Objective To analyze the MRI imaging characteristics of brain metastases in non-small cell lung cancer(NSCLC)with different epidermal growth factor receptor(EGFR)mutation types and programmed cell death-ligand 1(PD-L1)expression,and to provide imaging diagnostic support for patients who can't undergo genetic and immunohistochemical testing.Methods A retrospec-tive selection was performed in 88 patients diagnosed with brain metastases of NSCLC,all patients were divided into EGFR mutation group and wild group according to the results of genetic testing,and patients with EGFR mutation group were divided into EGFR mutation with PD-L1 expression positive group and EGFR mutation with PD-L1 expression negative group according to whether the expression of PD-L1 was≥1％.The clinical data and MR image characteristics of brain metastases were compared in EGFR mutation group and wild group,as well as in EGFR mutation with PD-L1 expression positive group and EGFR mutation with PD-L1 expres-sion negative group.Results There were statistically significant differences in smoking history and intracranial symptoms between EGFR mutation group and wild group(P＜0.05).The edema diameter,edema index and enhancement ratio of EGFR mutation group and wild group were(0.67±1.10)cm,0.39±0.54,0.32±0.17 and(1.57±2.04)cm,1.05±1.21,0.53±0.27,respectively,and the differences were statistically significant(P＜0.05).There were 43 cases and 23 cases in EGFR mutation group and wild group with ≥2 metastases,respectively,and the difference was statistically significant(P＜0.05).Compared with＞60 years old,there were 15 patients(75％)of EGFR mutation with PD-L1 expres-sion positive in≤60 years old(P＜0.05).Conclusion Compared with EGFR wild patients,patients with EGFR mutation have more brain metastases(≥2),milder enhancement,less peritumoral edema,and fewer intracranial symptoms at initial diagnosis,and patients with EGFR mutation aged≤60 years are more likely to have PD-L1 expression positive.

Objective To analyze the MRI imaging characteristics of brain metastases in non-small cell lung cancer(NSCLC)with different epidermal growth factor receptor(EGFR)mutation types and programmed cell death-ligand 1(PD-L1)expression,and to provide imaging diagnostic support for patients who can't undergo genetic and immunohistochemical testing.Methods A retrospec-tive selection was performed in 88 patients diagnosed with brain metastases of NSCLC,all patients were divided into EGFR mutation group and wild group according to the results of genetic testing,and patients with EGFR mutation group were divided into EGFR mutation with PD-L1 expression positive group and EGFR mutation with PD-L1 expression negative group according to whether the expression of PD-L1 was≥1％.The clinical data and MR image characteristics of brain metastases were compared in EGFR mutation group and wild group,as well as in EGFR mutation with PD-L1 expression positive group and EGFR mutation with PD-L1 expres-sion negative group.Results There were statistically significant differences in smoking history and intracranial symptoms between EGFR mutation group and wild group(P＜0.05).The edema diameter,edema index and enhancement ratio of EGFR mutation group and wild group were(0.67±1.10)cm,0.39±0.54,0.32±0.17 and(1.57±2.04)cm,1.05±1.21,0.53±0.27,respectively,and the differences were statistically significant(P＜0.05).There were 43 cases and 23 cases in EGFR mutation group and wild group with ≥2 metastases,respectively,and the difference was statistically significant(P＜0.05).Compared with＞60 years old,there were 15 patients(75％)of EGFR mutation with PD-L1 expres-sion positive in≤60 years old(P＜0.05).Conclusion Compared with EGFR wild patients,patients with EGFR mutation have more brain metastases(≥2),milder enhancement,less peritumoral edema,and fewer intracranial symptoms at initial diagnosis,and patients with EGFR mutation aged≤60 years are more likely to have PD-L1 expression positive.