肺癌是台灣癌症死亡的主要原因。表皮生長因子（epidermal growth factor receptor, EGFR）突變，主要為exon 19 deletion和exon 21 L858R突變，在東亞是46.7%的非小細胞肺癌（non-small-cell lung cancer, NSCLC）患者的已知致癌驅動因子。具EGFR突變之NSCLC患者的腦轉移累積發生率比EGFR野生型（wild-type）患者還高。由於具EGFR突變之NSCLC患者的存活期不斷改善，腦轉移的處理成為一更大的挑戰。放射治療（radiotherapy, RT）無論是全腦放療（whole brain radiotherapy, WBRT）還是立體定位放射手術（stereotactic Radiosurgery, SRS），是治療腦轉移的主要方法。第一代和第二代tyrosine kinase inhibitors（TKIs）已被證實在治療具EGFR突變之腦轉移具有療效。Osimertinib是第三代EGFR TKI，也已被證實在第一線治療具EGFR突變之晚期NSCLC及具有T790M抗藥突變的患者中具有效益且有顯著中樞神經系統活性。在這幾代EGFR-TKI的發現和發展之後，因為單獨使用EGFR-TKI已可顯著提高這些患者的腦轉移治療效益，腦部放射對未經治療的EGFR突變NSCLC腦轉移患者的臨床價值因此產生了爭議。然而，合併EGFR TKI和腦部放射治療的組合是否比單獨使用EGFR-TKI有更好的效益仍不清楚。在這裡，我們回顧了前期腦部放射治療合併EGFR-TKI與單獨使用EGFR-TKI以治療EGFR突變之晚期NSCLC腦轉移患者的相關文獻來探討前期腦部放射治療的角色。

Lung cancer is a leading cause of cancer mortality in Taiwan. Epidermal growth factor (EGFR) mutations, predominantly exon 19 deletions and exon 21 L858R mutations, are known oncogenic drivers in 46.7% of non-small-cell lung cancer (NSCLC) patients in East Asia. The accumulative incidence of brain metastasis in EGFR-mutant NSCLC patients is greater than EGFR wild-type patients. Because long-term survival outcomes in EGFR-mutant NSCLC patients continue to improve, the management of brain metastasis becomes a greater challenge. Radiotherapy (RT), either whole-brain radiotherapy (WBRT) or stereotactic radiosurgery (SRS), has been the mainstay of treatment for brain metastases. The first and second generation tyrosine kinase inhibitors (TKIs) have proven to have efficacy in the treatment of EGFR-mutant brain metastasis. Osimertinib is a third-generation EGFR TKI with proven activity in the front-line setting as well as in patients with a T790M acquired resistance mutation with remarkable central nervous system (CNS) activity. After the discovery and development of these generations of EGFR-TKIs, the clinical value of cranial radiotherapy became questionable for untreated EGFR-mutant NSCLC patients with brain metastases, since EGFR-TKI alone has significantly improved potency against brain metastases in these patients. However, whether the combination of EGFR TKIs and brain RT is better than EGFR-TKIs alone remains unclear. Here, we review the literature related to the role of upfront cranial radiotherapy plus EGFR-TKIs compared with EGFR-TKIs alone for the treatment of brain metastases in EGFR-mutant advanced NSCLC patients.