Study Indicates Potential for Dramatic Reduction in TomoTherapy Treatment Time With Improved Radiation Therapy Plan Quality

MADISON, WI--(Marketwire - November 24, 2009) - TomoTherapy Incorporated (NASDAQ: TOMO) announced today that a research study published in the November 11, 2009 International Journal of Radiation Oncology * Biology * Physics -- commonly known as the Red Journal -- indicated that TomoTherapy(SM) treatment times could be reduced by up to 66 percent using advanced radiation delivery techniques. In addition, these techniques were able to improve plan quality by further minimizing the amount of radiation normal tissue received.

The study, entitled "Dynamic Jaws and Dynamic Couch in Helical TomoTherapy," was led by Dr. Florian Sterzing of the Department of Radiation Oncology at University Clinic Heidelberg to explore the benefits of the Advanced TomoTherapy Delivery Technique. This delivery technique would rely on a dynamic collimator that can automatically adjust the size of the radiation beam to optimize dosage at the target and spare surrounding healthy tissue. Another key component would be a patient couch that can be designed to accelerate treatment time by moving faster between target tumors or in those areas that do not require high doses of radiation. The University Clinic Heidelberg study concluded that with the combination of these two research advancements, they were able to develop treatment plans that indicated significantly shortened treatment times and improved quality of the treatment plan.

"Our experience treating patients with TomoTherapy led us to believe that the techniques we explored in our research could result in more accurate and faster treatments," said Dr. Sterzing. "While we limited our study to nasopharyngeal cancer applications, we believe that these techniques also would have great value in treating cancers throughout the body, particularly cancers of the prostate and those involving multiple metastases."

New TomoHD™ Treatment System Equipped to Accommodate Advanced Delivery Technique
"At the Annual Meeting of the American Society for Radiation Oncology (ASTRO) earlier this month, we debuted the TomoHD treatment system and demonstrated how the Advanced TomoTherapy Delivery Technique could be used in conjunction with this new treatment system," said Fred Robertson, M.D., TomoTherapy's president and CEO. "We believe the combination of the multipurpose platform along with the Advanced Delivery Technique being explored at University Clinic Heidelberg will allow TomoTherapy to continue to advance patient care. These innovations will improve upon our unique form of beam delivery, already widely considered to be the gold standard."

The TomoHD treatment system will be commercially available in the second half of 2010 and has been designed to support the Advanced TomoTherapy Delivery Technique. The Advanced TomoTherapy Delivery Technique is currently a work-in-progress and is not available for sale.

University Clinic Heidelberg is a research partner of TomoTherapy Incorporated. Representatives of TomoTherapy are co-authors on the study noted above.

About TomoTherapy Incorporated
TomoTherapy Incorporated develops, markets and sells advanced radiation therapy solutions that can be used to treat a wide variety of cancers, from the most common to the most complex. The ring gantry-based TomoTherapy® platform 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. TomoTherapy's suite of solutions include its flagship Hi·Art® treatment system, which has been used to deliver more than three million CT-guided, helical intensity-modulated radiation therapy (IMRT) treatment fractions; the TomoHD™ treatment system, designed to enable cancer centers to treat a broader patient population with a single device; and the TomoMobile™ relocatable radiation therapy solution, designed to improve access and availability of state-of-the-art cancer care. TomoTherapy'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 or product capabilities, events, expectations and other similar matters, including but not limited to statements using the terms "expected to", "should", "could", "believe(s)", "suggests" or "indicates" 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 such as our ability to gain customer acceptance, ability to complete development in a timely manner, ability to protect intellectual property, risks of interruption due to events beyond the company's control, 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 the 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.

©2009 TomoTherapy Incorporated. All rights reserved. The following marks as used herein in italicized or stylized text are among trademarks, service marks or registered trademarks of TomoTherapy Incorporated in the United States and other countries: TomoTherapy, Tomo, TomoDirect, TomoHelical, TomoHD, TomoMobile, TQA, Hi·Art, and the TomoTherapy logo.