An ablation catheter configured to ablate tissue in a lung of a patient including: a flexible shaft that advances endobronchially into an airway of the lung and has an outer diameter of 2.0 mm or less； an ablation electrode attached to a distal portion of the flexible shaft and to deliver radiofrequency (RF) electrical current to the tissue and conductively connectable to an RF electrical energy source external to the patient； wherein an outer diameter of an assembly of the flexible shaft and the ablation electrode is no greater than 2.0 mm； a liquid outlet on the distal portion and configured to be in fluid communication with a source of hypertonic saline solution； and a first occluder attached to the flexible shaft proximal to the ablation electrode and proximal to the liquid outlet, wherein the first occluder is configured to expand to occlude the airway.
