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Systematic Reviews Dec 2022Vestibular schwannomas are benign tumours for which various treatments are available. We performed a systematic review of prospective controlled trials comparing the... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vestibular schwannomas are benign tumours for which various treatments are available. We performed a systematic review of prospective controlled trials comparing the patient-relevant benefits and harms of single-fraction stereotactic radiosurgery (sfSRS) with microsurgical resection (MR) in patients with vestibular schwannoma.
METHODS
We searched for randomized controlled trials (RCTs) and non-randomized prospective controlled trials in MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and study registries (last search: 09/2021) and also screened reference lists of relevant systematic reviews. Manufacturers were asked to provide unpublished data. Eligible studies investigated at least one patient-relevant outcome. We assessed the risk of bias (high or low) at the study and outcome level. If feasible, meta-analyses were performed. We graded the results into different categories (hint, indication, or proof of greater benefit or harm).
RESULTS
We identified three non-randomized prospective controlled trials of generally low quality with evaluable data on 339 patients with unilateral vestibular schwannoma. There was an indication of greater benefit of sfSRS compared with MR for facial palsy (OR 0.06, 95% CI 0.02-0.21, p < 0.001, 2 studies), hearing function (no pooled estimate available, 2 studies), and length of hospital stay (no pooled estimate available, 2 studies). We found no clinically relevant differences for mortality, vertigo, headaches, tinnitus, balance function, work disability, adverse events, and health-related quality of life.
CONCLUSIONS
Our systematic review indicates that sfSRS has greater benefits than MR in patients with unilateral vestibular schwannoma. However, it is unclear whether this conclusion still holds after 2 years, as long-term studies are lacking. It is also unclear whether the effects of sfSRS are similar in patients with bilateral vestibular schwannomas. Long-term prospective studies including patients with this condition would therefore be useful.
SYSTEMATIC REVIEW REGISTRATION
The full (German language) protocol and report (Commission No. N20-03) are available on the institute's website: www.iqwig.de/en/projects/n20-03.html.
Topics: Humans; Microsurgery; Neuroma, Acoustic; Radiosurgery; Treatment Outcome; Controlled Clinical Trials as Topic
PubMed: 36503553
DOI: 10.1186/s13643-022-02118-9 -
Neurotoxicology Jul 2017The overall aim of this systematic review was to identify risk factors for onset and natural progression, which were shown to increase, decrease, or have a null... (Review)
Review
The overall aim of this systematic review was to identify risk factors for onset and natural progression, which were shown to increase, decrease, or have a null association with risk of primary brain tumour. For onset, the project was separated into two phases. The first phase consisted of a systematic search of existing systematic reviews and meta-analyses. Moderate to high methodological quality reviews were incorporated and summarized with relevant observational studies published since 2010, identified from a systematic search performed in phase 2. For natural progression, only the first phase was conducted. Standard systematic review methodology was utilized. Based on this review, various genetic variants, pesticide exposures, occupational farming/hairdressing, cured meat consumption and personal hair dye use appear to be associated with increased risk of onset amongst adults. The specific EGF polymorphsm 61-A allele within Caucasian populations and having a history of allergy was associated with a decreased risk. For progression, M1B-1 antigen was shown to increase the risk. High birth weight, pesticide exposure (childhood exposure, and parental occupational exposure) and maternal consumption of cured meat during pregnancy may also increase the risk of onset of childhood brain tumours. Conversely, maternal intake of pre-natal supplements (folic acid) appeared to decrease risk. Children with neurofibromatosis 2 were considered to have worse overall and relapse free survival compared to neurofibromatosis 1, as were those children who had grade III tumours compared to lesser grades.
Topics: Age of Onset; Brain Neoplasms; Disease Progression; Epidermal Growth Factor; Humans; Ki-67 Antigen; Mutation; Neurofibromatosis 1; Neurofibromatosis 2; Pesticides; Risk Factors; Von Hippel-Lindau Tumor Suppressor Protein
PubMed: 27212451
DOI: 10.1016/j.neuro.2016.05.009 -
Otology & Neurotology : Official... Mar 2021To perform a systematic review and meta-analysis summarizing the current evidence on the management of intracanalicular vestibular schwannoma. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To perform 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.
Topics: Aged; Hearing; Hearing Loss; Hearing Tests; Humans; Neuroma, Acoustic; Radiosurgery; Treatment Outcome
PubMed: 33555742
DOI: 10.1097/MAO.0000000000002979 -
Wideochirurgia I Inne Techniki... Sep 2022Intracanalicular vestibular schwannomas (IVS) account for 8% of all vestibular schwannomas and their detection is still increasing due to high availability of magnetic... (Review)
Review
Intracanalicular vestibular schwannomas (IVS) account for 8% of all vestibular schwannomas and their detection is still increasing due to high availability of magnetic resonance (MRI). Radiosurgery is one of several commonly acceptable methods of IVS treatment, but some risk may still exist with that treatment. The aim of this study is to analyze the clinical outcomes in tumor control and hearing preservation after radiosurgery of IVS. The retrospective analysis included 14 scientific papers available in the PubMed database. Assessment of tumor volume was performed based on gadolinium-enhanced T1-weighted scans. Hearing preservation was assessed using the Gardner-Robertson classification (GR class). Statistical analysis was performed using IBM SPSS Statistics 27. It was revealed that tumor growth control in IVS treated with radiosurgery was higher than in the wait-and-see strategy. The hearing preservation was similar in patients after wait and see and the surgical group. Radiosurgery was associated with low risk of facial nerve dysfunction.
PubMed: 36187055
DOI: 10.5114/wiitm.2022.115169 -
The Laryngoscope Sep 2023To systematically review and evaluate metformin's potential impact on vestibular schwannoma (VS) growth. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To systematically review and evaluate metformin's potential impact on vestibular schwannoma (VS) growth.
DATA SOURCES
PubMed, Cochrane Library, and Embase.
REVIEW METHODS
A retrospective cohort study was performed on sporadic VS patients undergoing initial observation who had at least two magnetic resonance imaging studies. Patients were stratified by metformin use during the observation period. Primary endpoint was VS growth, defined as at least a 2 mm increase in diameter. Survival free of tumor growth was evaluated between groups. Systematic review and meta-analysis were performed to produce a pooled odds ratio [OR]. Study heterogeneity was assessed and post-hoc power analysis was performed.
RESULTS
A total of 123 patients were included, of which 17% were taking metformin. Median patient age was 56.6 years (range, 25.1-84.5). There were no statistically significant differences between the groups. Survival analysis did not demonstrate a statistically significant difference in time to VS growth between groups (hazard ratio = 0.61, 95% confidence interval [CI] = 0.29-1.29). Furthermore, logistic regression analysis did not demonstrate a statistically significant difference between groups in the odds of VS growth (OR = 0.46, 95% CI = 0.17-1.27). Systematic review identified 3 studies. Meta-analysis suggested that metformin reduces the odds of developing VS growth (pooled OR = 0.45, 95% CI = 0.29-0.71). Studies demonstrated low between-study heterogeneity. Power analysis demonstrated a sample size of 220 patients with equal randomization would be required to prospectively identify a true difference with 80% power.
CONCLUSIONS
Metformin use may reduce the odds of VS growth. A randomized trial would be ideal to identify an unbiased estimate of metformin's effect on VS growth. Laryngoscope, 133:2066-2072, 2023.
Topics: Humans; Adult; Middle Aged; Aged; Aged, 80 and over; Neuroma, Acoustic; Metformin; Retrospective Studies; Magnetic Resonance Imaging; Survival Analysis
PubMed: 36744870
DOI: 10.1002/lary.30601 -
Frontiers in Surgery 2022Survival amongst posterior fossa tumour (PFT) patients is improving. Clinical endpoints such as overall survival fail to depict QoL. There is yet to be a review of... (Review)
Review
INTRODUCTION
Survival amongst posterior fossa tumour (PFT) patients is improving. Clinical endpoints such as overall survival fail to depict QoL. There is yet to be a review of current QoL instruments used for adult PFTs. Aim of this review is to outline the QoL reporting in the management of PFTs and measure participation level.
METHODS
This systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis. A search strategy to identify adult patients with PFTs who took part in QoL metrics was conducted. Observational and experimental studies published from 1990 to date were included. Studies with a sample size less than 10 and performance measures such as Karnofsky Performance Status were not considered.
RESULTS
A total of 116 studies were included in the final analysis. Vestibular schwannomas were the most common tumour pathology ( = 23,886, 92.6%) followed by pilocytic astrocytomas ( = 657, 2.5%) and meningiomas ( = 437, 1.7%) Twenty-five different QoL measures were used in the study pool. SF-36 was the most common ( = 55, 17 47.4%) QoL metric in the whole study pool, followed by the Penn Acoustic Neuroma QoL scale ( = 24, 20.7%) and Dizziness Handicap Inventory ( = 16, 13.8%). Seventy-two studies reported less-than 100% participation in QoL evaluation. The commonest reason for non-participation was a lack of response ( = 1,718, 60.8%), incomplete questionnaires ( = 268, 9.4%) and cognitive dysfunction ( = 258, 9.1%).
CONCLUSION
Informed clinical decision-making in PFT patients requires the development of specific QoL outcomes. Core outcome sets, and minimal clinically important differences (MCID) are essential for these metrics to show clinically significant improvements in patient QoL.
PubMed: 36303860
DOI: 10.3389/fsurg.2022.970889 -
International Journal of Occupational... Feb 2017Results of epidemiological studies on the association between use of mobile phone and brain cancer are ambiguous, as well as the results of 5 meta-analysis studies... (Meta-Analysis)
Meta-Analysis Review
Results of epidemiological studies on the association between use of mobile phone and brain cancer are ambiguous, as well as the results of 5 meta-analysis studies published to date. Since the last meta-analysis (2009), new case-control studies have been published, which theoretically could affect the conclusions on this relationship. Therefore, we decided to perform a new meta-analysis. We conducted a systematic review of multiple electronic data bases for relevant publications. The inclusion criteria were: original papers, case-control studies, published till the end of March 2014, measures of association (point estimates as odds ratio and confidence interval of the effect measured), data on individual exposure. Twenty four studies (26 846 cases, 50 013 controls) were included into the meta-analysis. A significantly higher risk of an intracranial tumor (all types) was noted for the period of mobile phone use over 10 years (odds ratio (OR) = 1.324, 95% confidence interval (CI): 1.028-1.704), and for the ipsilateral location (OR = 1.249, 95% CI: 1.022-1.526). The results support the hypothesis that long-term use of mobile phone increases risk of intracranial tumors, especially in the case of ipsilateral exposure. Further studies are needed to confirm this relationship. Int J Occup Med Environ Health 2017;30(1)27-43.
Topics: Brain Neoplasms; Case-Control Studies; Cell Phone; Electromagnetic Fields; Environmental Exposure; Humans; Salivary Gland Neoplasms
PubMed: 28220905
DOI: 10.13075/ijomeh.1896.00802 -
World Neurosurgery Apr 2022A meta-analysis of patients with sporadic vestibular schwannoma (VS) primarily treated with stereotactic radiosurgery (SRS) or microsurgery (MS) was performed, and... (Meta-Analysis)
Meta-Analysis Review
Primary Treatment of Small to Medium (<3 cm) Sporadic Vestibular Schwannomas: A Systematic Review and Meta-Analysis on Hearing Preservation and Tumor Control Rates for Microsurgery versus Radiosurgery.
BACKGROUND
A meta-analysis of patients with sporadic vestibular schwannoma (VS) primarily treated with stereotactic radiosurgery (SRS) or microsurgery (MS) was performed, and hearing preservation outcome (HPO), tumor control (TC), and facial nerve dysfunction (FND) were analyzed.
METHODS
A systematic review was conducted (Medline and Scopus database) for the period January 2010-June 2020 with appropriate MeSH. English language articles for small to medium sporadic VS (<3 cm) using SRS or MS as primary treatment modality, with minimum follow-up of 3 years, were included. Studies had to report an acceptable standardized hearing metric.
RESULTS
Thirty-two studies met the inclusion criteria: 10 MS; 23 radiosurgery, and 1 comparative study included in both. HPO, at approximately 65 months follow-up, were comparable between MS group (10 studies; 809 patients) and SRS group (23 studies; 1234 patients) (56% vs. 59%; P = 0.1527). TC, at approximately 70 months follow-up, was significantly better in the MS group (9 studies; 1635 patients) versus the SRS group (19 studies; 2260 patients) (98% vs. 92%; P < 0.0001). FND, at approximately 12 months follow-up, was significantly higher in the MS group (8 studies; 1101 patients) versus the SRS group (17 studies; 2285 patients) (10% vs. 2%; P < 0.0001).
CONCLUSIONS
MS and SRS are comparable primary treatments for small (<3 cm) sporadic VS with respect to HPO at 5-year follow-up in patients with serviceable hearing at presentation; approximately 50% of patients for both modalities likely lose serviceable hearing by that time point. High TC rates (>90%) were seen with both modalities; MS 98% versus SRS 92%. The posttreatment FND was significantly less with the SRS group (2%) versus the MS group (10%).
Topics: Follow-Up Studies; Hearing; Humans; Microsurgery; Neuroma, Acoustic; Radiosurgery; Retrospective Studies; Treatment Outcome
PubMed: 34838768
DOI: 10.1016/j.wneu.2021.11.083 -
Otology & Neurotology : Official... Dec 2017The objective is to perform a systematic review and meta-analysis of the literature on the long-term results of hearing preservation after vestibular schwannoma... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The objective is to perform a systematic review and meta-analysis of the literature on the long-term results of hearing preservation after vestibular schwannoma resection.
DATA SOURCES
Ovid/Medline, PubMed, Embase, and the Cochrane library from January 1980 to January 2015.
STUDY SELECTION
Inclusion criteria: age ≥18 years, minimum 10 patients in the treatment group, hearing preserving microsurgery, no previous radiation treatment, serviceable hearing at immediate postop follow-up, hearing outcomes reported using Gardner Robinson or the American Academy of Otolaryngology-Head and Neck Surgeons hearing grading scales, and average follow-up of 5 years. Preoperative, immediate postoperative, and last follow-up audiograms were required. Exclusion criteria included neurofibromatosis type 2 patients and surgery for salvage therapy or decompression.
DATA EXTRACTION
Quality evaluated using Methodological Index for Non-Randomized Studies.
DATA SYNTHESIS
Meta-analysis was performed using R v3.2.2, Metafor package v 1.9-7. Cohen's D was used to determine effect size. Ten reports had at least 5-year follow-up and used standardized hearing grading scales. The systematic review found that if hearing was preserved at Class A or B at early postop visit, the chance of preserving hearing at 5 years was excellent. Those who maintained speech discrimination score ≥ 89% at the early postoperative follow-up had better long-term hearing preservation. The meta-analysis reveals that only preoperative and postoperative pure-tone average was associated with long-term hearing preservation.
CONCLUSION
Long-term (>5 yr) hearing durability rates are generally very good. Most studies do not report patient and tumor characteristics, therefore precluding combining studies for meta-analysis. Only preoperative and postoperative postoperative pure-tone average was associated with long-term hearing durability.
Topics: Adult; Female; Hearing; Humans; Male; Middle Aged; Neuroma, Acoustic; Postoperative Period; Treatment Outcome
PubMed: 29140965
DOI: 10.1097/MAO.0000000000001560 -
Journal of Neuro-oncology Oct 2023To perform a systematic review of literature specific to single-fraction stereotactic radiosurgery (SRS) for large vestibular schwannomas (VS), maximum... (Review)
Review
Single-fraction radiosurgery outcomes for large vestibular schwannomas in the upfront or post-surgical setting: a systematic review and International Stereotactic Radiosurgery Society (ISRS) Practice Guidelines.
PURPOSE
To perform a systematic review of literature specific to single-fraction stereotactic radiosurgery (SRS) for large vestibular schwannomas (VS), maximum diameter ≥ 2.5 cm and/or classified as Koos Grade IV, and to present consensus recommendations on behalf of the International Stereotactic Radiosurgery Society (ISRS).
METHODS
The Medline and Embase databases were used to apply the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach. We considered eligible prospective and retrospective studies, written in the English language, reporting treatment outcomes for large VS; SRS for large post-operative tumors were analyzed in aggregate and separately.
RESULTS
19 of the 229 studies initially identified met the final inclusion criteria. Overall crude rate of tumor control was 89% (93.7% with no prior surgery vs 87.7% with prior surgery). Rates of salvage microsurgical resection, need for shunt, and additional SRS in all series versus those with no prior surgery were 9.6% vs 3.3%, 4.7% vs 6.4% and 1% vs 0.9%, respectively. Rates of facial palsy and hearing preservation in all series versus those with no prior surgery were 1.3% vs 3.4% and 34.2% vs 40.4%, respectively.
CONCLUSIONS
Upfront SRS resulted in high rates of tumor control with acceptable rates of facial palsy and hearing preservation as compared to the results in those series including patients with prior surgery (level C evidence). Therefore, although large VS are considered classic indication for microsurgical resection, upfront SRS can be considered in selected patients and we recommend a prescribed marginal dose from 11 to 13 Gy (level C evidence).
Topics: Humans; Radiosurgery; Retrospective Studies; Neuroma, Acoustic; Prospective Studies; Facial Paralysis; Treatment Outcome; Follow-Up Studies
PubMed: 37843727
DOI: 10.1007/s11060-023-04455-8