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ITV Internal Target Volume
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IM = Internal Margin, uncertainties in size, shape, and position of the CTV
within the patient
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ITV useful in clinical situations where uncertainties in CTV location
dominates setup uncertainties
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Uncertainties in GTV delineation generally propagate to CTV delineation.
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This, together with other geometric uncertainties, are taken into
account in the CTV-to-PTV margin
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How do I quantify the uncertainties due to organ motion?
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Adaptive strategy: repeat the CT (or CBCT), repeat contouring, co-
register
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Probabilistic strategy: measure, statistics
2016/Athens