  The normal tissue complication probability (NTCP) is a measure for the
estimated side effects of a given radiation treatment schedule. Here we use a
stochastic logistic birth death process to define an organ specific and patient
specific NTCP. We emphasise an asymptotic simplification which relates the NTCP
to the solution of a logistic differential equation. This framework allows for
a direct use of the NTCP model in clinical practice. We formulate, but do not
solve, related optimization problems.
