A pulmonary treatment system , comprising: a nerve modification assembly configured to assume a reduced profile for passage through a lumen of an elongate device and positioning in an airway of a patient, and configured to assume an expanded profile once positioned in the airway, the nerve modification assembly including - an elongate shaft having proximal and distal ends, a fluid delivery lumen extending from the proximal end to the distal end, and a fluid return lumen extending from the proximal end to the distal end; an energy delivery portion coupled to the elongate shaft near the distal end and configured to generate heat energy to ablate nerve tissue of a nerve trunk in an airway wall of the airway, wherein the energy delivery portion comprises a flexible fluid delivery conduit and an electrode disposed on the conduit ; a conformable expandable member coupled proximate the distal end of the elongate shaft and wherein the distal end of the conformable expandable member is fluidly coupled to the flexible fluid delivery conduit and the proximal end of the conformable expandable member is fluidly coupled to the fluid return lumen , characterized in that the energy delivery portion has an ovoid or eye-shaped cross-sectional shape, and wherein the nerve modification assembly is configured such that delivery of fluid into the expandable member causes the nerve modification assembly to assume the expanded profile in which at least a portion of the conduit extends around an external surface of the expandable member and the energy delivery portion is in contact with the airway wall, and a sidewall of the expandable member contacts the airway wall adjacent to the energy delivery portion with sufficient surface contact to minimize air gaps between the sidewall of the expandable member and the airway wall. a nerve modification assembly configured to assume a reduced profile for passage through a lumen of an elongate device and positioning in an airway of a patient, and configured to assume an expanded profile once positioned in the airway, the nerve modification assembly including - an elongate shaft having proximal and distal ends, a fluid delivery lumen extending from the proximal end to the distal end, and a fluid return lumen extending from the proximal end to the distal end; an energy delivery portion coupled to the elongate shaft near the distal end and configured to generate heat energy to ablate nerve tissue of a nerve trunk in an airway wall of the airway, wherein the energy delivery portion comprises a flexible fluid delivery conduit and an electrode disposed on the conduit ; a conformable expandable member coupled proximate the distal end of the elongate shaft and wherein the distal end of the conformable expandable member is fluidly coupled to the flexible fluid delivery conduit and the proximal end of the conformable expandable member is fluidly coupled to the fluid return lumen , characterized in that the energy delivery portion has an ovoid or eye-shaped cross-sectional shape, and wherein the nerve modification assembly is configured such that delivery of fluid into the expandable member causes the nerve modification assembly to assume the expanded profile in which at least a portion of the conduit extends around an external surface of the expandable member and the energy delivery portion is in contact with the airway wall, and a sidewall of the expandable member contacts the airway wall adjacent to the energy delivery portion with sufficient surface contact to minimize air gaps between the sidewall of the expandable member and the airway wall. <EOS>