Physics Bucharest 2017

Linear Quadratic Model of cell survival • Second order polynomial with a zero constant term so SF = 1 at zero dose • Models in vivo and in vitro responses well • α – probability of damage due to single track event • β – probability of damage due to two independent track events • Key features of graph • Continuously bending • Semi-log plot

• α/β (Gy) is dose where linear component to damage (αD) = quadratic component (βD 2 )