Lower GI 2017

Therapeutic ratio (II)

TCP

R =

NTCP

Easy to interpret: this is the cure rate in percentage point per percentage point patients with toxicity

Very sensitive to statistical uncertainty for small values of NTCP

Face validity?

TCP=40% and NTCP=1% ⇒ R=40 TCP=80% and NTCP=2% ⇒ R=40