Electron therapy or electron beam therapy ( EBT) is a kind of external beam radiotherapy where electrons are directed to a tumor site for medical treatment of cancer.
Equipment
Electron beam therapy is performed using a medical linear accelerator. The same device can also be used to produce high energy photon beams. When electrons are required, the X-ray target is retracted out of the beam and the electron beam is
Collimator with a piece of apparatus known as an applicator or an additional collimating insert, constructed from a low melting point alloy.
Properties
Electron beams have a finite range, after which dose falls off rapidly. Therefore, they spare deeper healthy tissue. The depth of the treatment is selected by the appropriate energy. Unlike photon beams there is no surface sparing effect, so electron therapy is used when the target extends to the patient's
skin.
Indications
Electron beam therapy is used in the treatment of superficial tumors like cancer of skin regions, or total skin (e.g. mycosis fungoides), diseases of the limbs (e.g.
melanoma and
lymphoma), nodal irradiation, and it may also be used to boost the radiation dose to the surgical bed after
mastectomy or
lumpectomy. For deeper regions
IOERT might be applied.
See also
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Intraoperative electron radiation therapy (IOERT)
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External beam radiotherapy (EBRT)
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Proton therapy
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Eric E. Klein: "Electron-Beam Therapy: Dosimetry, Planning, and Techniques" in: Edward C. Halperin, Carlos A. Perez, Luther W. Brady (ed.): Perez and Brady's Principles and Practice of Radiation Oncology, 5th. edition, 2008
