General Information about Superior Vena Cava Syndrome
Causes of Superior Vena Cava Syndrome
Diagnosis of Superior Vena Cava Syndrome
Managing Superior Vena Cava Syndrome
Social Considerations of Superior Vena Cava Syndrome
Superior Vena Cava Syndrome in Children

General Information about Superior Vena Cava Syndrome

Superior vena cava syndrome (SVCS) is a group of symptoms that occur when the superior vena cava becomes partially blocked.

The right atrium (chamber) of the heart receives blood from two major veins: the superior (upper) vena cava and the inferior (lower) vena cava.

• The superior vena cava returns blood from the upper body to the heart.
• The inferior vena cava returns the blood from the lower body to the heart.

The superior vena cava is thin-walled, and the blood is under low pressure. If a tumor forms in the chest or nearby lymph nodes become swollen (as from lymphoma), the superior vena cava can be squeezed. Blood flow slows. Complete blockage of the vein can occur. Sometimes, the other veins can become larger and take over for the superior vena cava if it is blocked, but this takes time. Superior vena cava syndrome (SVCS) is the group of symptoms that occur when this vein is partially blocked.

The location of the blocked area and how fast the blockage occurs affect the symptoms.

The symptoms will be more severe if the vein becomes blocked quickly. This is because the other veins do not have time to widen and take over the increased blood flow from the superior vena cava.

The location of the blocked area also affects how severe the symptoms will be:

• If the blockage is above where the superior and inferior vena cava veins join, other veins can become larger over time and take over the increased blood flow. The symptoms may be milder.
• If the blockage occurs below where the superior vena cava and inferior vena cava meet, the blood must be returned to the heart by the veins in the upper abdomen and the inferior vena cava, which require higher pressure. Symptoms may be more severe.

Common symptoms of SVCS include breathing problems and coughing.

The most common symptoms are these:

• Problems breathing.
• Coughing.
• Swollen face, neck, upper body, and arms.

Less common symptoms include the following:

• Hoarse voice.
• Chest pain.
• Problems swallowing and/or talking.
• Coughing up blood.
• Swollen veins in the chest or neck.
• Bluish color to the skin.
• Drooping eyelid.

Superior vena cava syndrome (SVCS) is usually caused by cancer. In adults, SVCS most commonly occurs with lung cancer or non-Hodgkin lymphoma. A tumor in the chest or swollen lymph nodes can press on the superior vena cava, blocking the blood flow. There are other less common causes for the superior vena cava to become blocked:

• A blood clot that forms as a side effect from the use of intravenous catheters (a flexible tube used to put fluids into or take blood out of a vein). A clot may also form as a side effect of pacemaker wires.
• Infection in the chest that causes affected tissues to become thick and hard.
• Other cancers, including metastatic breast cancer, metastatic germ cell tumors, colon cancer, esophageal cancer, Kaposi sarcoma, fibrous mesothelioma (cancer of the epithelium), and Hodgkin lymphoma.
• Bechet syndrome (a disease of the immune system).
• Tumors in the thymus or thyroid.
• Sarcoidosis (a disease of the lymph nodes that acts like tuberculosis).

The following tests may be done to diagnose SVCS and find the location of the blockage:

• Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. A CT scan of the chest will be done to diagnose SVCS.
• Venography: A procedure to x-ray veins. A contrast dye is injected into the veins to outline them on the x-rays.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
• Ultrasound: A procedure in which high-energy sound waves (ultrasound) are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram.

The type of cancer can affect the type of treatment needed; for this reason, a diagnosis of suspected cancer should be made before treatment of SVCS is begun. Unless the airway is blocked or the brain is swelling, waiting to start treatment while a diagnosis is made usually presents no problem in adults. If lung cancer is suspected, a sputum sample and a biopsy may be taken.

This summary is about treatment for superior vena cava syndrome (SVCS) caused by cancer. Treatment will depend on the following:

• The type of cancer.
• The cause of the blockage.
• How severe the symptoms are.
• The prognosis (chance of recovery).
• The patient's wishes.

Treatment of SVCS may include the following:

Watchful waiting

Watchful waiting is closely monitoring a patient’s condition without giving any treatment unless symptoms appear or change. A patient who has good blood flow through other veins and mild symptoms may not need treatment.

The following may be used to relieve symptoms and keep the patient comfortable:

• Keeping the upper body raised higher than the lower body.
• Corticosteroids (drugs that reduce swelling).
• Diuretics (drugs that make excess fluid pass from the body in urine). Patients taking diuretics are closely monitored because these drugs can cause dehydration (loss of too much fluid from the body).

Radiation therapy

If the blockage of the superior vena cava is caused by a tumor that is not sensitive to chemotherapy, radiation therapy may be given. Radiation therapy uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.

Chemotherapy

Chemotherapy is the usual treatment for tumors that respond to anticancer drugs, including small cell lung cancer and lymphoma. This treatment would not be changed for patients who have SVCS. Chemotherapy uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).

Thrombolysis

SVCS may occur when a thrombus (blood clot) forms in a partially blocked vein. Thrombolysis is a method used to break up and remove blood clots. This may done using a drug put directly into the clot, through a catheter, or by a thrombectomy (the use of a device inserted into the vein).

Stent placement

A stent may be used to open up the blocked vein. A stent is a tube-like device that is inserted into the blocked area of a vein to allow blood to pass through. This helps most patients. Patients may also receive an anticoagulant to keep more blood clots from forming.

Surgery

Surgery to bypass (go around) the blocked part of the vein is sometimes used for cancer patients, but is used more often for patients without cancer.

Superior vena cava syndrome is serious and the symptoms can be upsetting to the patient and family. It is important that patients and family members receive information about the causes of superior vena cava syndrome and how to treat it. This can help relieve anxiety over symptoms such as swelling, trouble swallowing, coughing, and hoarseness.

When a patient has chosen not to receive aggressive treatment because of terminal cancer, palliative treatment can help keep the patient comfortable by relieving symptoms. Patients and family members can be taught how to provide palliative care to relieve symptoms and improve quality of life.

Superior vena cava syndrome in a child is a serious medical emergency because the child's windpipe can become blocked.

Superior vena cava syndrome (SVCS) in children can be life threatening. This is because blockage of the child's trachea (windpipe) can quickly occur along with SVCS. In adults, the windpipe is fairly hard, but in children, it is softer and can more easily be squeezed shut. Also, the diameter of a child's windpipe is smaller, so any amount of swelling can cause breathing problems. Squeezing of the trachea is called superior mediastinal syndrome (SMS). Because SVCS and SMS often occur together in children, the two syndromes are considered to be the same.

The most common symptoms of SVCS in children are similar to those in adults.

Common symptoms include the following:

• Coughing.
• Hoarseness.
• Problems breathing.
• Chest pain.

There are other less common but more serious symptoms:

• Fainting.
• Anxiety.
• Confusion.
• Tiredness.
• Headache.
• Vision problems.
• A sense of fullness in the ears.

The causes, diagnosis, and treatment of SVCS in children are not the same as in adults.

The most common cause of SVCS in children is non-Hodgkin lymphoma.

SVCS in children is rare; the most common cause is non-Hodgkin lymphoma. As in adults, SVCS may also be caused by a blood clot that forms as a side effect of using an intravenous catheter.

SVCS in children may be diagnosed and treated before a definite diagnosis of cancer is made.

A physical exam, chest x-ray, and medical history are usually all that are needed to diagnose superior vena cava syndrome in children. If cancer is suspected, a biopsy is not done unless the lungs and heart of the child with SVCS are able to handle the anesthesia needed. Other imaging tests may be done to help determine if anesthesia can be safely used. In most cases, treatment will begin before a definite diagnosis of cancer is made.

It is important that treatment begins right away.

The following treatments may be used for SVCS in children:

• Radiation therapy

  Radiation therapy is usually used to treat a tumor that is causing the blocked vein. After radiation therapy, breathing may become more difficult because swelling narrows the windpipe. A drug to reduce swelling may be given.

• Drugs

  Anticancer drugs, steroids, and/or other drugs may be used. If the tumor does not respond, it may be benign (not cancer).

• Surgery

  This may include surgery to bypass (go around) the blocked part of the vein or to place a stent to open the vein.

Glossary Terms

The area of the body that contains the pancreas, stomach, intestines, liver, gallbladder, and other organs.

A quickly growing cancer.

A loss of feeling or awareness caused by drugs or other substances. Anesthesia keeps patients from feeling pain during surgery or other procedures. Local anesthesia is a loss of feeling in one small area of the body. Regional anesthesia is a loss of feeling in a part of the body, such as an arm or leg. General anesthesia is a loss of feeling and a complete loss of awareness that feels like a very deep sleep.

A drug that helps prevent blood clots from forming. Also called blood thinner.

Feelings of fear, dread, and uneasiness that may occur as a reaction to stress. A person with anxiety may sweat, feel restless and tense, and have a rapid heart beat. Extreme anxiety that happens often over time may be a sign of an anxiety disorder.

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

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

A mass of blood that forms when blood platelets, proteins, and cells stick together. When a blood clot is attached to the wall of a blood vessel, it is called a thrombus. When it moves through the bloodstream and blocks the flow of blood in another part of the body, it is called an embolus.

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

A surgical procedure in which the doctor creates a new pathway for the flow of body fluids.

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 flexible tube used to deliver fluids into or withdraw fluids from the body.

A hollow area or hole. It may describe a body cavity (such as the space within the abdomen) or a hole in a tooth caused by decay.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Treatment with drugs that kill cancer cells.

An x-ray of the structures inside the chest. An x-ray is a type of high-energy radiation that can go through the body and onto film, making pictures of areas inside the chest, which can be used to diagnose disease.

Cancer that forms in the tissues of the colon (the longest part of the large intestine). Most colon cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids).

A mental state in which one is not thinking clearly.

A dye or other substance that helps show abnormal areas inside the body. It is given by injection into a vein, by enema, or by mouth. Contrast material may be used with x-rays, CT scans, MRI, or other imaging tests.

Any steroid hormone made in the adrenal cortex (the outer part of the adrenal gland). They are also made in the laboratory. Corticosteroids have many different effects in the body, and are used to treat many different conditions. They may be used as hormone replacement, to suppress the immune system, and to treat some side effects of cancer and its treatment. Corticosteroids are also used to treat certain lymphomas and lymphoid leukemias.

A series of detailed pictures of areas inside the body taken from different angles. The pictures are created by a computer linked to an x-ray machine. Also called CAT scan, computed tomography scan, computerized axial tomography scan, and computerized tomography.

A condition caused by the loss of too much water from the body. Severe diarrhea or vomiting can cause dehydration.

The process of identifying a disease, such as cancer, from its signs and symptoms.

The length of a straight line that extends from one edge of a tumor or other object, through its center and to the opposite edge. It is usually used to measure the size of round or spherical shapes.

A drug that increases the production of urine.

Any substance, other than food, that is used to prevent, diagnose, treat or relieve symptoms of a disease or abnormal condition. Also refers to a substance that alters mood or body function, or that can be habit-forming or addictive, especially a narcotic.

A thin layer of tissue that covers organs, glands, and other structures within the body.

Cancer that forms in tissues lining the esophagus (the muscular tube through which food passes from the throat to the stomach). Two types of esophageal cancer are squamous cell carcinoma (cancer that begins in flat cells lining the esophagus) and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids).

A type of radiation therapy that uses a machine to aim high-energy rays at the cancer from outside of the body. Also called external-beam radiation therapy.

Containing or resembling fibers.

A substance that flows smoothly and takes the shape of its container. Liquids and gases are fluids.

A type of tumor that begins in the cells that give rise to sperm or eggs. Germ cell tumors can occur almost anywhere in the body and can be either benign or malignant.

A cancer of the immune system that is marked by the presence of a type of cell called the Reed-Sternberg cell. The two major types of Hodgkin lymphoma are classical Hodgkin lymphoma and nodular lymphocyte-predominant Hodgkin lymphoma. Symptoms include the painless enlargement of lymph nodes, spleen, or other immune tissue. Other symptoms include fever, weight loss, fatigue, or night sweats. Also called Hodgkin disease.

In medicine, a process that makes pictures of areas inside the body. Imaging uses methods such as x-rays (high-energy radiation), ultrasound (high-energy sound waves), and radio waves.

The complex group of organs and cells that defends the body against infections and other diseases.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

A large vein that empties into the heart. It carries blood from the legs and feet and from organs in the abdomen and pelvis.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

A type of radiation therapy in which radioactive material sealed in needles, seeds, wires, or catheters is placed directly into or near a tumor. Also called brachytherapy, implant radiation therapy, and radiation brachytherapy.

Into or within a vein. Intravenous usually refers to a way of giving a drug or other substance through a needle or tube inserted into a vein. Also called IV.

A type of cancer characterized by the abnormal growth of blood vessels that develop into skin lesions or occur internally.

One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.

A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called lymph gland.

Cancer that begins in cells of the immune system. There are two basic categories of lymphomas. One kind is Hodgkin lymphoma, which is marked by the presence of a type of cell called the Reed-Sternberg cell. The other category is non-Hodgkin lymphomas, which includes a large, diverse group of cancers of immune system cells. Non-Hodgkin lymphomas can be further divided into cancers that have an indolent (slow-growing) course and those that have an aggressive (fast-growing) course. These subtypes behave and respond to treatment differently. Both Hodgkin and non-Hodgkin lymphomas can occur in children and adults, and prognosis and treatment depend on the stage and the type of cancer.

The area between the lungs. The organs in this area include the heart and its large blood vessels, the trachea, the esophagus, the thymus, and lymph nodes but not the lungs.

A benign (not cancer) or malignant (cancer) tumor affecting the lining of the chest or abdomen. Exposure to asbestos particles in the air increases the risk of developing malignant mesothelioma.

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, to regularly watch and check a person or condition to see if there is any change. Also refers to a device that records and/or displays patient data, such as for an electrocardiogram (EKG).

A procedure in which radio waves and a powerful magnet linked to a computer is used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. MRI makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. MRI is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called magnetic resonance imaging, NMRI, and nuclear magnetic resonance imaging.

Any of a large group of cancers of lymphocytes (white blood cells). Non-Hodgkin lymphomas can occur at any age and are often marked by lymph nodes that are larger than normal, fever, and weight loss. There are many different types of non-Hodgkin lymphoma. These types can be divided into aggressive (fast-growing) and indolent (slow-growing) types, and they can be formed from either B-cells or T-cells. B-cell non-Hodgkin lymphomas include Burkitt lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), diffuse large B-cell lymphoma, follicular lymphoma, immunoblastic large cell lymphoma, precursor B-lymphoblastic lymphoma, and mantle cell lymphoma. T-cell non-Hodgkin lymphomas include mycosis fungoides, anaplastic large cell lymphoma, and precursor T-lymphoblastic lymphoma. Lymphomas that occur after bone marrow or stem cell transplantation are usually B-cell non-Hodgkin lymphomas. Prognosis and treatment depend on the stage and type of disease. Also called NHL.

A procedure in which radio waves and a powerful magnet linked to a computer is used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. Nuclear magnetic resonance imaging makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. Nuclear magnetic resonance imaging is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called magnetic resonance imaging, MRI, and NMRI.

A part of the body that performs a specific function. For example, the heart is an organ.

An electronic device that is implanted in the body to monitor heart rate and rhythm. It gives the heart electrical stimulation when it does not beat normally. It runs on batteries and has long, thin wires that connect it to the heart. Also called artificial pacemaker and cardiac pacemaker.

Treatment given to relieve the symptoms and reduce the suffering caused by cancer and other life-threatening diseases. Palliative cancer therapies are given together with other cancer treatments, from the time of diagnosis, through treatment, survivorship, recurrent or advanced disease, and at the end of life.

An exam of the body to check for general signs of disease.

The likely outcome or course of a disease; the chance of recovery or recurrence.

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.

Giving off radiation.

A small, radioactive pellet that is placed in or near a tumor. Cancer cells are killed by the energy given off as the radioactive material breaks down and becomes more stable.

Treatment with anticancer drugs directed to a specific area of the body.

An inflammatory disease marked by the formation of granulomas (small nodules of immune cells) in the lungs, lymph nodes, and other organs. Sarcoidosis may be acute and go away by itself, or it may be chronic and progressive. Also called sarcoid.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

An aggressive (fast-growing) cancer that forms in tissues of the lung and can spread to other parts of the body. The cancer cells look small and oval-shaped when looked at under a microscope.

A computer picture of areas inside the body created by bouncing high-energy sound waves (ultrasound) off internal tissues or organs. Also called ultrasonogram.

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

Mucus and other matter brought up from the lungs by coughing.

A device placed in a body structure (such as a blood vessel or the gastrointestinal tract) to keep the structure open.

A type of drug used to relieve swelling and inflammation. Some steroid drugs may also have antitumor effects.

The large vein that carries blood from the head, neck, arms, and chest to the heart.

A condition in which a tumor presses against the superior vena cava (the large vein that carries blood from the head, neck, arms, and chest to the heart). This pressure blocks blood flow to the heart and may cause coughing, difficulty in breathing, and swelling of the face, neck, and upper arms.

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

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

A set of symptoms or conditions that occur together and suggest the presence of a certain disease or an increased chance of developing the disease.

Treatment with anticancer drugs that travel through the blood to cells all over the body.

Disease that cannot be cured and will cause death.

Surgery to remove a thrombus (blood clot) from a blood vessel.

The process of breaking up a thrombus (blood clot) that is blocking blood flow. The blood clot may be dissolved using drugs delivered through a catheter (tube) into the clot.

A blood clot that forms on the wall of a blood vessel or in the heart when blood platelets, proteins, and cells stick together. A thrombus may block the flow of blood.

An organ that is part of the lymphatic system, in which T lymphocytes grow and multiply. The thymus is in the chest behind the breastbone.

A gland located beneath the larynx (voice box) that makes thyroid hormone and calcitonin. The thyroid helps regulate growth and metabolism. Also called thyroid gland.

A group or layer of cells that work together to perform a specific function.

The airway that leads from the larynx (voice box) to the bronchi (large airways that lead to the lungs). Also called windpipe.

A disease caused by a specific type of bacteria that spreads from one person to another through the air. Tuberculosis can affect many parts of the body, but most often affects the lungs. A person may not have symptoms of tuberculosis for years, but they may appear when the patient becomes ill with a serious condition like diabetes, AIDS, or cancer. Tuberculosis can usually be treated and cured with antibiotics. Also called TB.

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 procedure in which high-energy sound waves are bounced off internal tissues or organs and make echoes. The echo patterns are shown on the screen of an ultrasound machine, forming a picture of body tissues called a sonogram. Also called ultrasonography.

Fluid containing water and waste products. Urine is made by the kidneys, stored in the bladder, and leaves the body through the urethra.

A blood vessel that carries blood to the heart from tissues and organs in the body.

A procedure in which an x-ray of the veins is taken after a special dye is injected into the bone marrow or veins.

Closely monitoring a patient's condition but withholding treatment until symptoms appear or change. Also called active surveillance, expectant management, and observation.

A type of high-energy radiation. In low doses, x-rays are used to diagnose diseases by making pictures of the inside of the body. In high doses, x-rays are used to treat cancer.