Stereotactic radiation therapy , or stereotactic radiosurgery (SRS), delivers large doses of radiation in one single fraction or in multiple smaller doses to a small area. The radiation beams are very precise, and this enables the radiation oncologist to protect more healthy tissue than other forms of EBRT. This treatment is appropriate only for certain types of cancer and is most commonly used for brain and spinal cord tumors. Stereotactic radiation therapy usually requires special equipment to help your child stay in the right position for the treatment. Intraoperative radiation therapy involves delivery of radiation in the operating room directly to the tumor or tumor bed during surgery. This allows the radiation oncologist to clearly see the area to be treated and more precisely define the treatment field. Intraoperative radiation therapy also enables the radiation oncologist to deliver high doses of radiation therapy to the treatment site while protecting the nearby tissues and structures. Proton beam therapy uses protons to deliver most of their energy at the end of their path, resulting in less radiation to normal tissue around the tumor or targeted area. This treatment usually is reserved for situations when tumors are located in areas for which surgery is not an option or when structures near the tumor may not be able to handle other types of radiation therapy. If this treatment is recommended for your child, you may be referred to another treatment center because not all radiation therapy facilities offer proton beam therapy. Neutron beam therapy is another form of EBRT used to treat tumors that do not respond to other types of radiation therapy. Neutron beam therapy also may be used in combination with chemotherapy and/or surgery to reduce the risk that the cancer will return or to remove small amounts of remaining cancer. Neutron therapy often requires fewer treatments than other forms of radiation therapy; however, it is available only at a few centers in the United States. Total body irradiation (TBI) is external beam radiation to the entire body in preparation for bone marrow (stem cell) transplantation. The goal of TBI is to suppress the immune system, kill any remaining cancer cells, and create room for the new bone marrow to grow. TBI usually is performed two or three times each day for several days before the bone marrow transplant. Vital organs that are very sensitive to radiation, such as the lungs, may be protected with lead shielding devices for a portion of the treatment. Brachytherapy Brachytherapy is radiation given from inside the body. Radioactive material is sealed in a small container called an implant and placed into the area of the body to be treated. The implant may be permanent or temporary and can be placed in almost any cavity of the body where the tumor is located, in the space left after the tumor is removed (surgical bed), or near the tumor itself. Brachytherapy enables the radiation oncologist to deliver higher doses of radiation to the tumor in a short amount of time. This may be done over several days or weeks. Systemic Radiotherapy Systemic radiotherapy may be given by mouth or intravenously (IV) so that the radioactive material travels throughout the entire body. Some tumors, such as thyroid cancer, may be treated with systemic radiation. Newer treatments, such as radiolabeled antibodies, have radioactive particles attached to an antibody. An antibody is found in the blood or other body fluids and is used to identify and destroy foreign cells in the body. The antibody recognizes the cancer cells, attaches to them, and gives off radiation that causes damage or death to the cancer cells.
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