While the determination of
D
from
Ψ
, the solution of the so-called
forward problem
, is always possible, the
inverse problem
, i.e.
determination of
Ψ
for a specified
D
is not always possible.
The forward problem is the
dose calculation
problem for which a unique
solution exists.
{Ψ*}, {D*} : all
possible
{Ψ}, {D} : physically
possible,
achievable
(feasible)
Introduction on Dose Optimisation