In early 2008, during a 37-year-old woman's routine optometry appointment, visual field testing revealed that she was rapidly losing her vision. When a community ophthalmologist followed up with an MR scan, he discovered a meningioma that sent the woman on an anxious tour of potential surgeons. She settled on Michael McDermott, M.D., of UCSF Medical Center.
"In surgeries of this type, one key patient consideration is high volume," says McDermott." At this facility, despite remaining conservative in our treatment recommendations, we resect about 140 to 160 meningiomas a year."
In this case, the tumor was directly between the optic nerves. Because retraction of the brain during the initial craniotomy was a concern, McDermott chose an anterior skull base approach: an extended bifrontal craniotomy that reduced the retraction risk and provided direct access to the tumor.
"We removed the tumor below the chiasm, but like most tuberculum sellae meningiomas, this one had also grown into the sella turcica and down the optic canals," says McDermott. After using a diamond drill to open the optic canals, he opened the optic nerve sheaths and removed the rest of the tumor on the medial side of the optic canals.
"During this part of the process, you see the small arteries supplying the chiasm and pituitary stalk, and they are about two hair strands thick," says McDermott. The procedure became even more complicated when McDermott and the surgical team discovered an aneurysm coming off the superior hypophyseal artery, which vascular neurosurgeon Michael Lawton, M.D., came in and clipped off.
"Finally, we put the skull back together using a cosmetic technique I have learned from [Chief of the UCSF Division of Plastic and Reconstructive Surgery] Bill Hoffman, [M.D.,]" says McDermott. "We countersink the plates so they can't be seen or felt, fill the gaps in with hydroxyapatite, then irrigate and sand down with an instrument scratch pad."
The procedure took nearly 10 hours, slightly more than average. But, says McDermott, it was worth it. "The patient went home on the fourth postoperative day with her vision restored and no need for additional treatment — just monitoring," he says.
Despite such success stories, McDermott — who is also neurosurgical director of the UCSF Gamma Knife Radiosurgery Program and a member of the Brain Tumor Research Center — notes that open surgery is no longer the only option for treating meningiomas.
"Gamma Knife and CyberKnife radiosurgery is especially effective for treatment of small, recurrent tumors where traditional surgery will not be able to remove the entire tumor," says McDermott.
At UCSF Medical Center, decisions about the proper approach emerge from discussions among neurosurgeons, radiation oncologists, neuro-otologists, head and neck surgeons, and neuro-oncologists during multidisciplinary tumor board, radiosurgery and skull base conferences.
Finally, McDermott hopes that medical oncology may someday help avoid some operations for recurrent tumors. He is working with the director of the Meningioma Research Lab, Anita Lal, Ph.D., radiation oncologists Igor J. Barani, M.D., and Penny Sneed, M.D., as well as Randy Hawkins, M.D., Ph.D., from Nuclear Medicine, to try to develop an intravenous radiopharmaceutical for recurrent meningioma treatment.
"It would be an antibody with a radioactive element attached that binds to the tumor cell, irradiates it, and either stops further tumor cell growth or eliminates the tumor," says McDermott. "We're in the early stages, but we're hopeful it can provide more targeted treatment."
For more information, contact Michael McDermott, M.D., at (415) 353–7500.
UCSF Rises to Second in NIH Funding
UCSF was the second largest recipient of National Institutes of Health (NIH) research support in 2008. UCSF received more than $444 million in research and training grants, fellowships and other awards.