The aim of this study is to determine the diagnostic values of EBUS-TBNA in the mediastinal re-staging after induction treatment in patients with non-small cell lung cancer.

Primary objective:

1. To determine the sensitivity, specificity, positive predictive value, negative predictive value and the accuracy of EBUS-TBNA in the detection of mediastinal metastasis in mediastinal re-staging after induction treatment.

Secondary objectives:

1. To compare the diagnostic values of EBUS-TBNA and integrated PET/CT in mediastinal re-staging
2. To evaluate the changes of ultrasonographic features of mediastinal lymph nodes after induction therapy
3. To determine procedure related complications

Inclusion Criteria:

• Histologically proven non-small cell lung cancer
• Patients who have initially histologically proven N2 disease (Stage IIIA)
• Patients who underwent induction treatment (chemotherapy or chemoradiation therapy) and are considred for surgery
• Written informed consent

Exclusion Criteria:

• Contraindications for bronchoscopy
• Medically inoperable patients
• Patients who are found to have M1 disease, inoperable T4 disease or supraclavicular metastasis after induction treatment