The present invention provides methods, devices, and systems for in vivo treatment of cell proliferative disorders. Included is a method of treating tissue with electrical energy, the method comprising: delivering electrical energy to tissue using one or more electroporation devices comprising one or more electrodes; and cooling the tissue, surrounding tissue, one or more of the electrodes, or one or more of the electroporation devices to minimize heating. In embodiments, the invention can be used to treat solid tumors, such as brain tumors, and in some embodiments, exemplary methods rely on non-thermal irreversible electroporation (IRE) to cause cell death in treated tumors.