Immune Checkpoint Inhibitors in the Management of Brain Metastases from Non-Small Cell Lung Cancer: A Comprehensive Review of Current Trials, Guidelines and Future Directions

Background: Brain metastases (BM) are a common, severe complication in patients with non-small cell lung cancer (NSCLC) and are difficult to treat due to their complex tumor biology and the intricate microenvironment of the brain. Objectives: This review examines the current role of immune checkpoint inhibitors (ICIs) in treating NSCLC with BM, focusing on the latest clinical trials, emerging strategies, current guidelines, and future directions. We highlight the efficacy of ICIs as monotherapy and in combination with other treatments such as radiotherapy, stereotactic radiosurgery, chemotherapy, and anti-VEGF agents. Results: While no single treatment sequence is universally accepted, combining ICIs with traditional therapies forms the core of the current treatment protocols. ICIs targeting the PD-1/PD-L1 pathway have significantly advanced NSCLC treatment, demonstrated by improved overall and progression-free survival in various settings. However, optimizing these benefits requires careful consideration of potential side effects, including cognitive decline and radiation necrosis, and the impact of steroid use on ICI efficacy. Conclusion: The review underscores the necessity for a personalized, integrated multidisciplinary treatment approach. Future research should focus on refining combination therapies and understanding the optimal sequence and timing of treatment.