Common Medical Procedures for Childhood Cancers

Evaluation and treatment of a young person with cancer involve a variety of diagnostic procedures. Many of these are repeated at intervals over the course of treatment to monitor progress and response to therapy. These procedures should be carefully explained to you and your child before they are carried out. If you have any questions, do not hesitate to ask your physician or another member of the treatment team.

Angiograms

Angiograms reveal blocking, deviation, or abnormal development of blood vessels, which may indicate the presence of a growing tumor. The blood vessels are injected with dye and then X-rayed. A similar type of study, lymphangiography, can be used when cancer involving the lymphatic system is suspected.

Biopsy

Biopsy is a surgical procedure used to determine whether tumor tissue is benign or cancerous. For this test, a small piece of tissue is removed from the tumor and then examined under a microscope to check for the presence of cancer cells. The tissue is examined by a pathologist, a physician who is an expert at identifying the changes in body tissue caused by disease. This microscopic study of the tissue confirms or rules out a diagnosis of cancer.

Blood Studies

Blood studies evaluate the young person's blood and the components of the blood using a variety of tests. The blood studied in these tests is obtained by drawing blood from a vein with a syringe or by a "fingerstick," in which a small prick is made in a fingertip and a few drops drawn off.

Different tests that may be performed to study the blood include:

• White Blood Cell Count (WBC)--Blood cells ("blood smear") are stained on a slide and examined under a microscope. The white blood cells, those components of the blood that fight infection, are counted, and the number of those cells per cubic millimeter of blood is established. Young people receiving chemotherapy generally have a lower white cell count than normal. This test is also used to detect the presence of leukemic blasts.

• Hemoglobin--Measurements are taken of the amount of hemoglobin, the substance in the red blood cell that carries oxygen and is responsible for the blood's red color. Lower amounts than normal of this substance in the red blood cells indicate anemia. If the patient shows a low hemoglobin, physicians may do other tests to find out why and give medication (iron supplements in some cases) to correct it. A sudden appearance of anemia may suggest a relapse or be a side effect of chemotherapy.

• Hematocrit--This is a measure of the amount of red blood cells and is expressed as the percentage of the whole blood that is made up of red cells. A low count may indicate anemia.

• Platelet--The number of platelets (the component of the blood that helps stop bleeding in case of injury) per cubic millimeter of blood is counted. A platelet count below normal range may be due to relapse, side effects of medication, or infection. If platelet counts are low, more tests may be necessary to find out the reason.

Bone Marrow Aspiration

Bone marrow aspiration evaluates the stem cells that mature into normal blood cells. The procedure is used to diagnose leukemia and to check the response to treatment. In young people with other cancers, it determines whether the disease has spread to the bone marrow.

Bone marrow aspirations in young people are usually done in the pelvis (hip bone). The patient lies on the stomach with a pillow under the pelvis, and the area is cleaned with an iodine solution to kill skin bacteria. Then the skin is numbed with a local anesthetic, and the bone marrow needle is put through the skin and into the spongy part of the bone. A sensation of pressure is felt; some patients also complain of pain. Once the needle is in place, marrow is quickly drawn into a syringe. This is the most painful phase, but lasts only a second or two.

The entire procedure usually takes about 5 minutes and is not dangerous, but it may be stressful to the patient. Attempts to reduce a patient's anxiety and get him or her to relax may reduce the pain of this procedure and certainly the stress. Usually there is only temporary tenderness at the site, and the young person can get up and go immediately afterward.

Computerized Tomography

Computerized tomography (CTscan) is an x-ray technique for detecting masses in the body. While the young person lies still, a narrow x-ray beam directed by a computer revolves around him or her. In a matter of seconds the machine registers thousands of bits of information, which are translated into a cross-sectional picture on a viewing screen. The physician can also refer to a printout for more detailed analysis.

In computerized axial tomography, a computer directs X-ray beams from a rotating disc at regular intervals. The beams travel through the portion of the body being studied onto a device that registers the beam's path. The results are analyzed by a computer, and the data appear as a three-dimensional image on a TV screen.

Magnetic Resonance Imaging

Magnetic resonance imaging is a new technique that uses magnetic fields and radio waves linked to a computer to create pictures of areas inside the body. The patient lies on a table that slides into a tunnel-shaped piece of equipment. Antennas within the MRI machine pick up the radio waves within and feed them into a computer which assembles a picture. Because MRI can "see" through bone, it can provide clearer pictures of tumor located near bone, especially brain tumors. MRI takes longer than a CT scan, and it is very noisy, which may be scary for some children.

Lumbar Puncture

Lumbar puncture (L.P. or spinal tap) is used to determine whether cancer cells or infection is present in the cerebrospinal fluid (CSF) that surrounds the brain and spinal cord. It is also used to deliver anticancer drugs directly to the brain and spinal cord.

An L.P. is done while the patient is lying on one side or sitting. In either instance, it is very important that the patient be in a tight ball so the lower back is rounded and the backbone projects backward. After the young person is in position, a local anesthetic is given in the lower back. The patient is held in a tight ball and the needle is inserted between the vertebrae into the fluid space around the spinal cord. The patient may feel some pressure. A sample of CSF is collected and examined for blood and cancer cells. It also is checked for the level of sugar and protein and can be cultured to check for infection. After the fluid is collected, medicines may be given through the puncture. The patient may feel anxious, but some of this may be alleviated if the patient can learn to relax during the procedure.

Usually there are no aftereffects, but sometimes the young person may get a headache when sitting or standing. Sometimes the headache can be prevented by lying flat for about an hour after the procedure and by increasing fluid intake for 24 hours afterward. Fortunately, headaches are uncommon, and usually the young person can return to normal activity.

When anticancer drugs are given into the spinal fluid, nausea and vomiting may occur. Antinausea medicines may be prescribed by the physician.

Scans or Radioisotope Studies

Scans or radiosiotope studies are used to discover abnormalities in the liver, brain, bones, kidneys, and other organs. In these tests, chemicals that collect in particular organs can be "labeled" with a harmless radioactive material. The young person swallows the material or it may be injected into a vein. After a short waiting period, electronic devices are used to track the radioactive material as it collects within the body. Looking at how the material distributes itself in the body, the physician can then "see" whether an organ is functioning correctly or if it contains an abnormal mass or masses. Your child will not be radioactive during or after these tests.

Ultrasound Studies

Ultrasound studies determine the presence of tumors in the young person's body. Because tumors generate different "echoes" than normal tissue, sound waves above the range of human hearing can be bounced off tissue and then changed electronically into images. Ultrasound is particularly effective in diagnosis because it can "recognize" masses that are not cancerous.

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.