Provided herein is a method of treating primary lung cancer or metastatic cancer to the lung in an individual by delivering at least once to the respiratory tract of the individual via inhalation a nebulized liposomal aerosol comprising a dilauroylphosphatidylcholine liposome containing camptothecin or a derivative thereof in an amount sufficient to deliver a pharmacologically effective dose of the camptothecin or its derivative to treat the cancer. Also provided is a nebulized liposomal aerosol comprising the DLPC containing the camptothecin or its derivative and a method of making the liposome-drug comprising the aerosol.