In March 2011, TomoTherapy Inc was acquired by previousl SBIR-involved firm Accuray. TomoTherapy develops radiotherapy devices that are designed to locate specific sites for radiation treatments for cancers, with minimal damage to surrounding tissues. A spin out from the University of Wisconsin Madison, TomoTherapy develops, manufactures, and sells the Hi-Art system, a radiation therapy system for the treatment of various types of cancers. The Hi-Art system was marketed to hospitals and cancer treatment centers in North America, Europe, and Asia. Tomotherapy is developing a more cost effective radiation treatment for cancer patients. The firm manufactures radiation therapy equipment designed a helical tomotherapy system to target radiation treatment on the patient's tumor while helping to limit damage as much as possible to the surrounding tissues. The system delivers intensity modulated radiotherapy (IMRT) using a multileaf collimator. IMRT involves changing the size, shape, and intensity of the radiation beam to conform to the size, shape, and location of the patient's tumor.