Medical Dosimetry Certification 2026 – 400 Free Practice Questions to Pass the Exam

Cutouts are commonly used to shape electron fields in radiation therapy because they provide a means to customize the radiation beam's geometry to fit the specific treatment area. They are typically made from materials that effectively attenuate the radiation, allowing for precise shaping of the beam while simultaneously limiting the exposure of surrounding healthy tissues.

Using cutouts enables medical dosimetrists and radiation oncologists to tailor the treatment plan to the unique contours of a patient's anatomy, ensuring that the maximum dose of radiation is delivered to the tumor while minimizing the dose to adjacent tissues.

Blocks may also shape fields but are generally used for photon beams rather than electron beams. Filtration layers serve to modify the energy spectrum of the radiation and are not used for shaping fields directly. Collimators are devices that narrow the beam of radiation but do not provide the same level of customizable shaping that cutouts offer. Thus, cutouts are the most appropriate choice for shaping electron fields.