Dose Course 2018_Flipping book
9
Tolerances δ for the local dose deviation d%(i)
Region
Homogenous, simple geometry
Complex geometry (wedge, inhomogeneity, asymmetry, blocks / MLC)
More complex geometries****
Central beam axis data – high dose, low dose gradient Build-up region of central axis beam, penumbra region of the profiles - high dose, high dose gradient Outside central beam axis region - high dose, low dose gradient Outside beam edges – low dose, low dose gradient Radiological width – high dose, high dose gradient. Beam fringe – high dose, high dose gradient
δ 1
2%
3%
4%
δ 2
*
2 mm or 10%
3 mm or 15%
3 mm or 15%
δ 3
3%
3%
4%
δ 4
**
30% (3%)
40% (4%)
50% (5%)
RW 50 *** δ 50-90
2 mm or 1%
2 mm or 1%
2 mm or 1%
2 mm
3 mm
3 mm
(normalized at central axis same depth)
Adopted from Venselaar, 2001
Dublin 2018
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