A vapor-based ablation method mitigates constriction of the airways for the treatment of asthma and COPD. A vapor ablation catheter is advanced along the airways, through the airway wall, and to an extra-airway target tissue. The position of the catheter is assessed to determine whether the catheter is in contact with the target tissue. In embodiments, the distal energy delivery section of the catheter is manipulated to contact an exterior surface of the target tissue, or to enter the target tissue. Once the position is confirmed, vapor is delivered to the target tissue through an egress port with a sufficient amount of energy to ablate the target tissue. The target tissue may vary and include smooth muscle surrounding the airways, and nerves that control the smooth muscle. Methods for treating lung cancer are also described including delivering a vapor at lung tumors and growths, and blood vessels feeding the lung tumors and growths.
