Assess the Efficacy of Whole Brain Radiation Therapy in Lung Cancer Patients With Brain Metastasis

Inclusion Criteria:

* Patients must have signed a written informed consent form prior to any study specific screening procedures
* 18 years or older
* KPS ≥ 50%
* Histologically confirmed adenocarcinoma of the lung
* Activating mutation of EGFR
* Newly diagnosed CNS metastasis or in progression with at least one measurable lesion in the brain (defined as any lesion \> 1 cm on T1-weighted contrast enhanced MRI)
* Patients could enter the study regardless of previous treatment (included chemotherapy) for metastatic extracranial disease, except TKI.
* No steroids or stable or decreasing dose of steroids for at least 5 days before the MRI evaluation.
* Adequate hematologic, liver and renal functions: neutrophil count ≥ 1.5 x 109/L; platelets ≥ 100 x 109/L; Hb ≥ 9 g/Dl; Total bilirubin \< 1.5 x ULN; AST or ALT \< 2.5 x ULN (\< 5 x ULN in patients with liver metastases); Serum creatinine ≤ 1.5 x ULN or Creatinine clearance ≥ 50 mL/min

Exclusion Criteria:

* Prior treatment of brain metastases with WBRT or TKI
* Patient eligible for radiosurgery or surgical resection
* Contre indication at the radiotherapy
* Leptomeningeal disease
* Previous history of cancer (other than curatively treated basal and squamous cell carcinoma of the skin and/or in-situ carcinoma of the cervix) within the the 5 years before study entry
* Prior treatment with Gefitinib or other TKI
* Pregnant or breast feeding women
* Women with an intact uterus (unless amenorrhoeic for the last 24 months) not using effective means of contraception