Wafers used to treat recurring pituitary tumors

Tumors in the pituitary gland — the pea-sized organ at the base of the brain that regulates important bodily processes like reproduction — are the third most common type of intracranial tumor. In most cases, pituitary tumors are not cancerous and can be removed surgically. But in about 15 to 20 percent of patients, the pituitary tumors grow back even after surgical resection. These aggressively recurrent pituitary tumors can cause serious neurological complications, including blindness.

To help prevent the recurrence of aggressive pituitary tumors, neurosurgeons at the University of Virginia Health System are studying a new treatment: chemotherapy wafers that are implanted in the bony structure that partly surrounds the pituitary gland.

“The wafers are made of a special polymer and contain a chemotherapeutic drug called bischoloroethyl-nitrosourea, or BCNU,” said Dr. Edward R. Laws Jr., professor of neurosurgery at U.Va. and a pioneer in pituitary-surgery techniques. “The wafers are about half an inch in diameter and are in direct contact with tumor cells. They slowly release the chemotherapy agent, but are far enough away from a patient’s brain to alleviate complications in vital brain cells.”

Laws and his U.Va. colleagues developed a Phase I study of the wafers involving 10 patients with aggressive pituitary tumors. Reporting in the August 2003 edition of Neurosurgery journal, the research team found that treatment with as many as eight wafers is safe, has no adverse reactions, and is feasible for patients with two types of recurring pituitary tumors: adenomas and craniopharyngiomas.

In the U.Va. study, six of the 10 patients who had wafers implanted experienced good pituitary-tumor control. While the results are encouraging, “the group of patients studied is too small and too diverse to lead to definitive recommendations on care at the present time,” Laws said.

Laws plans to enroll more patients in the wafer study at U.Va. to order to gather additional, more robust medical data.