Brain tumors at the base of the skull may be treated effectively with lower doses of radiosurgery to preserve both hearing and facial nerve function using Gamma Knife radiosurgery, according to findings being presented at the annual meeting of the American Association of Neurological Surgeons (AANS) in San Diego this week.
Researchers at the University of California, San Francisco analyzed outcomes in thousands of patients who underwent Gamma Knife (Elekta, Norcross, GA) radiosurgery treatment for vestibular schwannomas. Also called acoustic neuromas, vestibular schwannomas are common skull-base brain tumors that account for 57% of all nerve sheath tumors and 5% of all primary brain tumors. The tumors arise near nerves that control hearing and movement of the face.
Dr. Isaac Yang, a senior resident in the department of neurological surgery, and colleagues conducted a retrospective review of the outcomes of 6,438 patients who underwent Gamma Knife radiosurgery for vestibular schwannomas. Gamma Knife radiosurgery uses 3D computerized imaging to precisely target a high concentrated dose of radiation to the tumor site.
If facial nerve function and hearing were preserved prior to treatment, 96% of patients retained facial nerve function and 51% had their hearing preserved, according to the researchers. The average follow-up was four years.
Patients who had the best facial and hearing outcomes were those treated with lower doses of radiosurgery, at 13 Gy or less. Hearing was preserved for 61% of these patients, compared with 50% of those who had more than a 13 Gy dose. Facial nerve function was preserved for 98% of the lower-dose patients, compared with 95% of those who received a standard dose.
The AANS, headquartered in Rolling Meadows, IL, selected this study for its annual Leksell Radiosurgery Award.
Related Reading
Radiosurgery effective for vestibular schwannomas with neurofibromatosis type 2, February 6, 2009
Gamma Knife provides local control for some low-grade gliomas, December 23, 2008
Lower radiation dose saves hearing in acoustic neuromas, November 8, 2006
Hearing loss still common after low-dose radiation for vestibular schwannomas, August 18, 2005
Copyright © 2009 AuntMinnie.com
