Radiation therapy for neuroblastoma

Radiation therapy uses high-energy rays or particles to destroy cancer cells. It is sometimes used to treat neuroblastoma. Your child’s healthcare team will consider your child’s personal needs to plan the type and amount of radiation, and when and how it is given. Your child may also receive other treatments.

Radiation therapy is given for different reasons. Your child may have radiation therapy to:

• treat high-risk or recurrent neuroblastoma
• destroy cancer cells left behind after surgery or chemotherapy and lower the risk that the cancer will recur (called adjuvant therapy)
• treat larger tumours that cause serious problems, such as trouble breathing or spinal cord compression, and that do not respond quickly to chemotherapy
• try to reverse vision loss if a tumour in the eye socket causes partial or complete blindness
• relieve pain or control the symptoms of advanced neuroblastoma (called palliative therapy)

The following types of radiation therapy are most commonly used to treat neuroblastoma.

Neuroblastoma is usually treated with external radiation therapy (also called external beam radiation therapy). During external radiation therapy, a machine directs radiation through the skin to the tumour and some of the tissue around it.

Radioisotope therapy is a way of giving internal radiation therapy. Internal radiation therapy places radioactive materials in the body. Larger doses of radiation can be given with internal radiation therapy than with external radiation therapy. Radioisotope therapy travels through the blood to reach cells all over the body (called systemic radiation). Radioisotope therapy may be used in a clinical trial to treat high-risk neuroblastoma or recurrent high-risk neuroblastoma. It is also called radionuclide therapy or radiopharmaceutical therapy. It is given by injection into a vein (intravenous injections).

Radioisotope therapy uses radioactive metaiodobenzylguanidine (MIBG). MIBG binds to receptors on the neuroblastoma cells. This allows the radiation to be delivered directly to the cancer cells and limits its effects on normal cells. This treatment is only available in a few Canadian centres and is often only given within a clinical trial. Stem cell rescue may be required after MIBG treatment to help the bone marrow to recover.

Side effects can happen with any type of treatment for neuroblastoma, but every child's experience is different. Some children have many side effects. Others have few or none at all.

During external radiation therapy, the healthcare team protects healthy cells in the treatment area as much as possible. Damage to these healthy cells can happen and may cause side effects. Side effects can happen any time during, immediately after or a few days or weeks after radiation therapy. Sometimes late side effects develop months or years after radiation therapy. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.

Side effects of external radiation therapy will depend mainly on the size of the area being treated, the specific area or organs being treated, the total dose of radiation, the treatment schedule and your child's age. Some common side effects of radiation therapy for neuroblastoma include:

• bone marrow suppression
• fatigue
• skin problems
• nausea and vomiting
• diarrhea
• sore mouth and throat
• difficulty swallowing
• radiation enteritis

Most children do not have serious side effects from radioisotope therapy. It can sometimes cause mild nausea and vomiting and fatigue.

Other side effects can develop months or years after treatment for neuroblastoma. Find out more about late effects for neuroblastoma.

Tell the healthcare team if your child has these side effects or others you think might be from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help your child deal with them.

Find out more about radiation therapy and side effects of radiation therapy. To make the decisions that are right for your child, ask the healthcare team questions about radiation therapy.