Is a flattening filter used in a 60 Co beam?

The use of a flattening filter is not applicable to a 60Co (Cobalt-60) beam because of the inherent characteristics of how the radiation is emitted. Cobalt-60 emits gamma rays isotropically, meaning the radiation is emitted uniformly in all directions from the source. This isotropic emission provides a more uniform dose distribution without the need for a flattening filter, which is typically employed with linear accelerators for high-energy photon beams.

The presence of a flattening filter in such scenarios is to shape the beam and ensure uniformity across the treatment field, especially where there is significant variation in radiation intensity. However, this principle does not translate to the Cobalt-60 source, where the radiation profile does not require artificial modification to achieve uniformity in dose distribution.