[The radiologist as the treating physician for cancer: interventional oncology]

Interventional oncology is a new specialism which focuses on image-guided minimal-invasive treatment of cancer patients. Interventional oncology has joined the traditional treatments of surgery, chemotherapy and radiotherapy as the fourth pillar of cancer care. Oncological interventions can be divided into three categories: intra-arterial techniques, tumour ablation techniques, and palliative procedures. Two examples of such interventions in Dutch hospitals are the intra-arterial Yttrium-90 microsphere radioembolisation of colorectal liver metastases and the CT-guided radiofrequency ablation of tumours such as renal cell carcinoma. In interventional oncology all procedures are performed under image guidance. Imaging is used to guide the instruments and for real-time monitoring of the procedure.