2148-2149 / 3107
Plan quality vs Delivery accuracy - VMAT
Leaf motion constraint
•
max distance a MLC leaf can travel
between adjacent control points
•
ensures the deliverability of the
optimized plan, but it also impacts
the plan quality, delivery accuracy
and efficiency
Gamma-analysis
Chen F et al. Med Phys (38) 2011
•
a less restrictive leaf motion
constraint ( > 5 mm/deg) results in
> plan quality but < accurate dose
distribution
•
g
-analysis passing rate from 98% to
80% when the allowable leaf motion
increased from 3 to 20 mm/deg.