TomoTherapy Incorporated develops, manufactures, markets and sells the Hi-Art system, a radiation therapy system for the treatment of a range of cancer types. The Company manufactures each Hi Art system in a 64,000 square foot facility in Madison, Wisconsin. The Hi Art system combines integrated computerized tomography (CT) imaging with radiation therapy to deliver radiation treatment while reducing radiation exposure to surrounding healthy tissue.It markets and sell the Hi Art system to hospitals and cancer treatment centers in North America, Europe, the Middle East and Asia-Pacific, and offer customer support services in each region. North America, Europe and Asia-Pacific accounted for 67%, 24% and 9%, respectively, of the Company's revenue during the year ended December 31, 2008. On October 31, 2008, the Company acquired Chengdu Twin Peak Accelerator Technology Inc. (Twin Peak), a privately held company based in Chengdu, China.