Patients with radiologically early stage lung cancer who are candidates for SBRT will be enrolled in this study. Prior to enrollment, patients are required to be evaluated by an experienced thoracic surgeon, radiation oncologist or medical oncologist to determine operability. Patients will udergo computed tomography (CT) and positron emission tomography (PET) prior to EBUS- TBNA. EBUS-TBNA will be performed at the Interventional Thoracic Surgery Suite (ITSS) located at Toronto General Hospital by a Thoracic Surgeon. The procedure will be performed under local anesthesia with conscious sedation. Mediastinal as well as hilar lymph nodes will be assessed by EBUS-TBNA. The result of pathological diagnosis using EBUS-TBNA will be compared with the result of radiological staging (CT and PET-CT). Patients who are negative for mediastinal lymph node metastasis by EBUS-TBNA will undergo SBRT. In addition, the treatment outcome will be evaluated based on the clinical chart review.