Madison-based TomoTherapy, a health care technology innovator, has sold out to another niche radiology technology company, California-based Accuray. The combined company will be better able to afford the direct sales and service forces and R&D investments critical to success when selling against radiology leaders like General Electric (GE), Varian Medical Systems and Siemens. Accuray’s superior financial performance made it the acquirer. Many in the region had hoped when TomoTherapy went public at a high valuation that it would join Epic and Promega as mid-sized companies headquartered in our region anchoring Madison’s biotech community.  Had TomoTherapy evolved its business model strategy, it just might have succeeded. Instead, a plummeting then flat stock price led to the sale and, with it, an anticipated loss of high paying management jobs from Madison. TomoTherapy invented a break-through niche radiology product that enabled higher doses of radiation to…