BARCELONA, Spain, September 10 /PRNewswire/ --

- Worldwide Availability of Monte Carlo Dose Calculation Software
Announced at European Radiation Oncology Meeting in Barcelona

Accuray Incorporated (Nasdaq: ARAY), a global leader in the field of
radiosurgery, announced today that its Monte Carlo Dose Calculation algorithm
has received 510(k) clearance from the U.S. Food and Drug Administration and
is now commercially available worldwide. This announcement was made as part
of the product's launch at the 9th Biennial European Society for Therapeutic
Radiology and Oncology (ESTRO) meeting on Physics and Radiation Technology
for Clinical Radiotherapy in Barcelona, Spain.

Treatment with radiation therapy or radiosurgery requires a linear
accelerator to deliver one or more x-ray beams to a target. Each beam is made
up of trillions of photons, and each photon follows an individual path to the
target. Traditional dose calculation methods assume all photons take a single
path and therefore use a single calculation to represent the dose delivered
by all photons.

Monte Carlo methods are considered the gold standard of probabilistic
statistics. The Monte Carlo dose calculation method takes the probability and
potential interactions for each individual photon into account when it
calculates the dose being delivered by a single photon. It then considers the
probabilities for each of millions of photons to generate a dose calculation
for the target and surrounding structures.

Previously, because of the repetition of algorithms and the large number
of calculations involved, Monte Carlo dose calculations were time consuming
to compute and therefore were difficult to employ in clinical settings. Now,
by integrating various speed-up techniques, Accuray has developed a Monte
Carlo dose calculation algorithm that can more quickly and precisely predict
the dose of radiation that will be delivered to tumors.

"The clearance and commercial availability of Accuray's Monte Carlo Dose
Calculation algorithm is a significant milestone in the use of radiosurgery
to treat tumors anywhere in the body, particularly lung tumors" said Euan S.
Thomson, Ph.D., president and CEO of Accuray. "We are extremely excited to be
the first to market with a Monte Carlo dose calculation algorithm for photon
beam radiation treatment that is capable of calculating the results within
minutes. Now our customers will have access to the most state-of-the-art
radiosurgery system with the most cutting-edge dose calculation algorithm."

The Monte Carlo dose calculation methodology is ideal for use in treating
lung tumors, which are solid masses surrounded by air cavities, because it
takes into account varying tissue densities. By integrating the Monte Carlo
Dose Calculation algorithm with the CyberKnife(R) Robotic Radiosurgery
System, Accuray offers clinicians one of the most advanced tools available
today for treating lung cancer.

"Current dose calculation algorithms work well for treating most tumors
because the surrounding tissue is relatively uniform, but assumptions had to
be made within areas like the lungs and sinuses where tissue densities
differ," said Charlie Ma, Ph.D., director of radiation physics at Fox Chase
Cancer Center in Philadelphia, who helped develop this customized version of
Monte Carlo dose calculation for the CyberKnife System. "Now Accuray's Monte
Carlo Dose Calculation algorithm provides the most accurate physics-based
model of radiation transfer available to date and the system is capable of
computing complex dose distributions within minutes. This is a significant
step forward in cancer treatment."

The Monte Carlo Dose Calculation capability will be available for
purchase as a software upgrade for customers with the Multiplan(R) 2.0
Treatment Planning System and is scheduled to begin shipping toward the end
of this calendar year. For customers who do not already have the MultiPlan
2.0 System, the Monte Carlo Dose Calculation feature will be available to
them with the purchase of a MultiPlan 2.0 System. This new feature will also
be available to customers who have previously signed Accuray's Diamond Elite
Service Agreement. The Diamond Elite Service Agreement enables customers to
choose the right upgrades to fit their clinical strategy. Unlike traditional
industry service programs, Accuray's Diamond Elite Service Agreement
maintains client investments with obsolescence protection, which ensures
their systems' clinical capabilities remain at the forefront of technological
advances.

"With Accuray's service program we've been able to upgrade our system
with the latest technologies as soon they become available - keeping our
CyberKnife System on the cutting edge," said Alan Beckman, M.D., Chief of
Radiation Oncology at Central Baptist Hospital in Lexington, Ky. "Through the
service agreement we look forward to acquiring the new Monte Carlo Dose
Calculation feature in order to enhance our CyberKnife practice even further
with this gold standard capability."

About the CyberKnife(R) Robotic Radiosurgery System

The CyberKnife Robotic Radiosurgery System is the world's only robotic
radiosurgery system cleared by the FDA to treat tumors anywhere in the body
non-invasively and with sub-millimeter accuracy. Using continual image
guidance technology and computer controlled robotic mobility, the CyberKnife
System automatically tracks, detects and corrects for tumor and patient
movement in real-time throughout the treatment. This enables the CyberKnife
System to deliver precise, high-dose radiation, minimizing damage to
surrounding healthy tissue and eliminating the need for invasive head or body
stabilization frames.

About Accuray

Accuray Incorporated (Nasdaq: ARAY), based in Sunnyvale, Calif., is a
global leader in the field of radiosurgery dedicated to providing an improved
quality of life and a non-surgical treatment option for those diagnosed with
cancer. Accuray develops and markets the CyberKnife Robotic Radiosurgery
System, which extends the benefits of radiosurgery to include extracranial
tumors, including those in the spine, lung, prostate, liver and pancreas. To
date, the CyberKnife System has been used to treat more than 35,000 patients
worldwide and currently more than 100 systems have been installed in leading
hospitals in the Americas, Europe and Asia. For more information, please
visit www.accuray.com.

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The foregoing may contain certain forward-looking statements that involve
risks and uncertainties, including uncertainties associated with the medical
device industry. Except for the historical information contained herein, the
matters set forth in this press release regarding procedure growth and market
acceptance, clinical studies, regulatory review and approval, and
commercialization of products are forward-looking statements within the
meaning of the "safe harbor" provisions of the Private Securities Litigation
Reform Act of 1995. Forward-looking statements speak only as of the date the
statements are made and are based on information available at the time those
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with respect to future events. You should not put undue reliance on any
forward-looking statements. Important factors that could cause actual
performance and results to differ materially from the forward-looking
statements we make include: market acceptance of products; competing
products, the combination of our products with complementary technology; and
other risks detailed from time to time under the heading "Risk Factors" in
our report on Form 10-K for the fiscal year ended June 30, 2007 fiscal 2007
as may be updated from time to time by our other filings with the Securities
and Exchange Commission. The Company's actual results of operations may
differ significantly from those contemplated by such forward-looking
statements as a result of these and other factors. We assume no obligation to
update forward-looking statements to reflect actual performance or results,
changes in assumptions or changes in other factors affecting forward-looking
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Web site: http://www.accuray.com