May 24, 2002
MEDIA CONTACT: Gary Stephenson
Hopkins To Establish Gamma Knife Center To Treat Brain Tumors, Other Brain Abnormalities
The Johns Hopkins Hospital is establishing a new $4.5 million Gamma Knife Center to provide advanced treatment for brain tumors and other neurological conditions.
The gamma knife is a highly sophisticated instrument that precisely delivers beams of gamma radiation to brain tumors or to malfunctioning regions of the brain. This treatment destroys the target while preserving the surrounding normal brain. It has proven especially effective in destroying both malignant and benign brain tumors and vascular malformations, and in the treatment of trigeminal neuralgia (facial pain), according to Jeffery Williams, M.D., director of stereotactic radiosurgery in the departments of Neurosurgery and Oncology. It is also a treatment alternative for patients with brain tumors or other neurological disorders for whom conventional surgery is not an option.
"The Johns Hopkins Hospital gamma knife program will provide effective, non-invasive, outpatient treatment for patients having vascular (blood vessel) abnormalities and a wide range of both benign and malignant brain tumors," says Dr. Williams. "The capacity to bring relief to patients having functional disorders of the brain, such as trigeminal neuralgia, is especially exciting."
"Because of its capacity to treat a variety of conditions, the gamma knife program will facilitate advanced treatments and collaboration among disparate disciplines including neurosurgery, radiation oncology and neurology," he adds.
Under an agreement with American Shared Hospital Services (ASHS), Hopkins will lease the gamma knife for the center, expected to open in early 2003 in the Harry and Jeanette Weinberg Building, part of the Sidney Kimmel Comprehensive Cancer Center at Hopkins, on North Broadway.
Although called the gamma "knife," the instrument actually uses no blades and in fact makes no incisions at all. It performs "surgery" using radiation that is emitted from 201 separate cobalt-60 sources. All of the radiation sources are aimed at a single point. The headpiece (stereotactic frame) attaches to the patient's head and allows precise positioning of the target site at the focal point of the radiation beams. Each individual beam provides only a relatively weak dose of radiation, but when all of the beams converge on the target site, the combination is powerful enough to destroy the abnormal tissue. Because the beams focus so tightly on the target, surrounding brain tissue remains unharmed.
The procedure is painless. Although the entire process generally takes several hours, the actual treatment phase only lasts about 15 minutes to an hour, depending on the size of the abnormality being treated. After the patient is fitted with the headpiece under local anesthesia with mild sedation, CT or MRI scans (or angiograms, if the problem is vascular) determine the precise location of the tumor or abnormality. The computerized treatment-planning system automatically positions the path of the beams so that they converge only on the targeted site. After the treatment, patients usually return home the same day.