RICHLAND, Wash.--(BUSINESS WIRE)--IsoRay Medical, Inc., the sole manufacturer and distributor of Cesium-131 seeds used in brachytherapy for the treatment of prostate cancer, announced the signing of an agreement with Energy Northwest’s Applied Process Engineering Laboratory (APEL) of Richland to lease an additional 15,340 square feet of space at the APEL facility to house its Cesium-131 brachytherapy seed production. IsoRay currently leases approximately 4,000 square feet of space at the facility for laboratory and office space.