SBRT2015

Systematic Errors Only (M sys

= 2.5 S )

 The systematic set-up errors are described by a 3D Gaussian distribution  How to choose M sys to ensure a high probability that the prescribed dose is delivered to the CTV?

95%

 Choice: for 90% of all possible systematic set-up errors, the full CTV is within the PTV (=95% isodose)