Early Versus Late Concurrent Chemoradiation for Limited Stage Small-cell Lung Cancer

Inclusion Criteria: * histologically confirmed small-cell lung cancer * limited disease status * with evaluable disease * 18 years or older * ECOG performance status 0,1,2 * expected survival time should be 12 weeks or longer * Adequate organ function as evidenced by the following; Absolute neutrophil count \> 1.5 x 109/L; platelets \> 100 x 109/L; total bilirubin ≤1.5 UNL; AST and/or ALT \< 5 UNL; creatinine clearance ≥ 50mL/min * Written informed consent form Exclusion Criteria: 1. Uncontrolled systemic illness such as DM, CHF, unstable angina, hypertension or arrhythmia 2. Patients with active infection requiring antibiotics 3. Pregnant or nursing women ( Women of reproductive potential have to agree to use an effective contraceptive method) 4. Prior history of malignancy within 5 years from study entry except for a adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer, well-treated thyroid cancer 5. previous history of chemotherapy or radiotherapy