Precision

With unrivaled modulation capability and a helical delivery pattern, the TomoTherapy® Hi·Art® treatment system literally reshapes radiation therapy. 

While conventional radiation therapy machines have been adapted and re-adapted to keep up with advances in the field, the Hi·Art treatment system was designed without legacy constraints.

Along with integrated CT guidance, two fundamental differences enhance the precision of our approach:

  • A ring gantry design for helical delivery
  • A superior binary multi-leaf collimator (MLC) for beam shaping and modulation

image As the ring gantry rotates in simultaneous motion to the couch, helical fan-beam IMRT is continuously delivered from all angles around the patient.

The width of the fan-beam projected to the axis is 40 cm, and the maximum length the couch can transport the patient is 160 cm. This means very large volumes can be treated in a single, simple set-up. In fact, it is possible to treat anywhere within a cylindrical volume 40 cm in diameter by 160 cm long. Even larger diameter volumes can be treated with a reduced number of beams.

Typically, tens of thousands of beamlets are included in a precisely-optimized Hi·Art system treatment fraction. A single beamlet corresponds to the radiation emitted through an open leaf of our patented MLC with the gantry at any given angle, during any given rotation.

The need for a large number of beam angles to achieve a highly-conformal dose distribution is much like the need for a large number of image projection angles in CT imaging.

CT scanners acquire hundreds of very narrow images with each gantry rotation. Without that large number of projection angles, you simply couldn’t get a clear, high-resolution 3D image in which small and complex-shaped objects can easily be seen. In the same manner, with only a few beam angles in radiation therapy plan optimization, the dose cannot conform to small or complex tumors as well as it should.