1305 / 1544
ESTRO IMRT course 2015
Dose Calculation in Static and Rotational IMRT
Brussels October 8th, 2015
-35-
Kernel-based methods:
‘Collapsed Cone’ approximation for efficient density rescaling
•
separate treatment of deposited
primary enery and deposited
phantom scattered dose
•
further approximations for
polyenergetic photon beams
(details depend on
implementation): Energy-
averaged TERMA and point
kernel; approximate or no
modelling of beam hardening; …
Further ‘smart’ approximations for efficient numerical implementation:
More details: Ahnesjö and Aspradakis 1999
(PMB 44(11))
primary photons
primary charged
particles
deposited
primary energy
Bremsstrahlung and
annihilation photons
charged particles from
Bremsstrahlung and
annihilation photons
scattered primary
photons
charged particles from
scattered prim. photons
deposited scatter
energy
Bremsstrahlung and
annihilation energy
deposited
Primary dose
Direct beam
phantom scatter dose
deposited
pri ary energy
deposited scatter
energy
Bre sstrahlung and
annihilation energy
deposited