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Dose modelling dose in small & composite fields
Other aspects of modelling treat ent planning systems (TPS)
affecting dose calculations in small photon fields
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Aspects of beam modelling on treatment planning systems (TPS) that play major
role on the calculation of dose in plans comprising of small MV photon beams:
•
finite size of beam source (also referred to as
focal spot
)
•
jaw and MLC leaf edges
•
resolution: choice of pixel/voxel sizes in fluence and dose matrixes
•
Inhomogeneities