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acoustic neuroma: a benign, slow growing tumor that forms on the sheath of the eighth cranial nerve. This tumor can cause hearing loss, balance problems, and facial palsy.

adjuvant treatment: a treatment given in addition to another to make each work more effectively.

angiogram: a type of X-ray that takes pictures of blood vessels with the help of contrast dye injected via a catheter into the blood stream.

anterior: from the front.

arteriovenous malformation (AVM): a congenital disorder in which there is an abnormal connection between arteries and veins without an intervening capillary bed.

astrocytoma: a tumor arising in the supportive cells (astrocytes) of the brain; most common primary CNS tumor, representing about half of all primary brain and spinal cord tumors.

benign: not cancerous.

bilateral: occurring on both sides of the body.

brainstem: the bottom-most portion of the brain connecting the cerebrum with the spinal cord; midbrain, pons, medulla oblongata and reticular formation are all part of the brainstem.

bone scan: a nuclear medicine test that detects areas of increased or decreased bone metabolism. A radioactive material is injected into the bloodstream where it collects in the bones of the body and is detected by a gamma camera. The test is commonly used to diagnose tumors, infections, or fractures of the bone.

cancer: generic term for more than 100 different diseases caused by uncontrolled, abnormal growth of cells. Cancer cells can invade and destroy normal tissue, and can travel through the bloodstream and lymphatic system to reach other parts of the body.

cavernoma: abnormal cluster of enlarged capillaries with no significant feeding arteries or veins.

cavernous sinus: A large channel of venous blood creating a "sinus" cavity bordered by the sphenoid bone and the temporal bone of the skull. The cavernous sinus is an important structure because of its location and its contents which include the third and fourth cranial nerves, parts 1 and 2 of the fifth cranial nerve, and the sixth cranial nerve.

chemotherapy: treatment with toxic chemicals (e.g., anticancer drugs).

chronic: a condition of slow progression and continuing over a long period of time, opposite of acute.

chondroma: a rare, slow growing, benign tumor arising at the base of the skull, especially in the area near the pituitary gland.

chondrosarcoma: a rare tumor arising from bone and composed of cartilage. It is a locally invasive malignant tumor.

chordoma: a rare, benign, slow growing tumor that occurs at the base of the skull in about 1/3 of patients or at the end of the spine.

computed tomography (CT) scan: a type of diagnostic X-ray that views anatomical structures of the brain and spine, especially bones, soft tissues and vessels. Images are viewed in "slices".

congenital: existing before or at birth.

contrast agent: a liquid that is injected into the body to make certain tissues more visible during diagnostic imaging (angiography, CT, myelogram, MRI).

corticosteroid: a hormone produced by the adrenal gland or synthetically. Regulates salt and water balance and has an anti-inflammatory effect.

craniopharyngioma: a benign tumor arising from small nests of cells located near the pituitary stalk.

craniotomy: a circular opening made in the skull to expose the brain.

cyst: a fluid-filled mass, usually enclosed by a membrane.

edema: tissue swelling caused by the accumulation of fluid.

ependymoma: a benign tumor arising from the ependymal cells inside the ventricles.

familial: tending to occur repeatedly in family members, but is not genetic (inherited). Might indicate a susceptibility, or a common environmental influence.

focal: limited to one specific area.

fluoroscopy: an imaging device that uses x-ray or other radiation to view structures in the body in real time, or "live".

fractionated: delivering the radiation dose over multiple sessions.

fractionated stereotactic radiotherapy (FSRT): a moderately high dose radiation treatment received over more than 1 single session or fraction.

glioblastoma multiforme (GBM): a malignant, fast growing, tumor of the astrocytes which commonly invades adjacent tissue and spreads like fingers throughout the brain.

glioma: any tumor arising from glial or astrocytic tissue of the brain, which provides energy, nutrients and other support for nerve cells in the brain.

glomus jugulare: a very rare, slow growing, benign tumor that invades the temporal bone.

glossopharyngeal neuralgia: A painful disorder of the ninth cranial nerve (glossopharyngeal nerve). Irritation of this nerve causes intense pain on one side of the throat near the tonsil area that can radiate to the ear.

hematoma: a blood clot.

hemifacial spasm: an irritation of the seventh cranial nerve (facial nerve) causing involuntary contraction of the muscles on one side of the face, also known as tic convulsif. Can sometimes cause pain behind the ear and loss of hearing.

hemorrhage: external or internal loss of blood from damaged blood vessels. Hemorrhage is stopped by blood clotting.

hydrocephalus: an abnormal build-up of cerebrospinal fluid usually caused by a blockage of the ventricular system of the brain. Increased intracranial pressure can compress and damage brain tissue. Also called "water on the brain."

hyperfractionation: an increased number of smaller dosage treatments of radiation therapy.

hypofraction: delivering the radiation dosage in more than 1 session but in than less than what is generally considered "standard" fractionation.

immunotherapy: treatment designed to improve or restore the immune system's ability to fight infection and disease.

infarct: an area of dead tissue caused by a blockage of its blood supply.

intensity modulated radiation therapy (IMRT): the intensity of the radiation beam can be changed during treatment to spare adjoining normal tissue and increase the dose to the tumor.

iodine: a non metallic element used in contrast agent that makes vessels and tissues show up on diagnostic imaging (angiogram, CT, myelogram).

intracerebral: located within the cerebral hemispheres.

intracerebral hemorrhage (ICH): bleeding directly into the brain tissue; may cause a stroke.

intracranial: within the skull.

intraventricular: within the ventricles or cavities in the brain, which are filled with cerebrospinal fluid and linked by ducts so the fluid can circulate.

invasive: refers to a tumor that invades healthy tissues; also called diffuse or infiltrating.

irradiation: radiation therapy; treatment by ionizing radiation.

karnofsky score: a performance scale for rating a person's usual activities; used to evaluate a patient's progress before or after a therapeutic procedure.

lesion: a general term that refers to any change in tissue, such as tumor, blood vessel malformation, infection or scar tissue.

linear accelerator (LINAC): a machine that creates a high-energy radiation beam, using electricity to form a stream of high energy x-rays and/or electrons.

lipoma: a rare, benign tumor composed of fat tissue, commonly located in the corpus callosum or cauda equina-filum terminale

local: in the area of the tumor; confined to one specific area.

magnetic resonance imaging (MRI): a diagnostic test that uses a strong magnet to view tissues in your body and displays them in a series of "slices."

malignant: cancerous.

mass effect: damage to the brain due to the bulk size of a tumor, and/or excess accumulation of fluid within the brain or skull.

medulloblastoma: a fast-growing, invasive tumor usually located in the cerebellum that frequently spreads to other parts of the central nervous system via the spinal fluid.

medical physicist: a member of the multi-disciplinary team who helps in the commissioning of new equipment and planning of radiotherapy treatments.

meninges: the three membranes (pia mater, arachnoid mater, and dura mater) that surround the brain and spinal cord.

meningioma: a tumor that grows from the meninges, the membrane that surrounds the brain and spinal cord.

metastasis: in cancer patients, the spreading of malignant cells.

metastatic: cancerous tumor that has spread from its original source through the blood or lymph systems.

myelogram: a diagnostic test in which a special dye is injected into the space around the spinal cord causing the spinal cord and nerves to show up on an X-ray.

necrosis: dead cells.

neoplasm: a tumor, either benign or malignant.

neuralgia: severe nerve pain caused by nerve compression or the breakdown of the protective myelin sheath surrounding a nerve. This disrupts the normal signal of the nerve and causes pain which begins as "pins and needles" followed by an electrical shock sensation.

neurosurgeon: a doctor who operates on the brain and spinal cord.

oligodendroglioma: a tumor arising from the support cells (oligodendroglia) of the brain - a form of glioma

optic chiasm: the anatomical point behind the eyes in front of the pituitary gland where the left and right branches of the optic nerves join to form a cross-shaped structure Within the optic chiasm, some of the nerve fibers cross.

palliative: treatment focused on maintaining the best quality of remaining life; not curative.

positron emission tomography (PET): a diagnostic test using nuclear medicine in which tissue function can be imaged. Damaged tissues have reduced metabolic activity; therefore, gamma radiation from these areas is reduced or absent.

posterior: from the back.

posterolateral: behind and to one side.

primitive neuroectodermal tumor (PNET): a tumor which appears identical under the microscope to the medulloblastoma, but occurs primarily in the cerebrum and most frequently occurs in very young children.

radiation: high-energy rays or particle streams used to treat disease.

radiation oncologist: a doctor who specializes in prescribing radiation in the treatment of cancer and other diseases.

radiation therapist: a specially trained individual that delivers the radiotherapy daily.

radiologist: a doctor who specializes in reading X-rays and other diagnostic scans.

radiology department: rooms designated for examining and imaging the body by use of x-rays or magnetic fields.

radiotherapy: a course of radiation commonly given over multiple sessions, but may be given in a single fraction.

radioresistant: resistant to radiation therapy.

radiosensitive: responsive to radiation therapy.

recurrence: the return of symptoms or the tumor itself.

resection: surgical removal

residual tumor: tumor remaining after surgery.

Stereotactic radiosurgery (SRS): a high dose of radiation given in one treatment; uses a precisely aimed, highly focused radiation beams and stereotactic localization to target a specific area.

stereotaxis: a precise method for locating deep brain structures by the use of 3-dimensional coordinate system.

steroid: A large group of chemical substances related in structure to one another and each containing the same chemical backbone. Many hormones, body constituents, and drugs are steroids. Examples: drugs used to relieve swelling and inflammation such as prednisone, dexamethasone, vitamin D, and the sex steroids such as testosterone.

target: area where radiation beams are aimed; usually a tumor, malformation, or other abnormality of the body.

trigeminal neuralgia: a painful disorder of the fifth cranial nerve (trigeminal nerve). Resulting in intense and very episodic pain that affects one side of the face usually in the forehead, cheek, jaw, or teeth.

tumour: an abnormal growth of tissue resulting from uncontrolled multiplication of cells and serving no physiological function. A tumour can be benign or malignant.

ultrasound: sound waves of extremely high frequency which reflect off body structures to create a picture. Can also be used as a form of medical treatment to break up kidney stones.

x-ray: a small amount of electromagnetic radiation used in diagnostic imaging to view shadows of tissue density in the body, also called roentgenogram.


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