3: Introduction To Electron Beam Radiotherapy

Electron beams are an important modality of treatment that is useful for certain sites. Electrons have a much different dose distribution and are attenuated through different means. As charged particles they tend to interact with most atoms they encounter, as opposed to the uncharged photons which are attenuated more gradually.
Electrons are generated in a linear accelerator in nearly all cases, but instead of bombarding a target and creating bremsstrahlung radiation the electrons pass into the treatment head for further modification.