An apparatus and method are disclosed for ablation of diseased tissue. The method includes introducing a flexible elongate member into a predetermined tissue site with a flexible elongate member having a proximal end, a distal end and a longitudinal first lumen extending therebetween. A slidable conductor is positioned through the lumen proximate to the tissue site and energy is transmitted to the distal end of the elongate member through the conductor. A deflection member fixedly attached to the distal end of the elongate member can be manipulated to cause the distal end of the elongate member to bend. The target tissue is ablated, coagulated or photochemically modulated without damaging surrounding tissue. The apparatus can be energy transparent and include deflection members to manipulate distal portions of the apparatus. Suitable types of energy for ablation include ultrasound and laser energy.