ABSTRACT
Steve Webb has shown how robotic intensity modulated radiation therapy (IMRT) might become the ultimate IMRT delivery technique in that it can sculpt contorted dose distributions with high precision. Related to the development of robotics and other special purpose accelerators, a Medical Physics ‘Point and Counterpoint’ argues the case for and against a purpose-built linac for IMRT. Webb proposed a radically new concept for a multileaf collimator (MLC) for a photon linear accelerator for delivering IMRT with high monitor unit (MU) efficiency. Shuttling MLC can increase the MU efficiency of IMRT compared with the multiple-static-field technique or dMLC technique with conventional MLCs. However, the MU efficiency is considered to be too low compared with the use of an MLC. Webb et al extended the concepts of using a tertiary mask plus jaws for delivering IMRT without an MLC. The main pieces of apparatus for delivering IMRT are the NOMOS multivane intensity-modulating collimator and MLC.
