The Course of Hearing Loss in Patients With a Progressive Vestibular Schwannoma.

OBJECTIVE: This study evaluates the natural course of hearing loss (HL) prior to treatment in patients with progressive tumors and an indication for active intervention. Evaluating this patient group specifically can put hearing outcomes after vestibular schwannoma therapy into an adequate context. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. METHODS: Inclusion criteria comprised unilateral vestibular schwannomas prior to active treatment, with ≥2 mm extracanalicular (EC) tumor growth and ≥2 audiograms. We performed a comprehensive assessment of hearing using multiple outcome parameters including (the annual decrease in) pure-tone averages (PTAs; an average of 0.5, 1, 2, and 3 kHz). Predictors for HL were evaluated (patient age, tumor size/progression, follow-up duration, baseline hearing). RESULTS: At presentation, 86% of patients suffered from sensorineural HL on the affected side (≥20 dB PTA) with a median of 39 dB (interquartile rate [IQR]: 27-51 dB). The median follow-up duration was 21 months (IQR: 13-34 months), after which 58% (187/322) of patients experienced progressive HL (≥10 dB), with a median increase of 6.4 dB/year. At the last follow-up, the median PTA was 56 dB (IQR: 37-73). Median speech discrimination scores deteriorated from 90% (IQR: 70%-100%) to 65% (IQR: 35%-100%). Tumor progression (maximal EC diameter) was significantly correlated to the progression of sensorineural HL, corrected for follow-up (F(2,228) = 10.4, p < .001, R2 = 8%). CONCLUSION: The majority of patients (58%) with radiologically confirmed progressive vestibular schwannomas experience progressive sensorineural HL during observation. Tumor progression rate, EC tumor extension, and longer follow-up are factors associated with more sensorineural HL.

A prediction model for recurrence after translabyrinthine surgery for vestibular schwannoma: toward personalized postoperative surveillance.

PURPOSE: The aim of this study is to compute and validate a statistical predictive model for the risk of recurrence, defined as regrowth of tumor necessitating salvage treatment, after translabyrinthine removal of vestibular schwannomas to individualize postoperative surveillance. METHODS: The multivariable predictive model for risk of recurrence was based on retrospectively collected patient data between 1995 and 2017 at a tertiary referral center. To assess for internal validity of the prediction model tenfold cross-validation was performed. A 'low' calculated risk of recurrence in this study was set at < 1%, based on clinical criteria and expert opinion. RESULTS: A total of 596 patients with 33 recurrences (5.5%) were included for analysis. The final prediction model consisted of the predictors 'age at time of surgery', 'preoperative tumor growth' and 'first postoperative MRI outcome'. The area under the receiver operating curve of the prediction model was 89%, with a C-index of 0.686 (95% CI 0.614-0.796) after cross-validation. The predicted probability for risk of recurrence was low (< 1%) in 373 patients (63%). The earliest recurrence in these low-risk patients was detected at 46 months after surgery. CONCLUSION: This study presents a well-performing prediction model for the risk of recurrence after translabyrinthine surgery for vestibular schwannoma. The prediction model can be used to tailor the postoperative surveillance to the estimated risk of recurrence of individual patients. It seems that especially in patients with an estimated low risk of recurrence, the interval between the first and second postoperative MRI can be safely prolonged.

Prognostic Factors for the Outcome of Translabyrinthine Surgery for Vestibular Schwannomas.

OBJECTIVE: To identify predictors of tumor recurrence and postoperative facial nerve function after translabyrinthine surgery for unilateral vestibular schwannomas. STUDY DESIGN: Retrospective study. SETTING: Tertiary referral center. PATIENTS: Between 1996 and 2017 a total of 596 patients with unilateral vestibular schwannoma underwent translabyrinthine surgery. Pre- and postoperative clinical status, radiological, and surgical findings were evaluated. INTERVENTIONS: Translabyrinthine surgery. MAIN OUTCOME MEASURES: Potential predictors for tumor recurrence and facial nerve outcome were analyzed using Cox regression and ordinal logistic regression, respectively. RESULTS: The extent of tumor removal was total in 32%, near-total in 58%, and subtotal in 10%. In 5.5% (33/596) of patients the tumor recurred. Subtotal tumor resection (p = 0.004, hazard ratios [HR] = 10.66), a young age (p = 0.008, HR = 0.96), and tumor progression preoperatively (p = 0.042, HR = 2.32) significantly increased the risk of recurrence, whereas tumor size or histologic composition did not. A good postoperative facial nerve function (House-Brackmann grade 1-2) was achieved in 85%. The risk of postoperative facial nerve paresis or paralysis increased with tumor size (p < 0.001, OR = 1.52), but was not associated with the extent of tumor removal, histologic composition, or patient demographics. CONCLUSIONS: Translabyrinthine surgery is an effective treatment for vestibular schwannoma, with a good local control rate and facial nerve outcome. The extent of tumor removal is a clinically relevant predictor for tumor recurrence, as are young patient age and preoperative tumor progression. A large preoperative tumor size is associated with a higher risk of postoperative facial nerve paresis or paralysis.

Pediatric Auditory Brainstem Implant Users Compared With Cochlear Implant Users With Additional Disabilities.

OBJECTIVES: To evaluate long-term language development in children with prelingual deafness who received auditory brainstem implants (ABIs) compared with children who received cochlear implants (CIs) at the same hospital. Additional non-auditory disabilities were taken into account. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: Ten children with bilateral malformations of the cochlea and/or cochlear nerve who received ABIs, including seven with additional disabilities, and 147 children with CIs as a reference group, including 22 children with additional disabilities. INTERVENTION: ABIs were implanted at 1.3 to 6.2 years of age. Follow-up ranged from 1.1 to 7.7 years. MAIN OUTCOME MEASURES: Receptive and expressive language abilities were assessed using the Infant Toddler Meaningful Auditory Integration Scale (IT-MAIS), the Categories of Auditory Performance (CAP), the Meaningful Use of Speech Scale (MUSS), and the Speech Intelligibility Rate (SIR). RESULTS: Of the 10 children with ABIs, seven had long-term follow-up data. Within 1 year, six of the seven children with ABIs could identify sounds, respond to speech, and use their voice to attract attention. Language skills developed at a slower rate than in children with CIs and reached the same competence level when additional disabilities were absent. These language skills matched, on average, those of children with CIs with additional disabilities. CONCLUSION: For deaf children with bilateral inner ear malformations, ABIs provide satisfactory auditory input. Children with ABIs are able to develop receptive and expressive language skills comparable to those of children with CIs with additional disabilities. Using this knowledge, preoperative parent counselling can be refined.

Mathematical Models for Tumor Growth and the Reduction of Overtreatment.

Background To improve our understanding of the natural course of head and neck paragangliomas (HNPGL) and ultimately differentiate between cases that benefit from early treatment and those that are best left untreated, we studied the growth dynamics of 77 HNPGL managed with primary observation. Methods Using digitally available magnetic resonance images, tumor volume was estimated at three time points. Subsequently, nonlinear least squares regression was used to fit seven mathematical models to the observed growth data. Goodness of fit was assessed with the coefficient of determination ( R 2 ) and root-mean-squared error. The models were compared with Kruskal-Wallis one-way analysis of variance and subsequent post-hoc tests. In addition, the credibility of predictions (age at onset of neoplastic growth and estimated volume at age 90) was evaluated. Results Equations generating sigmoidal-shaped growth curves (Gompertz, logistic, Spratt and Bertalanffy) provided a good fit (median R 2 : 0.996-1.00) and better described the observed data compared with the linear, exponential, and Mendelsohn equations ( p < 0.001). Although there was no statistically significant difference between the sigmoidal-shaped growth curves regarding the goodness of fit, a realistic age at onset and estimated volume at age 90 were most often predicted by the Bertalanffy model. Conclusions Growth of HNPGL is best described by decelerating tumor growth laws, with a preference for the Bertalanffy model. To the best of our knowledge, this is the first time that this often-neglected model has been successfully fitted to clinically obtained growth data.

BCRP expression in schwannoma, plexiform neurofibroma and MPNST.

BACKGROUND: peripheral nerve sheath tumors comprise a broad spectrum of neoplasms. Vestibular schwannomas and plexiform neurofibromas are symptomatic albeit benign, but a subset of the latter pre-malignant lesions will transform to malignant peripheral nerve sheath tumors (MPNST). Surgery and radiotherapy are the primary strategies to treat these tumors. Intrinsic resistance to drug therapy characterizes all three tumor subtypes. The breast cancer resistance protein BCRP is a transmembrane efflux transporter considered to play a key role in various biological barriers such as the blood brain barrier. At the same time it is associated with drug resistance in various tumors. Its potential role in drug resistant tumors of the peripheral nervous system is largely unknown. OBJECTIVE: to assess if BCRP is expressed in vestibular schwannomas, plexiform neurofibromas and MPNST. MATERIAL AND METHODS: immunohistochemical staining for BCRP was performed on a tissue microarray composed out of 22 vestibular schwannomas, 10 plexiform neurofibromas and 18 MPNSTs. RESULTS: sixteen out of twenty-two vestibular schwannomas (73%), nine out of ten plexiform neurofibromas (90%) and six out of eighteen MPNST (33%) expressed BCRP in the vasculature. Tumor cells were negative. CONCLUSION: BCRP is present in the vasculature of vestibular schwannomas, plexiform neurofibromas and MPSNT. Therefore, it may reduce the drug exposure of underlying tumor tissues and potentially cause failure of drug therapy.

Age and Tumor Volume Predict Growth of Carotid and Vagal Body Paragangliomas.

Objective Treatment for head and neck paragangliomas (HNGPL) can be more harmful than the disease. After diagnosis, an initial period of surveillance is often indicated, and surgery or radiotherapy is reserved for progressive disease. With the aim to optimize this "wait and scan" strategy, we studied growth and possible predictors. Design A retrospective cohort study was conducted. Setting This study was conducted at a tertiary referral center for patients with HNGPL. Methods Tumor volume was estimated for 184 SDHD -related carotid and vagal body paragangliomas using sequential magnetic resonance imaging. Cox regression was used to study predictors of tumor growth. Results The estimated fraction of growing tumors ranged from 0.42 after 1 year of follow-up to 0.85 after 11 years. A median growth rate of 10.4 and 12.0% per year was observed for carotid and vagal body tumors, respectively. Tumor location, initial volume, and age ( p < 0.05) were included in our prediction model. The probability of growth decreased with increasing age and volume, indicating a decelerating growth pattern. Conclusions We created a prediction model (available online), enabling a more individualized "wait and scan" strategy. The favorable natural course of carotid and vagal body paragangliomas was confirmed; although with long follow-up growth will be observed in most cases.

Quality of Life in 807 Patients with Vestibular Schwannoma: Comparing Treatment Modalities.

Objective In vestibular schwannoma treatment, the choice among treatment modalities is controversial. The first aim of this study was to examine the quality of life of patients with vestibular schwannoma having undergone observation, radiation therapy, or microsurgical resection. The second aim was to examine the relationship between perceived symptoms and quality of life. Last, the association between quality of life and time since treatment was studied. Study Design Cross-sectional study. Setting Tertiary referral center. Subjects and Methods A total of 1208 patients treated for sporadic vestibular schwannoma between 2004 and 2014 were mailed the disease-specific Penn Acoustic Neuroma Quality of Life (PANQOL) questionnaire and additional questions on symptoms associated with vestibular schwannoma. Total and domain scores were calculated and compared among treatment groups. Propensity scores were used, and results were stratified according to tumor size to control for potential confounders. Correlations were calculated to examine the relationship between self-reported symptoms and quality of life, as well as between quality of life and time since treatment. Results Patients with small tumors (≤10 mm) under observation showed a higher PANQOL score when compared with the radiation therapy and microsurgical resection groups. A strong negative correlation was found between self-reported symptoms and quality of life, with balance problems and vertigo having the largest impact. No correlation was found between PANQOL score and time since treatment. Conclusion This study suggests that patients with small vestibular schwannomas experience better quality of life when managed with observation than do patients who have undergone active treatment.

The art of perception: Patients drawing their vestibular schwannoma.

OBJECTIVES/HYPOTHESIS: Drawings made by patients are an innovative way to assess the perceptions of patients on their illness. The objective of this study, at a university tertiary referral center, on patients who have recently been diagnosed with vestibular schwannoma, was to examine whether patients' illness perceptions can be assessed by drawings and are related to their quality of life. STUDY DESIGN: Cross-sectional study. METHODS: Patients diagnosed with vestibular schwannoma (mean age [range], 55.4 [17-85] years) between April 2011 and October 2012 were included (N = 253). Sociodemographics, illness perceptions (Brief Illness Perception Questionnaire [B-IPQ]), and disease-specific quality of life (Penn Acoustic Neuroma Quality of Life [PANQOL] scale) were assessed to evaluate the impact of being diagnosed with vestibular schwannoma. Furthermore, patients' drawings of their tumor were analyzed to explore the association between illness perceptions, drawings, and quality of life. RESULTS: Comparison of the B-IPQ scores of the current sample (N = 139; response rate 54.9%) with other disease samples shows a significantly lower score for patients with vestibular schwannoma on the Coherence dimension, indicating a low understanding of the illness. Illustration of emotions (N = 12) in the drawings gave a negative association with quality of life. Intercorrelations indicate a positive association between a low amount of physical and emotional consequences of the illness and a higher score on the Balance, Hearing, and Energy dimensions of the PANQOL. CONCLUSIONS: Patients' drawings give an insight into their perception of the tumor inside their head. Use of drawings may be helpful when developing and offering self-management programs. Quality of life appears to be significantly affected by the diagnosis. LEVEL OF EVIDENCE: 4.

Tumor Biology of Vestibular Schwannoma: A Review of Experimental Data on the Determinants of Tumor Genesis and Growth Characteristics.

OBJECTIVE: Provide an overview of the literature on vestibular schwannoma biology with special attention to tumor behavior and targeted therapy. BACKGROUND: Vestibular schwannomas are benign tumors originating from the eighth cranial nerve and arise due to inactivation of the NF2 gene and its product merlin. Unraveling the biology of these tumors helps to clarify their growth pattern and is essential in identifying therapeutic targets. METHODS: PubMed search for English-language articles on vestibular schwannoma biology from 1994 to 2014. RESULTS: Activation of merlin and its role in cell signaling seem as key aspects of vestibular schwannoma biology. Merlin is regulated by proteins such as CD44, Rac, and myosin phosphatase-targeting subunit 1. The tumor-suppressive functions of merlin are related to receptor tyrosine kinases, such as the platelet-derived growth factor receptor and vascular endothelial growth factor receptor. Merlin mediates the Hippo pathway and acts within the nucleus by binding E3 ubiquiting ligase CRL4. Angiogenesis is an important mechanism responsible for the progression of these tumors and is affected by processes such as hypoxia and inflammation. Inhibiting angiogenesis by targeting vascular endothelial growth factor receptor seems to be the most successful pharmacologic strategy, but additional therapeutic options are emerging. CONCLUSION: Over the years, the knowledge on vestibular schwannoma biology has significantly increased. Future research should focus on identifying new therapeutic targets by investigating vestibular schwannoma (epi)genetics, merlin function, and tumor behavior. Besides identifying novel targets, testing new combinations of existing treatment strategies can further improve vestibular schwannoma therapy.

Emotional intelligence in association with quality of life in patients recently diagnosed with vestibular schwannoma.

OBJECTIVE: The objective of this study was two-fold. First, to examine the levels of emotional intelligence in patients recently diagnosed with vestibular schwannoma, in comparison to those of healthy individuals and patients with other physical illness. Second, to evaluate the correlation between Emotional Intelligence and quality of life. STUDY DESIGN: Cross sectional study in a university tertiary referral center. METHODS: Consecutive patients (mean age [range], 56.4 [17-85] yr) diagnosed with vestibular schwannoma between April 2011 and October 2012 (N = 254). Sociodemographic characteristics, clinical characteristics, disease-specific quality of life (PANQOL), and Emotional Intelligence (TEIQue-SF) were assessed by questionnaire before the start of medical treatment. RESULTS: Levels of Emotional Intelligence in patients with vestibular schwannoma (N = 178; response rate 70.1%) were significantly lower compared with healthy individuals and patients with cancer. Emotional Intelligence was highly positively correlated to disease-specific quality of life. Balance disorders and cranial nerve dysfunction made a significant negative contribution to the quality of life. For educational level, a significant positive contribution was found as well. CONCLUSION: The substantial impact of a vestibular schwannoma-diagnosis on a psychological measure (i.e., Emotional Intelligence) in the affected patients as demonstrated in our study has important clinical and research implications when developing guidelines about counselling of these patients. This also has to be taken into account when making clinical decisions about the proposed treatment. Addressing Emotional Intelligence may be helpful in the development of a self-management program for patients with vestibular schwannoma.

Validating the Penn Acoustic Neuroma Quality Of Life Scale in a sample of Dutch patients recently diagnosed with vestibular schwannoma.

OBJECTIVE: To examine the validity of the Penn Acoustic Neuroma Quality-of-Life Scale (PANQOL) in a sample of Dutch patients recently diagnosed with vestibular schwannoma. STUDY DESIGN AND SETTING: Cross-sectional study in a university tertiary referral center. METHODS: Between April 2011 and March 2012 consecutive patients (mean age, 56.4; range, 17-85 yr) diagnosed with vestibular schwannoma (n = 155) were included. The PANQOL was translated into Dutch according to the accepted rules of forward-backward translation. Quality of life at diagnosis was measured with the generic SF-36 and the disease-specific PANQOL. Factor analysis was used to explore the factor structure of the PANQOL. The scores of the patients in the current study were compared with those of patients from the United States of America. Correlations between SF-36 and PANQOL were examined to study psychometric characteristics of the PANQOL. RESULTS: One hundred nineteen patients (76.8%) completed the questionnaires. SF-36 scores are comparable to previously published studies measuring Quality of Life at diagnosis. Factor analysis on our data has confirmed the original 7-dimensional structure of the PANQOL. The PANQOL scores from the Dutch and the USA patients are comparable. Correlations between PANQOL and SF-36 dimensions corroborate the validity of the Dutch PANQOL version. CONCLUSION: Vestibular schwannoma patients experience a reduced quality of life immediately after the diagnostic process. The PANQOL seems to be a valid disease-specific measure of quality of life in Dutch patients who have recently been diagnosed with vestibular schwannoma.

Tumor-associated macrophages are related to volumetric growth of vestibular schwannomas.

HYPOTHESIS: Tumor-associated macrophages contribute to vestibular schwannoma development. OBJECTIVE: An important clinical problem regarding vestibular schwannoma treatment is their variable growth rate. Tumor biological research can help to clarify this growth rate and may offer targets for therapy. Inflammation is an important biological process involved in the development of many solid tumors. Macrophages are major determinants of intratumoral inflammation. Macrophages can be divided into two groups; the M1- and M2-type macrophages. M2-type macrophages are associated with tumor-promoting processes like angiogenesis, tumor cell growth, and downregulation of the antitumor immune response. Both macrophages and angiogenesis can serve as targets for therapy. CD163 is a specific marker for M2-type macrophages. The goal of this study was to investigate if the expression of CD163 positive macrophages in sporadic vestibular schwannomas is associated with angiogenesis and tumor growth. METHODS: CD163 expression in 10 fast-growing vestibular schwannomas was compared with CD163 expression in 10 slow-growing vestibular schwannomas. Tumor growth was determined by comparing preoperative tumor volume measurements on MRI. The relation between macrophage expression and angiogenesis was evaluated by assessing microvessel density (CD31). RESULTS: CD163 expression and microvessel density were significantly higher in fast-growing vestibular schwannomas (p < 0.001 and p = 0.019, respectively). Tumors with higher CD163 expression contained significantly more microvessels (p = 0.014). CONCLUSION: This study demonstrates that M2-type macrophages in vestibular schwannomas relate to angiogenesis and volumetric tumor growth. These results imply that the M2-type macrophage infiltrate contributes to progressive tumor growth, making it a potential target for pharmacologic therapy.

High prevalence of occult paragangliomas in asymptomatic carriers of SDHD and SDHB gene mutations.

Hereditary paraganglioma is a benign tumor syndrome with an age-dependent penetrance. Carriers of germline mutations in the SDHB or SDHD genes may develop parasympathetic paragangliomas in the head and neck region or sympathetic catecholamine-secreting abdominal and thoracic paragangliomas (pheochromocytomas). In this study, we aimed to establish paraganglioma risk in 101 asymptomatic germline mutation carriers and evaluate the results of our surveillance regimen. Asymptomatic carriers of an SDHD or SDHB mutation were included once disease status was established by MRI diagnosis. Clinical surveillance revealed a head and neck paraganglioma in 28 of the 47 (59.6%) asymptomatic SDHD mutation carriers. Risk of tumor development was significantly lower in SDHB mutation carriers: 2/17 (11.8%, P=0.001). Sympathetic paragangliomas were encountered in two SDHD mutation carriers and in one SDHB mutation carrier. In conclusion, asymptomatic carriers of an SDHD mutation are at a high risk for occult parasympathetic paraganglioma. SDHB carrier risk is considerably lower, consistent with lower penetrance of SDHB mutations. For both syndromes, the risk of symptomless sympathetic paragangliomas is small.

Mutations affecting BRAF, EGFR, PIK3CA, and KRAS are not associated with sporadic vestibular schwannomas.

Sporadic vestibular schwannomas are benign tumors originating from the Schwann cells of the vestibular portion of the eigth cranial nerve. An important clinical hallmark of these tumors is their variable growth rate. Investigating vestibular schwannoma biology can help to clarify this variable growth rate and may offer targets for therapeutic treatment. A recent mutation analysis on sporadic non-head and neck schwannomas detected BRAF mutations in around 20 % of tumors. BRAF is part of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. MAPK/ERK activation is associated with an uncontrolled cell growth. Mutated BRAF can function as a target to inhibit this pathway. Mutations in BRAF and other members of the MAPK/ERK pathway have not been investigated in sporadic vestibular schwannomas before. The goal of this study was to investigate if these mutations are present in vestibular schwannomas and whether these mutations correlate with tumor growth. Tumor specimens of 48 patients surgically treated for a sporadic vestibular schwannoma were analyzed. An allele-specific quantitative real-time PCR assay was performed to detect the 13 most frequent mutations affecting BRAF, EGFR, PIK3CA, and KRAS. Radiologically measured tumor growth was included in the analysis to identify potential relationships between these mutations and tumor progression. No activating hotspot mutations in BRAF, EGFR, PIK3CA, or KRAS were detected. The 13 most frequent mutations affecting BRAF, EGFR, PIK3CA, and KRAS are not involved in sporadic vestibular schwannoma development. These results are in contrast to the recent detection of these BRAF mutations in non-head and neck schwannomas.

Intratumoral hemorrhage, vessel density, and the inflammatory reaction contribute to volume increase of sporadic vestibular schwannomas.

Vestibular schwannomas show a large variation in growth rate, making prediction and anticipation of tumor growth difficult. More accurate prediction of clinical behavior requires better understanding of tumor biological factors influencing tumor progression. Biological processes like intratumoral hemorrhage, cell proliferation, microvessel density, and inflammation were analyzed in order to determine their role in vestibular schwannoma development. Tumor specimens of 67 patients surgically treated for a histologically proven unilateral vestibular schwannoma were studied. Preoperative magnetic resonance imaging (MRI) scans were used to determine tumor size and to classify tumors as homogeneous, inhomogeneous, and cystic. Immunohistochemical studies evaluated cell proliferation (histone H3 and Ki-67), microvessel density (CD31), and inflammation (CD45 and CD68). Intratumoral hemorrhage was assessed by hemosiderin deposition. The expression patterns of these markers were compared with tumor size, tumor growth index, MRI appearance, patients' age, and duration of symptoms. No relation between cell proliferation and clinical signs of tumor volume increase or MRI appearance was found. Intratumoral hemosiderin, microvessel density, and inflammation were significantly positively correlated with tumor size and the tumor growth index. Cystic and inhomogeneous tumors showed significantly more hemosiderin deposition than homogeneous tumors. The microvessel density was significantly higher in tumors with a high number of CD68-positive cells. The volume increase of vestibular schwannomas is not based on cell proliferation alone. Factors like intratumoral bleeding, (neo)vascularization, and intensity of the inflammatory reaction also influence tumor volume.

Conservative treatment of vestibular schwannoma: a follow-up study on clinical and quality-of-life outcome.

OBJECTIVE: To determine the natural history and long-term quality-of-life (QOL) outcome after conservative treatment for vestibular schwannoma. STUDY DESIGN: Prospective study conducted in a university-based tertiary referral center. PATIENTS: A total of 70 vestibular schwannoma patients who were initially included in the wait and scan protocol between January 2002 and December 2003 were followed with a mean observation time of 43 months. All patients had small- or medium-sized tumors when they were included in the protocol. QOL was measured at diagnosis and at the end of follow-up in those patients who were still conservatively treated using the Short Form 36 Health Survey (SF-36). The study group was characterized by nongrowing small tumors and relatively stable symptoms over time. MAIN OUTCOME MEASURES: Clinical, audiometric, radiologic, and QOL results. RESULTS: In 44 patients (63%), growth of the tumor was not observed, and 25 (36%) tumors did grow. Of the 70 included patients, 27 patients (39%) required treatment. Forty-one patients (59%) were still conservatively treated at the end of follow-up (mean 47 +/- 16 mo). Hearing was preserved in 16 (57%) of the 28 patients with useful hearing at diagnosis. At the end of follow-up, SF-36 scores were only slightly deteriorated for almost all subscales when compared with scores at diagnosis; however, differences were statistically not significant (p > 0.05). There was no significant correlation between the presence of cochleovestibular symptoms and QOL scores (p > 0.05). CONCLUSION: Conservative observation of small vestibular schwannomas may be regarded as a reasonable management option because most of these tumors do not grow during an initial period of observation. Conservative treatment of this subset of patients with small, nongrowing tumors does not significantly affect life functioning, as reflected in SF-36 survey data. However, hearing loss did progress in this population. Thus, patients should be counseled regarding this risk and generic QOL measures such as the SF-36 should be used with caution in future assessments. This study emphasizes the importance of combining generic and disease-specific QOL measures in future studies of protocols of vestibular schwannoma management.

A meta-analysis of surgical treatment for vestibular schwannoma: is hospital volume related to preservation of facial function?

OBJECTIVE: To investigate the relation between hospital volume and preservation ratios of facial function in surgery for vestibular schwannoma. DATA SOURCES: A meta-analysis was conducted on current literature concerning preservation ratios of facial function after surgical resection of vestibular schwannoma. Studies reported by the House-Brackmann grading system for facial function were searched; all studies were published in English in peer-reviewed journals between 1992 and 2007. STUDY SELECTION: Articles had to report 1) patients who had surgery for vestibular schwannoma, 2) House-Brackmann grades for facial function, and 3) calendar time and number of procedures. DATA EXTRACTION: Standard methods for meta-analysis were adapted. DATA SYNTHESIS: Data were pooled by weighing studies according to their accuracy. Results were sorted for low-, moderate-, and high-volume hospitals. Linear relations were quantified by metaregression analysis (n = 5,560). CONCLUSION: Findings of this meta-analysis suggest that there is a linear relation between hospital volume and preservation ratio of facial function. The concentration of surgical treatment might be a consideration to optimize clinical outcome. Prospective and nationwide registration of surgical results might contribute to more definitive conclusions regarding outcome of vestibular schwannoma surgery.

Surgery for large vestibular schwannoma: residual tumor and outcome.

OBJECTIVE: To evaluate clinical outcome with regard to the amount of residual tumor after surgery for large vestibular schwannoma. PATIENTS: Between January 2000 and December 2005, 51 large vestibular schwannoma tumors with extrameatal diameter of 2.6 cm or greater (mean, 32 mm; median, 30 mm; range, 26-50 mm) were operated using the translabyrinthine approach. The extent of the resection was intraoperatively estimated as complete, near, and subtotal. The amount of residual tumor was measured, and the shape and localization was scored on gadolinium-enhanced magnetic resonance imaging (MRI). Correlation between intraoperative and MRI assessment was performed using the Fisher's exact test. Potential growth of residual tumor was documented with frequent MRI follow-up. Postoperative facial nerve function was classified according to the House-Brackmann classification. RESULTS: Complete resection was performed in 26% of the patients, near-total resection in 58%, and subtotal resection in 16%. Magnetic resonance imaging showed residual tumor in 46% of patients (mean, 16.7 mm; SD, +/-8, range, 5-36 mm). Postoperative facial nerve function was House-Brackmann Grades I to II in 78% of the patients. The intraoperative assessment of near-total resection did not correlate with postoperative MRI (p = 0.25). Postoperative MRI showed either no residual tumor or residue that should actually have been classified as a subtotal resection. After a follow-up of 4 years (49 mo; mean, 48 mo), 94% of patients did not show changes on MRI. CONCLUSION: Tumor control with good facial nerve function could be obtained in most patients. Intraoperative assessment did not correlate with the amount of residual tumor on postoperative MRI. Objective documentation with postoperative MRI to measure the extent of removal is therefore mandatory.