New radiation therapy for prostate cancer has fewer side effects

Jan 5 2006

A new radiation therapy for prostate cancer -- Cesium-131 brachytherapy -- has fewer side effects than other treatments. NewYork-Presbyterian Hospital/Weill Cornell Medical Center is the only hospital in the Northeast to offer the new therapy.

Brachytherapy involves the implantation of radioactive seeds into the tumor site. Radiation kills or arrests the growth of the cancer with minimal damage to healthy tissue. This helps prevent incontinence and preserve the nerves that allow for erection.

The radioactive isotope Cesium-131, which was approved in 2003 by the FDA for use in brachytherapy for prostate cancer and other malignancies, has several advantages over other isotopes. Compared to Iodine-125 and Palladium-103, it has a higher energy, shorter half-life, and uses a lower total dose of radiation.

Cesium-131 has a half-life of about 10 days, compared to a half-life of 17 days and 60 days for Palladium-103 and Iodine-125, respectively. A shorter half-life means faster dose delivery, that cancer cells have less opportunity to repopulate, and less protracted radiation to normal healthy tissues. The energy emitted by Cesium-131 is stronger than Iodine-125 and Palladium-103 (29 KeV vs. 28 KeV and 21 KeV, respectively). Because the energy is stronger, fewer radioactive seeds are required. This reduces risk of urinary reactions following implantation.

"Cesium-131 brachytherapy is nothing less than a new standard of care for treatment of prostate cancer, giving patients an improved quality of life and peace of mind," says Dr. Dattatreyudu Nori, professor of clinical radiology at Weill Medical College of Cornell University and radiation oncologist-in-chief at NewYork-Presbyterian/Weill Cornell.

A pioneer in the field of brachytherapy, Dr. Nori was among those who helped introduce Iodine-125 in 1970 and Palladium-103 in 1985. "The introduction of a new isotope has happened every 15 to 20 years," he says.

Cesium-131 brachytherapy is available to low-risk/early-stage prostate cancer patients. In the near future it may also be available to intermediate-risk patients, eliminating the need for supplemental external beam radiation in this population.

Cesium-131 brachytherapy treatment is manufactured by IsoRay Medical of Richland, Wash.