IMRT

• NTCP models do not HAVE to be based solely on the DVH. This has been a pragmatic approach to date which seems to work reasonably well. • There are models which are true 3D spatial models, but they are complex to apply (Rutkowska et al , Phys Med Biol 2010) • There are metrics like the (rectal) dose-surface map (Fiorino C et al , Phys Med Biol 2003, 2603-2616 )

Sanchez-Nieto B, Fenwick JF, Nahum A E et al 2001 Biological dose surface maps: evaluation of 3D dose data for tubular organs Radiother. Oncol. 61 S52