Report on Use of a Methodology for Commissioning and Quality Assurance of a VMAT System
Figure 2
Model of a daily QA device on the treatment planning system.
The three chambers were contoured with a PTV expansion of 1 cm on the circumference and 0.5 cm ant-to-post. The VMAT plan delivers a homogeneous dose distribution (200 cGy) at each chamber using a 6X beam moving from 60° to 300°.