TBI (Total Body Irradiation)

TBI (Total Body Irradiation) is a form of radiation therapy in which the entire body is exposed to radiation. It's primarily used as part of (conditioning) regimens before bone marrow or stem cell transplantation.

What Is TBI Used For?

The goal is to:

  • Destroy cancerous or abnormal bone marrow cells

  • Suppress the immune system to prevent rejection of the transplanted cells

  • Clear space in the bone marrow for new, healthy cells to grow

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Common Indications for TBI

Condition Purpose of TBI
Leukemia (AML, ALL) Eradicate residual cancer cells
Lymphoma (Hodgkin’s, NHL) Condition the body for transplant
Aplastic anemia Immune suppression before transplant
Bone marrow/stem cell transplant Conditioning + immune reset

How TBI Is Delivered

  • Radiation is given in fractions (multiple smaller doses) or a single large dose depending on the protocol.

  • The patient is often treated in a standing, sitting, or lying position.

  • Shielding may be used to protect sensitive organs (e.g., lungs, eyes, kidneys).

Benefits

  • Uniform radiation dose across the entire body

  • Can eliminate microscopic disease throughout the system

  • Enhances success of stem cell/bone marrow transplants

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Side Effects of TBI

TBI affects the whole body, so side effects can be significant:

Short-term:

  • Nausea, vomiting, fatigue

  • Skin redness or peeling

  • Mouth sores

  • Hair loss

  • Low blood counts (immune suppression)

TBI is a specialized radiation therapy used mostly to:

  • Prepare patients for stem cell or bone marrow transplantation

  • Eliminate widespread cancer cells

  • Suppress the immune system