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Updated: Oct 31, 2025
A Unified Methodological Framework for Vestibular Schwannoma Research
Published on: June 20, 2017
Preplanned Partial Surgical Removal Followed by Low-Dose Gamma Knife Radiosurgery for Large Vestibular Schwannomas
Yoshiyasu Iwai1, Kenichi Ishibashi2, Kazuhiro Yamanaka2
1Department of Neurosurgery, Tominaga Hospital, Osaka, Japan. y-iwai@rc5.so-net.ne.jp.
Objective:
The present study evaluated outcomes after preplanned partial surgical removal of a large vestibular schwannoma (VS) followed by low-dose Gamma Knife surgery (GKS).
Methods:
Between January 2000 and May 2015, 47 patients with a unilateral VS (median maximum diameter 32 mm) underwent preplanned partial tumor removal at our clinic. GKS for a residual lesion was done within a median time interval of 3 months. The median prescription dose was 12 Gy. The median length of subsequent follow-up was 74 months.
Results:
The actuarial tumor growth control rates without a need for additional management at 3, 5, and 15 years after GKS were 92%, 86%, and 86%, respectively. At the time of the last follow-up, the function of the ipsilateral facial nerve corresponded to House-Brackmann grade I in 92% of patients. Significant improvement of ipsilateral hearing was noted in two patients after partial tumor removal and in one after GKS. Among 16 patients who presented with ipsilateral serviceable hearing, it was preserved immediately after surgery in 81% of cases and at the time of the last follow-up in 44%. Salvage surgical treatment was required in 9% of patients.
Conclusion:
Preplanned partial surgical removal followed by low-dose GKS provides a high level of functional preservation in patients with a large VS.
