Brain cancer belongs to malignant tumors, and malignant tumors include two aspects: First, malignant tumors belonging to the brain of origin, such as glioma, germ cell tumors of the pineal gland of the brain. Secondly, brain metastases, brain metastases include lung cancer brain metastases, breast cancer brain metastases, liver cancer brain metastases, etc. Brain metastases are multiple tumors that easily cause headache, vomiting, optic papilloedema, and even hemiplegia and other manifestations of cranial hypertension. Primary gliomas mainly cause clinical manifestations such as epilepsy and limb movement disorders. Benign tumors, such as meningioma, do not belong to the category of brain cancer. Therefore, brain cancer mainly refers to malignant tumors of brain, including two major aspects of primary brain tumors and malignant tumors that metastasize to brain.