The diagnosis of intracranial or spinal neoplasms is usually done by a neurologist.Treatment is generally rendered by neurosurgeon,radiation oncologist and/or medical oncologist,depending on the location and nature of the tumor.
Interventional neuroradiologists are also starting to try novel treatments in brain cancers. I know my husband has witnessed INRs directly injecting chemo into veins around brain tumors. Studies to date don't show this to be more effective than other methods, but apparently it is becoming a new area of interest within this specialty.
Schwannomas (acoustic, facial, and olfactory) are often excised by otolaryngologists, especially those trained in neurotology and skull base surgery. Also, some tumors along the floor of the cranial fossa wil be excised by neurosurgeons but the approach will be the job of the otolaryngologist.