Physics Bucharest 2017

Add random errors  M PTV

= 2.5Σ + 0.7σ

x

planned (static) 95% isodose

2.5Σ

blurred 95% isodose “seen by” CTV

CTV

y

planning isoc

Probability of CTV underdose > 10%

95%

planned dose blurred dose

Solution:

PTV

M PTV

= 2.5Σ + ….

2.5Σ

CTV