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FIND A RADIATION ONCOLOGIST

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Find A Radiation Oncologist

External Beam Radiation Therapy

External beam radiation therapy usually involves a series of outpatient treatments using a linear accelerator, or linac. Similar to an X-ray, treatment X-rays cannot be seen or felt. Radiation does not travel throughout the body and is only directed to the treatment site. The only time radiation is present is during your treatment session while the machine is turned on. You will not be radioactive afterwards. Treatments are typically given daily, Monday to Friday, and can be a single treatment or up to multiple consecutive weeks.

Before beginning treatment, you will be scheduled for a planning session, called a simulation, to map out your treatment area. Simulation involves a CT scan which is performed while lying on a table, usually with the aid of a form-fitting mask or a head frame to help the radiation therapist precisely position you for daily treatment. Your doctor will design an individualized treatment plan based on the results of the simulation scan together with other imaging studies you have undergone including MRIs.

Different techniques can be used to give radiation for brain tumors. Radiation treatment plans are created to deliver precise doses of radiation to the areas of the brain at risk while avoiding normal organs. Tailoring each of the radiation beams to the patient’s tumor allows coverage of the diseased cells while keeping radiation away from nearby organs, such as the eyes.

Intensity modulated radiation therapy (IMRT) is a form of external beam therapy that further modifies the amount (intensity) and shape of the radiation within each of the radiation beams. At most centers, X-rays (photons) are used for treatment.

Image guided radiation therapy (IGRT) can be used with any of these techniques. IGRT uses imaging (X-rays, CT and MRI scans) to verify that you are positioned correctly each day before the radiation beam turns on.

Hippocampus Avoiding IMRT (HA-IMRT) is an advanced form of radiation used for treatment of brain metastases (cancer that has spread from another part of the body to the brain). The hippocampus has been shown to be related to preserving short term memory after radiation to the brain. This type of treatment is commonly combined with a medicine called memantine. If your doctor has recommended whole brain radiation, you can ask whether hippocampal avoiding IMRT is appropriate in your case.

These more precise treatment techniques can be used if the tumor is in a sensitive part of the brain or if you have had radiation treatments in the past. Ask your radiation oncologist about which radiation technique is best for treating your tumor.