Dose Course 2018_Flipping book

pencil kernel determination:

Beam modelling refresher: spectrum determination to make a polyenergetic kernel from a library of Monte Carlo generated monoenergetic kernel:

  

  

  

  

electron cont

(

)

(

)

(

)

fsize depth 

ebin 

1 2 s s e e

D

, ... s s d 

d

e e



1 2 , ..., , ...

=

c

−



+

, ...

fsize depth, fsize

ebin 1 2

depth, fsize, ebin

depth

1 2

Measured depth dose, phantom scatter normalized

MC calc depth doses for monoenergetic photons

Error norm to minimize by varying parameters

Spectrum model, constrained to a “physical” shape

Electron contamination model

A Ahnesjö and P Andreo (1989) Phys Med Biol 34 , 1451-64.

A Ahnesjö et al (1992) Med Phys 19, 263-273