Intracranial Tumors January 6, 1997

Intracranial Tumors January 6, 1997

Also known as brain tumors, secondary ones are mostly metastases from systemic malignancies. Among males, lung cancer is most common, while among females, breast cancer takes the lead. Primary intracranial tumors are predominantly gliomas, accounting for about half of all cases; these are malignant, whereas meningiomas, pituitary adenomas, ventricular tumors, nasopharyngeal tumors, and vascular tumors are generally benign. Gliomas are the most frequent type of brain tumor, more common in males than females, and tend to occur in children and young to middle-aged adults. Among them, astrocytomas account for 40%, oligodendrogliomas and ependymal gliomas each make up 10%; these gliomas are relatively low-grade and grow slowly. Medulloblastomas and glioblastomas together constitute 30%, characterized by high malignancy and rapid growth. Both medulloblastomas and glioblastomas are sensitive to radiotherapy, typically requiring irradiation at doses of 5,000–7,000 cGy; however, since radiotherapy often damages brain tissue, the condition may even worsen during treatment, with noticeable improvement only after more than 20 sessions. Therefore, surgical intervention should be considered first upon hospitalization, with preoperative chemotherapy possible, preferably using lomustine, and methotrexate can be administered via intrathecal injection once or twice a week.