title: Clarification of the AAPM Task Group 21 protocol.
abstract: In light of recent questions and comments from the physics community, a review is made of the AAPM protocol for high-energy x-ray and electron beam dosimetry.
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D006801:Humans; D008953:Models, Anatomic; D011874:Radiometry; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy