Early Prophylactic Versus Late Salvage Recombinant Human Endostatin in Managing Radiosurgery-Induced Brain Injury for NSCLC Brain Metastases

Primary Purpose:To preliminarily evaluate the efficacy and safety of recombinant human endostatin (Endostar) in the early prophylactic cohort (Cohort A) and late salvage cohort (Cohort B) for radiation-induced brain injury after stereotactic radiosurgery (SRS) in patients with non-small cell lung cancer (NSCLC) brain metastases, with a focus on the improvement rate of peritumoral brain edema.Secondary Purpose:To explore the effects of Endostar treatment on neurological function, quality of life, and survival outcomes in patients with NSCLC brain metastases following SRS; and to evaluate the convenience and compliance of the "72-hour continuous intravenous pump infusion" regimen.

Inclusion Criteria 1. Karnofsky performance status (KPS) score ≥60. 2. Histologically or cytologically confirmed non-small cell lung cancer (NSCLC). 3. Baseline contrast-enhanced brain MRI confirms 1-15 brain metastases, with a total volume of all lesions \2), where EI = (tumor volume + edema volume) / tumor volume. Cohort B: Radiographic (MRI) evidence of radiation-induced brain edema/necrosis after SRS (usually ≥3 months after SRS). 5. Prior or concurrent radiotherapy for extracranial lesions is allowed. Prior TKI, chemotherapy, or immunotherapy is allowed. After enrollment, systemic therapy may be continued or adjusted according to clinical need. 6. Within 14 days before study treatment, bone marrow and major organ function must meet the following criteria: ANC ≥1.5×10\^9/L; platelets ≥100×10\^9/L; hemoglobin ≥90 g/L; total bilirubin ≤1.5×ULN; AST and ALT ≤1.5×ULN; serum creatinine ≤1.5×ULN or CrCl ≥45 mL/min; INR ≤1.5; APTT ≤1.5×ULN; urine protein \100 mmHg). 4. History of major bleeding (e.g., hemoptysis, gastrointestinal bleeding) or current active bleeding, bleeding tendency, or coagulation disorder. 5. History of arterial thromboembolic events (e.g., MI, unstable angina, CVA, or TIA) within 6 months before the first dose. 6. Symptomatic CHF (NYHA Class ≥ II) or severe arrhythmia requiring treatment. 7. Severe hepatic/renal insufficiency: total bilirubin \>1.5×ULN; or ALT/AST \>2.5×ULN; or serum creatinine \>1.5×ULN and CrCl \