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Journal of Neurological Surgery. Part... Apr 2023K -67 is often used as a proliferation index to evaluate how aggressive a tumor is and its likelihood of recurrence. Vestibular schwannomas (VS) are a unique benign...
K -67 is often used as a proliferation index to evaluate how aggressive a tumor is and its likelihood of recurrence. Vestibular schwannomas (VS) are a unique benign pathology that lends itself well to evaluation with K -67 as a potential marker for disease recurrence or progression following surgical resection. All English language studies of VSs and K -67 indices were screened. Studies were considered eligible for inclusion if they reported series of VSs undergoing primary resection without prior irradiation, with outcomes including both recurrence/progression and K -67 for individual patients. For published studies reporting pooled K -67 index data without detailed by-patient values, we contacted the authors to request data sharing for the current meta-analysis. Studies reporting a relationship between K -67 index and clinical outcomes in VS for which detailed patients' outcomes or K -67 indices could not be obtained were incorporated into the descriptive analysis, but excluded from the formal (i.e., quantitative) meta-analysis. A systematic review identified 104 candidate citations of which 12 met inclusion criteria. Six of these studies had accessible patient-specific data. Individual patient data were collected from these studies for calculation of discrete study effect sizes, pooling via random-effects modeling with restricted maximum likelihood, and meta-analysis. The standardized mean difference in K -67 indices between those with and without recurrence was calculated as 0.79% (95% confidence interval [CI]: 0.28-1.30; = 0.0026). K -67 index may be higher in VSs that demonstrate recurrence/progression following surgical resection. This may represent a promising means of evaluating tumor recurrence and potential need for early adjuvant therapy for VSs.
PubMed: 36895813
DOI: 10.1055/a-1760-2126 -
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 -
Neurosurgery Jun 2023Stereotactic radiosurgery (SRS) is one of the main treatment options in the management of small to medium size vestibular schwannomas (VSs), because of high tumor... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Stereotactic radiosurgery (SRS) is one of the main treatment options in the management of small to medium size vestibular schwannomas (VSs), because of high tumor control rate and low cranial nerves morbidity. Series reporting long-term hearing outcome (>3 years) are scarce.
OBJECTIVE
To perform a systematic review of the literature and meta-analysis, with the aim of focusing on long-term hearing preservation after SRS.
METHODS
Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we reviewed articles published between January 1990 and October 2020 and referenced in PubMed or Embase. Inclusion criteria were peer-reviewed clinical study or case series of VSs treated with SRS (single dose), reporting hearing outcome after SRS with a median or mean audiometric follow-up of at least 5 years. Hearing preservation, cranial nerves outcomes, and tumor control were evaluated.
RESULTS
Twenty-three studies were included. Hearing preservation was found in 59.4% of cases (median follow-up 6.7 years, 1409 patients). Main favorable prognostic factors were young age, good hearing status, early treatment after diagnosis, small tumor volume, low marginal irradiation dose, and maximal dose to the cochlea. Tumor control was achieved in 96.1%. Facial nerve deficit and trigeminal neuropathy were found in 1.3% and 3.2% of patients, respectively, both significantly higher in Linear Accelerator series than Gamma Knife series ( P < .05).
CONCLUSION
Long-term hearing preservation remains one of the main issues after SRS, with a major impact on health-related quality of life. Our meta-analysis suggests that hearing preservation can be achieved in almost 60% of patients after a median follow-up of 6.7 years, irrespective of the technique.
Topics: Humans; Neuroma, Acoustic; Radiosurgery; Treatment Outcome; Quality of Life; Hearing; Follow-Up Studies; Retrospective Studies
PubMed: 36735500
DOI: 10.1227/neu.0000000000002354 -
Journal of Clinical Neurology (Seoul,... May 2023Vestibular schwannoma (VS) is the most common type of tumor found in the cerebellopontine angle that accounts for 8% of all intracranial tumors. VS management is...
BACKGROUND AND PURPOSE
Vestibular schwannoma (VS) is the most common type of tumor found in the cerebellopontine angle that accounts for 8% of all intracranial tumors. VS management is currently a challenge due to the unpredictable nature of the tumor. Few studies have compared the results and complications of various therapeutic approaches to VS. Therefore, as a treatment option for VSs smaller than 25 mm, we conducted a systematic review to compare Gamma Knife radiosurgery (GKRS) with conventional surgery.
METHODS
Literature searches were conducted of four online databases (PubMed, Google Scholar, Cochrane, and ScienceDirect) using the following keyword search: ("vestibular schwannoma" OR "acoustic neuroma") AND ("gamma knife" OR "gamma knife radiosurgery") AND ("resection" OR "open surgery") AND ("hearing preservation" OR "facial nerve" OR "tumor growth").
RESULTS
We identified six retrospective cohort studies, five of which were of fair-to-good quality. All studies showed that GKRS was superior to surgery in hearing preservation. Two studies indicated that surgery was superior to GKRS in maintaining tumor control, one indicated that GKRS was superior, and the remainder indicated that there was no significant difference in maintaining tumor control between GKRS and microsurgery.
CONCLUSIONS
Based on the three outcomes chosen for this review, GKRS was superior to microsurgery in small VS.
PubMed: 36647227
DOI: 10.3988/jcn.2022.0116 -
The Journal of Laryngology and Otology Nov 2023Magnetic resonance imaging of the internal auditory meatus is a highly sensitive and specific way to diagnose vestibular schwannoma. However, the rate of incidental...
OBJECTIVE
Magnetic resonance imaging of the internal auditory meatus is a highly sensitive and specific way to diagnose vestibular schwannoma. However, the rate of incidental findings with this method is believed to be high and can lead to increased patient anxiety and health interventions with unclear benefit.
METHOD
A systematic review of the literature was performed using the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines to identify incidental findings from magnetic resonance imaging of the internal auditory meatus; 12 studies were identified for inclusion within this review.
RESULTS
A total of 10 666 patients were included within the review. The overall rate of diagnosis of vestibular schwannoma was 0.87 per cent; 21 per cent of the study population had incidental findings on magnetic resonance imaging of the internal auditory meatus, and 9.56 per cent had clinically significant incidental findings.
CONCLUSION
Standardised pre-scan counselling may mitigate the risks of overdiagnosis, but future work should be undertaken to assess the benefits of such a strategy as well as the exact significance of some incidental findings.
Topics: Humans; Anxiety; Incidental Findings; Magnetic Resonance Imaging; Neuroma, Acoustic
PubMed: 36514824
DOI: 10.1017/S0022215122002596 -
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 -
Acta Neurochirurgica Apr 2023Hybrid peripheral nerve sheath tumors (HPNST) are a newly recognized class of peripheral nerve sheath tumor, composed of at least two areas characteristic of...
PURPOSE
Hybrid peripheral nerve sheath tumors (HPNST) are a newly recognized class of peripheral nerve sheath tumor, composed of at least two areas characteristic of perineurioma, schwannoma, or neurofibroma. The literature consists only of case reports and small series; therefore, we present an illustrative case and an analysis of all reported cases of HPNST with a perineurioma component in the literature.
METHODS
A systematic search of the literature was performed to identify all reported cases of hybrid perineurioma-schwannoma or perineurioma-neurofibroma in the world's literature. Individual cases were analyzed for demographics, clinical features, imaging, and outcomes.
RESULTS
A total of 159 cases were identified across 41 studies. Hybrid tumors tended to present in mid-adulthood (median 38.5 years), predominantly affected females (57%, 89/156), as a painless (63%, 63/100) mass, or swelling. Ten patients (10/74, 14%) had a history of neurofibromatosis 1, and 2 patients a history of neurofibromatosis 2 (2/74, 3%). The majority (78%, 122/157) of cases occurred superficially, most commonly in the lower extremity (25%, 39/157). Perineurioma-schwannoma was the most reported (86%, 137/159) pathologic diagnosis, with 3 cases presenting with malignant features. Two cases reocurred after resection.
CONCLUSION
HPNST tend to occur in mid-adulthood and present as slowly progressive, painless, superficial masses, with a heterogeneous appearance on imaging. These entities pose a unique diagnostic challenge and likely remain under-recognized in the literature and current clinical practice. They pose low risk of recurrence or malignant transformation, and future work regarding the association with neurofibromatosis and genetic profiles is needed.
Topics: Female; Humans; Adult; Nerve Sheath Neoplasms; Neurilemmoma; Neurofibroma; Neurofibromatosis 2; Neurofibromatosis 1
PubMed: 36396843
DOI: 10.1007/s00701-022-05413-5 -
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 -
Journal of Personalized Medicine Sep 2022Management of vestibular schwannoma (VS) is a complex process aimed at identifying a clinical indication for fractionated stereotactic radiotherapy (sRT) or... (Review)
Review
Management of vestibular schwannoma (VS) is a complex process aimed at identifying a clinical indication for fractionated stereotactic radiotherapy (sRT) or microsurgical resection or wait and scan (WS). The aim of the review was to clarify which patient and tumor parameters may lead to different therapeutic choices, with a view to a personalized VS approach. A systematic review according to Preferred Reporting Items for Systematic Review and Meta-Analysis criteria was conducted between February and March 2022. The authors defined six parameters that seemed to influence decision-making in VS management: 1-incidental VS; 2-tumor size; 3-tumor regrowth after sRT; 4-subtotal resection; 5-patients' age; 6-symptoms. The initial search yielded 3532 articles, and finally, 812 articles were included. Through a qualitative synthesis of the included studies, management strategies were evaluated and discussed. An individualized proposal of procedures is preferable as compared to a single gold-standard approach in VS decision-making. The most significant factors that need to be considered when dealing with a VS diagnosis are age, tumor size and hearing preservation issues.
PubMed: 36294756
DOI: 10.3390/jpm12101616 -
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