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Which Plan Characteristics?
Plan Characteristic
TPS Modelling
Linac Delivery
MLC
MLC Modulation
Poor modelling of T&G
magnified
MLC Transmission
modelling issues magnified
Avg. MLC Speed
Magnifies Gantry
Resolution Limitation
Increased MLC errors
MLC Speed Variation
Increased MLC errors
Mean Gap between MLCs
More sensitive to dose-
grid, gantry resolution &
small field output factor
limitations
Delivery more sensitive to
MLC errors
(lower MLC speeds -
dynamic errors low)
MU
Average Dose-Rate
Beam Stability Issues at
lower Dose-Rates
Avg. Dose-Rate Variation
Increased MU errors
Beam Stability Errors
Gantry
Gantry Speed Variation
Gantry Resolution
Gantry errors