What is total body irradiation? (Total Body Irradiation) Let's talk about this simply.

When talking about cancer treatment, you may have heard of radiation therapy, or radiation. But when you hear "radiation to the whole body," you may feel a little scared. But this is a very important treatment that sometimes has to be done. So today, let's talk about what Total Body Irradiation (TBI) is, why it's done, and how it works.

Simply put, what is Total Body Irradiation (TBI)?

Total Body Irradiation (TBI) is a type of radiation therapy. However, unlike regular radiation therapy, radiation is not directed at just one area of ​​the body. Instead , a very small dose of radiation is delivered to your entire body .

Think of it this way: regular radiation therapy is like shining a torch on a single spot. But TBI is like turning on a light in the entire room, making a small amount of light fall everywhere. The dose of radiation used here is much lower than a single spot treatment.

Why is this treatment being done? What is the purpose of it?

TBI treatment is mainly done to prepare you for a bone marrow transplant or stem cell transplant. There are three main reasons why your doctor may recommend this treatment.

• Destroy cancer cells: This helps to completely destroy cancer cells that are hidden in your bone marrow, nervous system, or places that other treatments cannot easily reach.
• Make room for bone marrow: This treatment helps to make room inside the body for newly transplanted healthy bone marrow and reduce the activity of old bone marrow.
• Control your immune system: This helps to keep your immune system from recognizing the newly transplanted bone marrow as "foreign" and rejecting it, thereby making the transplant much more likely to be successful.

What conditions are treated with TBI?

TBI treatment is not usually done alone. It is often used in conjunction with other cancer treatments, such as chemotherapy. The table below lists some of the most common conditions for which this treatment is used.

What happens before treatment? (Simulation)

Before you receive your TBI treatment, you will have a special appointment called a "simulation." This is like taking measurements before you get a suit made. It's like a practice session before you receive the treatment. The main purpose of this is to plan the best position for you to be in to ensure that your body receives the right dose of radiation, in the right way .

In this simulation:

• You will be positioned on a special table and a CT scan will be performed to map the area to be treated.
• The radiation therapist will take several measurements of your body.
• After determining the best position for your body, they will make some very small marks on your skin. They will also take pictures. These will help you stay in the same position on the day of the treatment. These marks may be permanent, but they are very small.

What happens during treatment?

You may need to stay in the hospital for a few days after receiving TBI treatment. Here's what happens during treatment:

• The radiation therapist will place you in the same position as you were in the previously planned simulation.
• To reduce the radiation dose to certain organs, such as your lungs, special panels or shields can be placed over those organs.
• To ensure that the radiation is evenly distributed throughout your body, you can also set up something like a large screen in front of you.
• Then the therapist leaves the room. But don't worry, you're not alone. You can talk to them through an intercom. They're watching you from outside.
• A large machine called a "linear accelerator" moves around you, delivering radiation in a planned manner.

A typical session can last up to 60 minutes. Your first session may take a little longer because the therapist will take some additional X-rays to make sure your posture is 100% correct. You may also be allowed to do things like listen to music during this time.

How long will I have to take this treatment?

Most people receive TBI treatment two or three times a day for three to five days. Your medical team will explain how many treatment sessions you will need before you start treatment.

What are the risks and side effects of this?

As with any treatment, TBI treatment can have side effects. These side effects can vary from person to person. There are several factors that can affect them:

• The number of treatment sessions you will receive.
• The dose of radiation given.
• Your overall health.

Side effects can be mainly divided into two categories: short-term and long-term.

Short-term side effects

These usually appear a few days or weeks after starting treatment and disappear over time.

Long-term side effects

These are very rare, may appear long after treatment, and may last for a long time.

• Cataracts: Clouding of the lens of the eye.
• Infertility: Affecting the ability to have children.
• Pulmonary fibrosis: Scarring of the lung tissue, causing difficulty breathing.
• Hypothyroidism: Decreased production of thyroid hormone, which controls the body's metabolism.

How can you take care of yourself after treatment?

Managing side effects can go a long way in making this treatment period easier. Here are some things you can do:

• If you are feeling nauseous, don't hesitate to ask for medicine .
• Take care of your skin. Follow your doctor's skin care instructions. Apply moisturizer regularly.
• If you can, join a support group with people who have had similar experiences.
• Share your thoughts and feelings about this treatment with someone you trust (a therapist, family member, friend).
• Try to get at least eight hours of good sleep every night.
• After leaving the hospital, if possible , take some time off from work and rest well.

When do you need to talk to the doctor?

If you experience any of the following symptoms during or after treatment, notify your doctor immediately.

• Chills
• Fever
• Skin changes (e.g., blistering, peeling skin)

It's normal to feel scared when you hear the words "total body radiation" and who doesn't? But talk to your radiation oncologist about any questions or concerns you may have. TBI uses much lower doses of radiation than other radiation treatments. New technology has also significantly reduced the amount of radiation that is used to treat healthy tissue. It can kill cancer cells that are resistant to other treatments. It also greatly increases the chance of a bone marrow transplant being successful without rejection.