Diapositive 1

Dose per MU formalism:

Varian Eclipse v13.6 TPS

Open beams

1. The dose engine calculates the ratio of dose per energy fluence in the treatment field

and under reference conditions.

2. This ratio of doses is corrected by a factor interpolated from the CBSC table for the

equivalent square of the beam aperture, as defined by the upper collimator or by the

MLC (if the MLC is the upper jaw, as is the case on an Elekta linac).

The MUs to deliver the prescribed dose at a point in an arbitrary field are thus given by:

presc

calc

Ψ Τ#

calc ref

Ψ Τ#

∙

ref

∙