treatment options according to clinical practice. Standard follow-up program is followed, as per clinical practice. If the initial MRI scan of cerebrum detects brain metastasis this will be treated and followed as per clinical practice. Translational blood samples will be drawn at inclusion and at every imaging schedule up til 5 times
A single arm observational study investigating the incidence of brain metastasis in patients with cancer recti and lung metastasis