The invention relates to a steerable catheter device and method for the chemoembolization and/or embolization of vascular structures, tumours and/or organs. The catheter is formed by a tubular body containing one or more channels for the administration of a drug, vacuum channels associated with different electrodes, channels for housing radio frequency wave-conducting cables, channels for housing laser light-transmitting optical fibres, a guide cable for performing the catherization and other components, the proximal end of the catheter being connected to a power unit and to other pressure devices and/or devices for the application or dosing of substances. The invention is also optionally provided with an inflatable balloon in order to help obstruct the vessel, as well as one or two conducting films or electrodes at the distal end of the catheter. The aim of the catheter is to obtain improved results in treatments with embolization and/or chemoembolization and to improve monitoring of the drug and/or the tissue in the area to be treated.