====== Vestibular Schwannoma Meta-analysis ======

===== 2021 =====
Neves Cavada et al. performed a systematic review and meta-analysis summarizing the current evidence on the management of intracanalicular vestibular schwannoma.

Data sources: Embase (1947-), Medline (1946-), Cochrane library (1947-), Scopus (2010-), and CINAHL (1961-) were searched from 1969 to October 5, 2019 (50 years).

Study selection: A search strategy was performed to identify patients with [[vestibular schwannoma]] confined to the internal auditory canal without extension to the cerebellopontine angle. Studies with patients aged less than 18, Neurofibromatosis type 2, revision cases, and non-English language were excluded.

Data extraction: A standardized collection sheet was used for the extracted data and a quality assessment was performed using the Newcastle-Ottawa Scale with the comparability criterion omitted.

Data synthesis: Seventy-one studies were included with 24 on observation, 14 on radiotherapy, and 34 on surgery. The primary outcome was serviceable hearing preservation. Secondary outcomes were preservation of facial nerve function, growth, involution, and dizziness. Sub-analysis on the type of surgery and type of radiotherapy were performed. Excel 2016 with MIX 2.0 Pro add-on package was used to analyze the data and create forest plots. Data were presented in proportion with a 95% confidence interval.

Conclusions: Serviceable hearing was observed in 31% of patients after observation, 56% after radiotherapy, and 51% after surgical treatment with mean follow-up time of 4.04 years, 4.92 years, and 2.23 years, respectively. Facial nerve function was found to be best preserved in both observation and radiotherapy groups. Vestibular schwannoma growth occurred in 33% of patients under observation. Involution occurred in 2% of patients under observation and in 38% after radiotherapy
((Neves Cavada M, Fook-Ho Lee M, Jufas NE, Harvey RJ, Patel NP. Intracanalicular Vestibular Schwannoma: A Systematic Review and Meta-analysis of Therapeutics Outcomes. Otol Neurotol. 2021 Mar 1;42(3):351-362. doi: 10.1097/MAO.0000000000002979. PMID: 33555742.)).

===== 2020 =====

The optimal management of large vestibular schwannomas continues to be debated. We constituted a task force comprising the members of the EANS skull base committee along with international experts to derive recommendations for the management of this problem from a European perspective.

Material and methods: A systematic review of MEDLINE database, in compliance with the PRISMA guidelines, was performed. A subgroup analysis screening all surgical series published within the last 20 years (January 2000 to March 2020) was performed. Weighted summary rates for tumor resection, oncological control, and facial nerve preservation were determined using meta-analysis models. This data along with contemporary practice patterns were discussed within the task force to generate consensual recommendations regarding preoperative evaluations, optimal surgical strategy, and follow-up management.

Results: Tumor classification grades should be systematically used in the perioperative management of patients, with large vestibular schwannomas (VS) defined as > 30 mm in the largest extrameatal diameter. Grading scales for pre- and postoperative hearing (AAO-HNS or GR) and facial nerve function (HB) are to be used for reporting functional outcome. There is a lack of consensus to support the superiority of any surgical strategy with respect to extent of resection and use of adjuvant radiosurgery. Intraoperative neuromonitoring needs to be routinely used to preserve neural function. Recommendations for postoperative clinico-radiological evaluations have been elucidated based on the surgical strategy employed.

Conclusion: The main goal of management of large vestibular schwannomas should focus on maintaining/improving quality of life (QoL), making every attempt at facial/cochlear nerve functional preservation while ensuring optimal oncological control, thereby allowing to meet patient expectations. Despite the fact that this analysis yielded only a few Class B evidences and mostly expert opinions, it will guide practitioners to manage these patients and form the basis for future clinical trials
((Starnoni D, Giammattei L, Cossu G, Link MJ, Roche PH, Chacko AG, Ohata K, Samii M, Suri A, Bruneau M, Cornelius JF, Cavallo L, Meling TR, Froelich S, Tatagiba M, Sufianov A, Paraskevopoulos D, Zazpe I, Berhouma M, Jouanneau E, Verheul JB, Tuleasca C, George M, Levivier M, Messerer M, Daniel RT. Surgical management for large vestibular schwannomas: a systematic review, meta-analysis, and consensus statement on behalf of the EANS skull base section. Acta Neurochir (Wien). 2020 Nov;162(11):2595-2617. doi: 10.1007/s00701-020-04491-7. Epub 2020 Jul 29. PMID: 32728903; PMCID: PMC7550309.)).
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A broad search of the literature was conducted in October 2018 through the PubMed, Scopus, Embase, Web of Science, and Cochrane databases. Meta-analysis was conducted on tumor control rates and heterogeneity between articles was assessed using τ2, Cochran's Q, and I2 statistics.

Results: A total of 246 patients underwent SRS for cystic VS, with reported mean or median follow-up ranging from 49.7 to 150 months, and an overall range of 6-201 months. Following SRS treatment for cystic VS across all studies, 92% of patients had tumor control at follow-up, (95%-CI: 88-95%). The tumor control rate specifically for patients who underwent GammaKnife was 93% (95-CI: 88%-95%).

Conclusion: Despite the paucity of pertinent data, the results of our meta-analysis suggest that SRS exhibits effective tumor control rates in patients with cystic VS. Therefore, SRS can be considered a viable treatment modality when choosing amongst interventions for cystic VS
((Ding K, Ng E, Romiyo P, Dejam D, Udawatta M, Sun MZ, Gopen Q, Yang I. Meta-analysis of tumor control rates in patients undergoing stereotactic radiosurgery for cystic vestibular schwannomas. Clin Neurol Neurosurg. 2020 Jan;188:105571. doi: 10.1016/j.clineuro.2019.105571. Epub 2019 Oct 31. PMID: 31756616.)). 

===== 2018 =====

The aim of a study was to provide a systematic review and meta-analysis of the available literature regarding the combined strategy of subtotal resection (STR) followed by stereotactic radiosurgery (SRS) for large VSs. METHODS The authors performed a systematic review and meta-analysis in compliance with the PRISMA guidelines for article identification and inclusion using the PubMed, Embase, and Cochrane databases. Established inclusion criteria were used to screen all identified relevant articles published before September 2017 without backward date limit. RESULTS The authors included 9 studies (248 patients). With a weighted mean follow-up of 46 months (range 28-68.8 months), the pooled rate of overall tumor control was 93.9% (95% CI 91.0%-96.8%). Salvage treatment (second STR and/or SRS) was necessary in only 13 (5.24%) of 18 patients who experienced initial treatment failure. According to the House-Brackmann (HB) grading scale, functional facial nerve preservation (HB grade I-II) was achieved in 96.1% of patients (95% CI 93.7%-98.5%). Serviceable hearing after the combined approach was preserved in 59.9% (95% CI 36.5%-83.2%). CONCLUSIONS A combined approach of STR followed by SRS was shown to have excellent clinical and functional outcomes while still achieving a tumor control rate comparable to that obtained with a total resection. Longer-term follow-up and larger patient cohorts are necessary to fully evaluate the rate of tumor control achieved with this approach
((Starnoni D, Daniel RT, Tuleasca C, George M, Levivier M, Messerer M. Systematic review and meta-analysis of the technique of subtotal resection and stereotactic radiosurgery for large vestibular schwannomas: a "nerve-centered" approach. Neurosurg Focus. 2018 Mar;44(3):E4. doi: 10.3171/2017.12.FOCUS17669. PMID: 29490553.)).

===== 2014 =====
The purpose of a meta-analysis was to analyze the progress in the treatment of vestibular schwannoma using Gamma Knife radiosurgery based on data in the literature of the last five years.

In the collected English-language literature from the years 2007-2011, contained in 20 scientific journals, clinical articles of many years of study at a single center were extracted, and also review papers and case reports. The main criteria of our own analysis were: patient age, tumor size, the dose in Gy, the time from surgery to follow-up, the degree of tumor growth inhibition, and hearing preservation. For statistical calculations comparing series of studies, we used nonparametric analysis of variance and tests at the significance level of p > 0.05.

The 46 evaluated clinical articles show the results of studies over many years. A comparison of the results of the analysis made on the basis of papers published in the period 1998-2007 with the results of the current series from the period 2007-2011 allowed us to establish that the average dose applied to the periphery of the tumor was lower (12.4 Gy) than in the earlier series of 1998-2007 (14.2 Gy), and hearing preservation was higher (66.45% vs. 51.0%).

Clinical findings widely documented in the literature over the past five years indicate the progress in the treatment of vestibular schwannoma using Gamma Knife radiosurgery
((Rykaczewski B, Zabek M. A meta-analysis of treatment of vestibular schwannoma using Gamma Knife radiosurgery. Contemp Oncol (Pozn). 2014;18(1):60-6. doi: 10.5114/wo.2014.39840. Epub 2014 Jan 25. PMID: 24876823; PMCID: PMC4037985.)).

===== 2000 =====

[[Vestibular Schwannoma Meta-analysis]] from early experience showed that 44% with serviceable hearing prior to treatment retained their ability after SRS, a statistically equivalent rate to the surgical data. This evidence also suggest that 37.9% of patients have other complications
((Kaylie DM, Horgan MJ, Delashaw JB, McMenomey SO. A meta-analysis comparing outcomes of microsurgery and gamma knife radiosurgery. Laryngoscope. 2000 Nov;110(11):1850-6. doi: 10.1097/00005537-200011000-00016. PMID: 11081598.)).