This technology transfer story epitomizes the value of a national laboratory in enabling a small business to develop its breakthrough can-cer therapy technology to the point where it is helping treat and cure cancer patients. Pacific Northwest National Laboratory (PNNL) provided access to equipment and two user facilities in a unique way to transfer its radiological expertise to IsoRay Medical, Inc. (IsoRay) of Richland, Washington, to enable the successful launch of its commercial product. IsoRay is producing a powerful new kind of brachytherapy seed made from cesium-131 (131Cs) for treating prostate and other cancers.Through access to specialized PNNL facilities, equipment, and expertise under a variety of collaborative agreements between IsoRay and PNNL since 1998, researchers from both or-ganizations contributed to the development of the brachytherapy seed and associated fabri-cation process. This brachytherapy seed uses 131Cs, which has a low-energy x-ray that effec-tively provides a cancer-killing dose to a tumor in a short period of time. In the October 13, 2005 Business Wire, IsoRay’s 131Cs brachy-therapy seed is described as a “breakthrough” and “the biggest advancement in seed brachytherapy since the introduction of palladium-103 19 years ago.”IsoRay, which became a publicly owned compa-ny in July 2005, started the effort to produce the seeds commercially using PNNL’s Radiochemi-cal Processing Laboratory (RPL) in May 2004 under the current agreement with PNNL. Such an arrangement provided critical and timely na-tional laboratory support for IsoRay in working toward a commercial production facility of its own. In October 2004, the world’s first 131Cs seed implant was performed at the University of Washington Medical Center in Seattle. Since then, approximately 90 patients have been im-planted to treat, and hopefully cure, prostate cancer using 131Cs seeds. 131Cs brachy-therapy procedures are currently available at 17 treatment centers in 13 states. IsoRay is currently housed in a PNNL- and Department of Energy-sponsored and supported incubator user facility, the Applied Process Engineering Laboratory. The company conducts its produc-tion operations under a first-of-its-kind arrange-ment with PNNL using the RPL to process and purify source material, manufacture its product, and qualify it under stringent Food and Drug Administration standards.