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