1. What are the precursors of brain metastasis in lung cancer patients? What are the common symptoms of lung cancer brain metastasis patients? Patients with lung cancer, such as headache, vomiting, epilepsy and focal neurological deficits, often indicate the possible occurrence of brain metastasis. Therefore, patients with a history of lung cancer should go to neurosurgery department as soon as the above symptoms appear. 2. How to confirm the diagnosis of lung cancer brain metastasis? What tests are required? For patients who present with headache, vomiting, epilepsy and focal neurological deficits and who are suspected of lung cancer brain metastasis, initial screening can be performed by head CT examination, but some smaller lesions may be missed, especially those in the brainstem and cerebellum located in the posterior cranial fossa. Therefore, plain + enhanced cranial MRI is preferable, which typically shows homogeneous enhancing or ring enhancing lesions in the gray-white matter junction area of the brain, with intra-tumoral hemorrhage and necrosis and severe peritumoral edema. 3. How long can brain metastasis of lung cancer live? In the past, the prognosis of stage IV lung cancer patients including brain metastases was thought to be very poor, and the 1-year survival rate was about 10%-20%, and the prognosis of brain metastases appearing simultaneously with lung tumors was worse than those appearing at different times. However, the past experience of our department shows that whether the brain metastases can be completely removed is the most important factor affecting the survival and quality of life of patients, and the treatment of primary lung foci also plays an important role in the survival of patients. Some patients with lung cancer who underwent aggressive surgery to remove brain metastases and received follow-up treatment in our department not only had their neurological symptoms such as hemiplegia, aphasia, epilepsy, severe headache and projectile vomiting disappeared, but also their quality of life improved significantly and they fully regained their self-care ability after surgery, and some of them survived for several years.