VMAT for Lung SABR With a New 160 Leaf MLC

Corresponding author’s e-mail:jlilley@leedsth.nhs.uk Planning study Monaco† v3.2 was used for VMAT planning, working to dose criteria defined by the UK SABR consortium for a total dose of 55Gy in five fractions (prescribed to the 80% isodose) to a peripheral lung tumour. Another planning aim was to limit the complexity of delivery, keeping segment shapes relatively simple in order to minimise potential interplay effects between leaf motion and tumour motion during VMAT delivery.