Patients with acoustic neuroma (also known as vestibular schwannoma) appear to have good tumor response and few toxic effects after treatment with fractionated stereotactic radiation therapy, according to a study published in the International Journal of Radiation, Oncology, Biology, Physics .
Acoustic neuroma is a benign tumor that develops from nerves that supply the inner ear. Since these nerves affect balance and hearing, acoustic neuromas may cause hearing loss (generally only on one side), ringing in the ear, dizziness, or loss of balance. Acoustic neuromas may also press on facial nerves, causing facial numbness or weakness in the facial muscles. If acoustic neuromas grow large enough, they can be life-threatening. Treatment options for acoustic neuroma include surgery, radiation therapy, or monitoring.
To assess the safety and effectiveness of radiation therapy for treatment of acoustic neuroma, researchers in Germany evaluated 106 patients who were treated with fractionated stereotactic radiation therapy. Fractionated stereotactic radiation therapy involves the delivery of radiation to a very precise location in the brain. The total radiation dose is broken up into several smaller doses. The objective of this approach is to maximize the effect of radiation on tumor cells while minimizing the effect on normal tissue.
Rates of positive outcomes were high for treatment with fractionated stereotactic radiation therapy; tumors were controlled for at least five years in 93% of patients, and hearing was preserved in 94% of patients. A small minority of patients (2-3%) experienced damage to the trigeminal or facial nerves as a result of treatment.
The researchers conclude that fractionated stereotactic radiation therapy appears to be safe and effective for acoustic neuroma and may offer an alternative to surgery.
Combs SE, Volk S, Schulz-Ertner D et al. Management of acoustic neuromas with fractionated stereotactic radiotherapy (FSRT): Long-term results in 106 patients treated in a single institution. International Journal of Radiation, Oncology, Biology, Physics. 2005;63:75-81.
National Institute on Deafness and Other Communication Disorders. Vestibular Schwannoma (Acoustic Neuroma) and Neurofibromatosis. http://www.nidcd.nih.gov/health/hearing/acoustic_neuroma.asp (accessed September 15, 2005).