Source: www.businesswire.com
Author: press release

IsoRay, Inc. announced today that on June 4, 2009, Dr. Karen Pitman of the Department of Otolaryngology and Communicative Sciences and Dr. Michael Baird of the Radiation Oncology Department of the University of Mississippi Medical Center performed the world’s first head and neck permanent seed Cesium-131 implant.

The implant was performed using Vicryl-embedded seeds in the tonsilar area in a patient who had locally failed IMRT external beam radiation and chemotherapy. Drs. Pitman and Baird chose Cesium-131 for this implant based on its high energy (30.4 kev) and short half-life (9.7 days). This combination allowed them to achieve a high dose of radiation to the recurrent disease, while limiting the dose to the previously heavily irradiated tissues of the neck. Cesium’s short half-life reduced the duration of side effects and the need for radiation protection.

Dr. Baird stated, “Although too early to determine the overall efficacy of treatment, the patient’s tolerance to the implant has been good. His acute reactions peaked at three weeks, and have resolved by six weeks. His clinical reaction in the implant volume corresponds well to the post implant dosimetry.”

Until now clinical experience with Cesium-131 has been focused on prostate cancer and ocular melanoma. However, Cesium-131 has been cleared by the FDA for use in the treatment of malignant disease (e.g., prostate, ocular melanoma, head and neck, lung, brain, breast, etc.) and may be used in surface, interstitial, and intracavitary applications for tumors with known radiosensitivity.

Dwight Babcock, IsoRay’s CEO, stated “This is an important development in our strategy to significantly broaden our base beyond prostate cancer. Cesium-131 has unique characteristics for treating many additional cancers such as this new application that provided a minimally invasive treatment option for this patient.”

About IsoRay
IsoRay, Inc., through its subsidiary, IsoRay Medical, Inc., is the sole producer of the Proxcelan Cesium-131 brachytherapy seeds, used to treat prostate, ocular melanomas, and other cancers. Proxcelan seeds offer 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.

Notes:
(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.