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A Practical Example: SRT Case
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Intracranial lesion: 3 x 8 Gy @ 80%
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SD of the penumbra is 3.2 mm
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E2E test device error (1 SD) = 0.4 mm (measured over a long period)
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Localization (delineation) error = 1.0 mm (1 SD)
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Systematic error = 0.5 mm (1 SD) [measured from 30-fraction treatments]
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Random error = 0.5 mm (1 SD) [measured from 30-fraction treatments]
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Intra-fraction error = 0.5 mm ( 1 SD) [measured from 30-fraction treatments
at end of treatment]