In this phase II trial with single arm, we aim to investigate the clinical efficacy and toxicity profile of local radiotherapy on all disease sites for EGFR-mutant oligo-metastatic NSCLC (no more than 3 metastatic lesions) who did not experience disease progression after at least 3 months of TKI therapy.

Tyrosine kinase inhibitor (TKI) has been widely accepted as the first-line therapy for stage IV NSCLC with active mutation of EGFR. Olio-metastasis is a disease status between localized and extended status of disease, namely with the limited number of lesions, which is generally defined as ≤ 5. A couple of phase II studies have shown that consolidation local management was able to prolong the local-regional tumor control and might further improve overall survival (OS) for oligo-metastatic NSCLC who have gained disease control from systemic therapy. However, there is lack of data regarding whether local radiotherapy (RT) could improve progression free survival (PFS) and OS for NSCLC with active EGFR mutation who have benefited from TKI. In this phase II trial with single arm, we aim to investigate the clinical efficacy and toxicity profile of local radiotherapy on all disease sites for EGFR-mutant oligo-metastatic NSCLC (no more than 3 metastatic lesions) who did not experience disease progression after at least 3 months of TKI therapy.

Inclusion Criteria:

• Age ≥18 and ≤75;
• ECOG performance status 0-1;
• Patients must provide study specific informed consent prior to study entry;
• Pathologically or cytologically diagnosed as NSCLC;
• EGFR activating mutation to TKI approved by histology, cytology or circulation tumor DNA;
• Stage IV NSCLC with ≤ 3 metastatic lesions (AJCC, 8th ed.) confirmed by meticulous radiographic examination. Brain MRI and 18F PET/CT is strongly recommended unless there is a contraindication;
• Patients have received≥3 months of TKI therapy and do not received disease progression;
• HB ≥ 10.0 g/dL;
• Absolute number of neutrophil granulocyte ≥ 1.5 × 109/L;
• Absolute number of PLT ≥ 100 × 109/L;
• Total bilirubin ≤ 1.5 folds of the maximum extent;
• ALT and AST ≤ 2.0 folds of the maximum extent;
• Cr ≤ 1.25 folds of the maximum extent and Ccr ≥ 60mLl/min.

Exclusion Criteria:

• Patients have received thoracic radiotherapy before;
• Malignant pleural effusion, pericardial effusion or peritoneal effusion;
• Patients have severe pulmonary comorbidity, such as ILD, COPD or other active pulmonary disease;
• Any unstable systemic disease including active infection, uncontrolled hypertension, unstable angina, CHF (NYHA ≥ II), MI within 6 months of enrollment, severe arrhythmia requiring medication，hepatic, nephric or metabolic disease;
• HIV infection；
• Pregnancy or lactation women;
• ECOG status ≥2；
• Mixed SCLC component;
• Other factors that is considered ineligible.