Brower Piven Encourages Investors Who Have Losses in Excess of $100,000 From Investment in TomoTherapy, Inc. to Inquire About the Lead Plaintiff Position in Securities Fraud Class Action Lawsuit Before the July 29, 2008 Lead Plaintiff Deadline

Brower Piven, A Professional Corporation announces that a class action lawsuit has been commenced in the United States District Court for the Western District of Wisconsin on behalf of purchasers of the common stock of TomoTherapy, Inc. ("TomoTherapy" or the "Company") (NASDAQ: TOMO) between February 13, 2008 and April 17, 2008, inclusive (the "Class Period"). No class has yet been certified in this action.

Members of the Class will be represented by the lead plaintiff and counsel chosen by the lead plaintiff. If you wish to choose counsel to represent you and the Class, you must apply to be appointed lead plaintiff no later than July 29, 2008 and be selected by the Court. The lead plaintiff will direct the litigation and participate in all important decisions including whether to accept a settlement and how much of a settlement to accept for the Class in the action. The lead plaintiff will be selected from among applicants claiming the largest loss from investment in the Company during the Class Period. If you have a net loss in excess of $100,000 incurred from transactions in TomoTherapy securities during the Class Period and are interested in directing the course of this litigation for plaintiffs, please contact Brower Piven ( hoffman@browerpiven.com or 410/332-0030) to answer any questions you may have in that regard.

The complaint alleges that, during the Class Period, the Company, and certain of its officers and/or directors, violated federal securities laws by withholding material facts from the investing public. TomoTherapy develops, markets and sells the Hi-Art system, is a radiation therapy system for the treatment of various types of cancer. As alleged in the complaint, defendants concealed in their February Press Release that (a) a larger percentage of TomoTherapy's revenue backlog at December 31, 2007 and TomoTherapy's new orders received through February 12, 2008 were from for-profit entities which had ordered multi-unit Hi-Art Systems and had scheduled deliveries of the multi-units sequentially throughout 2008 and 2009; (b) the average selling prices were lower in Q1'08 by approximately 11% than they had been in Q1'07 because Q1'07 sales included a large number of European sales denominated in Euros; (c) new sales orders from Europe had slowed in Q1'08 through February 12, 2008 and TomoTherapy was experiencing a serious delay in closing European orders; (d) TomoTherapy's gross margins in Q1'08 were and would continue to be approximately 20% lower than they had been in Q1'07; and (e) TomoTherapy's revenues in Q1'08 would be substantially lower and would not show increased growth from either Q1'07 or Q4'07 and that TomoTherapy would suffer a loss in Q1'08. Shortly after the February Release, director Neis sold approximately 917,621 shares of TomoTherapy common stock during February 26, 2008 through March 14, 2008.

If you have suffered a net loss for all transactions in TomoTherapy securities during the Class Period (including shares or possibly calls purchased during, but retained after, the Class Period or possibly put options sold but not covered until after the Class Period), you may obtain additional information about this lawsuit and your ability to become a lead plaintiff by contacting Brower Piven at www.browerpiven.com , by email at hoffman@browerpiven.com , by calling 410-332-0030, or at Brower Piven, A Professional Corporation, The World Trade Center-Baltimore, 401 East Pratt Street, Suite 2525, Baltimore, Maryland 21202. Attorneys at Brower Piven have combined experience litigating securities and class action cases of over 40 years. If you choose to retain counsel, you may retain Brower Piven without financial obligation or cost to you, or you may retain other counsel of your choice.

CONTACT: Brower Piven, A Professional Corporation Baltimore, Maryland Charles J. Piven 410/332-0030 Email Contact