The past decade has seen steady advances in the field of radiation therapy, impacting definitive treatment options for early and advanced tumors, as well as identifying further roles for adjuvant and palliative therapy. The widespread availability of (18)F-fluoro-2-deoxy-D-glucose positron emission tomographic (FDG PET) imaging has improved staging, and better defines a population that will benefit from aggressive local therapy. Technological advances in radiation treatment planning allow for less normal lung irradiation, allowing increasing dose and decreasing normal tissue toxicity. Ongoing clinical investigations in the role of radiosurgery for early lung tumors, postoperative radiation of locally advanced non-small-cell lung cancer (NSCLC), and prophylactic cranial irradiation in small-cell lung cancer (SCLC) help to identify patients who may benefit from treatment.