Total Body Irradiation (TBI)

What is total body irradiation (TBI)?

Total body irradiation (TBI) is radiation therapy given to the whole body using high-energy x-rays. TBI is an important part of the stem cell (bone marrow) transplant process.

Before a stem cell transplant, a conditioning or preparative treatment gets the body ready for the new and healthy stem cells.

The conditioning treatment includes chemotherapy with or without TBI. TBI may occur before or after the chemotherapy. The goals of this conditioning are to:

• Make room for the donor cells to grow
• Weaken the immune system to make the body more accepting of the new donor cells
• Kill any cancer cells left in the body

TBI may be given 1 to 2 times per day over 1 to 4 days, depending on the treatment plan. In some treatment plans, TBI is given as a single dose.

Getting ready for TBI

Pre-Treatment Evaluation

About 1-2 weeks before TBI, you will meet with a radiation oncologist (a cancer doctor who specializes in radiation therapy). The radiation oncologist will explain the treatment and discuss the benefits and potential side effects of TBI.

You will also meet other care team members. These include nurses, child life specialists, and radiation therapists (the people who give the TBI treatments). Your care team will ask a parent or guardian to sign a consent form to give permission for TBI.

The care team will help you know what to expect and answer your questions.

Simulation visit

A simulation visit is a planning visit to help your child get ready for the actual treatment. During the simulation visit, your care team will plan the radiation treatment and explain the process to you and your child. This visit can take up to 2 hours.

The radiation therapist may use shielding blocks to keep some parts of the body from getting full dose radiation during TBI. The therapist will take x-rays to guide making the shielding blocks to cover and protect certain areas of the body. Blocks may be used for the lungs, thymus, ovaries, or testes. This helps to lower the risk of side effects in those areas.

During simulation, staff will also make customized body molds to position your child for TBI.

Your child will:

1. Lie on their back on a bag like a body pillow. A vacuum will remove the air from the bag, so it conforms to the body. An additional bag will be made to be placed over the stomach.
2. Lie down on their stomach on another bag. An additional bag will be made to be placed over the back.

TBI uses a special bed that turns for treatment. The bags (body molds) will help hold your child securely in place.

What to expect during TBI

Your child will not feel anything during TBI treatment. The machine might make a humming sound or other noises. Some patients may feel nauseous (sick to their stomach).

While getting radiation, your child must lie very still. The body molds will help keep your child in place. You may bring your child’s favorite music playlist or audiobook to play during the radiation treatments. Encourage your child to relax and breathe normally during treatment.

On the first treatment day, the radiation therapist may use a marking pen to outline the lungs or other areas which will be shielded or blocked during treatment. Do not wash these marks off until the last radiation treatment is complete. The care team will take x-rays called a “port film” to make sure that the blocks are in the right place each day of radiation therapy.

Using the body mold, the radiation therapist will position your child on the radiation table. After your child is secured, the bed will turn to one side, and TBI will begin. One side of the body is treated. The radiation therapist will help your child turn over and lie face down. After your child is secured, the bed will turn once more. The other side of the body will be treated.

It usually takes about 20 minutes to treat each side of the body. The total time for the TBI treatment may be up to 90 minutes. This includes treating both sides of the body and time for the imaging team to check position.

Your child will be alone in the room while receiving TBI when the machine is on. The radiation therapists will watch on the TV monitor and can see, hear, and talk to your child.

After treatment, there is no radiation in your child’s body or on their clothes. Your child is not radioactive and is safe to be around. Your child will go back to their hospital room after treatment.

Side effects of TBI

Your child may have one or more of the side effects listed below. Because TBI is given as part of other treatments, it is hard to know whether a side effect is caused by radiation, chemotherapy, or other treatments. Most side effects of TBI go away after treatment. Your child will get medicine to help with some of the side effects.

Side effects are referred to as “early” or “late,” depending on when they occur in relation to the radiation treatment.

Early side effects of TBI

Early side effects occur shortly after the start of TBI up to 6 months after TBI ends. They can include:

• Fatigue
• Nausea and vomiting
• Diarrhea or upset stomach
• Sores in the mouth
• Jaw pain or swollen salivary glands
• Dry mouth
• Sore throat
• Trouble swallowing
• Skin redness
• Hair loss
• Low blood counts

Late side effects of TBI

Late side effects are those that occur 6 months to several years after TBI. They can include:

• Cataracts
• Decrease in growth
• Hormone problems
• Infertility
• Lung problems
• Thyroid disease
• Other cancers

Taking care of your child during TBI

Follow these tips to help care for your child during TBI:

• Remove jewelry and contact lenses for TBI. They may be worn between treatments.
• Follow your child’s mouth care program. Keep the mouth clean to help heal and prevent sores.
• Your child may have jaw pain during TBI caused by swelling of the salivary glands. It may hurt to open the mouth. This sometimes happens after the first TBI treatment and then goes away within a few days. Tell your nurse or doctor so that you can discuss options for pain relief.
• Give medicines as instructed to control nausea and vomiting.
• Do not wash off any pen marks used for positioning or shielding until the TBI treatments are over.
• Do not use oil-based creams or lotions on the days of TBI. Some lotions can interfere with treatment. Use only lotions that are ordered by the care team until the last treatment is over. Then, use creams or lotions as recommended to keep the skin soft and moist.
• Take care of the skin. Use mild soaps, such as Dove® or Ivory®. You may use the soap that is provided on the Transplant Unit for bathing. Avoid deodorant soaps. Do not use hot blow dryers on the skin or scalp.
• Your child’s skin will be sensitive to sunlight and will burn more easily now and in the future. Always use sunscreen with 30 SPF or higher and limit sun exposure when possible.