If lung cancer metastasizes to the brain, it is the last stage, or stage IV, which is the most advanced stage. At this time, symptoms of intracranial hypertension, including headache, dizziness, and jet nausea and vomiting, will usually appear. At this time, if no treatment is done, it is usually one to three months at most. If treatment is done, generally chemotherapy for cranial metastases is not effective, only radiotherapy can be done, and if radiotherapy is done, this treatment will be extended for a few months (if the effect is good). But if the metastasis is extensive and dense, like the stars, the effect of radiotherapy will not be very good.