Eligible patients are administered with oral icotinib 125mg three times daily for two months, in which responsive patients (partial response and stable disease) are randomized (1: 1: 1) and receive icotinib plus concurrent radiotherapy, or chemotherapy plus concurrent radiotherapy, or icotinib monotherapy.

Eligible patients are administered with oral icotinib 125mg three times daily for two months, in which responsive patients (partial response and stable disease) are randomized (1: 1: 1) and receive icotinib plus concurrent radiotherapy, or chemotherapy plus concurrent radiotherapy, or icotinib monotherapy. The primary endpoint is progression-free survival, and the incidence of radiation-induced lung injury.

Inclusion Criteria:

• Aged 18 to 75 years
• Pathologically documented NSCLC
• Unresectable stage III or oligometastasis (less than three metastasis lesions, brain metastasis is not permitted) stage IV confirmed by CT and/or MRI
• Positive EGFR mutation confirmed by ARMS
• At least 3-month life expectancy
• KPS ≥ 70
• Adequate hematological values: hemoglobin ≥ 100 g/L, absolute neutrophils count ≥ 1.5 x 109/L, platelets count ≥ 100 x 109/L
• Adequate hepatic function: bilirubin ≤ 1.5 x ULN, AST/ALT ≤ 1.5 x ULN
• Written informed consent before patient registration and any protocol-related procedures

Exclusion Criteria:

• Previous radiotherapy
• Received other investigational systemic drugs within 4 weeks prior to study entry
• Severe or uncontrolled systemic disease
• Active autoimmune disease, or a documented history of autoimmune/acquired immune disease, or a history of organ transplant
• Pregnant or lactating, women of childbearing potential, unless using effective contraception as determined by the investigator
• Any other serious underlying medical (e.g. active uncontrolled infection, active gastric ulcer, uncontrolled seizures), psychological and other condition that, in the judgment of the investigator, may interfere with the planned staging, treatment and follow-up, affect patient compliance or place the patient at high risk from treatment-related complications.