“…These studies were criticized for including only central tumours and for not using either tomography or mediastinoscopy in the staging. In addition, in the former, many of the patients studied would not be operable with current criteria, and the intraoperative staging did not require radical mediastinal lymphadenectomy, while in the second, stages T1-T2 N0 were specifically excluded [23,24]. In the early 1990s, two meta-analysis [25,26] confirmed that adding thoracic RT to CT significantly improved long term survival for patients with limited disease.…”