TomoTherapy and Vision RT Partner to Expand Hi-Art(R) System Imaging Options

TomoTherapy Incorporated (NASDAQ: TOMO) announced today that it has partnered with Vision RT to expand imaging options for Hi-Art(R) treatment system users. The companies will jointly introduce AlignRT(R) 3D imaging technology for the Hi-Art platform at the annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) in Boston, Mass., Sept. 21-25, 2008. TomoTherapy will distribute AlignRT(R) for use with both its TomoHelical(TM) and new TomoDirect(TM) delivery modes.

“We are excited about our strategic alliance with Vision RT, a company that is as focused on best-in-class clinical workflow and high-quality patient treatments as we are,” said Fred Robertson, CEO of TomoTherapy. “AlignRT(R) does for Hi-Art system imaging what TomoDirect does for Hi-Art treatment delivery: both provide a new option for our users that can significantly improve patient throughput across a broad range of cancer cases.”

AlignRT(R) for the Hi-Art platform will consist of two ceiling-mounted 3D camera units, each focused toward the external isocenter of the radiotherapy device. Immediately prior to treatment, the patient will lie on the treatment couch for initial set-up. The cameras will then quickly acquire a surface scan of the body in treatment position, and state-of-the-art software will be used to register real-time image data to the reference surface scan, and–within seconds–provide new couch coordinates for optimal patient positioning.

According to Corey Lawson, director of product strategy for TomoTherapy, the AlignRT(R) offering complements the Hi-Art system’s integrated CTrue(TM) imaging technology: “CTrue will continue to be used extensively when the tumor is deep-seated, or can move internally without external evidence. However, we believe AlignRT(R) will prove useful in approximately 40 percent of cases, based on a standardized mix. Where this technology is best suited, we estimate a 50 percent reduction in setup and registration time.”

“The Hi-Art treatment system offers an innovative approach to radiation therapy,” said Dr. Norman Smith, CEO of Vision RT. “We are delighted to partner with TomoTherapy to expand imaging options while boosting patient throughput for this next-generation platform. In addition, through this partnership, we look forward to developing advanced features that will further enhance the accuracy and precision of TomoTherapy treatments for a broad patient population.”

For more information and a product demonstration of AlignRT(R) for the TomoTherapy Hi-Art treatment system, please join TomoTherapy and Vision RT in booth #1533 at ASTRO 2008.

About Vision RT

Vision RT Limited is a UK based company that has developed a novel approach to enhance the crucial process of patient setup, surveillance and respiratory gating during radiation therapy for the treatment of cancer. Vision RT’s revolutionary products, AlignRT(R), GateCT(R) and GateRT(R) utilise a proprietary real-time 3D surface imaging technology to provide exceptional speed and accuracy designed to improve the efficacy and precision of radiation treatments. Further information on Vision RT and its products may be found on www.visionrt.com.

About TomoTherapy Incorporated

TomoTherapy Incorporated has developed, markets and sells the TomoTherapy(R) Hi-Art(R) treatment system, an advanced radiation therapy system for the treatment of a wide variety of cancers. The Hi-Art treatment system combines integrated CT imaging with conformal radiation therapy to deliver sophisticated radiation treatments with speed and precision while reducing radiation exposure to surrounding healthy tissue. The company’s stock is traded on the NASDAQ Global Select Market under the symbol TOMO. To learn more about TomoTherapy, please visit TomoTherapy.com.

Forward-Looking Statements

Statements in this release regarding future products, events, expectations and other similar matters, including but not limited to statements using the terms “will”, “can”, “believe”, “is expected to”, or “should” constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements contained in this press release are subject to risks and uncertainties that could cause actual results to differ materially from those anticipated, including but not limited to factors to risks inherent in the development and commercialization of new technology and products, and the other risks listed from time to time in TomoTherapy’s filings with the U.S. Securities and Exchange Commission, which by this reference are incorporated herein. These forward-looking statements represent TomoTherapy’s judgments as of this date of this press release. TomoTherapy assumes no obligation to update or revise the forward-looking statements in this release because of new information, future events or otherwise.

(C)2008 TomoTherapy Incorporated. All rights reserved. TomoTherapy, TomoDirect, the TomoTherapy logo and Hi-Art are among trademarks, service marks or registered trademarks of TomoTherapy Incorporated. AlignRT is a registered trademark of Vision RT, Ltd.