Hearing loss in acoustic neuromas following stereotactic radiotherapy.

BACKGROUND

Hearing preservation is a major concern in the management of acoustic neuroma (AN), whether treated by surgery or radiation or followed conservatively.

OBJECTIVE

To assess the change in hearing in patients who underwent radiotherapy for ANs and to compare it with data from conservatively managed patients.

DESIGN

Prospective case series.

SETTING

Neuro-otology, neurosurgery, and radiation oncology practices in tertiary care hospitals of the University Health Network, University of Toronto.

PATIENTS AND

METHODS

Between 1991 and 1999, 32 patients who underwent radiotherapy were followed prospectively. Seventeen patients had pretreatment measurable hearing and a minimum 1-year follow-up. Twelve of these patients underwent Gamma Knife radiation and five had fractionated radiation therapy with a linear accelerator. Pre- and post-treatment hearing was classified according to the Gardner-Robertson (GR) classificatiom and according to the 1995 guidelines of the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium (AAO-HNS CHE).

OUTCOME MEASURE: Change in hearing post-treatment.

RESULTS

Mean follow-up was 48 months. Deterioration in the level of hearing was observed in 8 and 11 of the patients using the AAO-HNS CHE and the GR classifications, respectively. Forty-four to 70% of the patients had lost their pretreatment serviceable hearing, depending on the classification of hearing used and how serviceable hearing was defined. Compared with series of patients followed conservatively in our institution and in other studies, patients who receive stereotactic radiation appear to lose hearing at least at the same rate.

CONCLUSION

Our data suggest that hearing loss continues to occur despite radiotherapy, and patients should be advised accordingly.