Furmonertinib Combined With Intrathecal Chemotherapy and Stereotactic Radiotherapy (SRT) for EGFR-Mutated NSCLC Patients With Brain Parenchymal and Leptomeningeal Metastases

Inclusion Criteria: * 18 to 75 years old, male or female; * Histopathologically confirmed, unresectable, and not amenable to curative radiotherapy treatment-naïve locally advanced or metastatic lung adenocarcinoma; * The patient was confirmed by a local laboratory to have one of the following EGFR mutations :19Del or L858R; * The patient has not received any systemic anti-tumor treatment in the locally advanced (the researcher judged that it was not suitable for surgery or radiotherapy) or metastatic NSCLC; * At least one measurable tumor lesion (according to RECIST1.1); * Confirm the simultaneous presence of brain parenchymal and meningeal metastasis; * Laboratory tests indicated that the subjects had adequate organ functions, including: 1) ANC ≥1.5×109/L; PLT ≥100×109/L; HGB ≥90g/L; 2) TBIL ≤1.5 times the upper limit of the normal value, AST and ALT ≤2.5 times the upper limit of the normal value (for those with liver metastasis, total bilirubin ≤ 3 times the upper limit of the normal value, AST and ALT≤ 5 times the upper limit of the normal value are allowed); 3) CrCL ≥50 ml/min (calculated according to the Cockcroft-Gault formula); * The ECOG score at the time of screening was 0-2, and there was no significant deterioration of the disease within 2 weeks before the screening; * The expected survival period is greater than 12 weeks; * Non-pregnant female patients of childbearing potential with no pregnancy plan. Female subjects of childbearing potential and male subjects mu…