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 commom 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.