A treatment planning system uses the beam data from a linear accelerator to model the distribution of radiation within a patient or phantom. There are several steps in the commissioning of a treatment planning system.
Acquisition of beam data
The treatment planning system must be supplied with data relating to:
- Depth dose data, for all beam energies and field sizes from 3 cm to the maximum field size, for the reference source-surface distance as well as other commonly used SSDs
- Tissue-phantom ratios for all beam energies and representative field sizes
- Output factors (due to field size, wedge factor, tray factor etc)
- Beam profile at various depths and energies
Input into TPS
The data must be input into the treatment planning system
The dose distribution must be verified by using the treatment planning system to calculate a dose distribution, and comparing this with the actual dose distribution measured in solid water and anthropomorphic phantoms.
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