ABSTRACT
Helical tomotherapy offers fan beam treatment delivery with intensity-modulated radiotherapy. The 6 MV linac is mounted on a treatment gantry similar to a CT scanner. Pre-treatment imaging is performed using megavoltage CT. The idea of helical tomotherapy was formed in the late 1980s and the linac components and planning system were developed specifically for tomotherapy. This chapter reviews the features of the helical tomotherapy machine, its treatment planning system and dosimetry.
