A Study of Hypofractionated Radiotherapy for Limited Metastatic NSCLC Harboring Sensitizing EGFR Mutations After First Line TKI Therapy

Inclusion Criteria:

* Newly diagnosed metastatic lung adenocarcinoma harboring sensitizing EGFR mutations (L858R, exon 19 deletion), and became oligometastatic disease after 3 months TKI, evaluated by PET/CT scan, brain MRI, and abdomen ultrasound (≤6 discrete lesions of disease, exclusive of the brain metastases, ≤3 lesions in the liver, ≤3 lesions in the lung);
* All sites of disease must be amenable to definitive RT;
* An intrathoracic lymph nodal station is considered 1 discrete lesion, according to IASLC lymph nodal station map;
* Age 18 years or older;
* ECOG Performance Status 0-2;
* Adequate bone marrow, liver and renal function, as specified below: Absolute Neutrophil Count (ANC) ≥ 1.5 x 109/L; Hemoglobin ≥ 8 g/dL; Platelets ≥ 100 x 109/L; Serum total bilirubin ≤ 1.5 x upper limit of normal (ULN) ; AST and ALT ≤ 2.5 x ULN or ≤ 5 x ULN if liver metastases are present; Serum creatinine ≤ 1.5 x upper limit of normal or creatinine clearance ≥ 60ml/min for patients with creatinine levels above institutional normal;
* For women of child-bearing potential, negative pregnancy test within 14 days prior to starting treatment;
* Men and women of childbearing age must be willing to use effective contraception while on treatment and for at least 3 months thereafter;
* Patients and their family signed the informed consents;

Exclusion Criteria:

* Received chemotherapy before TKI therapy;
* Brain parenchyma or leptomeningeal disease;
* Any site of disease that is not amenable to definitive RT;
* Concurrent malignancies other than non-melanoma skin cancer that require active ongoing treatment;
* Any medical co-morbidities that would preclude radiation therapy.