This method produces a neutron beam with depth dose characteristics roughly similar to those of a 4MV photon beam.

In order to plan the delivery of radiation therapy, the radiation produced by the sources is usually characterized with percentage depth dose curves and dose profiles measured by medical physicists.

The electron component alters the depth dose in the buildup region in a way that depends on the photon beam energy, the field size, and the distance of the spoiler from the treatment surface.

Study of the depth dose distribution inside a human phantom using the MATROSHKA facility on board the Russian Segment of the International Space Station (MATROSHKA-2B)

In Radiotherapy, a percentage depth dose curve (PDD) (sometimes percent depth dose curve) relates the absorbed dose deposited by a radiation beam into a medium as it varies with depth along the axis of the beam.