Microsoft Word - 0_Florence_Masterclass_2017_Programme

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How to deal with Lorentz forces on
scatter electrons
• The trajectories of scattered
electrons will curve in a magnetic
field
• This effect is most prominent at the
interface between tissue and air
(‘Electron Return Effect’)
Options
1. Minimize the B0 field
2. irradiate parallel to the B0 field
3. choose clever beam geometries
4. Accept and incorporate in dose
calculation (Monte Carlo)
Raaijmakers et al. Phys. Med. Biol. 50, 1363 (2005);