About Cesium-131

History of Cesium-131 - Prostate Cancer Brachytherapy Isotope

The introduction of Cesium-131 represents the culmination of decades of work and millions of dollars of investment. Top medical centers, hospitals and clinics across the United States are now offering this breakthrough treatment for prostate cancer patients.

The word brachytherapy derives from the Greek prefix brachy, meaning "short" or "close," because the titanium capsules containing the radioisotope are implanted directly into the cancerous prostate gland.

Treatment of cancer using low dose radiation or "seed" brachytherapy was pioneered in the 1960's as an effective alternative to radical prostatectomy. Pioneers in brachytherapy research initially theorized about the use of Cesium-131 in a titanium capsule, however scientific and economic limitations at the time prevented its development and Iodine-125 emerged as an alternative.

Beginning in 1967, Iodine-125 became the first radioisotope manufactured in a titanium capsule, or seed. While its use continues to this day, many patients and doctors in recent years have chosen Palladium-103, a faster-acting, shorter half-life isotope than Iodine-125. In order to obtain the clinical benefits of Palladium's short half-life, patients and clinicians were forced to settle for less energy or tissue penetrating power.

A team of scientists, including Donald C. Lawrence, one of the founding fathers of seed brachytherapy and Lane A. Bray, Chief Chemist for IsoRay Medical™, Inc., continued to believe the physical characteristics of Cesium-131 could potentially provide superior clinical benefits for prostate seed brachytherapy patients. Bray eventually developed the patented process for economically separating and purifying Cesium-131. In 1998 IsoRay Medical, Inc. was founded to manufacture and market seeds containing this faster, more aggressive isotope.

Cesium-131 received FDA clearance in 2003 for treatment of malignant disease of the head and neck, brain, breast, prostate and other organs. The first Cesium-131 patient was implanted at the University of Washington Medical Center in Seattle, WA on October 2004. To date there have been more than 1,000 Cesium-131 implants performed. Cesium-131 is now offered at over 50 clinics across the United States.