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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 -
Neuro-oncology Practice Dec 2021Differences in long-term outcomes of single-fraction stereotactic radiosurgery (SRS) between gamma knife (GK) and linear accelerator (LINAC) systems for vestibular... (Review)
Review
BACKGROUND
Differences in long-term outcomes of single-fraction stereotactic radiosurgery (SRS) between gamma knife (GK) and linear accelerator (LINAC) systems for vestibular schwannoma (VS) management remain unclear. To investigate differences in safety and efficacy between modalities, we conducted a meta-analysis of studies over the past decade.
METHODS
MEDLINE, EMBASE, and Cochrane databases were queried for studies with the following inclusion criteria: English language, published between January 2010 and April 2020, cohort size ≥30, and mean/median follow-up ≥5 years. Odds ratios (OR) compared rates of tumor control, hearing preservation, and cranial nerve toxicities before and after SRS.
RESULTS
Thirty-nine studies were included (29 GK, 10 LINAC) with 6516 total patients. Tumor control rates were 93% (95% CI 91-94%) and 94% (95% CI 91-97%) for GK and LINAC, respectively. Both GK (OR 0.06, 95% CI 0.02-0.13) and LINAC (OR 0.47, 95% CI 0.29-0.76) reduced odds of serviceable hearing. Neither GK (OR 0.71, 95% CI 0.41-1.22) nor LINAC (OR 1.13, 95% CI 0.64-2.00) impacted facial nerve function. GK decreased odds of trigeminal nerve (TN) impairment (OR 0.55, 95% CI 0.32-0.94) while LINAC did not impact TN function (OR 1.45, 95% CI 0.81-2.61). Lastly, LINAC offered decreased odds of tinnitus (OR 0.15, 95% CI 0.03-0.87) not observed with GK (OR 0.70, 95% CI 0.48-1.01).
CONCLUSIONS
VS tumor control and hearing preservation rates are comparable between GK and LINAC SRS. GK may better preserve TN function, while LINAC decreases tinnitus rates. Future studies are warranted to investigate the efficacy of GK and LINAC SRS more directly.
PubMed: 34777833
DOI: 10.1093/nop/npab052 -
Journal of Neurological Surgery. Part... Dec 2021Ipsilateral cochlear implantation (CI) in vestibular schwannoma (VS) has been an emerging trend over the last two decades. We conducted the first systematic review...
Ipsilateral cochlear implantation (CI) in vestibular schwannoma (VS) has been an emerging trend over the last two decades. We conducted the first systematic review of hearing outcomes comparing neurofibromatosis 2 (NF2) and sporadic VS undergoing CI. A comparison of the two populations and predictor of outcome was assessed. This is an update to a previously presented study. Systemic data searches were performed in PubMed NCBI and Scopus by an academic librarian. No restrictions based on the year of publication were used. Studies were selected if patients had a diagnosis of NF2 and a CI placed in the affected side with reports of hearing outcome. Two independent reviewers screened each abstract and full-text article. Studies were extracted at the patient level, and the assessment of quality and bias was evaluated according to the National Institutes of Health Quality Assessment Tool. Outcome predictors were determined by using the chi-square test and Student's -test. Overall, most CI recipients functioned in the high-to-intermediate performer category for both sporadic and NF2-related VS. Median AzBio (Arizona Biomedical Institute Sentence Test) was 72% (interquartile range [IQR]: 50) in NF2 patients and 70% (IQR: 7.25) in sporadic patients. Larger tumor size predicted a poorer final audiometric outcome. Categorization of hearing outcome into superior performance and inferior performance based on sentence recognition revealed a generally good hearing outcome regardless of treatment or patient population. Select patients with sporadic and NF2 VS may benefit from CI.
PubMed: 34745832
DOI: 10.1055/s-0040-1715606 -
The Journal of International Advanced... Sep 2021Vestibular schwannomas (VS) frequently lead to ipsilateral sensorineural hearing loss (HL) as part of its natural history or as a result of treatment. Cochlear...
BACKGROUND AND OBJECTIVES
Vestibular schwannomas (VS) frequently lead to ipsilateral sensorineural hearing loss (HL) as part of its natural history or as a result of treatment. Cochlear implantation represents a well-documented treatment of profound HL that cannot be treated adequately with a conventional hearing aid, thus being offered to selected VS patients. A functional cochlea and cochlear nerve are prerequisites for sound perception with a cochlear implant (CI). The potential impact of radiotherapy on these structures is thus an important issue for subsequent CI hearing outcomes. The objective of this article is to present a case and to review the existing literature on the outcomes of cochlear implantation in irradiated VS patients systematically.
METHODS
A systematic literature review using preferred reporting items for systematic reviews and meta-analyses was conducted. Medline was searched systematically. Papers reporting ipsilateral CI outcomes after radiotherapy of VS were included. Additionally, results of CI after stereotactic radiotherapy in a 54-year-old male with neurofibromatosis type 2 are presented.
RESULTS
A total of 14 papers (33 patients) fulfilled inclusion criteria. Moderate preoperative HL was found in 11 patients. Six had moderate to severe HL, whereas 16 had severe HL or total deafness. Postoperative hearing outcomes varied from poor in 27% of patients to excellent in 19%, with remaining cases lying in between (mean follow-up of 19 months). Most patients achieved improvement in hearing and quality of life.
CONCLUSION
Despite variation in the degree of hearing outcome, CI after radiotherapy of VS appears to be effective in the majority of cases, as more than 70% of patients have good or excellent outcomes within 1-2 years post-implantation. Subjective benefits are considerable, even in cases with relatively poor objective outcome.
Topics: Cochlear Implantation; Cochlear Implants; Hearing Loss, Sensorineural; Humans; Male; Middle Aged; Neuroma, Acoustic; Quality of Life; Speech Perception; Treatment Outcome
PubMed: 34617898
DOI: 10.5152/iao.2021.21008 -
Otology & Neurotology : Official... Jan 2022Vestibular schwannomas (VS) are benign intracranial tumors originating from the vestibular division of the eighth cranial nerve. Treatment options include microsurgery,...
BACKGROUND
Vestibular schwannomas (VS) are benign intracranial tumors originating from the vestibular division of the eighth cranial nerve. Treatment options include microsurgery, radiotherapy, and surveillance. Endoscopy is becoming more widely used as an adjunct in skull base surgery and may influence outcomes in surgically managed VS.
METHODS
A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies involving endoscope-assisted and fully endoscopic procedures for sporadic VS resection were identified. Facial nerve function, hearing preservation, extent of resection, and complications were analyzed.
RESULTS
Thirty-one studies were included (27 endoscope-assisted, four fully endoscopic). Subgroup analyses were performed to assess outcomes according to tumor size and surgical approach. Overall, endoscopic facial nerve preservation rates were comparable to microsurgical treatment. A subgroup analysis suggested that functional facial nerve preservation rates may be higher when endoscopic assistance is used for smaller (Koos I-II) tumors using the retrosigmoid or translabyrinthine approach. The gross total resection rate for small tumors was higher in retrosigmoid ES-assisted microsurgery (96.2%) compared to rates in the literature for the standard, open retrosigmoid approach. Hearing outcomes were more variable and were under-reported.
CONCLUSIONS
Current data suggest that ES-assisted resection of sporadic VS is not inferior to microsurgical resection with respect to facial nerve outcomes and extent of resection. However, some ES series report poor hearing outcomes, which are under-reported in the literature. Further prospective studies are required to ascertain if endoscopic assistance can improve outcomes for VS resection, particularly for smaller (Koos I-II) tumors.
Topics: Endoscopy; Humans; Microsurgery; Neuroma, Acoustic; Neurosurgical Procedures; Postoperative Complications; Retrospective Studies; Treatment Outcome
PubMed: 34510120
DOI: 10.1097/MAO.0000000000003347 -
Otolaryngology--head and Neck Surgery :... Aug 2022Ubiquitous throughout the literature and during patient counseling, vestibular schwannoma is often quoted to affect about 1 per 100,000 people. Yet, reports from...
OBJECTIVE
Ubiquitous throughout the literature and during patient counseling, vestibular schwannoma is often quoted to affect about 1 per 100,000 people. Yet, reports from distinct international populations suggest that the incidence is likely much higher. The objective of the current work was to systematically characterize the global incidence of sporadic vestibular schwannoma.
DATA SOURCES
Scopus, Embase, and PubMed.
REVIEW METHODS
Population-based studies reporting incidence rates of sporadic vestibular schwannoma between January 2010 and August 2020 were searched with language restrictions requiring reports to be published in Chinese, English, German, Italian, or Spanish. The protocol was registered with PROSPERO (CRD42021228208) prior to commencement of data collection. PRISMA guidelines for transparent reporting of systematic reviews were followed.
RESULTS
Among 424 citations, 6 publications covering 4 distinct populations from Denmark, the Netherlands, Taiwan, and the United States met inclusion criteria. Most recent incidence rates of among all ages ranged between 3.0 and 5.2 per 100,000 person-years. Highest incidence rates were reported among patients aged ≥70 years, peaking at 20.6 per 100,000 person-years. One study from the United States reported the incidence of asymptomatic, incidentally diagnosed tumors at a rate of 1.3 per 100,000 person-years from 2012 to 2016.
CONCLUSIONS
Recent international incidence rates of sporadic vestibular schwannoma exceed the commonly quoted "1 per 100,000" figure by up to 5-fold among all ages and by up to 20-fold among age groups at highest risk. Based on modern incidence rates, the lifetime prevalence of developing sporadic vestibular schwannoma likely exceeds 1 per 500 persons.
Topics: Child, Preschool; Humans; Incidence; Language; Neuroma, Acoustic; Prevalence; Taiwan
PubMed: 34464224
DOI: 10.1177/01945998211042006 -
Journal of Neurosurgery Nov 2020Multiple short series have evaluated the efficacy of salvage microsurgery (MS) after stereotactic radiosurgery (SRS) for treatment of vestibular schwannomas (VSs);... (Review)
Review
OBJECTIVE
Multiple short series have evaluated the efficacy of salvage microsurgery (MS) after stereotactic radiosurgery (SRS) for treatment of vestibular schwannomas (VSs); however, there is a lack of a large volume of patient data available for interpretation and clinical adaptation. The goal of this study was to provide a comprehensive review of tumor characteristics, management, and surgical outcomes of salvage of MS after SRS for VS.
METHODS
The Medline/PubMed, Scopus, CINAHL, Cochrane Library, and Google Scholar databases were queried according to PRISMA guidelines. All English-language and translated publications were included. Studies lacking adequate study characteristics and outcomes were excluded. Cases involving neurofibromatosis type 2, previous MS, or malignant transformation were excluded when possible.
RESULTS
Twenty studies containing 297 cases met inclusion criteria. Three additional cases from Rush University Medical Center were added for 300 total cases. Tumor growth with or without symptoms was the primary indication for salvage surgery (92.3% of cases), followed by worsening of symptoms without growth (4.6%) and cystic enlargement (3.1%). The average time to MS after SRS was 39.4 months. The average size and volume of tumor at surgery were 2.44 cm and 5.92 cm3, respectively. The surgical approach was retrosigmoid (42.8%) and translabyrinthine (57.2%); 59.5% of patients had a House-Brackmann (HB) grade of I or II. The facial nerve was preserved in 91.5% of cases. Facial nerve preservation and HB grades were lower for the translabyrinthine versus retrosigmoid approach (p = 0.31 and p = 0.18, respectively); however, fewer complications were noted in the translabyrinthine approach (p = 0.29). Gross-total resection (GTR) was completed in 55.7% of surgeries. Studies that predominantly used subtotal resection (STR) were associated with a lower rate of facial nerve injury (5.3% vs 11.3%, p = 0.07) and higher rate of HB grade I or II (72.9% vs 48.0%, p = 0.00003) versus those using predominantly GTR. However, majority STR was associated with a recurrence rate of 3.6% as compared to 1.4% for majority GTR (p = 0.29).
CONCLUSIONS
This study showed that the leading cause of MS after SRS was tumor growth at an average of 39.4 months after radiation. There were no significant differences in outcomes of facial nerve preservation, postoperative HB grade, or complication rate based on surgical approach. Patients who underwent STR showed statistically significant better HB outcomes compared with GTR. MS after SRS was considered by most authors to be more difficult than primary MS. These data support the notion that the surgical goals of salvage surgery are debulking of tumor mass, decreasing compression of the brainstem, and not necessarily pursuing GTR.
PubMed: 34331121
DOI: 10.3171/2020.7.JNS2044 -
Neuro-oncology Practice Aug 2021Large vestibular schwannomas (VS) pose a treatment challenge for both microsurgery (MS) and stereotactic radiosurgery (SRS). Technical developments have allowed for... (Review)
Review
BACKGROUND
Large vestibular schwannomas (VS) pose a treatment challenge for both microsurgery (MS) and stereotactic radiosurgery (SRS). Technical developments have allowed for safer irradiation of large tumors. It remains unclear if SRS can achieve appropriate tumor control and acceptable cranial nerve toxicities. In this study, we assess outcomes of irradiation for large VS.
METHODS
PubMed MEDLINE, EMBASE, Web of Science, and Cochrane were searched for all the studies assessing SRS outcome in large VS. Primary endpoints included clinical and radiographic tumor control, need for salvage surgery, serviceable hearing, cranial nerve V and VII impairment, presence of hydrocephalus requiring shunting, and presence of vertigo/dizziness.
RESULTS
Twenty-two studies were identified that met selection criteria for analysis from an initial pool of 1272 reports. They were evaluated according to treatment protocol: 1) single-dose SRS (13 studies, 483 patients), 2) combination of MS and SRS (7 studies, 182 patients), and 3) fractionated SRS (3 studies, 82 patients). Tumor control was achieved in 89%, 94%, and 91% of patients, respectively. Odds ratios (ORs) of post- over pretreatment serviceable hearing were 0.42 ( < .01), 0.47 ( = .05), and 0.60 ( = .22); for facial nerve impairment, these ORs were 1.08 ( = .69), 3.45 ( = .28), and 0.87 ( = .71), respectively.
CONCLUSIONS
The management of large VS remains challenging. All treatment modalities resulted in high tumor control rates and worsening of pretreatment hearing. None, however, caused significant facial nerve impairment, suggesting that management strategies incorporating focal irradiation can be successful.
PubMed: 34277019
DOI: 10.1093/nop/npab011 -
American Journal of Otolaryngology 2021The anti-angiogenic agent bevacizumab is currently the only drug used clinically for neurofibromatosis type 2-related vestibular schwannomas (NF2-VS). Though benefits... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The anti-angiogenic agent bevacizumab is currently the only drug used clinically for neurofibromatosis type 2-related vestibular schwannomas (NF2-VS). Though benefits have been demonstrated in several cases, the standardized dosage remains unclear.
OBJECTIVE
Our meta-analysis was performed to systematically and comprehensively investigate the reliability and toxicity of bevacizumab in the treatment of NF2-VS, with particular emphasis on the impact of dosage.
METHODS
The literature search was conducted for studies providing data on patients treated with bevacizumab for NF2-VS across PubMed, Embase, and Cochrane Library until December 31, 2020. Two reviewers extracted the incidence rate of results independently. Then we calculated and pooled unadjusted incidence rate with 95% CIs for each study. The subgroups analyzed were conducted.
RESULTS
Fourteen citations (prospective or retrospective observational cohort studies) were eligible based on data from a total of 247 patients with NF2 and 332 related VSs. The pooled results showed that the radiographic response rate (RRR) was 30% [95% CI (20%-42%)], the hearing response rate (HRR) was 32% [95% CI (21%-45%)]. The incidence of major complications was: hypertension 29% [95% CI (23%-35%)], proteinuria 30% [95% CI (18%-44%)], menstrual disorders 44% [95% CI (16%-73%)], hemorrhage 14% [95% CI (4%-26%)], grade3/4 events 12% [95% CI (4%-22%)].
CONCLUSIONS
Nearly one-third of NF2-VS patients may benefit significantly from bevacizumab due to hearing improvement and tumor reduction. Menstrual disorders were the most common adverse events. The high-dose regimen didn't show better efficacy, but results varied considerably according to age.
Topics: Adult; Age Factors; Bevacizumab; Dose-Response Relationship, Drug; Female; Hearing; Hemorrhage; Humans; Hypertension; Male; Menstruation Disturbances; Neurofibromatosis 2; Neuroma, Acoustic; Prospective Studies; Proteinuria; Retrospective Studies; Vestibulocochlear Nerve; Young Adult
PubMed: 34214711
DOI: 10.1016/j.amjoto.2021.103148 -
La Clinica Terapeutica May 2021Over the process of establishing the causal relation-ship, medical and legal methodologies may be at variance over the definitional standards and terminologies applied,...
Can a causal relationship be established between acoustic neuroma and occupational exposure to non-ionizing radiations from mobile devices? Comparison between scientific literature data and medico-legal methodology.
BACKGROUND
Over the process of establishing the causal relation-ship, medical and legal methodologies may be at variance over the definitional standards and terminologies applied, which can hinder the activities of expert witnesses.
OBJECTIVES
The article's authors have set out to assess whether, and under what conditions, a causal relationship can be established between acoustic neuroma and exposure to non-ionizing radiation from mobile communication devices.
METHODS
The study design is a Systematic Review. The authors have drawn upon a 2020 Turin Court of Appeals ruling which found such a causal relationship in a somewhat peculiar case: rare tumor and exposure to non-ionizing radiation of unusually long and regular dura-tion. The case presents several peculiarities, herein analyzed in light of a) scientific evidence relative to the etiopathogenesis of the neuroma; b) available medico-legal literature defining causality evaluation criteria, and lastly c) court filings in regard to the probability standards applied to prove causal relationship.
RESULTS
A direct tie cannot be proven, not even in cases of sub-stantially intense and lengthy exposure, if the medico-legal standards applied are not consistent enough to prove that nexus is more likely than not.
DISCUSSION
Several elements suggest a causal relationship is unlikely: a) a dearth of evidence on humans; b) rats exposed to such radiation have developed cardiac tumors, not in their ears; c) exposure has caused no tumors in mice; d) the length of exposure is incompat-ible with tumor size and type. That fourth point only concerns the case herein explored, whereas the first three have a general scope of validity. The main limitation of the present study design is the heterogeneity among the included studies. Retrospective and prospective studies have been included, which may be a source of bias.
Topics: Animals; Causality; Computers, Handheld; Humans; Mice; Neuroma, Acoustic; Occupational Exposure; Radiation, Nonionizing; Rats; Risk Factors
PubMed: 33956036
DOI: 10.7417/CT.2021.2313