This is a prospective non-randomized multicenter clinical trial performing endobronchial and esophageal ultrasound for mediastinal lymph node staging of operable and resectable cT1-T2-selectedT3 cN1 cM0 NSCLC.

Provided no mediastinal lymph node metastases are proven by echoendoscopy, all patients will subsequently undergo surgical staging. Patients without tissue proof of mediastinal nodal disease at surgical staging will undergo a thoracotomy with systematic lymph node dissection. Provided mediastinal lymph node metastases are proven by echoendoscopy, the patient goes off study protocol and can further be assessed/treated according to local clinical practice.

Inclusion Criteria:

• Patients with operable and resectable (suspected) NSCLC
• Patients with clinical N1 staging based on PET/CT
• Only T1, T2, and selected T3 (i.e. intraparenchymal tumour >7cm, chest wall, or additional nodule in the same lobe) are allowed.

Exclusion Criteria:

• Patients with enlarged mediastinal lymph nodes on chest CT or FDG-PET positive mediastinal lymph nodes
• Patients with a central tumour staged T3 or any T4.
• All stage IV patients.
• Patient unable to give informed consent.
• Patient previously underwent a mediastinoscopy.
• Tracheal or upper airway stenosis.