Acquired Immune Deficiency Syndrome (AIDS), a collection of symptoms caused by infection with the human immunodeficiency virus (HIV). HIV can be transmitted from person to person by coming into direct contact with certain body fluids from an infected person, such as blood (from a needle or syringe) or semen, rectal fluids, vaginal fluids, and from mother-to-child through breast milk.

acute lymphoblastic leukemia (ALL), (also called acute lymphocytic leukemia), a type of cancer of the blood and bone marrow — the spongy tissue inside bones where blood cells are made. It is the most common type of cancer in children, and treatments result in a good chance for a cure.

acute myelogenous leukemia (AML), (also called acute myeloid leukemia, acute non-lymphocytic leukemia), cancer of the blood and bone marrow — the spongy tissue inside bones where blood cells are made. It affects a group of white blood cells (called myeloid cells) which normally develop into mature blood cells such as red blood cells, white blood cells and platelets. The disease has rapid progression.

allogeneic stem cell transplant, using healthy blood stem cells from a donor to replace bone marrow that’s not producing enough healthy blood cells. A donor may be a family member, often a sibling, an acquaintance or someone you don’t know with a matching marrow type.

autologous stem cell transplant, using healthy blood stem cells from one’s own body to replace bone marrow that’s not working properly; healthy stem cells are extracted and cryopreserved (frozen) until ready for the transplant. Using cells from one’s own body has the advantage of not having to worry about incompatibility between a donor’s cells and the recipient’s cells.

anaplasia, loss of structural and functional differentiation of normal cells

astrocytoma, a brain tumor that arises from star-shaped cells called astrocytes. Low-grade astrocytomas grow slowly, and many types have a favorable prognosis. High-grade astrocytomas grow quickly and are more difficult to treat.

benign, noncancerous

brachytherapy, a procedure used to treat certain types of cancer and other conditions that involves placing radioactive material inside or next to the area requiring treatment; sometimes called internal radiation

brain stem glioma, slow or fast-growing brain tumor that starts in the brain stem, which connects the brain to the spinal cord

CAR (chimeric antigen receptor) T-cell therapy, type of immunotherapy used to treat some blood cancers by infusing new T-cells into the patient’s blood that have a new gene receptor (chimeric antigen receptor) equipped to attack cancer cells and kill them. This therapy is being studied for treatment of other types of cancer.

consolidation/intensification phase of chemotherapy, second phase of chemotherapy after remission is achieved to destroy any remaining cancer cells

cryotherapy, sometimes called cryosurgery, used to treat small primary tumors or new tumors that develop by applying extreme cold by a small probe placed directly on the tumor

dry eyes, a condition caused by decreased tear production and causes dry eyes and blurred vision

enucleation, removal of the eye

ependymoma, a tumor that usually grow on the internal surfaces of the brain and spinal cord.

Ewing sarcoma, a group of bone or soft tissue cancers that mostly affect children, teenagers and young adults, often developing during puberty when bones grow rapidly; typically appear in legs, arms and pelvis

granulocytes, a type of white blood cell

graft-versus-host disease (GVHD), a frequent complication of allogeneic stem cell transplants when the bone marrow provided by the donor (the graft) attacks the tissues and organs of the recipient host. GVHD does not occur when stem cells come from host’s own body (autologous) or from an identical twin (syngeneic).

hematopoietic stem cell transplantation also known as stem cell transplant, (formerly called bone marrow transplant) a procedure that involves administering healthy stem cells (e.g., bone marrow, cord blood, or peripheral blood) to patients after the bone marrow has been destroyed by disease, chemotherapy (chemo), or radiation

histiocytosis, a disease in which histiocytes (cells in bone marrow) multiply and accumulate in various organs or bones in the body; diagnosis is by examination of a sample of affected tissue under an electron microscope

histology, how cells look under a microscope

Hodgkin lymphoma (formerly called Hodgkin’s disease), a type of cancer that affects the lymphatic system which is part of the body’s germ-fighting immune system. White blood cells called lymphocytes grow out of control, causing swollen lymph nodes and growths throughout the body. Advances in diagnosis and treatment have helped give people with this disease the chance for a full recovery.

induction, the most intense phase of chemotherapy with a goal of killing as many leukemia cells in the shortest amount of time

Involved Field Radiation Therapy (IFRT), radiation technique that delivers radiation to only those areas of the body involved with disease and is more precise and limits exposure to healthy tissue

maintenance phase of chemotherapy, the last phase of chemotherapy that consists of daily low-dose chemotherapy that continues for 2 to 3 years

malignant, cancerous cells that grow uncontrollably and spread locally and/or to distant sites in the body

neuroblastoma, a cancer that develops from immature nerve cells found in several areas of the body; most commonly in and around the adrenal glands but can also develop in other areas of the abdomen and in the chest, neck and near the spine. Infant form of neuroblastoma may go away on their own, while others may require multiple treatments.

non-Hodgkin lymphoma (NHL), a type of cancer that begins in the lymphatic system which is the body’s germ/disease-fighting system; white blood cells called lymphocytes grow abnormally and can form tumors throughout the body; the lymphatic system includes the spleen, thymus, lymph nodes, and tonsils and adenoids.

Intensity-modulated radiation therapy, also called IMRT, is an advanced type of radiation therapy that uses powerful energy beams to kill cancer cells. The beams of radiation are carefully customized and shaped to match the shape of the cancer and can deliver a precisely controlled radiation dose as safely and efficiently as possible. The goal of IMRT is to deliver the correct dose of radiation to the target and minimize radiation outside of the target. This helps lower the risk of hurting nearby healthy tissue.

Intraocular Retinoblastoma Staging System, asub-classification system that divides intraocular retinoblastomas into 5 sub-goups based on tumor size, location, and presence of disease within the layers of the retina; stages from 0 to IV, Stage 0 having a good outcome with treatment, and Stage IV a poor prognosis of likelihood of the eye being saved using current treatment options

mantle radiation, a radiation technique used in 1970s to the 1990s to treat a large area of the neck, chest, armpits and mediastinum (area between the lungs) in order to cover all areas with cancer involvement; rarely used today in current treatment

medulloblastoma, a brain tumor that is fast-growing, malignant and located in the cerebellum/posterior fossa (back of the brain); diagnosed most often in children ages 4 to 8 and more common in boys

nephrectomy, surgical removal of a kidney

optic nerve gliomas, tumors located along the optic nerves and the optic chiasm and connect the nerve to the eye. Sometimes the glioma may enter into the hypothalamus.

osteosarcoma, (also called osteogenic sarcoma) is the most common type of cancer that starts in the bones. The cancer cells in these tumors look like early forms of bone cells that normally help make new bone tissue, but the bone tissue is not as strong as that in normal bones. Most osteosarcomas occur in children, teens, and young adults.

proton therapy, or proton beam therapy, a type of radiation treatment that uses a beam of protons to deliver radiation directly to the tumor. A proton beam conforms to the shape and depth of a tumor while sparing healthy tissues and organs. The advantage of proton therapy is that the physician can control where the proton releases the bulk of its cancer-fighting energy and deliver the most damage to the targeted tumor cells and less damage to surrounding organs and tissue in the rest of the body.

retinoblastoma, a malignant tumor of the retina in the eye that occurs in stages from 0-IV, with Stage 0 having a good outcome with treatment, and Stage IV retinoblastoma with metastases a poor prognosis

rhabdomyoblasts, primitive muscle cells

rhabdomyosarcoma (RMS), the most common childhood soft tissue sarcoma made up primitive muscle cells called rhabdomyoblasts; most commonly found in the head and neck, genitourinary tract, extremities, chest and lungs

second cancer, cancer that occurs after treatment (e.g. radiation and/or chemotherapy) for a first (primary) cancer and is a new and different type of cancer, which usually arises in a different organ or tissue from the first (primary) cancer

subsequent malignancy (also referred to as, second cancer), cancer that occurs after treatment (e.g. radiation and/or chemotherapy) for a first (primary) cancer and is a new and different type of cancer, which usually arises in a different organ or tissue from the first (primary) cancer

stem cell transplantation, also known as hematopoietic stem cell transplant, procedure that involves administering healthy stem cells (e.g., bone marrow, cord blood, or peripheral blood) to patients after the bone marrow has been destroyed by disease, chemotherapy (chemo), or radiation

stereotactic radiation therapy, type of radiation therapy using 3D or 4D imaging and highly focused radiation beams that send high doses of radiation to the area to be treated resulting in the least amount of damage to the healthy tissues around the area; used to treat tumors in the lungs, spine, liver, neck, lymph nodes or other soft tissues

syngeneic bone marrow transplants (BMTS), bone marrow transplant in which the donor of the bone marrow is the patient’s identical twin

total body irradiation (TBI), a type of radiation therapy that delivers radiation to the entire body; commonly used for the treatment of certain blood cancers before a bone marrow transplant

stages of cancer, the extent to which a cancer has progressed or grown; stage I through IV with stage I being the earliest stage of the cancer, and stage IV being the highest/worst stage

Wilms tumor, a primary cancer of the kidney that accounts for 5 to 6 percent of all childhood cancers in the United States most commonly in children younger than age 5. Approximately 500 children are diagnosed each year.