Advantages of TomoTherapy(R) Platform for Radiation Therapy Highlighted at 10th Biennial ESTRO Conference

MADISON, WI, Aug 27 (MARKET WIRE) --
TomoTherapy Incorporated (NASDAQ: TOMO) announced today that there will
be more than 40 presentations at the 10th Biennial ESTRO Conference on
Physics and Radiation Technology for Clinical Radiotherapy that explore
use of the TomoTherapy(R) treatment system. The TomoTherapy system -- a
versatile, CT scanner-based device that integrates image guidance for
increased treatment accuracy and helical radiation therapy delivery for
enhanced tumor targeting -- is helping cancer centers advance patient
care around the world. The papers cover a breadth of advantages related
to the TomoTherapy system, including the importance of daily imaging for
precise patient positioning and adaptive therapy purposes, fundamental
advancements in treatment planning and improvements in treatment quality
for the patient.

The ESTRO Conference will take place August 30 to September 3, 2009, in
Maastricht, The Netherlands. At booth 140, TomoTherapy will highlight how
its radiotherapy platform is reshaping radiation therapy, with exhibits
and presentations on topics such as the evolution and future of the
TomoTherapy platform, user case studies, use of TomoDirect(TM) technology
to increase system versatility and throughput, and the new TQA(TM)
quality assurance tool. The conference will feature more than 40
TomoTherapy-related papers, on a range of topics, including:

Clinically Applied Imaging

-- Adaptive Radiotherapy to Treatment Response - UCL-Cliniques
Universitaires Saint Luc, Brussels, Belgium. This study explores how recent
advancements in imaging, computational and technological fields may enable
clinicians to achieve high precision radiation dose delivery. Initial
results show that use of the TomoTherapy system's adaptive planning
capabilities allows for a significant reduction in the volume of tissue
irradiated to high dose and may assist in responding to dosimetric
variations caused by anatomical changes during treatment, providing the
opportunity to employ dose escalation strategies.

-- Evaluation of Megavolt CT (MVCT) Imaging Protocols in the Treatment of
Head and Neck Cancer with Helical TomoTherapy - ZNA Middelheim-UZA,
Antwerp, Belgium. This study was designed to evaluate several imaging
protocols based on the results of an extended evaluation of TomoTherapy
MVCT images, acquired on a daily basis, for head and neck cancer patients.
Researchers concluded that the TomoTherapy system enables quick and easy
daily imaging and reduces margins that account for set-up uncertainties,
which therefore reduces the amount of healthy tissue that is irradiated
during treatment.

-- Validation of an Elastic Registration Method to Parotid Shrinkage as
Assessed by MVCT Scans during TomoTherapy - Scientific Institute San
Raffaele, Milan, Italy; IBFM-CNR and Scientific Institute San Raffaele,
Milan, Italy; and IBNM-CNR and Politecnico, Milan, Italy. This paper
evaluated the use of MVCT images during TomoTherapy(SM) treatments to
address changes in the parotid gland as a way to reduce common side effects
of radiotherapy during treatment of head and neck cancer. The study
concludes that daily MVCT scans enabled clinicians to evaluate the
three-dimensional behavior of tissues during the course of radiotherapy,
with a detailed analysis of position, volume and shape, and calculate an
accurate dose received by the parotids during the course of treatment.

Technology Comparisons

-- BEUD/Secondary Malignancy Analysis: Comparison of HT, MLC-Based IMRT,
and CRT in Prostate Treatment Planning - Cancer Therapy & Research Center
at the University of Texas Health Science Center, San Antonio, Texas, and
Karolinska Institutet and Stockholm University, Stockholm, Sweden. This
study addresses development and assessment of treatment plans based on
radiobiological parameters, compared to conventional treatment planning
comparison techniques for prostate cancer. Early evidence in this study
indicates that helical TomoTherapy treatments results in a lower
probability of secondary malignancy than MLC-based IMRT and 3D conformal
radiation.

-- Comparison of IMRT Delivery Techniques and Helical TomoTherapy Using
Pareto Front Evaluation - Lund University Hospital, Lund, Sweden; and
Copenhagen University Hospital Herlev, Herlev, Denmark. This study was
designed to compare different IMRT treatment planning and delivery systems
using Pareto front evaluation. For the case examined in this study, the
TomoTherapy treatment planning system was deemed to be superior to
Nucletron's Oncentra Masterplan (OMP) and Varian's Eclipse systems
regarding target coverage and sparing of the parotid gland.

-- Assessment of the Treatment of Breast Carcinoma with TomoTherapy - UZ
Brussel, Oncologish Centrum, Brussels, Belgium; and Centre Paul Strauss,
Strasbourg, France. This study investigates use of helical TomoTherapy
treatments and its discrete-angle alternative, TomoDirect(SM) treatments,
compared to conventional radiotherapy for treatment of post-operative
breast carcinoma. Results show that helical TomoTherapy and TomoDirect
modalities can deliver dose distributions that the radiotherapist judges to
be equal to or better than conventional treatment according to the organ to
be protected.

Improved Treatment Quality

-- A Collaborative Dosimetric Comparison for Helical TomoTherapy and
Single-Arc Intensity Modulated Arc Therapy (IMAT) Between Two Institutions
- University of Wisconsin School of Medicine and Public Health, Madison,
Wisc.; University of Wisconsin Cancer Center, Wisconsin Rapids, Wisc.; and
University of Maryland, Baltimore, Md. This study was designed as a
dosimetric comparison of helical TomoTherapy treatments and Single-Arc IMAT
treatments. Results indicated that helical TomoTherapy provided better dose
uniformity by a factor of two, and slightly better dose sparing to 80
percent of the normal tissues studied, such as the lens, eyes, spinal cord,
parotid, rectum and bladder.

-- Safe Ultra-High Dose Escalation on Dominant Intraprostatic Lesions
(DIL) by TomoTherapy - Scientific Institute San Raffaele, Milan, Italy; and
Fondazione IRCCS Istituto Nazionale Dei Tumori, Milan, Italy. This
abstract examines dose escalation possibility for prostate tumors that are
considered to be resistant to radiation and need higher doses for control.
Researchers determined that the high-quality imaging and superior dosimetry
of the TomoTherapy system may permit clinicians to safely escalate the dose
to at least 100 Gy in the DIL volume and control exposure of critical
structures.

Quality Assurance

-- TomoTherapy Quality Assurance (TQA(TM)): A Fast and Comprehensive
Software Tool - UCL-Cliniques Universitaires Saint Luc, Brussels, Belgium.
This paper compares the TQA software tool with classical quality assurance
methodology. The researchers concluded that the TQA tool is not only a
fast and comprehensive quality assurance tool, it also provides accurate
and reliable information.

-- A New Method for Output Factors Measurements/MC Computations for
Stereotactic and Dynamic Jaws TomoTherapy - UCL-Cliniques Universitaires
Saint Luc, Brussels, Belgium; University of Wisconsin-Madison, Madison,
Wisc.; and TomoTherapy Inc. This paper -- which earned the ESTRO Varian
award for research in the field of radiobiology, radiation physics,
clinical radiotherapy or radiation technology -- discusses a method of
calculating output factors for small field sizes with the TomoTherapy
system, which was successfully verified by Monte Carlo simulations.

Also, this year ESTRO has recognized the 1993 paper "TomoTherapy: A
New Concept for Delivery of Dynamic Conformal Radiotherapy" as "A Classic
Medical Physics Paper." Lead author is Thomas "Rock" Mackie, PhD,
TomoTherapy's co-founder and chairman.

"It is rewarding to see how TomoTherapy users across the globe are
advancing cancer care by using our unique platform," said Mackie. "From
the wealth of data offered in the papers at ESTRO, it is clear that the
TomoTherapy system offers users the flexibility to cancers throughout the
body -- from the simple to the most complex -- with precise treatment
plans that result in more effective delivery of radiation and the
potential of fewer side effects for patients."

For more on TomoTherapy at the 10th Biennial ESTRO Conference, including
the full booth speaker schedule, please visit TomoTherapy.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 or product
capabilities, events, expectations and other similar matters, including
but not limited to statements using the terms "may", "should", "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 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.

Copyright2009 TomoTherapy Incorporated. All rights reserved. TomoTherapy,
Tomo, TomoDirect, TQA, the TomoTherapy logo and Hi-Art are among
trademarks, service marks or registered trademarks of TomoTherapy
Incorporated in the United States and other countries.

Investor Contact:
Thomas E. Powell
Chief Financial Officer
608.824.2800
Email Contact

Media Contacts:
Kevin O'Malley
Manager, Corporate Communications
608.824.3384
Email Contact

Susan Lehman
Rockpoint Public Relations
510.832.6006
Email Contact

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