The spinal cord and the brain together form the central nervous system (CNS). A CNS tumor develops when healthy cells in the brain or spinal cord start growing uncontrollably forming a mass. CNS tumors may be malignant or benign. Malignant tumors grow rapidly and can spread to other parts of the body whereas benign tumors grow slowly and do not spread to other parts of the body. Astrocytoma, diffuse intrinsic pontine glioma (DIPG or the brain stem glioma), ependymoma, germ cell tumor, medulloblastoma, primitive neuroectodermal tumor (PNET), and optic pathway glioma are a few types of CNS tumors. Diagnosis of CNS cancer is done using tests and procedures including neurological examination, imaging tests such as CT scan and MRI, and biopsy. Treatment options include radiation therapy, radiosurgery, chemotherapy, and targeted drug therapy. The results of various researches and advanced studies related to CNS tumors have been included in this book. It includes some of the vital pieces of work being conducted across the globe, on various topics related to CNS oncology. This book will help the readers in keeping pace with the rapid changes in this field.