A catheter for insertion into and treatment of tissue in a patient comprises a radio frequency (RF) electrode having an elongated body that conducts electrical RF energy to a conductive tip. An insulating sleeve surrounds the elongated body. In a first mode of operation, the conductive tip is exposed outside the insulating sleeve and the RF electrode delivers RF energy that erodes the tissue of the patient and creates a tunnel through which the catheter can advance into the tissue of the patient. In a second mode of operation, the insulating sleeve and/or the RF electrode is retracted and a second treatment apparatus treats the tissue.