RICHLAND, WA, 25 January 2010 – IsoRay, Inc. (Amex: ISR) announced today that it has successfully shipped the first set of Cesium-131 brachytherapy seeds to a Canadian customer for the purpose of furthering research and development of Cesium-131 in Canada. Cesium-131 is currently approved by Health Canada for the treatment of low-risk prostate cancers and has been cleared by the US FDA for treatment of a wide variety of malignant disease (e.g. prostate, head and neck, brain, breast, lung, eye, etc.).

IsoRay Medical in conjunction with its Canadian distribution partner, Inter V Medical, looks forward to expanding the application of Cesium-131 for other cancer treatment areas of the body. IsoRay is seeking additional clinical evidence to allow Health Canada to approve expanded indications for use of Cesium-131 for other malignant disease locations. The goal is to obtain approvals for a wide variety of malignant disease sites (as has already been obtained in the United States).

Dwight Babcock, Chairman and CEO, stated. “We are very excited to take this first step in gathering clinical data to support the expanded use of Cesium-131 in Canada. We have experienced successful treatments of numerous cancers here in the US, such as lung, head and neck, and colon cancers, and look forward to bringing this technology to physicians in Canada to use in treating their patients. We are working closely with our distribution partner Inter V Medical to expedite the penetration of the Canadian market.”

Babcock continued, “Inter V Medical, our distributor, brings to IsoRay Medical a team of nine dedicated sales professionals strategically placed across Canada with exclusive rights to sell Cesium-131 brachytherapy seeds. Inter V Medical has been bringing new medical technologies, including brachytherapy and related products, to the Canadian market for nearly twenty years.”

About IsoRay

IsoRay, Inc., through its subsidiary, IsoRay Medical, Inc., is the sole producer of the Cesium-131 brachytherapy seed.

The Cesium-131 seed offers a significantly shorter radiation half-life than the two other isotopes commonly used for brachytherapy, which results in a substantially faster delivery of therapeutic radiation, a theoretically improved radiation delivery against aggressively replicating cancer, and the potential for a reduced longevity of common brachytherapy side effects.

Cesium-131 is currently used in the treatment of prostate cancer and ocular melanoma, among other cancerous conditions.