IsoRay Medical spotlights launch of Proxcelan™ branding at ASTRO; leading physicians to release latest scientific findings focusing on effectiveness of Cesium-131 in treating prostate cancer

Booth #241 at ASTRO Annual Meeting, October 28-November 1 in Los Angeles

RICHLAND, Wash.—October 24, 2007--- IsoRay Medical™, Inc. will spotlight the brand introduction of Proxcelan™, the company’s existing proprietary Cesium-131 prostate cancer brachytherapy seeds, at the 49th ASTRO Annual Meeting, October 28-November 1, 2007 at the Los Angeles Convention Center.

IsoRay Medical is a wholly-owned subsidiary of a public company, IsoRay, Inc. (“IsoRay”) (AMEX Symbol: ISR), based in Richland, WA. Members of IsoRay’s senior management, technical staff and sales team will be available throughout the event at booth #241.  ASTRO is the largest radiation oncology organization of its kind, with over 9,000 members who include radiation oncologists, radiation oncology nurses, medical physicists, radiation therapists, dosimetrists and biologists.

 “ASTRO is a primary venue for us to convey our company’s latest advancements to the medical community, and is an exceptional forum for sharing the most recent scientific data about the effectiveness of Proxcelan,” said IsoRay chairman and CEO Roger Girard.

Under the name Proxcelan (www.proxcelan.com), IsoRay Medical continues to expand the marketing of its Cesium-131 seeds used in low dose radiation (LDR) brachytherapy for prostate cancer. Reflecting the new branding campaign, the IsoRay booth will showcase new graphics, video presentations and collateral materials for ASTRO attendees.

The latest scientific findings on the effectiveness of Proxcelan seeds in the treatment of prostate cancer will be released by leading physicians. They include: 

• Abstract Title:  Urinary Morbidity Following Cs-131 Brachytherapy for Localized Prostate Cancer

Brian Moran M.D., Chicago Prostate Cancer Center, Chicago, IL

• Abstract Title:  Results of a Multi-Institutional Trial Using Cesium-131 Permanent Prostate Brachytherapy.

Brad Prestidge, M.D., Texas Cancer Clinic, San Antonio, TX

• Abstract Title:  BED as a Predictive Tool for the Outcome of a Permanent Prostate Brachytherapy Trial Using Cesium-131 as Monotherapy.

William Bice Ph.D., Texas Cancer Clinic, San Antonio, TX

• Abstract Title:  Dosimetric Comparison of Cesium-131 and Palladium-103 for Permanent Prostate Brachytherapy.

J. S. Musmacher*, North Shore Medical Accelerator, Smithtown, NY

• Is Cs-131 or I-125 or Pd-103 the “Ideal” Isotope for Prostate Boost Brachytherapy? - A Dosimetric View Point.

R. Yaparpalvi, Montefiore Medical Center, New York, NY

A summary of the findings will be released following ASTRO and will be available at www.proxcelan.com and www.isoray.com.

ASTRO will also mark the new alliance between IsoRay and International Brachytherapy s.a. (IBt), a leading manufacturer and distributor of brachytherapy products based in Seneffe, Belgium.  The two companies recently signed a letter of intent to form a global strategic alliance focusing on worldwide market expansion of brachytherapy solutions in the treatment of prostate cancer and other malignant tissue cancers. Based on the letter, the two companies plan to collaborate in several areas, including technical advances and sales and marketing initiatives.

Reflecting the new relationship between the two companies, ASTRO attendees visiting the IBt location (booth #1024) will be directed to the IsoRay Medical display.

Proxcelan offers advantages over other isotopes used in LDR brachytherapy for prostate cancer. Available in leading facilities across the United States, Proxcelan with Cesium-131 delivers its therapeutic radiation faster than the other available isotopes-- Palladium-103 and Iodine-125--and at a reduced risk to patients when compared to surgery.  Due to its unique characteristics, Proxcelan patients receive a higher initial dosage of radiation that attacks and kills cancer cells quickly. Its short half-life means that radiation leaves the body more quickly than radiation from Iodine-125 and Palladium-103. [1]

For more information on the Proxcelan™ cancer treatment breakthrough, visit www.proxcelan.com or www.isoray.com.

FOOTNOTE:
[1]  Armpilia CI, Dale RG, Coles IP et al.  The Determination of Radiobiologically Optimized Half-lives for Radionuclides Used in Permanent Brachytherapy Implants.  Int. J. Radiation Oncology Biol. Phys. 2003; 55 (2):  378-385.

About IsoRay
IsoRay, Inc., through its subsidiary, IsoRay Medical, Inc. is the sole producer of the Proxcelan™ Cesium-131 brachytherapy seed, used to treat prostate and other cancers. The Proxcelan™ seed offers a significantly shorter half-life than the two other isotopes commonly used for brachytherapy, which results in a substantially faster delivery of therapeutic radiation, lower probability of cancer cell survival and reduction of the longevity of common brachytherapy side effects (a)(b). IsoRay is based in Richland, Washington. More information is available about IsoRay at www.isoray.com.

(a) Armpilia CI, Dale RG, Coles IP, et al. The Determination of Radiobiologically Optimized Half-lives for Radionuclides Used in Permanent Brachytherapy Implants. Int. J. Radiation Oncology Biol. Phys. 2003; 55 (2): 378-385.
(b) Prestidge B.R., Bice W.S., Jurkovic I., et al. Cesium-131 Permanent Prostate Brachytherapy: An Initial Report. Int. J. Radiation Oncology Biol. Phys. 2005; 63 (1): 5336-5337.

Safe Harbor Statement
Statements in this news release about IsoRay's future expectations, including: the advantages of our Proxcelan™ Cesium-131 seed, future demand for IsoRay's Proxcelan™ Cesium-131 seed, whether the letter of intent will result in any future definitive agreements between IsoRay and IBt, and all other statements in this release, other than historical facts, are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 ("PSLRA"). This statement is included for the express purpose of availing IsoRay, Inc. of the protections of the safe harbor provisions of the PSLRA.  It is important to note that actual results and ultimate corporate actions could differ materially from those in such forward-looking statements based on such factors as IsoRay's ability to successfully negotiate terms for and enter into the proposed future definitive agreements with IBt, successful completion of future research and development activities, physician acceptance, training and use of IsoRay's products, IsoRay's ability to successfully manufacture, market and sell its products, IsoRay's ability to manufacture its products in sufficient quantities to meet demand within required delivery time periods while meeting its quality control standards, IsoRay's ability to enforce its intellectual property rights, whether additional studies support the conclusions of early clinical studies, and other risks detailed from time to time in IsoRay's reports filed with the SEC.

Media Contacts:

Lori Woods, Vice President
IsoRay, Inc. 206.604.6400
lwoods@isoray.com

Ralph Schatzmair, Director--Investor Relations
IsoRay, Inc. 416.322.2225
rschatzmair@isoray.com

Barry Bartlett, The Bartlett Group Public Relations
206.285.0673; Cell: 206.335.4694
barry@bartlettgrouppr.com

IsoRay Medical, Inc.                                                            877.4.ISORAY
350 Hills Street, Suite 106                                                 509.375.1202 TEL    
Richland, WA 99352                                                           509.375.3473 FAX

www.isoray.com
www.cesium131.com
www.proxcelan.com