C4 Imaging LLC announced that Isoray Medical, Inc. has received U.S. Food and Drug Administration (FDA) 510(k) clearance for the use of C4 Imaging’s Sirius® positive-signal MRI (Magnetic Resonance Imaging) Markers with Isoray’s Cesium-131, brachytherapy seeds. Sirius is implanted during the treatment of prostate cancer with brachytherapy and is used to facilitate brachytherapy seed localization within the prostate utilizing a single post-implant MRI procedure. This allows the benefits of MRI assisted brachytherapy, also known as MRI assisted radiosurgery or MARS™, to be made available to all prostate cancer patients treated with brachytherapy. Brachytherapy, or internal radiation therapy, is a leading, cost-effective option for the treatment of prostate cancer. Isoray is the world’s only producer of Cesium-131, commercially known as Cesium Blu™, brachytherapy seeds. Cesium-131 is a radioactive isotope that delivers a minimally invasive and highly targeted treatment to the site of the cancer preserving healthy tissue and organs. Patients benefit from the rapid resolution of their side effects allowing them to return to their normal lives quickly.