2004-2005 / 2953
Modulation
Total dose delivered by multiple small beamlets
1. Output factor for very small fields difficult
to measure/model
2. Field penumbra directly in the target
3. Inter-leaf leakage exposing the target
4. Secondary dose calculation complicated
5. Interplay effect
05/04/2016
Limitations in beam modelling more important for IMRT.
Monte Carlo beam model could address 1-3 above.