SBRT 2016

How large should the margin be?

 What is the incentive?  99% of the target volume receives 95% of the prescribed dose or more (coverage probability) - Stroom et al.  90% of patients in the population receives a minimum cumulative CTV

dose of at least 95% of the prescribed dose - van Herk et al. Not all patients will be treated to 100% of the prescription dose in all fractions M = 2.5 Σ + 0.7 σ