Types of Brain Tumors Treatable by Gamma Knife Neurosurgery
An acoustic neuroma is a skull-based tumor that affects the sheath of the VIII cranial nerve. In general, this is a slow growing, benign tumor. Although it is a benign tumor, this tumor presses on the nerves associated with hearing and balance. The preservation of hearing is critical in the treatment of this disease.
Metastasis to the brain may originate from various different primary tumor locations including lung, breast, skin, kidney and colon. The most common source of brain metastases in males is lung cancer and in females is breast cancer. Metastatic tumors of the brain (otherwise referred to as “Mets”) can arise anywhere in the brain. Mets can present as a single lesion (solitary metastasis) or as more than one lesion (multiple metastasis). These presentations warrant different treatment regimens—gamma knife alone or in combination with surgery, radiation therapy or chemotherapy.
Gliomas are tumors that arise in the brain tissue itself, glial tissue (as opposed to metastatic brain tumors which arise from other body organs and travel to the brain). They are the most common type of brain tumor. There are several different types of gliomas: astrocytomas, oligodendrogliomas, ependymomas and glioblastoma multiforme.
Gliomas are identified by their microscopic appearance and are graded based on their level of malignancy. As the grade of the tumor increases, the tumor becomes more aggressive.
- Grade I: Pilocytic Astrocytoma, which is considered benign
- Grade II: Low-Grade Astrocytomas, which includes most oligodendrogliomas and ependymomas that are often mixed, hence mixed glioma. These tumors may be malignant or benign and may also be considered grade III.
- Grade III: Anaplastic Astrocytoma may be a reoccurrence of a lower grade, previously treated tumor.
- Grade IV: Glioblastoma Multiforme, which is the most malignant form of astrocytomas. Each grade of tumor can be treated with the Gamma Knife.
Meningiomas are tumors that arise from the leptomeninges or the brain lining tissue. Meningiomas are slow growing and, in general, are benign tumors. Treatment for meningiomas may include surgery, gamma knife or both.
The pituitary gland is also referred to as the “master” gland. This reference is made because the pituitary gland is responsible for regulating many functions performed by the other organs in the body. The pituitary gland will secrete hormones to these organs, which communicate to the organs. The gland is divided into two parts: the anterior pituitary and the posterior pituitary. Therefore, tumors of the pituitary gland can affect the entire body.