Dose Course 2018_Flipping book

Dose per MU formalisms: factor-based dose calculations

Inhomogeneities

Methods to account for inhomogeneities in factor-based dose/MU calculations :

Primary photon path

Patient

Either scale dosimetric parameters appropriately

Heterogeneities

Or

Scattered particle path

Determine a correction factor as a function of scaled dosimetric quantities

Dose calculation point

MU D

MU D

  

 

  

  

( ) ...

( ) ...

( ) ...

CF

=

ous heterogene

s homogeneou