Mark H. Bilsky, MD

Not cancerous. Benign tumors may grow larger but do not spread to other parts of the body. Also called nonmalignant.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.

A medical procedure that invades (enters) the body, usually by cutting or puncturing the skin or by inserting instruments into the body.

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

Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.

A type of slow-growing tumor that forms in the meninges (thin layers of tissue that cover and protect the brain and spinal cord). Meningiomas usually occur in adults.

Having to do with metastasis, which is the spread of cancer from the primary site (place where it started) to other places in the body.

In medicine, a term used to describe a treatment planning approach or team that includes a number of doctors and other health care professionals who are experts in different specialties (disciplines). In cancer treatment, the primary disciplines are medical oncology (treatment with drugs), surgical oncology (treatment with surgery), and radiation oncology (treatment with radiation).

A federal agency in the U.S. that conducts biomedical research in its own laboratories; supports the research of non-Federal scientists in universities, medical schools, hospitals, and research institutions throughout the country and abroad; helps in the training of research investigators; and fosters communication of medical information. Access the National Institutes of Health Web site at . Also called NIH.

Having to do with nerves or the nervous system.

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

The study of cancer.

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

Loss of ability to move all or part of the body.

Passing through the skin, as an injection or a topical medicine.

The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual’s sense of well-being and ability to carry out various activities.

Energy released in the form of particle or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, medical x-rays, and energy given off by a radioisotope (unstable form of a chemical element that releases radiation as it breaks down and becomes more stable).

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. 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, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

A doctor who specializes in creating and interpreting pictures of areas inside the body. The pictures are produced with x-rays, sound waves, or other types of energy.

Radiosurgery implies the delivery of a single, high dose of radiation using stereotactic techniques. Classically, for cranial radiosurgery, a rigid neurosurgical frame is attached to the patient’s skull, and a stereotactic localizing device is attached to the frame to allow for improved targeting accuracy. Commercial radiosurgery systems are available in which immobilization is achieved without a rigid neurosurgical frame. While there are innumerable commercial radiosurgery and stereotactic radiation therapy systems, all of these systems utilize the same underlying principles: (1) patient immobilization, (2) targeting accuracy, (3) delivery of high doses of radiation, and (4) heterogeneous dose distribution with a steep dose gradient. Commercial radiosurgery systems include Gamma Knife, which utilizes 201 radioactive cobalt sources positioned in a semispherical array, and Cyberknife, which utilizes robotics technology allowing the linear accelerator (LINAC) to track the patient position in real time during treatment. A standard LINAC can be equipped with cones attached to its head, allowing for circular collimation of the beam. The dose distribution from Gamma Knife, Cyberknife, or a standard LINAC equipped with cones is spherical, and thus treating nonspherically shaped targets requires the superposition of multiple spherical dose distributions. A LINAC equipped with multi-leaf collimators can also be used for radiosurgery, which allows more conformal beam shaping. Also called radiation surgery, stereotactic radiosurgery, and stereotaxic radiosurgery.

A column of nerve tissue that runs from the base of the skull down the back. It is surrounded by three protective membranes, and is enclosed within the vertebrae (back bones). The spinal cord and the brain make up the central nervous system, and spinal cord nerves carry most messages between the brain and the rest of the body.

The bones, muscles, tendons, and other tissues that reach from the base of the skull to the tailbone. The spine encloses the spinal cord and the fluid surrounding the spinal cord. Also called backbone, spinal column, and vertebral column.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.

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.

A legal document in which a person states what is to be done with his or her property after death, who is to carry out the terms of the will, and who is to care for any minor children.