Benign but Destructive

Targeting pituitary tumors with radiosurgery.

In 2001, when Charlotte Craven of Emory saw her doctor after a sudden, unexplained weight gain, blood work indicated her thyroid was not functioning. A thyroid problem is one thing—the real surprise was what showed up on her MRI: a pituitary adenoma, a tumor at the base of her brain.

“Pituitary adenomas are slowgrowing, benign tumors, but they can be very destructive because they’re located in a sensitive area,” says Cole Giller, M.D., Ph.D., medical director of the Baylor Radiosurgery Center and a neurosurgeon on the medical staff at Baylor University Medical Center at Dallas. They sometimes secrete excess growth hormone and adrenocorticotropic hormone (ACTH), causing abnormal body growth or Cushing’s disease. Pituitary tumors also may push on the optic nerve and impair vision.

When Craven started experiencing dizziness, focusing problems, headaches and light sensitivity, her sister insisted on consulting a specialist at the Baylor Radiosurgery Center.

Focus Factor
“Her tumor didn’t produce hormones, and it wasn’t yet affecting her vision, but it was close to her optic nerve,” Dr. Giller says.

Rather than a traditional surgical approach to remove the tumor—entering through the nose or mouth—Dr. Giller recommended radiosurgery with the Gamma Knife^®. There’s no incision involved; the Gamma Knife destroys the tumor noninvasively with precisely focused beams of radiation.

Radiation is a concern when treating pituitary adenomas near the optic nerve, however.

“The nerves that control vision are very sensitive to radiation, and the dose we wanted to administer to destroy her tumor was much higher than the limit for the optic nerve,” Dr. Giller says. Craven’s adenoma was far enough away from the optic nerve that they were able to administer a sufficient dose, “but we had to use specialized blocking techniques that diverted radiation from the sensitive area.”

The Royal Treatment
“I looked like Mrs. Frankenstein wearing that stereotactic frame and football helmet on my head,” Craven says with a laugh about her Gamma Knife surgery, which took place in March 2006. “But that’s OK, because it helps them measure where the radiation beams go.”

Since that one-time treatment, Craven’s tumor has shrunk a full centimeter and her symptoms have subsided. She returns to Baylor Radiosurgery Center every March for a follow-up.

“For anything else involving my tumor, I’m going right back to Baylor Dallas,” she says. “They treated me like a queen.”

By Deborah Paddison

For more information about the Baylor Radiosurgery Center.

Gamma Knife® and Leskell Gamma Knife are U.S. federally registered trademarks of Elecktra Instruments, S.A., Geneva, Switzerland.