CSF CTC-Capture-Guided EGFR-TKI and Bevacizumab Combination Therapy in EGFR-Mutant Advanced NSCLC

clinical trial The goal of this clinical trial is to learn whether the treatment of advanced non-small cell lung cancer with EGFR-TKIs, when combined with bevacizumab in the presence of positive circulating tumor cells in the cerebrospinal fluid, has better therapeutic efficacy. The main questions it aims to answer are:1.When EGFR-TKIs are sequentially combined with bevacizumab along with EGFR-TKIs for first-line treatment of advanced non-small cell lung cancer, how long can the participants survive? 2.What medical problems do participants have when using EGFR-TKIs sequentially combined with bevacizumab in conjunction with EGFR-TKIs. Participants will: Receive EGFR-TKIs treatment for a duration of 3 months, and upon a positive cerebrospinal fluid tumor cell status, subsequently receive bevacizumab combined with EGFR-TKIs treatment until disease progression. Visit the clinic for check-ups and tests every two weeks, and have follow-up visits every six weeks after the treatment ends. Keep a record of their symptoms and disease progression.