Treatment

In general, cancer in children is uncommon, so it can be hard for doctors to plan treatments unless they know what has been most effective in other children. That’s why more than 60% of children with cancer are treated as part of a clinical trial. Clinical trials are research studies that compare the standard treatments (the best treatments available) with newer treatments that may be more effective. Investigating new treatments involves careful monitoring using scientific methods and all participants are followed closely to track progress.

To take advantage of these newer treatments, all children with cancer should be treated at a specialized cancer center. Doctors at these centers have extensive experience in treating children with cancer and have access to the latest research. A doctor who specializes in treating children with cancer is called a pediatric oncologist. Many times, a team of doctors treats a child with cancer. Pediatric cancer centers often have extra support services for children and their families, such as nutritionists, social workers, and counselors. Special activities for kids with cancer may also be available.

The treatment of medulloblastoma depends on the size and location of the tumor, whether the cancer has spread, and the child’s overall health. Three types of treatment are typically used to treat medulloblastoma: surgery, radiation therapy, and chemotherapy. Sometimes, the treatments are used in combination. In some situations, stem cell or bone marrow transplantation may be recommended. Descriptions of the most common treatment options for medulloblastoma are listed below.

Surgery

Surgery is the first treatment most commonly used for medulloblastoma. A neurosurgeon is a doctor who specializes in treating a tumor in the brain or spine with surgery. The goal of medulloblastoma treatment is the complete surgical removal of the tumor. In addition to removing or reducing the size of the tumor, surgery can provide a tissue sample for biopsy analysis, as explained in the Diagnosis section.

Surgery to the brain requires the removal of part of the skull, a procedure called a craniotomy. After the surgeon removes the tumor, the patient’s own bone will be used to cover the opening in the skull. There have been rapid advances in surgery for brain tumors, including the use of cortical mapping (which allows doctors to identify certain areas of the brain that control the senses, language, and motor skills) and enhanced imaging devices to give surgeons more tools to plan and perform the surgery.

Some tumors cannot be removed by surgery because of their location; these tumors are called inoperable; in these cases, the doctor will recommend other treatment options. In a cancerous tumor, even if the cancer cannot be cured, its removal can relieve symptoms if it is creating pressure on parts of the brain.

Side effects from surgery for medulloblastoma can vary, and patients are encouraged to discuss possible short-term and long-term side effects with their doctor. Learn more about cancer surgery.

Radiation therapy

Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy or brachytherapy.

Because radiation therapy can sometimes interfere with the normal growth and development of the child’s brain and spine, the doctor may choose to treat the tumor in another way. If radiation therapy is recommended, the approach will be based on the child’s age. For children older than age three, radiation therapy includes a moderate dose to the entire brain and spine, followed by a higher dose directly aimed at the tumor bed (the tumor and the surrounding area) or the back part of the brain. For children younger than three years old, radiation therapy may be limited to the back part of the brain, or tumor bed, after surgery and chemotherapy (see below).

Side effects from radiation therapy may include fatigue, mild skin reactions, upset stomach, and loose bowel movements. Most side effects go away soon after treatment is finished. Learn more about radiation therapy.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication. Some people may receive chemotherapy in their doctor’s office; others may go to the hospital. A chemotherapy regime (schedule) usually consists of a specific number of cycles given over a specific time.

Chemotherapy for medulloblastoma may be given by mouth (orally) or by injection into a vein (by IV or intravenously) or muscle. Sometimes, it is delivered directly into the cerebrospinal fluid, which is fluid that circulates around the brain and spinal cord. Researchers are studying ways to use chemotherapy before, during, or after radiation therapy, as the two forms of treatment can be more effective when combined. High-dose chemotherapy may be used before or instead of radiation therapy for children younger than three to four years old. Several cycles of high-dose chemotherapy may be used before or after radiation therapy in children older than three to four years old. High-dose chemotherapy is most effective when there is little tumor left after surgery.

The side effects of chemotherapy depend on the individual and the dose used, but can include fatigue, risk of infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished.

Learn more about chemotherapy and preparing for treatment. The medications used to treat cancer are continually being evaluated. Talking with your child’s doctor is often the best way to learn about the medications prescribed for your child, their purpose, and their potential side effects or interactions with other medications. Learn more about your child’s prescriptions by using searchable drug databases.

Stem cell transplantation/bone marrow transplantation

A stem cell/bone marrow transplant may be used for children with recurrent medulloblastoma. A stem cell transplant is a medical procedure in which diseased bone marrow is replaced by highly specialized cells, called hematopoietic stem cells. Hematopoietic stem cells are found both in the bloodstream and in the bone marrow. Today, this procedure is more commonly called a stem cell transplant, rather than bone marrow transplant, because blood stems cells are typically what is being transplanted, not the actual bone marrow tissue.

There are two types of stem cell transplantation depending on the source of the replacement blood stem cells: allogeneic (ALLO) and autologous (AUTO). Only AUTO transplantation is used to treat medulloblastoma.

In an AUTO transplant, the patient’s own stem cells are used as the replacement cells. The stem cells are obtained from the patient when he or she is in remission (temporary or permanent disappearance of the signs and symptoms of a tumor but not necessarily the entire disease) from previous treatment. The stem cells are frozen until they are needed, usually after the high-dose treatment (explained below) is completed.

The goal of transplantation is to destroy cancer cells in the marrow, blood, and other parts of the body and have replacement blood stem cells create healthy bone marrow. In most stem cell transplants, the patient is treated with high doses of chemotherapy and/or radiation therapy to destroy as many cancer cells as possible. This also destroys the patient’s bone marrow tissue and suppresses the patient’s immune system. After the high-dose treatment is given, blood stem cells are infused into the patient’s vein to replace the bone marrow and restore normal blood counts.

Before recommending transplantation, doctors will talk with the patient about the risks of this treatment and consider several other factors, such as the type of cancer, results of any previous treatment, and patient’s age and general health.

In stem cell transplantation, replacement cells engraft (begin to make new blood cells) and turn into healthy, blood-producing tissue in 10 days to three weeks. Destroying the patient’s own marrow reduces the body’s natural defenses, temporarily leaving the patient at an increased risk of infection. Until the patient’s immune system is back to normal, patients may need antibiotics and blood transfusions.

In an AUTO transplant, there is little risk of tissue rejection because the replacement stem cells are the patient’s own cells. However, there is a risk in an autologous transplant that some of the cells that are put back into the patient could still be cancerous. Learn more about bone marrow and stem cell transplantation.

Recurrent medulloblastoma

Treatment of recurrent medulloblastoma depends on two factors:

• Whether the tumor recurred in the place where it began or in another part of the brain
  
  
• The type of treatment the child received for the original tumor

Depending on individual circumstances, the doctor may recommend surgery, radiation therapy, chemotherapy, or stem cell/bone marrow transplantation. High-dose chemotherapy may be a part of “salvage” treatment for children with recurrent medulloblastoma. Salvage chemotherapy refers to the use of chemotherapy for a patient who experiences a recurrence of cancer following initial treatment, in the hope of providing a cure or prolonging life.

Find out more about common terms used during cancer treatment.