This study aims to assess both the role and cost-effectiveness of EBUS in preoperative Non small cell lung cancer staging. This controlled multicentric study will be conducted in 22 centers in France. The study design includes two prospective phases. In phase 1, one investigator in each center will prospectively be evaluated for its ability to perform EBUS, with a required goal of 9 informative samplings out of 10 consecutive patients. The phase 2 will include the medico-economic assessment of the technique in the preoperative setting. A maximum of 420 patients for each phase is forecasted.

Inclusion Criteria:

• adult patients over 18
• non small cell lung cancer histologically or cytologically proved
• Clinical Stage IIIA
• anatomically and functionally resectable

Exclusion Criteria:

• uncorrected bleeding disorders
• absence of lymphadenopathy superior to 1cm in small axis at CT scan
• contraindication to bronchoscopy
• extrathoracic or intrathoracic metastasis
• respiratory function tests not compatible with curative resection of lung cancer

This study will include non small cell lung cancer patients, stage III A (before PET Scan), with resectable tumors.