Brain tumors growing in the parenchyma of the brain infiltrate diffusely, and the role of surgery is restricted to maximal tumor-bulk removal. Residual tumor cells beyond the surgical margin are not killed by conventional radiation therapy with 60 'Gy. Many clinical trials delivering chemotherapy during radiation therapy and after radiation therapy have been performed, but the results remain poor. Here the author reviews the current treatments of gliomas, malignant lymphomas, medulloblastomas, and germ cell tumors, and their results.