As an X-ray-based treatment, helical tomotherapy combines intensity modulated radiation therapy (IMRT) of applied conformation radiotherapy, image-guided radiation therapy (IGRT) and computed tomography (CT) together. The Hi-Art Treatment System developed via Accuray consists of the foregoing therapies and related control computer and software.

Basically, the helical tomotherapy system consists of a linear particle accelerator that rotates constantly in a circular frame and releases radioactive rays towards the center of the circular area for circular radiation. As the treatment couch slides into the circular equipment slowly, the patient on it is radiated via radioactive rays. For the purpose of increasing rays’concentration and evenness and rendering rays distribute with a high degree of freedom (also for simultaneous integrated boost (SIB)), the multileaf collimator pertain to the linear particle accelerator is controlled to operate. Totally distinguished from previous radiotherapy in which patients are radiated as per the marks put on their skin, thus resulted in big errors, this therapy is capable of aiming at the cancer focus (and part of benign tumors) for manipulated radiation that is restrained from normal tissues in close proximity. Meanwhile, through CT-based adjustment and radiation correction, the precision of such a therapy can be actualized.