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