Leukemia

Leukemia

Signs and Symptoms
Diagnosis
Treatment

Diagnosis

Understanding how certain diagnostic procedures are performed and why they are necessary may help you support and prepare your child for these tests.

Blood tests

Blood tests are done frequently to monitor the possible side effects of chemotherapy and radiation therapy. Because the results can influence treatment decisions, these tests often are done before treatment. Depending on the types of blood tests done, blood samples may be obtained by a small needle prick or finger stick on the inside tip of the finger or by inserting a needle into a vein, a procedure called a venipuncture. If a venipuncture is done, remember to apply EMLA cream, an anesthetic, to the puncture site one to two hours before the test. Ask your nurse to show you where and how to apply the cream. If your child has an external catheter, you will learn to draw blood samples at home to deliver to the lab.

Cultures

If your child has a fever or other signs of infection, one or more samples of blood, urine or stool, throat secretion or pus may be taken to check for infection. To confirm an infection, any organisms contained in these samples are allowed to grow in a culture for several days. To get a head start at fighting the infection, however, antibiotics may be prescribed before your child's doctor has the final results of the culture.

If a specific organism is identified, antibiotics may be changed for more effective treatment. Often a specific organism is never identified, in which case "broad-spectrum" antibiotic — effective against more than one organism — may be continued, depending on your child's condition.

Bone Marrow Biopsy

Understandably, bone marrow aspirations may be frightening to you and your child. But a local anesthetic is injected deep under the skin to numb the puncture site and takes effect quickly, helping to control the pain. Whenever possible, we give you the choice of having the procedure performed under general anesthesia.

Spinal Tap

A clear fluid called cerebrospinal fluid (CSF) surround the brain and spinal cord. Sometimes a sample of this fluid is removed and examined for cancer cells or signs of infection. Another name for a spinal tap is lumbar (lower spine) puncture or LP. This procedure takes about 15 minutes.

Bone Scan, Gallium Scan, MIBG

Evaluation and treatment of a child with cancer may involve specialized nuclear medicine scans of organs, tissues or bones to check for disease or infection. The three most common types of scans are bone scans, gallium scans and MIBG scans. MIBG stands for meta-iodobenzylguanidine. Both gallium and MIBG are radioactive substances that enable doctors to detect cancerous cells in the scans.

A nuclear medicine scan requires the injection of a small amount of a radioactive substance into the blood about two to three hours before a bone scan, 48 to 72 hours before the gallium scan and 24 hours before the MIBG scan. Registration and the injection of the radioactive substance should take no more than 15 minutes.

If your child does not have an external central catheter, remember to apply EMLA cream, a topical anesthetic, to the injection site one to two hours before the procedure. Ask your nurse to show you where and how to apply the cream.

Computerized Tomography (CT) Scan

Computerized tomography (CT) scans use computers and X-rays to create pictures with more detail than conventional X-rays. X-rays are sent through the body in thin cross sections to create images. These scans often supplement other diagnostic X-rays.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) uses magnets, rather than X-rays, to produce detailed images of the body. An MRI machine sends radio waves into the body and then measures the response with a computer. The computer makes an image or picture of the body's internal organs. MRIs are used for certain types tumors in certain locations of the body because they can produce a better image than X-rays.

Echocardiogram

Because certain types of chemotherapy can affect heart muscle, tests may be done periodically to detect changes in your child's heart to help identify problems before they become serious. An echocardiogram is used to record the echoes of sounds sent through the heart. This test shows the size of the four heart chambers, as well as how the heart muscle functions. Your child may need to remove clothing above the waist for this test.

Ultrasound

An ultrasound exam or sonogram uses high frequency sound waves to create images of organs in the body. No radiation is used. Sound waves bounce off tissue using the same principles as sonar. The echoes that return to a transducter are used to draw the images on the screen.

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 5, 2008