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Uncertainties
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IMRT/PT are generally more vulnerable to uncertainties
mainly because of the steeper dose gradient and highly
inhomogeneous in field fluence distribution.
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Many sources of uncertainty need to be taken into
account in treatment planning and delivery:
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Patient positioning uncertainties
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TPS Dose calculation algorithm approximations
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Segmentation of tumor and critical structures based on medical
images
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Anatomical changes (and motion) during imaging and
treatment (inter-fraction and intra-fraction).
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Machine technical delivery uncertainties
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RBE-weighted dose definition (only particle therapy)