VMAT2

This plan scored 143.06 out of 150 in the 2022 AAMD-Plan Study: SBRT Pancreas+Liver Mets (rank of 22 out of 203 submissions).

The plan consists of six VMAT arcs with the isocenter placed at the middle of the PTV50 and PTV40 targets. The six arcs helped in delivering the 10Gy/fraction dose with Halcyon’s 800MU/min dose rate. A unique collimator rotation was used for each arc to improve the dose fall off between each PTV and to allow for more variables during the optimization of OAR sparing.

To account for end capping, the PTV’s were expanded in the superior/inferior direction to maximize the amount of prescription coverage. Along with using the normal tissue objective, four ring structures were added to specifically improve the dose conformation at 20 and 40Gy. A separate PTV optimization structure was created to control the dose gradient for the region of PTV overlap with the duodenum and stomach.

_{Any reference to a "plan study" are simply what the organizers call each case and may not be a "study" in the FDA sense as they may not have been published in a peer reviewed journal.
Varian does not provide medical advice and these are illustrative examples only.
Leading plans by expert planner. Your results may vary.}