Glossary of Terms

Glossary of Terms

Ablation – Destroying tissue with heat or cold or by other methods such as surgery, hormones, drugs and radiofrequency.

Anaplastic astrocytoma – A rare cancerous brain tumor that forms in the supportive tissue of the brain.

Anesthesia – Treatment that prevents patients from feeling pain during surgery or other procedures. Local anesthesia affects one small area of the body. Regional anesthesia affects a larger part of the body, such as an arm or leg. General anesthesia creates a complete loss of awareness similar to a very deep sleep.

Benign – Not cancerous. A benign tumor may grow larger, but does not spread to other parts of the body. Also called nonmalignant.

Biopsy – The removal of tissue so it can be examined to determine if a disease such as cancer is present.

Brain stem – The part of the brain that is connected to the spinal cord. It relays signals between the two and controls the life-supporting functions of the nervous system that sends, receives, and interprets information from all parts of the body.

Cerebellum – The portion of the brain in the back of the head between the cerebrum and the brain stem. Controls balance for walking, standing, and other complex motor functions.

Cerebrum – The largest part of the brain. It is divided into two hemispheres, or halves, called the cerebral hemispheres. Controls muscle functions and speech, thought, emotions, reading, writing, and learning.

Chemotherapy – A treatment using powerful drugs to kill cancer cells.

Clinical trials – Studies of new medicines, equipment, or procedures that involve human volunteers. These trials help determine whether such treatment are safe and effective.

Congenital brain defect – An abnormality present at birth.

Cryotherapy – Destroying abnormal tissue by freezing it with substances such as liquid nitrogen, liquid nitrous oxide, or compressed argon gas. It may be used to treat certain types of cancer and some conditions that may become cancer. Also called cryoablation and cryosurgery.

Encephalitis – Acute inflammation of the brain due to infection. Usually caused by a virus such as measles or mumps. It can also be an effect of cancer, or be caused by autoimmune disease, bacteria, parasites, or an allergic reaction to vaccinations.

Epilepsy – A group of disorders marked by problems in the normal functioning of the brain. These problems can produce seizures, unusual body movements, loss of consciousness, or changes in consciousness, as well as mental problems or problems with the senses.

Epileptic lesions – Damaged areas of the brain that can trigger abnormal nerve impulses and cause symptoms common to epilepsy.

Genetic defect – An illness or disease caused by abnormal genes. If it is present at birth, it is called congenital.

Glioblastoma – Fast-growing type of central nervous system tumor that forms from glial (supportive) tissue of the brain and spinal cord. Usually occurs in adults and affects the brain more often than the spinal cord. Also called GBM, glioblastoma multiforme, and grade IV astrocytoma.

Glioma – A cancer of the brain that begins in the glial cells that surround and support nerve cells.

Hemorrhage – Loss of blood from deep inside the body or at the surface. Usually involves a large amount of bleeding in a short time.

Hyperthermia – Abnormally high body temperature that may be caused as part of treatment, by an infection, or by exposure to heat. Also used to describe a treatment in which body tissue is exposed to high temperatures to damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain cancer drugs.

Idiopathic – A disease of unknown cause.

Laser – A device that forms light into intense, narrow beams that may be used to cut or destroy tissues such as cancers.

Lesion – An area of abnormal tissue. A lesion may be benign (not cancer) or malignant (cancer).

Lobes of the brain – The four main parts of the brain. The frontal lobe at the front of the brain controls reasoning, motor skills, high level thought and expressive language. The temporal lobe at the bottom of the brain controls sounds, words and memories. The parietal lobe at the middle of the brain controls senses such as touch and pain. The occipital lobe at the back of the brain controls vision.

Magnetic resonance imaging (MRI) – A procedure that uses radio waves and a powerful magnet linked to a computer to create detailed pictures of the inside the body. MRI makes better images of organs and soft tissue than other scanning techniques. It is especially useful for imaging the brain, the spine, the soft tissue of joints, and the insides of bones.

Malignant – Cancerous. Malignant cells can invade and destroy nearby tissue and spread to other parts of the body.

Meninges – Three thin layers of tissue that cover and protect the brain and spinal cord.

Meningitis – Inflammation of the meninges usually caused by a bacterial or viral infection, but sometimes caused by cancer, drug allergies, or inflammatory diseases.

Metastasis – The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a metastatic tumor or a metastasis.

Metastatic tumor – Tumor that contains cancer cells that have spread from a tumor in another part of the body.

Minimally invasive surgery – Surgery performed with small instruments through a small opening in the body instead of a large incision. Minimally invasive surgery may cause less pain and scarring and less damage to healthy tissue. Patients usually recover faster than from traditional surgery.

Neuro-oncologist – A doctor who specializes in diagnosing and treating brain tumors and other tumors of the nervous system.

Neuro-radiologist – A doctor who specializes in diagnosing and treating diseases of the nervous system using radiation.

Neurosurgeon – A doctor who specializes in surgery on the brain, spine, and other parts of the nervous system.

Nonmalignant – Not cancerous. A nonmalignant tumor may grow larger, but does not spread to other parts of the body. Also called benign.

Palliative care – Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal is to prevent or treat disease symptoms, side effects caused by treatment, and psychological, social, and spiritual problems related to a disease or its treatment. Also called comfort care, supportive care, and symptom management.

Primary tumor – An original tumor in the body. Cancer cells from a primary tumor may spread to other parts of the body and form new, or secondary, tumors. This is called metastasis. These new tumors are the same type of cancer as the primary tumor.

Radiation oncologist – A doctor who specializes in using radiation to treat cancer.

Radiation therapy – The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors (also called irradiation and radiotherapy). Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance that travels in the blood to tissues throughout the body.

Stereotactic radiosurgery (SRS) – A type of radiation therapy that uses special equipment to position the patient and precisely give a single large dose of radiation to a tumor. It is used to treat brain tumors and other brain disorders that cannot be treated by regular surgery. Also called radiation surgery and radiosurgery.

Tumor – An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.

For more medical terms, visit the National Cancer Institute’s Dictionary of Cancer Terms.

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