SBRT 2016

Learning Objectives

 To give an overview of margin concepts  Why do we use or need margins?

 To provide a qualitative understanding of a margin recipe  To provide an overview of assumptions being made in the derivations of the van Herk margin recipe  To discuss applicability of “conventional” margin concepts in hypo-fractionated / single fraction SBRT  To discuss the effect of a limited number of fractions on random error  Explain why a random error for hypofractionated treatments results in a systematic error  Explain how to calculate margins for single fraction and hypofractionated treatment and provide some practical examples  How to add errors?  To discuss margins for tumors that move with respiration  To give suggestions for further reading