Radiation therapy uses high-energy radiation to shrink tumors and kill cancer cells by damaging their DNA, the genetic material in a cell. When DNA is damaged, cells either stop dividing or die. It is the single most effective cancer-treating agent.
While tumors are rarely resistant to radiation, this type of treatment can also harm normal healthy tissue. Better imaging, faster computers, and improved radiation delivery systems have improved the ability to localize radiation doses, sparing most normal tissue.
Designing a radiation treatment plan for a child is a three-part process:
- Consultation with a pediatric radiation oncologist to discuss the expected results and possible side effects of treatment. This is usually done on an outpatient basis but sometimes requires an overnight stay in the hospital.
- Planning to identify the area to be treated. This involves “mapping” with a CT-simulator, which produces scans that help doctors identify the best treatment approach for a child.
- After the simulation is completed, a calculation is made to determine the specific dose of radiation to be delivered and the most appropriate delivery vehicle is chosen.
Radiation therapy is delivered one of three ways:
- External-beam radiation therapy uses a machine that directs high-energy beams of radiation into the body
- Internal radiation therapy, also called brachytherapy, delivers radiation either inside a body cavity or within body tissue
- Systemic radiation, which involves swallowing or receiving an injection of a substance, such as radioactive iodine or radioactive material bound to a monoclonal antibody, that travels through the blood to locate and kill tumor cells