Comparable Study of Different Thoracic Radiotherapy Regimens for Extensive Stage Small Cell Lung Cancer

Inclusion Criteria: * 18 - 70 years old, ECOG 0-2. * Patients with histologically or cytologically proved small cell lung cancer. * Extensive stage small-cell lung cancer (ES-SCLC), was characterized by tumors beyond the hemithorax, hilar, mediastinal, and supraclavicular nodes. According to 2007 AJCC cancer staging 7th edition, stage I-IIIB with lung metastases and stage IV should be defined as LD. * Has 1-4 extracranial metastatic lesions. * No brain or central nervous system (CNS) metastases. * No prior history of anti-tumor treatment. * Response after 4 to 6 cycles of EP-based chemotherapy within the past 4 weeks. * No severe internal diseases and no organ dysfunction. * Written informed consent provided. Exclusion Criteria: * Malignant tumors of other sites. Non melanoma skin cancer and Cervical carcinoma in situ were not included if curable. * Active heart disease or acute myocardial infarction happen in six months. * Psychiatric history. * Pregnant woman or woman need to breast feed or woman with positive chorionic gonadotrophin (HCG). * Uncontrolled diabetes or hypertension. * Interstitial pneumonia or Active pulmonary fibrosis. * Acute bacterial or fungal infection. * Oral or intravenous use of steroids.