We detected high copy numbers of epidermal growth factor receptor mutations (L858R and T790M) in the cfDNA samples from stage IV NSCLC patients who underwent stereotactic body radiation therapy to treat brain metastasis related to tyrosine kinase inhibitor (TKI) treatment failure.
<b>Conclusions:</b> NSCLC patients harboring exon 19 deletion achieved better PFS and OS than those with L858R mutation, indicating that EGFR mutation is a significant prognostic factor for advanced NSCLC patients with and without brain metastasis receiving second-line EGFR-TKIs treatment.
The posterior fossa, the anatomic "watershed areas," and the gray-white matter junction were confirmed to be more commonly affected by lung cancer brain metastases, and brain metastases with epidermal growth factor receptor (EGFR) L858R mutation occurred more often in the caudate, cerebellum, and temporal lobe than those with exon 19 deletion of EGFR.