FDA Clears Brachytherapy System for Brain Cancer

Yael Waknine

September 14, 2011

September 14, 2011 — The US Food and Drug Administration (FDA) has cleared a radiation therapy system (GliaSite, IsoRay) for the delivery of brachytherapy in brain cancer patients.

The catheter has a dual balloon system, comprised of an inner balloon that holds a liquid radioactive source and an outer balloon to provide safety in the event the inner portion is damaged.

Insertion of the system into the brain cavity 1 week after tumor removal allows local delivery of high-dose radiation to the tumor site and environs for several days. At the same time, the system prevents exposure to the rest of the brain, which is a problem with external-beam radiation, according to the company. The likelihood of tumor recurrence is diminished with the system, which can have an impact on patient longevity and quality of life, a company news release states.

Lotrex (iodine-125) is currently being used as a radiation source with the system. However, the company plans to market the system with a proprietary isotope, Cesium-131, which is already available in seed form to treat various types of cancer. The liquid form has not yet been approved by the FDA, but is associated with a 5-fold shorter half-life than iodine-125 (9.7 vs 59.4 days), which reduces the time needed to deliver a dose of radiation.

Cesium-131 in seed form provides a high cancer-free success rate at 5 years in patients with prostate cancer, and represents "the greatest advancement in internal radiation therapy over the last 20 years," according to a company news release.

"FDA clearance of the [radiation therapy] system represents a key development in opening the door to further advances that can expand treatment efficacy as we seek clearance for the use of liquid Cesium-131," said Dwight Babcock, chief executive officer of IsoRay, in the news release. "We have already seen the importance of Cesium-131 internal radiation therapy seeds in effecting survivability and quality of life in the treatment of cancers throughout the body."


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