Nonvestibular Schwannoma Tumors in the Cerebellopontine Angle: A Single-Surgeon Experience

Stereotactic radiosurgery for cerebellopontine meningiomas: a systematic review and meta-analysis

OBJECTIVE

To (1) measure surgical outcomes associated with stereotactic radiosurgery treatment of cerebellopontine angle meningiomas, and (2) determine if differences in radiation dosages or preoperative tumor volumes affect surgical outcomes.

METHODS

A systematic search was performed on the PubMed, Medline, Embase and Cochrane Library databases searching for patients under stereotactic radiosurgery for meningiomas of the cerebellopontine angle. After data extraction and Newcastle-Ottawa scale quality assessment, meta-analysis of the data was performed with Review Manager 3.4.5.

RESULTS

In total, 6 studies including 406 patients were included. Postprocedure, patients had minimal cranial nerve complications while having an overall tumor control rate of 95.6%. Complications were minimal with facial nerve deficits occurring in 2.4%, sensation deficits of the trigeminal nerve in 4.0%, hearing loss in 5.9%, hydrocephalus in 2.0% and diplopia in 2.6% of all patients. Individuals with tumors extending into the internal auditory canal extension did not have significantly increases in hearing loss. There was a higher likelihood of tumor regression on postprocedure imaging in studies with a median prescription dose of >13 Gy (RR 1.27 [95% CI 1.04-1.56, p = 0.0225). There was no evidence of publication bias detected.

CONCLUSIONS

Radiosurgery is an effective modality for offering excellent tumor control of CPA meningiomas while allowing for only minimal complications postprocedure. A higher prescription dose may achieve higher tumor regression at follow up. Future studies should aim at establishing and optimizing accurate dosimetric guidelines for this patient population.

Treated large posterior fossa vestibular schwannoma and meningioma: Hearing outcome and willingness-to-accept brain implant for unilateral deafness

Background/Objective

To compare functional hearing and tinnitus outcomes in treated large (~ 3 cm) vestibular schwannoma (VS) and posterior fossa meningioma cohorts, and construct willingness-to-accept profiles for an experimental brain implant to treat unilateral hearing loss.

Methods

A two-way MANOVA model with two independent variables (tumor type; time from treatment) and three dependent variables (hearing effort of tumor ear; abbreviated Speech, Spatial, and Qualities of Hearing scale (SSQ12); Tinnitus Functional Index (TFI)) was used to analyze data from VS (N = 32) and meningioma (N = 50) patients who were treated at a tertiary care center between 2010 and 2020. A query to probe acceptance of experimental treatment for hearing loss relative to expected benefit was used to construct willingness-to-accept profiles.

Results

Tumor type was statistically significant on the combined dependent variables analysis (F[3, 76] = 19.172, p < .0005, Wilks' Λ = 0.569). Meningioma showed better outcome for hearing effort (F[1, 76] = 14.632, p < .0005) and SSQ12 (F[1, 76] = 16.164, p < .0005), but not for TFI (F[1, 76] = 1.247, p = .268) on univariate two-way ANOVA analyses. Superior hearing effort and SSQ12 indices in the short-term (< 2 years) persisted in the long-term (> 2 years) (p ≤ .017). At the 60% speech understanding level, 77% of respondents would accept an experimental brain implant.

Conclusion

Hearing outcome is better for posterior fossa meningioma compared to VS. Most patients with hearing loss in the tumor ear would consider a brain implant if the benefit level would be comparable to a cochlear implant.

Level of Evidence

2.

Predictors of hearing functional outcome following surgery for cerebellopontine angle meningioma

OBJECTIVE

Cerebellopontine angle (CPA) meningiomas can affect hearing function and require expeditious treatment to prevent permanent hearing loss. The authors sought to determine the factors associated with functional hearing outcome in CPA meningioma patients treated with surgery and/or radiation therapy in the form of either stereotactic radiosurgery or stereotactic radiation therapy.

METHODS

Consecutive patients with CPA meningiomas who had presented at our hospital from 2008 to 2018 were identified through retrospective chart review. Hearing function (as defined by pure tone average (PTA) and speech discrimination score (SDS) on Audiogram) was assessed before and after surgery for CPA meningioma. Audiograms with PTA > 50 dB and SDS < 69% were defined as poor hearing functional outcome. Multivariable Cox Proportional Hazards Regression Model was used to assess the associations between pre-operative hearing functional assessment and post-operative hearing functional outcomes.

RESULTS

The study cohort included 31 patients (80.6% females, with a mean age of 61.3 ± 15.2 years) with a median clinical follow-up of 5 months (range: 1 week-98 months). The mean pre-operative PTA and SDS were 23.8 ± 11.2 dB and 64.4 ± 22.2% respectively. At the last visit, there was significant hearing recovery, with an improvement of 29.7 ± 18.0 dB (p < 0.001) and 87.6 ± 17.8% (p < 0.001) in PTA and SDS respectively. After adjusting for age, gender, tumor volume, location, and tumor classification, Multivariable Cox Proportional Hazards Regression Model was conducted which revealed that patients undergoing surgery through retro sigmoid approach [Hazards Ratio (HR): 32.1, 95% Confidence Interval (CI): 2.11-491.0, p = 0.01] and gross total resection (GTR) (HR: 2.99, 95% CI: 1.09-9.32, p = 0.05) had significantly higher risk of poor hearing functional outcome compared to petrosal approach and near/subtotal resection. Moreover, patients with poor preoperative hearing had 85% higher chance of poor hearing functional outcome postoperatively (HR: 0.15, 95%CI: 0.03-0.59, p = 0.007).

CONCLUSION

Postoperative improvement in hearing is a reasonable expectation following surgery for CPA meningioma. Preoperative hearing, surgical approach and extent of surgical resection are predictive factors of postoperative hearing function outcome and can therefore aid in identification of patients at higher risk of hearing loss.

Management of non-vestibular schwannomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section Part III: Lower cranial nerve schwannomas, jugular foramen (CN IX, X, XI) and hypoglossal schwannoma (XII)

BACKGROUND

Non-vestibular schwannomas are relatively rare, with trigeminal and jugular foramen schwannomas being the most common. This is a heterogenous group which requires detailed investigation and careful consideration to management strategy. The optimal management for these tumours remains unclear, and there are several controversies. The aim of this paper is to provide insight into the main principles defining management and surgical strategy, in order to formulate a series of recommendations.

METHODS

A task force was created by the EANS skull base section committee along with its members and other renowned experts in the field to generate recommendations for the surgical management of these tumours on a European perspective. To achieve this, the task force performed an extensive systematic review in this field and had discussions within the group. This article is the third of a three-part series describing non-vestibular schwannomas (IX, X, XI, XII).

RESULTS

A summary of literature evidence was proposed after discussion within the EANS skull base section. The constituted task force dealt with the practice patterns that exist with respect to preoperative radiological investigations, ophthalmological assessments, optimal surgical and radiotherapy strategies and follow-up management.

CONCLUSION

This article represents the consensually derived opinion of the task force with respect to the treatment of non-vestibular schwannomas. For each of these tumours, the management paradigm is shifting towards the compromise between function preservation and progression free survival.

Small Cerebellopontine Angle Meningioma-Surgical Experience of 162 Patients and Literature Review

Objective

To retrospective analyze the clinical data of 162 patients with small cerebellopontine angle meningiomas. To compare with the nature of tumors, symptoms pre- and post-treatments, neurological deficit, and prognosis in literatures. To explore the surgical outcomes of small cerebellopontine angle meningiomas and summarize the surgical experience.

Methods

All of 162 patients with small cerebellopontine angle meningiomas underwent surgery between January 2010 and December 2019 in the neurosurgery department of the First Affiliated Hospital of Soochow University. This cohort of eight literatures reported about stereotactic radiotherapy of small cerebellopontine angle meningiomas between January 2010 and December 2019. All clinical data were obtained for analysis.

Results

Compared with stereotactic radiotherapy, surgical treatment for small cerebellopontine angle meningiomas lead to the better results in relieving symptoms and inhibiting tumor progression. Surgical treatment can obtain the exact pathological examination results to guide the further treatment.

Conclusions

Surgical treatment should be the first choice for small cerebellopontine angle meningiomas.