The purpose of this study is to determine whether hypofractionated concurrent chemo-radiotherapy has the same efficiency as conventionally fractionated concurrent chemo-radiotherapy in Limited Disease Small Cell Lung Cancer.

For patients with Limited Disease Small Cell Lung Cancer, 45Gy/15F of radiotherapy with concurrent chemotherapy will be used in experimental arm. While 60Gy/30F of radiotherapy with concurrent chemotherapy will be used in the control arm. Both survival and toxicity of the two arms will be observed and compared.

Inclusion Criteria:

• 18~70 years old, ECOG 0-2
• patients with histologically or cytologically proved small cell lung cancer
• Limited disease (LD), was characterized by tumors confined to one hemithorax. It may include ipsilateral hilar, both mediastinum and both supraclavicular nodes. Metastatic lymph nodes were defined as lymph nodes with short diameter of more than 1cm or FDG uptake in PET. The thickness of pleural effusion was less than 1cm unless malignant pleural effusion was cytologically proved. In a word, stage I-IIIB excluding the patients with lung metastases should be defined as LD according to AJCC cancer staging 7th edition.
• No progression after 2 cycles of chemotherapy with EP.
• No prior history of anti-tumor treatment.
• No severe internal diseases and no organ dysfunction
• Written informed consent provided and

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