TKI Followed by Thoracic Radiotherapy for Stage IV EGFR Mutant NSCLC

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.