A system comprising: a) a primary catheter, wherein said primary catheter comprises a primary lumen; b) a channel catheter, wherein said channel catheter is configured to fit within said primary lumen, and wherein said channel catheter comprises a channel lumen, wherein said channel catheter is constructed of a braided material, wherein said channel catheter is flexible, and wherein said channel catheter has a sufficient length to extend to a treatment site in a peripheral lung of a human subject from a mouth of said human subject and through a trachea of said human subject, c) a steerable navigation catheter, wherein said steerable navigation catheter is configured to fit within said channel lumen, and wherein said steerable navigation catheter comprises a steerable tip and a position sensing element, said steerable navigation catheter having a sufficient length to extend to a treatment site in a peripheral lung of a human subject from a mouth of said human subject and through a trachea of said human subject, and d) a microwave energy delivery device (100, 800, 1400, 1600, 1700) configured to fit within said channel lumen, wherein the microwave energy delivery device has a sufficient length to extend from an oral cavity of a human subject, through a trachea of the human subject, and to a peripheral lung of the human subject, the microwave energy delivery device has a diameter of 2mm or less, the microwave energy delivery device is flexible, the microwave energy delivery device comprises an inner conductor, an outer conductor, and a stylet tip, the inner conductor comprises a proximal end and a distal end, the outer conductor comprises a proximal end and a distal end, the stylet tip is added to the distal end of the microwave energy delivery device, the inner conductor comprises a cooling channel for circulating a coolant, the microwave energy delivery device comprises a temperature sensor, and the microwave energy delivery device is formed such that the coolant can circulate via the proximal end of the inner conductor, through the cooling channel of the inner conductor, out from the distal end of the inner conductor, via a region between the distal end of the inner conductor and the distal end of the outer conductor, through an interior space which is created within the outer conductor, and extends from the distal side of the outer conductor to the proximal side of the outer conductor, and via a region between the proximal end of the inner conductor and the proximal end of the outer conductor. a) a primary catheter, wherein said primary catheter comprises a primary lumen; b) a channel catheter, wherein said channel catheter is configured to fit within said primary lumen, and wherein said channel catheter comprises a channel lumen, wherein said channel catheter is constructed of a braided material, wherein said channel catheter is flexible, and wherein said channel catheter has a sufficient length to extend to a treatment site in a peripheral lung of a human subject from a mouth of said human subject and through a trachea of said human subject, c) a steerable navigation catheter, wherein said steerable navigation catheter is configured to fit within said channel lumen, and wherein said steerable navigation catheter comprises a steerable tip and a position sensing element, said steerable navigation catheter having a sufficient length to extend to a treatment site in a peripheral lung of a human subject from a mouth of said human subject and through a trachea of said human subject, and d) a microwave energy delivery device (100, 800, 1400, 1600, 1700) configured to fit within said channel lumen,