TQA

^™

at the 50th Annual American

Association of Physicists in Medicine (AAPM) Meeting in Houston,

July 27-31, 2008. TQA, or Tomo Quality Assurance^™,

is the first integrated, machine-specific quality assurance (QA)

solution to be offered by a radiation therapy vendor. The TQA application

streamlines the collection—and simplifies the

review—of data used to monitor radiation

therapy equipment and procedures. All TQA data can be easily

exported for third-party validation.

TQA has been developed by TomoTherapy in partnership with medical

physicists experienced in the clinical use of the Hi·Art^®

treatment system. Bob Cravens, M.S., TomoTherapy’s

lead applied physicist and TQA architect, believes customer input

was critical in bringing this powerful set of physics tools to market.

“TQA was built by, and for, our

physics colleagues in the clinic,” says

Cravens. “They helped us identify key data

and workflow requirements¹, and provided

valuable feedback throughout the development process. The result is an

application that integrates easily into daily workflow, increases

productivity and facilitates more informed decision-making.

Additionally, it better aligns our support team with TomoTherapy

customers, allowing them to share the same data set.”

The TQA application leverages the Hi·Art

treatment system’s unique platform

integration. It works by gathering data from the on-board detector and

other sub-systems that monitor the device continuously during delivery.

The data is then presented in a customizable, calendar-based interface

that is accessible from the Hi·Art

system’s operator station. With this

comprehensive data dashboard, any parameter’s

status can be identified at a glance and comparatively assessed via

automated reporting and trending features.

“TQA can provide a wealth of

additional information, which means I can work more proactively and

better assess the system with predictive analysis,”

said Walter Grant, Ph.D., chief of Physics at Baylor College of Medicine

and The Methodist Hospital in Houston, one of 16 customers to evaluate

the application. “TQA can also

save me considerable time. In evaluating the application, I have found

QA measurements that took over an hour to complete, analyze and document

can now be finished in 10 minutes. This will certainly make my life

easier.”

Cravens stated that TQA will provide immediate benefits to customers who

are new to the Hi·Art platform as

well: “We often hear that Hi·Art

is the easiest system to use, once our customers have become familiar

with it. TQA should help clinics hit the ground running even

faster. It’s a turnkey operation, complete

with QA guidelines, that eliminates unnecessary complexity.”

Noted TomoTherapy CEO Fred Robertson: “We are

excited to introduce TQA at AAPM’s 50^th

Annual Meeting. Integrated machine QA is one more example of what’s

possible with our truly integrated platform for radiation therapy, and

one more reminder that we are really just at the beginning of our

product lifecycle. There are many more productivity- and quality-focused

enhancements to come.”

Bob Cravens, M.S., and Walter Grant, Ph.D., will each be discussing TQA

in the TomoTherapy booth during AAPM. For exact times of these and more

presentations throughout the week, please visit AAPM booth #519, or the AAPM

overview page on TomoTherapy.com.

About TomoTherapy Incorporated

TomoTherapy Incorporated has developed, markets and sells the TomoTherapy^®

Hi·Art^®

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” 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 such as our

ability to integrate acquired assets, 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.

1. C. Ramsey, J. Gibbons, T. Holmes, K. Jeong, K. Langen, D. Low, S.

Meeks, N. Papanikolaou, K. Schubert, M. Tomsej – Mechanical and

Dosimetric Quality Assurance for Helical TomoTherapy – International

Journal of Radiation OncologyBiologyPhysics, Volume 69 , Issue 3 ,

Pages S699 – S699

©2008 TomoTherapy Incorporated. All rights

reserved. TomoTherapy, TQA, the TomoTherapy logo and Hi·Art

are among trademarks, service marks or registered trademarks of

TomoTherapy Incorporated.