PRESS RELEASE Stockholm, Sweden, June 18, 2007 One year after the first Leksell Gamma Knife® Perfexion™ treatment was performed in Marseille, France, the revolutionary radiosurgery system is exceeding expectations and delivering fast, effective, precise radiosurgery treatments and to date, has treated more than 300 patients. Physicians now have an unprecedented ability to develop and deliver complex treatment plans for patients with metastatic brain tumors.

In June, Washington Hospital Healthcare System, Freemont, CA, became the first U.S. site to treat patients with Leksell Gamma Knife Perfexion. “We treated three patients the first day, and our clinical team was astounded by the ease and speed of the treatments, as well as the ability to conform the dose to the target at a sub-millimeter level,” said David Larson, M.D., Ph.D., F.A.C.R., radiation oncologist and co-director of the Gamma Knife program at Washington Hospital.

“The patients we treated had very complex targets or multiple brain metastases, but the treatments only took one to two hours each,” said Larson. “In the past, equally conformal treatments would have required well over five hours, even with the most recent Gamma Knife model, which until now, was the fastest and most efficient radiosurgery device available.”

Gamma Knife surgery has become the world’s most widely used radiosurgery treatment for brain disorders due to its extraordinary accuracy, reduction of excess radiation dose to the body and extensive history and clinical documentation. Unlike other systems designed to treat the whole body, Leksell Gamma Knife is specifically designed to optimize treatment to the head – a fact appreciated by neurosurgeons and patients alike.

Developed in conjunction with leading neurosurgeons, Leksell Gamma Knife Perfexion is:

• Precise – thousands of radiation beams converge with a level of accuracy more than 0.5mm, about the thickness of a strand of hair, leaving nearby healthy tissue undamaged.

• Proven – With almost 500,000 patients treated worldwide, and thousands of peer-reviewed scientific articles, the system has unmatched clinical experience.

• Safe – Unwanted radiation dose to the body is up to 100 times less than that of competing technologies.

Gamma Knife surgery is the only stereotactic radiosurgery system specifically cleared by the FDA for treating metastatic brain tumors. In comparison to linac radiosurgery, peer-reviewed articles and publications prove the tremendous benefit of Gamma Knife surgery for significantly better local tumor control.(1)