| Preservation of Serviceable Hearing after Gamma Knife Radiosurgery for Vestibular Schwannoma |
|
Jye Young Song, Chang Jin Kim, Jung Kyo Lee, Young Hyun Cho, Do Hui Lee, Do Hoon Kwon |
|
Department of Neurosurgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea |
|
|
| Abstract |
Objective
This study evaluated the hearing function of patients with vestibular schwannoma (VS) who underwent gamma knife radiosurgery (GKS) to establish the factors associated with the preservation of serviceable hearing.
Methods
GKS was performed in 36 VS patients with serviceable hearing between January 2001 and December 2011. Their hearing tests, with a median audiological follow-up of 14.4 months (range, 1.3-70.2 months), were retrospectively reviewed. The test results were classified using the Gardner-Robertson (GR) grade and serviceable hearing was defined as GR grade I or II.
Results
Serviceable hearing was preserved in 20 patients (56%). Although patients with better pre-GKS GR grades had a higher hearing preservation rate, an analysis of those with a greater than 1-year follow-up period failed to demonstrate a significant association between superior GR grades and hearing preservation. An 82% hearing preservation rate was achieved with a mean cochlear dose of less than 4Gy in contrast to a 44% rate with a dose greater than 4Gy (p=0.047).There were no statistically significant correlations between the preservation of serviceable hearing and either age, sex, tumor volume, or change in tumor size.
Conclusion
The hearing grade prior to GKS is less likely to be associated with the preservation of serviceable hearing over a greater than 1-year follow-up after the treatment. A lower cochlear dose is associated with hearing preservation and the mean cochlear dose is recommended to be no more than 4Gy for patients with serviceable hearing. |
| Key Words:
Cochlear dose, Gamma knife radiosurgery, Hearing preservation, Stereotactic radiosurgery, Vestibular schwannoma. |
|
PDF Links
Full text via DOI
Download Citation
