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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 -
European Annals of Otorhinolaryngology,... Nov 2013The widespread development of cell-phones entails novel user exposure to electromagnetic fields. Health impact is a public health issue and a source of anxiety in the... (Review)
Review
The widespread development of cell-phones entails novel user exposure to electromagnetic fields. Health impact is a public health issue and a source of anxiety in the population. Some clinical studies reported an association between cell and cordless phone use and vestibular schwannoma; others found none. A systematic review was performed of all published clinical studies (cohort, registry, case-control and validation studies), with analysis of results, to determine the nature of the association and the level of evidence. Cohort studies were inconclusive due to short exposure durations and poor representativeness. Registry studies showed no correlation between evolution of cell-phone use and incidence of vestibular schwannoma. Case-control studies reported contradictory results, with methodological flaws. Only a small number of subjects were included in long-term studies (>10 years), and these failed to demonstrate any indisputable causal relationship. Exposure assessment methods were debatable, and long-term assessment was lacking. An on-going prospective study should determine any major effect of electromagnetic fields; schwannoma being a rare pathology, absence of association will be difficult to prove. No clinical association has been demonstrated between cell and cordless phone use and vestibular schwannoma. Existing studies are limited by their retrospective assessment of exposure.
Topics: Causality; Cell Phone; Cross-Sectional Studies; Electromagnetic Fields; Humans; Neuroma, Acoustic; Risk
PubMed: 23725662
DOI: 10.1016/j.anorl.2012.05.005 -
Brazilian Journal of Otorhinolaryngology 2008Telecommunications systems emit radiofrequency, which is an invisible electromagnetic radiation. Mobile phones operate with microwaves (450900 MHz in the analog service,... (Review)
Review
UNLABELLED
Telecommunications systems emit radiofrequency, which is an invisible electromagnetic radiation. Mobile phones operate with microwaves (450900 MHz in the analog service, and 1,82,2 GHz in the digital service) very close to the users ear. The skin, inner ear, cochlear nerve and the temporal lobe surface absorb the radiofrequency energy.
AIM
literature review on the influence of cellular phones on hearing and balance.
STUDY DESIGN
systematic review.
METHODS
We reviewed papers on the influence of mobile phones on auditory and vestibular systems from Lilacs and Medline databases, published from 2000 to 2005, and also materials available in the Internet.
RESULTS
Studies concerning mobile phone radiation and risk of developing an acoustic neuroma have controversial results. Some authors did not see evidences of a higher risk of tumor development in mobile phone users, while others report that usage of analog cellular phones for ten or more years increase the risk of developing the tumor. Acute exposure to mobile phone microwaves do not influence the cochlear outer hair cells function in vivo and in vitro, the cochlear nerve electrical properties nor the vestibular system physiology in humans. Analog hearing aids are more susceptible to the electromagnetic interference caused by digital mobile phones.
CONCLUSION
there is no evidence of cochleo-vestibular lesion caused by cellular phones.
Topics: Animals; Auditory Perceptual Disorders; Cell Phone; Electromagnetic Fields; Humans; Neuroma, Acoustic; Otoacoustic Emissions, Spontaneous; Rats; Risk Factors; Time Factors; Vestibule, Labyrinth
PubMed: 18392513
DOI: 10.1016/s1808-8694(15)30762-x -
Brazilian Journal of Otorhinolaryngology 2023To determine the cut-off point of the cochlear radiation dose as a risk factor for hearing loss in patients with vestibular schwannoma treated with radiosurgery. (Review)
Review
OBJECTIVES
To determine the cut-off point of the cochlear radiation dose as a risk factor for hearing loss in patients with vestibular schwannoma treated with radiosurgery.
METHODS
A systematic review of the literature was performed without language or publication year restrictions in the MEDLINE/PubMed, EMBASE, Web of Science, LILACS/VHL and Cochrane Library databases. Studies that met the following criteria were included: 1) population: adults of both sexes who underwent radiosurgery for vestibular schwannoma treatment; 2) exposure: cochlear radiation; 3) outcome: hearing loss; 4) type of study: cohort. Two independent reviewers conducted the entire review process. The registration number in PROSPERO was CRD42020206128.
RESULTS
From the 333 articles identified in the searches, seven were included after applying the eligibility criteria. There was no standardization as to how to measure exposure or outcome in the included studies, and most studies did not present sufficient data to enable meta-analysis.
CONCLUSION
It was not possible to determine a cut-off point for high cochlear dose that could be considered a risk factor for hearing loss.
Topics: Adult; Female; Humans; Male; Deafness; Hearing Loss; Neuroma, Acoustic; Radiation Dosage; Radiosurgery; Retrospective Studies; Treatment Outcome
PubMed: 37579571
DOI: 10.1016/j.bjorl.2023.101300 -
Stereotactic and Functional Neurosurgery 2021Trigeminal neuralgia (TN) secondary to tumors is encountered in up to 6% of patients with facial pain syndromes and is considered to be associated with tumors affecting... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Trigeminal neuralgia (TN) secondary to tumors is encountered in up to 6% of patients with facial pain syndromes and is considered to be associated with tumors affecting the trigeminal nerve pathways. The most frequent are meningiomas and vestibular schwannomas (VS). Stereotactic radiosurgery (SRS) has emerged as a valuable treatment, with heterogeneity of clinical results. We sought to review the medical literature on TN treated with SRS for meningiomas and VS and investigate the rates of improvement of TN symptoms.
METHODS
We reviewed articles published between January 1990 and December 2019 in PubMed. Pain relief after SRS, the maintenance of pain relief, and TN recurrence and complications were evaluated with separate meta-analyses, taking into account the data on individual patients.
RESULTS
Pain relief after SRS was reported as Barrow Neurological Institute (BNI) pain intensity scores of BNI I in 50.5% (range 36-65.1%) of patients and BNI I-IIIb in 83.8% (range 77.8-89.8%). There was no significant difference in series discussing outcomes for tumor targeting versus tumor and nerve targeting. Recurrences were described in 34.7% (range 21.7-47.6; tumor targeting). Maintenance of BNI I was reported in 36.4% (range 20.1-52.7) and BNI I-IIIb in 41.2% (range 29.8-52.7; tumor targeting series). When both the nerve and the tumor were targeted, only 1 series reported 86.7% with BNI I-IIIb at last follow-up. Complications were encountered in 12.6% (range 6.3-18.8; tumor targeting series) of patients; however, they were much higher, as high as 26.7%, in the only study reporting them after targeting both the nerve and the tumor. The most common complication was facial numbness.
CONCLUSION
SRS for TNB secondary to benign tumors, such as meningiomas and VS, is associated with favorable clinical course, but less favorable than in idiopathic TN. There was, however, heterogeneity among reports and targeting approaches. Although targeting both the nerve and the tumor seemed to achieve better long-term results, the rate of complications was much higher and the number of patients treated was limited. Future clinical studies should focus on the standard reporting of clinical outcomes and randomization of targeting methods.
Topics: Humans; Meningeal Neoplasms; Meningioma; Neuroma, Acoustic; Pain Management; Radiosurgery; Retrospective Studies; Treatment Outcome; Trigeminal Neuralgia
PubMed: 32906130
DOI: 10.1159/000509842 -
Journal of Neurological Surgery. Part... Jun 2022The center of excellence model of health care hypothesizes that increased volume in a specialized center will lead to better and more affordable care. We sought to...
The center of excellence model of health care hypothesizes that increased volume in a specialized center will lead to better and more affordable care. We sought to characterize the volume-outcome data for surgically treated sinonasal and skull base tumors and (chemo) radiation-treated nasopharyngeal malignancy. Systematic review of the literature. This review included national database and multi-institutional studies published between 1990 and 2019. PubMed was interrogated for keywords "hospital volume," "facility volume," and outcomes for "Nasopharyngeal carcinoma," "Sinonasal carcinomas," "Pituitary Tumors," "Acoustic Neuromas," "Chordomas," and "Skull Base Tumors" to identify studies. Single-institution studies and self-reported surveys were excluded. The main outcome of interest in malignant pathologies was survival; and in benign pathologies it was treatment-related complications. A total of 20 studies met inclusion criteria. The average number of patients per study was 4,052, and ranged from 394 to 9,950 patients. Six of seven studies on malignant pathology demonstrated improved survival with treatment in high volume centers and one showed no association with survival. Ten of thirteen studies on benign disease showed reduced risk of complications, while one study demonstrated both an increased and decreased association of complications. Two studies showed no volume-outcome associations. This systematic review demonstrates that a positive volume-outcome relationship exists for most pathologies of the skull base, with some exceptions. The relative dearth of literature supports further research to understand the effect of centralization of care on treatment outcomes.
PubMed: 35769793
DOI: 10.1055/s-0040-1721823 -
Journal of Neuro-oncology May 2009Facial nerve preservation is a critical measure of clinical outcome after vestibular schwannoma treatment. Gamma Knife radiosurgery has evolved into a practical... (Review)
Review
OBJECTIVE
Facial nerve preservation is a critical measure of clinical outcome after vestibular schwannoma treatment. Gamma Knife radiosurgery has evolved into a practical treatment modality for vestibular schwannoma patients, with several reported series from a variety of centers. In this study, we report the results of an objective analysis of reported facial nerve outcomes after the treatment of vestibular schwannomas with Gamma Knife radiosurgery.
MATERIALS AND METHODS
A Boolean Pub Med search of the English language literature revealed a total of 23 published studies reporting assessable and quantifiable outcome data regarding facial nerve function in 2,204 patients who were treated with Gamma Knife radiosurgery for vestibular schwannoma. Inclusion criteria for articles were: (1) Facial nerve preservation rates were reported specifically for vestibular schwannoma, (2) Facial nerve functional outcome was reported using the House-Brackmann classification (HBC) for facial nerve function, (3) Tumor size was documented, and (4) Gamma Knife radiosurgery was the only radiosurgical modality used in the report. The data were then aggregated and analyzed based on radiation doses delivered, tumor volume, and patient age.
RESULTS
An overall facial nerve preservation rate of 96.2% was found after Gamma Knife radiosurgery for vestibular schwannoma in our analysis. Patients receiving less than or equal to 13 Gy of radiation at the marginal dose had a better facial nerve preservation rate than those who received higher doses (
13 Gy = 94.7%, P < 0.0001). Patients with a tumor volume less than or equal to 1.5 cm(3) also had a greater facial nerve preservation rate than patients with tumors greater than 1.5 cm(3) ( 1.5 cm(3) 95.5%, P < 0.0001). Superior facial nerve preservation was also noted in patients younger than or equal to 60 years of age (96.8 vs. 89.4%, P < 0.0001). The average reported follow up duration in this systematic review was 54.1 +/- 31.3 months. CONCLUSION
Our analysis of case series data aggregated from multiple centers suggests that a facial nerve preservation rate of 96.2% can be expected after Gamma knife radiosurgery for vestibular schwannoma. Younger patients with smaller tumors less than 1.5 cm(3) and treated with lower doses of radiation less than 13 Gy will likely have better facial nerve preservation rates after Gamma Knife radiosurgery for vestibular schwannoma.
Topics: Age Factors; Facial Nerve; Facial Nerve Injuries; Humans; Middle Aged; Neuroma, Acoustic; Postoperative Complications; Radiosurgery; Radiotherapy Dosage
PubMed: 19430881
DOI: 10.1007/s11060-009-9842-3 -
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 -
Neurosurgical Review Dec 2021Vestibular schwannomas (VS) are slow-growing intracranial extraaxial benign tumors, developing from the vestibular part of the eight cranial nerves. Stereotactic... (Meta-Analysis)
Meta-Analysis Review
Vestibular schwannomas (VS) are slow-growing intracranial extraaxial benign tumors, developing from the vestibular part of the eight cranial nerves. Stereotactic radiosurgery (SRS) has now a long-term scientific track record as first intention treatment for small- to medium-sized VS. Though its success rate is very high, SRS for VS might fail to control tumor growth in some cases. However, the literature on repeat SRS after previously failed SRS remains scarce and reported in a low number of series with a limited number of cases. Here, we aimed at performing a systematic review and meta-analysis of the literature on repeat SRS for VS. Using PRISMA guidelines, we reviewed manuscripts published between January 1990 and October 2020 and referenced in PubMed. Tumor control and cranial nerve outcomes were evaluated with separate meta-analyses. Eight studies comprising 194 patients were included. The overall rate of patients treated in repeat SRS series as per overall series with first SRS was 2.2% (range 1.2-3.2%, p < 0.001). The mean time between first and second SRS was 50.7 months (median 51, range 44-64). The median marginal dose prescribed at first SRS was 12 Gy (range 8-24) and at second SRS was 12 Gy (range 9.8-19). After repeat SRS, tumor stability was reported in 61/194 patients, i.e., a rate of 29.6% (range 20.2-39%, I = 49.1%, p < 0.001). Tumor decrease was reported in 83/194 patients, i.e., a rate of 54.4% (range 33.7-75.1%, I = 89.1%, p < 0.001). Tumor progression was reported in 50/188 patients, i.e., a rate of 16.1% (range 2.5-29.7%, I = 87.1%, p = 0.02), rarely managed surgically. New trigeminal numbness was reported in 27/170 patients, i.e., a rate of 9.9% (range 1.4-18.3%, p < 0.02). New facial nerve palsy of worsened of previous was reported in 8/183 patients, i.e., a rate of 4.3% (range 1.4-7.2%, p = 0.004). Hearing loss was reported in 12/22 patients, i.e., a rate of 54.3% (range 24.8-83.8%, I = 70.7%, p < 0.001). Repeat SRS after previously failed SRS for VS is associated with high tumor control rates. Cranial nerve outcomes remain favorable, particularly for facial nerve. The rate of hearing loss appears similar to the one related to first SRS.
Topics: Facial Nerve; Follow-Up Studies; Humans; Neuroma, Acoustic; Radiosurgery; Retrospective Studies; Treatment Outcome
PubMed: 33847846
DOI: 10.1007/s10143-021-01528-y -
The Journal of International Advanced... Aug 2018In light of missing systematic reviews in the literature, the objective of this paper is to present the contemporary knowledge on the molecular biology of vestibular... (Meta-Analysis)
Meta-Analysis
In light of missing systematic reviews in the literature, the objective of this paper is to present the contemporary knowledge on the molecular biology of vestibular schwannomas (VS), based on a systematic literature search. In addition, current and prospected medical therapy based on molecular biology is addressed. A systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The systematic search was performed in the Pubmed and Embase databases. The following were the words searched: acoustic neuroma/vestibular schwannoma, molecular biology, gene, and microRNA. Specific inclusion and exclusion criteria were determined prior to search. The systematic search rendered 486 articles, ultimately yielding 69 included articles, whereas 35 were from relevant references. The occurrence of at least one mutation in the merlin gene was reported to range between 54% and 76%, whereas the loss of heterozygosity (LOH) corresponding to chromosome 22 occurs in 25% to 83% of sporadic VS. Global gene expression studies indicate that a number of genes other than merlin are at play. No high-level methylation of the merlin gene has been found. Several miRNAs are deregulated in tumor tissue, among others let-7d, miR-221, and miR-21. The acquired knowledge on molecular biology has led to several clinical implementations. Lack of the tumor suppressor merlin plays a principal role in the development of VS. Existing knowledge on the molecular biology has led to the first attempts of targeted medical treatment to prevent tumor growth. Future research is likely to introduce potential imaging markers with prognostic value and new targets for medical therapy.
Topics: Chromosomes, Human, Pair 22; DNA Methylation; Gene Expression; Humans; Loss of Heterozygosity; MicroRNAs; Molecular Biology; Mutation; Neuroma, Acoustic; Signal Transduction
PubMed: 30100540
DOI: 10.5152/iao.2018.4929