diagnostic services | medical services and treatments | surgical services

Diagnostic Services

Blood tests – Blood tests can be helpful in determining if a child has cancer. A complete blood count test, also known as “CBC,” counts the three types of blood cells: white blood cells, red blood cells and platelets. Doctors look for a change in the number of white blood cells or lymphocytes, which fight infection, red blood cells, which carry oxygen, and platelets, which help the blood to clot. The CBC is very important when a diagnosis is made because cancer can affect the amount of red blood cells, white blood cells and platelets present before treatment has begun. This blood test is also done after therapy has started. Cancer treatments using chemotherapy and radiation therapy decrease the number of red blood cells, white blood cells and platelets. When the number of blood cells are decreased, the child will have a “low blood count.” If the red blood count is low, the child may become pale and tire easily. When the white blood count or “white count” is low, the child is not able to fight infection and is more susceptible to getting an infection or cold. Finally, when the platelet count is low, the child may have increased bleeding, as seen by nosebleeds or bruising.

Bone marrow aspiration or biopsy – Many forms of cancer begin or spread to the bone marrow, which is liquid and looks like blood. It is found inside some of the bones of the body. Examining a sample of bone marrow under a microscope is the only test that can confirm the presence of certain cancers such as leukemia. A sample of bone marrow is usually removed, or “aspirated,” from the hip bone through a special needle while the child lies on his stomach or side.

Bone scan – This scan provides information about the bones in the body. Before the scan can be done, the child will have a radioactive material (isotope) injected intravenously. The child will then be asked to drink a large volume of water (1 quart for older children). This will help move the isotope in the blood stream. The actual scan will not take place for 3 to 6 hours. If a tumor has affected a bone, it will appear on the scan as an area of increased update of the radioactive material.

Spinal tap or lumbar puncture – Cerebrospinal fluid (CSF) surrounds the brain and spinal cord, and certain cancers are known to spread to this fluid. A lumbar puncture, also called a spinal tap, is performed while the child lies on his side with legs curled up to the chest. A needle is placed between the small bones of the back to collect the fluid, which is then checked for the presence of cancer.

CT (computed tomography) scan – This is a diagnostic test that uses special X-ray equipment to obtain cross-sectional pictures of the body. CT gives the treatment team detailed images of organs, bones and other tissues. CT is used in cancer diagnoses in several ways: 1) to detect or confirm the presence of a tumor; 2) to provide information about the size and location of the tumor and whether it has spread; 3) to guide a biopsy (which is the removal of cells or tissues for examination under a microscope); 4) to help plan radiation therapy or surgery; and 5) to determine whether the cancer is responding to treatment.

MRI (magnetic resonance imaging) – This is a diagnostic test similar to a CT scan but which employs powerful magnets instead of X-rays to create precise pictures of body tissues using radio waves. These radio waves are not harmful to tissues, and the procedure is painless. However, it may require sedation because the child must remain absolutely still.

Ultrasound – This painless procedure uses sound waves to examine internal body structures or tumors. The child likes down and lotion is spread over the area to be scanned. A probe is then rubbed over the area and a video image can be seen on a monitor.

Biopsy – Biopsies involve taking a sample of tissue, which is then studied in the laboratory. In a needle biopsy, a tissue sample is removed through a thin needle inserted into the tumor. Sometimes, surgery is required to remove the tissue. This is called an “excisional” or “incisions” biopsy, and is usually performed in an operating room by either surgeons or radiologists while the child is under general anesthesia.

Tumor markers – There are a number of laboratory tests that measure the chemicals made by certain tumor cells. These chemicals are called tumor markers. Not all childhood cancers have tumor markers. These tests are done at the time the child is diagnosed and will be repeated periodically, if positive, to determine the response of the tumor to therapy.

EEG – An EEG, or electroencephalogram, is a recording of the electrical waves in the brain. It measures electrical impulses that are sent between nerve cells. This diagnostic device can help doctors localize brain tumors and other lesions, and determine whether cancer has spread to the brain. An EEG uses small electrodes to measure the electrical activity within the brain. It does not deliver any electricity of its own. The technician uses a paste to attach 23 small electrodes to the person’s scalp. The electrodes carry information about the brain’s electrical activity to an amplifier. A special machine records the amplified brain waves, and produces a pattern of tracings called an electroencephalogram. While EEG is primarily used to complement CT and MRI studies, it provides the only continuous measure of cerebral function over time.

Electrocardiogram (EKG) – This test evaluates the conduction system of the heart. Small electrode patches are placed on the chest, wrist and ankles. These are connected to a machine that traces the electrical activity of the heart.

Brainstem audio evoked response (BAER) – This test measures hearing in children too young to cooperate for the audiogram. Sedation is given and small electrodes are placed on the child’s head and then connected to a machine. The child’s response to sounds is then measured by the electrical impulses recorded.

Pulmonary function test (PFT) – This is a group of tests that measures breathing and lung function. Usually only children old enough to cooperate with several instructions can perform these tests. These children are instructed to breathe into a machine that measures the capacity of their lungs. Occasionally, a small blood sample is needed to complete this testing.

Audiogram – This test measures the child’s hearing. During this test, the child wears earphones, and is asked to indicate by raising his/her hand when he/she hears the tone. This tone will vary in volume and sound frequency. The test is painless, and takes only a few minutes to complete. It is necessary that this test be performed in a room that is quiet. If there is too much noise in the child’s hospital room, it may be necessary to take the child to one of the treatment rooms where it is quieter, in order to perform this test.

Medical Services and Treatment

After a diagnosis is made, family members meet with the oncologist who will outline the child’s treatment plan. Treatment plans, which are called protocols, are based on a variety of factors including the type and extent of disease at diagnosis. A majority of CHOC protocols come from the Children’s Cancer Group (CCG), a national organization funded by the National Cancer Institute (NCI). The goal of CCG is to improve the treatment and increase the survival and cure rates of childhood cancer.

Different types of cancers call for one or more different treatment approaches. Family members receive a “roadmap,” which is the “calendar” of the treatment plan. The child’s nurse reviews the roadmap with each family. It may also be modified according to the child’s response.

Here is a brief overview of our medical services that may be included in the roadmap:

Chemotherapy – Chemotherapy is the treatment of cancer with drugs that can destroy cancer cells. When cancer occurs, cells in the body keep dividing and form more cells without control. Chemotherapy destroys cancer cells by stopping them from growing or multiplying. Healthy cells can also be harmed, especially those that divide quickly. Harm to healthy cells is usually what causes side effects, but they can usually repair themselves after chemotherapy. Chemotherapy can be used in several different ways: 1) to cure the cancer, 2) to control the cancer, 3) to relieve symptoms that the cancer may cause.

Radiation therapy – Radiation therapy is the treatment of cancer using penetrating beams of high-energy waves or streams of particles. This is called radiation, and when used in high doses, can kill cells or keep them from growing and dividing. Normal cells are also affected by radiation, but unlike cancer cells, most of them recover from the effects. Radiation therapy is often used with surgery to treat cancer. CHOC specialists may use radiation before surgery to shrink a tumor. This makes it easier to remove the cancerous tissue and may allow the surgeon to perform less radical therapy.

Surgical Services

Surgery also may be included in this “roadmap.” Patients at The CHOC Cancer Institute have direct access to the full range of surgical specialties including pediatric surgery, neurosurgery, ENT surgery, urology, orthopedic and thoracic surgery. All surgical services are child- and adolescent-centered, with surgeons and nurses specially trained to operate on children. Surgery can involve removing the tumor, or taking some tissue for a biopsy. It is often used in conjunction with chemotherapy and/or radiation to help remove as much of the cancer as possible.