Physics Bucharest 2017

Comparison of competing techniques Standard IMRT, Tomotherapy, VMAT

• Tomotherapy has greater flexibility of shaping dose in axial slices than both standard IMRT and VMAT: full IMRT per beam direction, and beams can come from all co-planar directions • Tomotherapy may in longitudinal direction be more restricted because of field width, if w=1cm → longer treatment times • Tomotherapy and VMAT have larger spreading of low doses over large volumes than standard IMRT • In contrast with standard IMRT, Tomotherapy and VMAT do not require selection of limited number of optimal beam directions • For simple cases, VMAT seems substantially faster than standard IMRT with comparable plan quality for PTV and OAR (but spreading) • In complex cases, single-arc VMAT with short treatment times may compromise quality of the dose distribution. • Only standard IMRT allows “free” use of non-coplanar beams

Bortfeld and Webb, 2009