- Limited disease (LD), was characterized by tumors confined to one hemithorax. It may include ipsilateral hilar, both mediastinum and both supraclavicular nodes. Metastatic lymph nodes were defined as lymph nodes with short diameter of more than 1cm or FDG uptake in PET. The thickness of pleural effusion was less than 1cm unless malignant pleural effusion was cytologically proved. In a word, stage I-IIIB excluding the patients with lung metastases should be defined as LD according to AJCC cancer staging 7th edition.