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Approximations in PK dose calculations
Infinite slab approximation: doses at phantom boundaries
The depth (
z
) is generally
assumed to be constant within
the lateral integration plane
during calculation of the
scatter dose to a point.
Scatter underestimated
Calculation
point
0
Primary
deposition
volume
z
Errors cancel (roughly)
Calculation
point
0
Primary
deposition
volume
z
Scatter overestimated
Calculation
point
0
Primary
deposition
volume
z
Calculation
point
0
Primary
deposition
volume
z
Backscatter overestimated
Calculation
point
0
Primary
deposition
volume
z
Ideal case