Management of sporadic vestibular schwannoma

Determining the Impact of Preoperative Psychiatric Comorbidities on Readmission After Resection of Vestibular Schwannoma

OBJECTIVE

To determine the impact of comorbid depression on readmission after vestibular schwannoma resection.

STUDY DESIGN

Retrospective database analysis.

SETTING

National database of readmitted patients.

PATIENTS

The Nationwide Readmission Database (NRD) was retrospectively reviewed for patients with history of vestibular schwannoma, identified by International Classification of Disease, Ninth Revision (ICD-9) code 225.1 and ICD-10 code D33.3, who underwent surgical resection (ICD-9 04.01, ICD-10-PCS 00BN0ZZ) in 2020.

INTERVENTIONS

Therapeutic.

MAIN OUTCOME MEASURES

Need for rehabilitation, need for procedures, length of stay, cost of readmission, and insurance status.

RESULTS

A total of 1997 patients were readmitted after resection of vestibular schwannoma in 2020. Of these patients, 290 had history of a comorbid depressive disorder.A significantly higher proportion of patients with history of comorbid depression were transferred to a rehabilitation facility after readmission (11.30% versus 4.30%, p < 0.001). Length of stay (p = 0.227) and total readmission cost (p = 0.723) did not differ significantly, but a significantly lower proportion had private insurance (55.40% versus 64.40%, p = 0.027).

CONCLUSION

Depression is associated with higher utilization of postoperative rehabilitation services and higher rates of medical comorbidities, and should be considered during preoperative evaluation.

Documented Initial Growth Does Not Necessarily Indicate Treatment for Sporadic Vestibular Schwannomas

OBJECTIVE

To report the natural history of vestibular schwannoma (VS) who elected an initial period of observation and identify prognostic factors. To describe the natural history of growing VS, identify prognostic factors, and review the most recent literature.

STUDY DESIGN

Prospective cohort study and literature review.

SETTING

Tertiary referral center.

PATIENTS

Adult patients diagnosed with a VS between January 1998 and February 2023.

INTERVENTION

Magnetic resonance imaging surveillance.

MAIN OUTCOME MEASURES

Growth-free survival and subsequent growth-free survival considering significant growth as a change in size of ≥2 mm.

RESULTS

Of 430 patients undergoing observation with serial magnetic resonance imaging, 193 (44.9%) demonstrated significant growth at a median of 1.6 years (interquartile range, 0.94-3.51). Of the 193 patients who presented an initial episode of growth, 137 elected to continue to be observed. Of those, 83 (60.6%) presented a second episode of growth at a median of 1.43 years (interquartile range, 1.00-2.49). The subsequent growth-free survival rates (95% confidence interval) at 1, 3, 5, 7, and 10 years were 91.79% (87.26-96.56%), 64.44% (56.56-73.42%), 52.52% (44.23-62.35%), 42.23% (33.92-52.56%), and 36.11% (27.89-46.76%), respectively. Univariate and multivariate Cox regression analyses showed that EC tumor location and initial growth rate were significant predictors of subsequent growth.

CONCLUSIONS

Close observation after documentation of growth is an appropriate management in well-selected cases given that only around 56% of the tumor will continue to grow. Extracanalicular tumor location and initial growth rate are promising prognostic factors to help determine which patient would be a better candidate for close surveillance after initial documentation of growth.

CyberKnife Stereotactic Radiosurgery for Growing Vestibular Schwannoma: Longitudinal Tumor Control, Hearing Outcomes, and Predicting Post-Treatment Hearing Status

OBJECTIVES

(1) To determine tumor control rates for treating growing vestibular schwannoma (VS) with CyberKnife stereotactic radiosurgery (CK SRS); (2) to determine hearing outcomes after CK SRS; (3) to propose a set of variables that could be used to predict hearing outcomes for patients receiving CK SRS for VS.

STUDY DESIGN

Retrospective case series review.

METHODS

127 patients who received CK SRS for radiographically documented growing VS were reviewed. Tumors were monitored for post-procedure growth radiographically with linear measurements and three-dimensional segmental volumetric analysis (3D-SVA). Hearing outcomes were reviewed for 109 patients. Cox proportional hazard modeling was used to identify variables correlated with hearing outcomes.

RESULTS

Tumor control rate was 94.5% for treating VS with CK SRS. Hearing outcomes were categorized using the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) classification system. As of their last available audiogram, 33.3% of patients with pre-treatment class A and 26.9% of patients with class B retained their hearing in that class. 15.3% of patients starting with class A or B with extended follow-up (>60 months), maintained hearing within this same grouping. Our final model proposed to predict hearing outcomes included age, fundal cap distance (FCD), tumor volume, and maximum radiation dose to the cochlea; however, FCD was the only statistically significant variable.

CONCLUSION

CK SRS is an effective treatment for control of VS. Hearing preservation by class was achieved in a third of patients. Finally, FCD was found to be protective against hearing loss.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:S1-S12, 2024.

Automated 2-Dimensional Measurement of Vestibular Schwannoma: Validity and Accuracy of an Artificial Intelligence Algorithm

OBJECTIVE

Validation of automated 2-dimensional (2D) diameter measurements of vestibular schwannomas on magnetic resonance imaging (MRI).

STUDY DESIGN

Retrospective validation study using 2 data sets containing MRIs of vestibular schwannoma patients.

SETTING

University Hospital in The Netherlands.

METHODS

Two data sets were used, 1 containing 1 scan per patient (n = 134) and the other containing at least 3 consecutive MRIs of 51 patients, all with contrast-enhanced T1 or high-resolution T2 sequences. 2D measurements of the maximal extrameatal diameters in the axial plane were automatically derived from a 3D-convolutional neural network compared to manual measurements by 2 human observers. Intra- and interobserver variabilities were calculated using the intraclass correlation coefficient (ICC), agreement on tumor progression using Cohen's kappa.

RESULTS

The human intra- and interobserver variability showed a high correlation (ICC: 0.98-0.99) and limits of agreement of 1.7 to 2.1 mm. Comparing the automated to human measurements resulted in ICC of 0.98 (95% confidence interval [CI]: 0.974; 0.987) and 0.97 (95% CI: 0.968; 0.984), with limits of agreement of 2.2 and 2.1 mm for diameters parallel and perpendicular to the posterior side of the temporal bone, respectively. There was satisfactory agreement on tumor progression between automated measurements and human observers (Cohen's κ = 0.77), better than the agreement between the human observers (Cohen's κ = 0.74).

CONCLUSION

Automated 2D diameter measurements and growth detection of vestibular schwannomas are at least as accurate as human 2D measurements. In clinical practice, measurements of the maximal extrameatal tumor (2D) diameters of vestibular schwannomas provide important complementary information to total tumor volume (3D) measurements. Combining both in an automated measurement algorithm facilitates clinical adoption.

Does Size Matter? On the Role of Stereotactic Radiosurgery for Large Vestibular Schwannomas as Seen in an Institutional Experience of Gamma Knife Radiosurgery for High-Grade Tumors

OBJECTIVE

Management of large vestibular schwannoma (VS) is controversial. Surgery has historically been the treatment of choice, but emerging literature suggests that definitive stereotactic radiosurgery is feasible. We report our institutional experience of control and morbidity outcomes treating Koos grade 3-4 VS with Gamma Knife radiosurgery (GKRS).

METHODS

An institutional review board-approved database compiled outcomes of Koos grade 3-4 VS treated by GKRS from March 2014 to January 2021 with >6 months' follow-up. Baseline symptoms per Common Terminology Criteria for Adverse Events definitions were recorded. Control rates, toxicities, and post-treatment volumetric changes were analyzed. Aggregate impairment scores (AIs) were defined by the sum of relevant Common Terminology Criteria for Adverse Events grades to categorize symptomatic burdens. Baseline and post-treatment AIs were tested for association with definitive versus adjuvant strategies.

RESULTS

In total, 34 patients with Koos grade 3-4 VS were identified, 19 treated with definitive GKRS (GKRS-D) and 15 with adjuvant GKRS (GKRS-A). Median follow-up was 34.2 months for GKRS-D and 48.8 months for GKRS-A. Patients who received GKRS-A had greater AIs at presentation (3.73 vs. 2.11, P = 0.017). Irrespective of treatment approach, tumor control rates were 100% without instances of brainstem necrosis or shunt placement. Six of 19 patients who received GKRS-D had improved post-treatment AI, and 63% of patients who received GKRS-D and 66% of patients who received GKRS-A had tumor shrinkage >20%.

CONCLUSIONS

In well-selected patients with Koos grade 3-4 VS, definitive stereotactic radiosurgery may be an appropriate strategy with excellent control and minimal toxicity. Our data suggest that the need for surgical decompression should be considered based on pretreatment symptom burden rather than tumor size.

Cochlear Implantation in Sporadic Vestibular Schwannoma and Neurofibromatosis Type II

Cochlear implantation offers significantly better hearing outcomes than auditory brainstem implantation in patients with vestibular schwannoma. Neither the primary treatment modality nor the cause of the tumor (neurofibromatosis type 2 related or sporadic) seems to have a significant effect on hearing outcome with cochlear implantation. Some uncertainty remains regarding long-term hearing outcomes; however, cochlear implantation in vestibular schwannoma serves to offer patients, with a functioning cochlear nerve, the probability of open set speech discrimination with a consequent positive impact on quality of life.

Translabyrinthine Approach for Sporadic Vestibular Schwannoma: Patient Selection, Technical Pearls, and Patient Outcomes

Herein we briefly describe the translabyrinthine approach to vestibular schwannoma resection as well as a focused literature review as to the best candidates, technical recommendations, and key outcomes with respect to other approaches.

Surgical management of skull base meningiomas and vestibular schwannomas

PURPOSE OF REVIEW

The aim of this study is to discuss surgical management of meningiomas and schwannomas of skull base.

RECENT FINDINGS

Meningiomas and schwannomas are typically benign neoplasm with a good prognosis after surgery. Patients should be treated individually related to several features: size and localization of tumor and its proximity with deep critical neurovascular structures, neurological status, age and comorbidity. Also, the widespread use of neuroimaging and the progressive and constant aging of the populations inevitably result in the increase of detection rate of incidental (asymptomatic) neoplasm.Nowadays, there are still controversies about the correct management strategy.

SUMMARY

Surgery represents the gold standard treatment, with the objective of gross total resection; however, it is not always feasible due to localization, encasement of neuro-vascular structure, invasion of cranial nerve and brain parenchyma. Stereotactic radiosurgery and radiation therapy are important to achieve a satisfactory functional outcome and tumor control in case of residue or recurrence. A multidisciplinary approach is pivotal.

Development and validation of a new disease-specific quality of life instrument for sporadic vestibular schwannoma: the Mayo Clinic Vestibular Schwannoma Quality of Life Index

OBJECTIVE

Facial nerve function, hearing preservation, and tumor control have been the primary benchmarks used to assess vestibular schwannoma (VS) outcomes. Acknowledging the frequent discrepancy between what physicians prioritize and what patients value, there has been increasing prioritization of patient-reported outcome measures when evaluating the impact of VS diagnosis and its treatment. Motivated by reported limitations of prior instruments used to assess quality of life (QOL) in patients with VS, the authors describe the development and validation of a new disease-specific QOL measure: the Vestibular Schwannoma Quality of Life (VSQOL) Index.

METHODS

The content development phase comprised identification of clinically important domains and prioritization of feelings or concerns individuals with VS may have. The validation phase encompassed determining how items were grouped into domains and eliminating redundant items. Both phases leveraged data from cross-sectional and longitudinal surveys, expertise from a multidisciplinary working group, and patients with a broad range of experiences with VS (n = 42 during content development and n = 263 during validation). Domain scores from the new instrument were assessed for reliability and correlation with other measures of similar constructs.

RESULTS

The VSQOL Index consists of 40 items that evaluate the impact of VS diagnosis and its management on QOL, treatment satisfaction, and employment and is estimated to take 8-10 minutes to complete. Domain scores range from 0 (worst) to 100 (best) and demonstrate excellent psychometric properties, including content, construct, and convergent validity and both internal consistency (Cronbach's alphas 0.83 to 0.91) and test-retest reliability (reliability coefficients 0.86 to 0.96).

CONCLUSIONS

The VSQOL Index is a valid and reliable measure that overcomes several limitations of prior instruments, including omission or underrepresentation of domains that frequently impact well-being, such as pain, cognition, satisfaction or regret surrounding treatment decisions, and occupational limitations, to comprehensively evaluate the impact of VS diagnosis or its treatment on QOL.

Predictors of Recurrence After Sub-total or Near-total Resection of Vestibular Schwannoma: Importance of Tumor Volume and Ventral Extension

OBJECTIVE

To evaluate the predictors of remnant tumor regrowth and need for salvage therapy after less than gross total resection (GTR) of vestibular schwannoma (VS).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary neurotologic referral center.

PATIENTS

Patients who underwent VS resection between 2008 and 2019 either with GTR, near total resection (NTR), and subtotal resection (STR).

INTERVENTIONS

Microsurgical resection, salvage radiosurgery.

MAIN OUTCOME MEASURES

Regrowth free interval, salvage free interval, tumor doubling rate.

RESULTS

Three hundred eighty five cases (GTR = 236, NTR = 77, and STR = 71) from 2008 to 2019 were included. STR cohort had much larger and complex tumors with significant differences in tumor volume, ventral extension and brainstem compression (p  < 0.001). On single predictor analysis, tumor volume, ventral extension, brainstem compression as well as STR strategy was associated with significant increased risk of regrowth and need for salvage therapy. Multivariate analysis revealed STR strategy as significant predictor of regrowth (hazard ratio 3.79, p  < 0.0005). Absolute remnant volume and extent of resection (EOR) did not predict regrowth. A small proportion of cases (NTR = 4%, STR = 15%) eventually needed salvage radiosurgery with excellent ultimate local tumor control with no known recurrence to date.

CONCLUSIONS

Conservative surgical strategy employing NTR or STR can be employed safely in large and complex VS. While there is increased risk of regrowth in the STR cohort, excellent local control can be achieved with appropriate use of salvage radiosurgery. No disceret radiologic or operative predictors of regrowth were identified.

Accuracy and outcomes of diffusion tensor imaging tractography in resection for vestibular schwannoma for facial nerve preservation

BACKGROUND

Impairment of facial nerve (FN) function is a common postoperative complication in surgical resections of Vestibular Schwannomas (VS). Diffusion tensor imaging (DTI) tractography creates in vivo imaging of the anatomical location of white matter tracts that can be preoperatively used to visualize the displaced FN. We present an analysis of patients who underwent DTI tractography imaging prior to VS resection.

METHODS

Patient charts were reviewed from March 2012 to April 2015 who underwent DTI tractography prior to surgical resection for VS. Reliability of this measure was compared to the intraoperative FN location as determined by the surgeon. House Brackmann (HB) score was used to assess facial nerve function.

RESULTS

A total of 11 patients were included with a mean age of 43 years (range: 19-64) and mean follow-up length of 11.9 months (range: 3.1-34.2). The average maximum tumor diameter was 2.82 cm (range: 1.7-4.2). DTI tractography was accurate in 90.9% (10/11) of patients. Postoperatively, 72.7% (8/11) had a HB score of I or II, 18.2% (2/11) had a HB score of III, and 9.1% (1/11) had a HB score of IV.

CONCLUSIONS

Facial nerve visualization for VS resection can be accurately visualized using DTI tractography. This modality may lead to reduction of postoperative FN damage.

Large and small vestibular schwannomas: same, yet different tumors

BACKGROUND

Vestibular schwannomas (VS) present at variable size with heterogeneous symptomatology. Modern treatment paradigms for large VS include gross total resection, subtotal resection (STR) in combination with observation, and/or radiation to achieve optimal function preservation, whereas treatment is felt to be both easier and safer for small VS. The objective is to better characterize the presentation and surgical outcomes of large and small VS.

METHODS

We collected data of patients who had surgically treated VS with a posterior fossa diameter of 4.0 cm or larger (large tumor group, LTG) and smaller than 1.0 cm in cisternal diameter (small tumor group, STG). Statistical significance was defined as p < 0.05.

RESULTS

LTG included 48 patients (average tumor size: 44.9 mm) and STG 38 (7.9 mm). Patients in STG presented more frequently with tinnitus and sudden hearing loss. Patients in LTG underwent more STR than STG (50.0% vs. 2.6%, p < 0.0001). LTG had more complications (31.3% vs. 13.2%, p = 0.049). Postoperative facial nerve function in STG was significantly better than LTG. STG had better hearing preoperatively (p < 0.0001) and postoperatively than LTG (p = 0.0002). Postoperative headache was more common in STG (13.2% vs. 2.1%, p = 0.045). The rate of recurrence/progression needing treatment was not statistically different between the groups (12.5% in LTG vs. 7.9% in STG, p = 0.49). Those patients who required periprocedural cerebrospinal fluid diversion had higher risk of infection (20.8% vs 4.8%, p = 0.022).

CONCLUSION

Large and small VS present differently. LTG showed more unsatisfactory outcomes in facial nerve function and postoperative hearing despite maximal efforts undertaken toward function-preservation strategy; however, similar tumor control was achieved.

The impact of vestibular schwannoma and its management on employment

BACKGROUND

Employment is an important factor in quality of life. For vestibular schwannoma (VS) patients, employment is not self-evident, because of the sequelae of the disease or its treatment and their effects on daily life.

OBJECTIVES

This study assessed employment status, sick leave (absenteeism) and being less productive at work (presenteeism) in the long-term follow-up of VS patients, and evaluated the impact of treatment strategy (active surveillance, surgery or radiotherapy).

METHODS

A cross-sectional survey study was performed in a tertiary university hospital in the Netherlands. Patients completed the iMTA-post productivity questionnaire (iPCQ). Employment status was compared to that of the general Dutch population. Employment, absenteeism and presenteeism were compared between patients under active surveillance, patients after radiotherapy and post-surgical patients.

RESULT

In total 239 patients participated, of which 67% were employed at the time of the study. Only 14% had a disability pension, which was comparable to the age-matched general Dutch population. The proportion of patients with absenteeism was 8%, resulting in a 4% reduction of working hours. Presenteeism was reported by 14% of patients, resulting in a 2% reduction of working hours. The median number of working hours per week was 36, and since the diagnosis, these hours had been reduced by 6%. There were no significant differences between treatment modalities.

CONCLUSION

On average, long-term employment status and working hours of VS patients are comparable to the age-matched general population. Treatment strategies do not seem to differentially impact on long-term employment of VS patients.

Prediction of Hearing Preservation in Vestibular Schwannoma Surgery According to Tumor Size and Anatomic Extension

OBJECTIVE

Vestibular schwannoma (VS) surgery is feasible for various tumor sizes that are inappropriate for wait and scan or radiosurgery. The predictive value of 2 grading systems was investigated for postoperative hearing preservation (HP) in a large series.

STUDY DESIGN

Retrospective analysis.

SETTING

Neurosurgical patient database of the University of Erlangen was queried between 2014 and 2017.

METHODS

Retrospective single-center analysis on 138 VSs operated on via a retrosigmoidal approach. The mean tumor size was 20.4 mm (SD, 7.6 mm) with fundal infiltration in 67.4%. The overall resection rate was 93.5%. Tumors were classified preoperatively by the 3-tier Erlangen grading system depending on size or the anatomically based 4-tier Koos grading system.

RESULTS

Preoperative hearing preservation was found in 70.3% of patients and was significantly correlated to tumor size (P = .001). For Erlangen grading, a mean postoperative serviceable hearing preservation rate of 32% was achieved: 83.3% for tumors <12 mm, 30.3% for tumors between 12 and 25 mm, and 5.3% for tumors >25 mm. In contrast, according to Koos grading, postoperative serviceable hearing preservation was 100% for grade 1 tumors (meatal), 35.6% for grade 2 (cisternal), 23.1% for grade 3 (brainstem contact), and 21.7% for grade 4 (brainstem compression). Of the total cohort, 86% had normal or nearly normal postoperative facial function (House-Brackmann grades 1 and 2).

CONCLUSION

Surgery on small VSs can achieve excellent hearing preservation. Different grading has a significant influence on and correlates with postoperative hearing preservation. Tumor size seems more important than anatomic relationship.

The microenvironment in sporadic and neurofibromatosis type II-related vestibular schwannoma: the same tumor or different? A comparative imaging and neuropathology study

OBJECTIVE

Inflammation and angiogenesis may play a role in the growth of sporadic and neurofibromatosis type 2 (NF2)-related vestibular schwannoma (VS). The similarities in microvascular and inflammatory microenvironment have not been investigated. The authors sought to compare the tumor microenvironment (TME) in sporadic and NF2-related VSs using a combined imaging and tissue analysis approach.

METHODS

Diffusion MRI and high-temporal-resolution dynamic contrast-enhanced (DCE) MRI data sets were prospectively acquired in 20 NF2-related and 24 size-matched sporadic VSs. Diffusion metrics (mean diffusivity, fractional anisotropy) and DCE-MRI-derived microvascular biomarkers (transfer constant [Ktrans], fractional plasma volume, tissue extravascular-extracellular space [ve], longitudinal relaxation rate, tumoral blood flow) were compared across both VS groups, and regression analysis was used to evaluate the effect of tumor size, pretreatment tumor growth rate, and tumor NF2 status (sporadic vs NF2-related) on each imaging parameter. Tissues from 17 imaged sporadic VSs and a separate cohort of 12 NF2-related VSs were examined with immunohistochemistry markers for vessels (CD31), vessel permeability (fibrinogen), and macrophage density (Iba1). The expression of vascular endothelial growth factor (VEGF) and VEGF receptor 1 was evaluated using immunohistochemistry, Western blotting, and double immunofluorescence.

RESULTS

Imaging data demonstrated that DCE-MRI-derived microvascular characteristics were similar in sporadic and NF2-related VSs. Ktrans (p < 0.001), ve (p ≤ 0.004), and tumoral free water content (p ≤ 0.003) increased with increasing tumor size and pretreatment tumor growth rate. Regression analysis demonstrated that with the exception of mean diffusivity (p < 0.001), NF2 status had no statistically significant effect on any of the imaging parameters or the observed relationship between the imaging parameters and tumor size (p > 0.05). Tissue analysis confirmed the imaging metrics among resected sporadic VSs and demonstrated that across all VSs studied, there was a close association between vascularity and Iba1+ macrophage density (r = 0.55, p = 0.002). VEGF was expressed by Iba1+ macrophages.

CONCLUSIONS

The authors present the first in vivo comparative study of microvascular and inflammatory characteristics in sporadic and NF2-related VSs. The imaging and tissue analysis results indicate that inflammation is a key contributor to TME and should be viewed as a therapeutic target in both VS groups.

Vestibular Schwannoma Practice Patterns: An International Cross-specialty Survey

OBJECTIVE

To assess vestibular schwannoma (VS) practice patterns among providers.

STUDY DESIGN

Cross-sectional survey.

SETTING

8th Quadrennial International Conference on Vestibular Schwannoma and Other CPA Tumors.

SUBJECTS

Clinicians who specialize in the management of VS.

MAIN OUTCOME MEASURES

Responses to questions on the management and anticipated outcomes of VS for a series of common clinical scenarios were compared by specialty (otolaryngology versus neurosurgery), level of experience, scope of practice (surgery versus radiation and surgery), and geographic location of practice (United States versus international).

RESULTS

Responses from 110 participants were analyzed. Overall, 53% of respondents were otolaryngologists, 60% had greater than 10 years of experience, and 57% practiced within the United States. In total, 86% of respondents would pursue initial observation for themselves if diagnosed with a 4 mm distal intracanalicular VS; however, practicing radiosurgeons were more likely to select stereotactic radiosurgery for this scenario compared with providers who solely practice surgery (14 versus 0%; p = 0.032). Otolaryngologists and neurosurgeons alike report that radiosurgery should not be considered a long-term hearing preservation strategy.Otolaryngologists were more optimistic regarding microsurgical hearing preservation outcomes for small distal intracanalicular tumors compared with neurosurgeons (11 versus 3% selected a high likelihood of maintaining class A/B hearing; p = 0.007). Ninety-five percent of respondents prioritized facial nerve outcome over complete disease removal in the context of microsurgical resection of large tumors.

CONCLUSIONS

Management decision-making and expected outcomes for various clinical scenarios were largely similar among providers; however, variances in several key clinical areas exist. This study points to the feasibility of developing a widely accepted consensus statement among VS experts across specialties.

"When the Benign Bleed" Vestibular Schwannomas with Clinically Significant Intratumoral Hemorrhage: A Case Series and Review of the Literature

Vestibular schwannomas (VSs) are slow-growing benign neoplasms commonly located at the cerebellopontine angle. Although clinically significant hemorrhagic VSs are rarely encountered with only 75 patients previously reported, they could be life threatening. We discuss the presentation and outcomes of three patients with hemorrhagic VS as well as review the literature for this phenomenon. Consecutive adult patients with a histologically proven diagnosis of VS over a 9-year period were retrospectively reviewed. Fifty adult patients were identified with three (6%) having clinically significant intratumoral hemorrhage. This was defined as patients having acute to subacute symptoms with frank radiological evidence of hemorrhage. The mean age of diagnosis was 62 ± 9 years and the male-to female ratio was 2:1. The mean duration of symptoms, namely headache, vertigo, and sensorineural hearing impairment, was 26 ± 4 days with one patient presenting with acute coma. Retrosigmoid craniotomy for tumor resection was performed for all patients. Histopathological examination revealed extensive areas of microhemorrhage with considerable macrophage infiltration. All three patients were discharged with no additional neurological deficit and good functional performance. Clinically significant hemorrhagic VSs are rare, and patients may present with acute to subacute (i.e., within a month) symptoms of hearing loss headache, facial, or trigeminal nerve palsy. Macrophage infiltration is frequently encountered in tumor specimens and reflects the pivotal role of chronic inflammation in their pathophysiology. Surgical resection can lead to good outcomes with timely intervention.

Pre-habilitation Before Vestibular Schwannoma Surgery-Impact of Intratympanal Gentamicin Application on the Vestibulo-Ocular Reflex

Background: Patients with vestibular schwannoma that show residual peripheral-vestibular function before surgery may experience sudden and substantial vestibular loss of function after surgical resection. To alleviate the sudden loss of peripheral-vestibular function after vestibular-schwannoma (VS) resection, pre-surgical intratympanic gentamicin application was proposed. Objective: We hypothesized that this approach allows for a controlled reduction of peripheral-vestibular function before surgery but that resulting peripheral-vestibular deficits may be canal-specific with anterior-canal sparing as observed previously in systemic gentamicin application. Methods: Thirty-four patients (age-range = 27-70 y) with unilateral VS (size = 2-50 mm) were included in this retrospective single-center trial. The angular vestibulo-ocular reflex (aVOR) was quantified before and after (29.7 ± 18.7 d, mean ± 1SD) a single or two sequential intratympanic gentamicin applications by use of video-head-impulse testing. Both aVOR gains, cumulative saccadic amplitudes, and overall aVOR function were retrieved. Statistical analysis was done using a generalized linear model. Results: At baseline, loss of function of the horizontal (20/34) and posterior (21/34) canal was significantly (p < 0.001) more frequent than that of the anterior canal (5/34). After gentamicin application, loss of function of the horizontal (32/34) or posterior (31/34) canal remained significantly (p ≤ 0.003) more frequent than that of the anterior canal (18/34). For all ipsilesional canals, significant aVOR-gain reductions and cumulative-saccadic-amplitude increases were noted after gentamicin. For the horizontal canal, loss of function was significantly larger (increase in cumulative-saccadic-amplitude: 1.6 ± 2.0 vs. 0.8 ± 1.2, p = 0.007) or showed a trend to larger changes (decrease in aVOR-gain: 0.24 ± 0.22 vs. 0.13 ± 0.29, p = 0.069) than for the anterior canal. Conclusions: Intratympanic gentamicin application resulted in a substantial reduction in peripheral-vestibular function in all three ipsilesional canals. Relative sparing of anterior-canal function noted at baseline was preserved after gentamicin treatment. Thus, pre-surgical intratympanic gentamicin is a suitable preparatory procedure for reducing the drop in peripheral-vestibular function after VS-resection. The reasons for relative sparing of the anterior canal remain unclear.

Merlin-Deficient Schwann Cells Are More Susceptible to Radiation Injury than Normal Schwann Cells In Vitro

Objectives Vestibular schwannomas (VS) are intracranial tumors, which are caused by NF2 gene mutations that lead to loss of merlin protein. A treatment for VS is stereotactic radiosurgery, a form of radiation. To better understand the radiobiology of VS and radiation toxicity to adjacent structures, our main objectives were (1) investigate effects of single fraction (SF) radiation on viability, cytotoxicity, and apoptosis in normal Schwann cells (SCs) and merlin-deficient Schwann cells (MD-SCs) in vitro, and (2) analyze expression of double strand DNA breaks (γ-H2AX) and DNA repair protein Rad51 following irradiation.

Study Design This is a basic science study.

Setting This study is conducted in a research laboratory.

Participants Patients did not participate in this study.

Main Outcome Measures In irradiated normal SCs and MD-SCs (0–18 Gy), we measured (1) viability, cytotoxicity, and apoptosis using cell-based assays, and (2) percentage of cells with γ-H2AX and Rad51 on immunofluorescence.

Results A high percentage of irradiated MD-SCs expressed γ-H2AX, which may explain the dose-dependent losses in viability in rodent and human cell lines. In comparison, the viabilities of normal SCs were only compromised at higher doses of radiation (>12 Gy, human SCs), which may be related to less Rad51 repair. There were no further reductions in viability in human MD-SCs beyond 9 Gy, suggesting that <9 Gy may be insufficient to initiate maximal tumor control.

Conclusion The MD-SCs are more susceptible to radiation than normal SCs, in part through differential expression of γ-H2AX and Rad51. Understanding the radiobiology of MD-SCs and normal SCs is important for optimizing radiation protocols to maximize tumor control while limiting radiation toxicity in VS patients.

Hearing Status and Aural Rehabilitative Profile of 878 Patients With Sporadic Vestibular Schwannoma

OBJECTIVES/HYPOTHESIS

To examine the hearing status and aural rehabilitative profile in a national cohort of patients with sporadic vestibular schwannoma (VS).

STUDY DESIGN

Cross-sectional survey METHODS: A cross-sectional survey of Acoustic Neuroma Association members diagnosed with sporadic VS was performed from February 2017 through January 2019. Self-reported results were used to determine the aural rehabilitative profile of respondents.

RESULTS

Among survey respondents, 62.2% (546/878) were not using any hearing-assistive device at time of survey. For the 37.8% (332/878) that were utilizing hearing-assistive devices, 32.8% (109/332) reported using a behind-the-ear hearing aid, 23.8% (79/332) used a contralateral routing of signal (CROS) hearing aid, and 21.7% (72/332) used a bone conduction device. Notably, 41.9% (278/663) of patients who previously underwent tumor treatment reported utilizing a hearing rehabilitation device at some point during VS management compared to 27.0% (58/215) of those undergoing observation with serial imaging (P < .001). Of 275 patients with functional hearing in the ipsilateral ear, 26.5% (73/275) reported having used at least one type of hearing device; 24.0% (66/275) reported use of a conventional hearing aid, 0.7% (2/275) a CROS aid, and 0.4% (1/275) a bone conduction device. Among respondents reporting ipsilateral nonfunctional hearing, 44.9% (258/575) reported having used at least one type of hearing device; 13.0% (75/575) a CROS aid, and 12.3% (71/575) a bone conduction device.

CONCLUSIONS

Even among a cohort with presumably elevated literacy surrounding hearing rehabilitation options, few patients with a history of unilateral vestibular schwannoma ultimately use hearing assistive devices long-term, suggesting that most patients sufficiently adjust to unilateral hearing loss or are unsatisfied with the benefits achieved with current device options.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1378-1381, 2021.

Patient-reported factors that influence the vestibular schwannoma treatment decision: a qualitative study

Purpose

In cases of small- to medium-sized vestibular schwannomas, three management strategies can be opted for: active surveillance, surgery or radiotherapy. In these cases, the patient’s preference is pivotal in decision-making. The aim of this study was to identify factors that influence a patient’s decision for a particular management strategy.

Methods

A qualitative inductive thematic analysis was performed based on semi-structured interviews. Eighteen patients with small- to medium-sized vestibular schwannomas were interviewed. All patients were diagnosed or treated at one of the two participating university medical centers in the Netherlands.

Results

Ten themes were identified that influenced the decision, classified as either medical or patient-related. The medical themes that emerged were: tumor characteristics, the physician’s recommendation, treatment outcomes and the perceived center’s experience. The patient-related themes were: personal characteristics, anxiety, experiences, cognitions, logistics and trust in the physician.

Conclusion

Knowledge of the factors that influence decision-making helps physicians to tailor their consultations to arrive at a true shared decision on vestibular schwannoma management.

Hemorrhagic Vestibular Schwannoma: Case Report and Literature Review of Incidence and Risk Factors

Hemorrhagic vestibular schwannoma (HVS) consisting of acute intratumoral and subarachnoid hemorrhage presents with acute nausea, vomiting, facial numbness, headache, loss of consciousness, and significant functional impairment of the facial and vestibulocochlear nerves. The current case is of a 31-year-old man who was presented with acute left lateral suboccipital headache, vomiting, ataxia, and loss of consciousness. Brain CT revealed a large iso-intense lesion with internal hematoma at the left cerebellopontine angle in association with internal acoustic canal dilation. In addition, MRI confirmed a 32 x 25 x 26 mm vestibular schwannoma (VS) with 20 x 15 x 5 mm intratumoral hematoma. The patient had undergone left lateral suboccipital craniotomy and microscopic tumor resection. Pathological findings revealed that his lesions were VS. The average incidence of HVS is around 2.15 cases per year worldwide. Therefore, HVS incidence in proportion to VS is very low and consequently rare.

A Novel Imaging Grading Biomarker for Predicting Hearing Loss in Acoustic Neuromas

PURPOSE

The aim of this study was to investigate an imaging biomarker based on contrast enhanced T1-weighted and T2-weighted magnetic resonance imaging (MRI) to determine the hearing loss related to acoustic neuromas (AN).

METHODS

In this retrospective study, 441 acoustic neuromas treated with microsurgery were included. The diagnostic and follow-up MRI and audiometry of these patients were compared.

RESULTS

We discovered a new MRI grading biomarker based on the percentage of tumor filling the inner auditory canal (TFIAC classification). The area under the receiver operating characteristics (AUROC) curve was highest for TFIAC (0.675), followed by period of observation (0.615) and tumor size (0.6) (P < 0.001). The percentage of patients in TFIAC grade III (90.1%) experiencing hypoacusis prior to microsurgery was significantly higher than that in TFIAC grade I (72.7%, P = 0.037) and TFIAC grade IV patients had a higher rate of non-serviceable hearing compared to TFIAC grade III patients (P < 0.001). During the follow-up, TFIAC grade IV patients experienced a significantly higher rate of non-serviceable hearing than TFIAC grade III patients in all ANs (P < 0.001) and in serviceable hearing acoustic neuroma cases prior to surgery (TFIAC grade IV 55.4%, TFIAC grade III 69.0%, P = 0.045). The TFIAC grade IV patients experienced a significantly higher rate of facial nerve dysfunction than TFIAC grade III patients after surgery (grade IV 48.0%, grade III 26.1%, P < 0.001).

CONCLUSION

The TFIAC classification serves as a potential imaging biomarker for preoperative and postoperative hearing prediction in ANs, which may aid neurosurgeons in predicting hearing loss and selecting optimal surgical strategies.

Disease-Specific Quality of Life in Vestibular Schwannoma: A National Cross-sectional Study Comparing Microsurgery, Radiosurgery, and Observation

OBJECTIVE

To examine the impact of treatment on disease-specific health-related quality of life (HRQOL) among patients with sporadic vestibular schwannoma (VS).

STUDY DESIGN

National cross-sectional study.

SETTING

Tertiary referral center and the Acoustic Neuroma Association.

SUBJECTS AND METHODS

Adult patients with VS who completed the Penn Acoustic Neuroma Quality of Life (PANQOL) survey. Patients were classified by treatment at the most recent survey as microsurgery, radiosurgery, observation, or recently diagnosed (RD). PANQOL scores were compared among VS treatment groups and with nontumor controls using analysis of covariance.

RESULTS

A total of 1362 respondents with VS were analyzed. Total PANQOL scores differed significantly by treatment (P = .024) with adjusted means of 60, 63, 65, and 62 for the microsurgery, radiosurgery, observation, and RD groups, respectively. Subdomain scores for facial function, balance, hearing loss, and pain differed significantly (P < .05) by treatment. Comparisons that surpassed thresholds for clinical significance included microsurgery compared to radiosurgery and observation for facial function, microsurgery compared to observation and RD for hearing loss, and microsurgery compared to radiosurgery and observation for pain. Subdomain scores for anxiety, facial function, balance, hearing loss, energy, and pain and total PANQOL scores for nontumor controls were significantly higher (ie, more favorable) compared to the VS groups (P < .05). General health scores did not differ significantly between the nontumor controls and the VS groups (P = .19).

CONCLUSION

Differences in HRQOL among treatment modalities are small and variably exceed the minimal clinically important difference. The impact of a VS diagnosis on HRQOL supersedes that of the treatment type.

Classification of Tinnitus: Multiple Causes with the Same Name

Tinnitus is spoken of as if it were a single thing, but there are many different causes, likely many different mechanisms, and many different subtypes. This article reviews a broad range of approaches to understand and demarcate different tinnitus subtypes, which will be critical for exploring and finding cures for different subtypes.

Gamma knife surgery in the treatment of intracanalicular vestibular schwannomas

OBJECTIVE

According to the literature, gamma knife surgery (GKS) is a promising method for intracanalicular vestibular schwannoma (IVS) management, providing excellent tumor growth control rates (91%-100%) and good hearing preservation rates (41%-76%), but this evidence originates primarily from a small series of patients. The aim of this study was to present the outcomes of GKS in the largest group of patients with IVS studied to date, with particular emphasis on the long-term outcomes of treatment.

METHODS

The study included 136 consecutive patients with unilateral IVS, who underwent GKS in 2011-2015. Mean age of the patients was 54 ± 12.6 years. All patients were operated on with a 192-source cobalt-60 gamma knife unit. All patients had complete follow-up documentation and the mean duration of the follow-up was 52 ± 13.8 months (6-83 months). Neurological status (facial and trigeminal nerve), hearing and instability/dizziness presence were determined prior to GKS, immediately after the procedure, and during the follow-up visits.

RESULTS

Tumor growth control was obtained in 124/136 (~91.2%) patients. Hearing improvement was observed in 32/136 (23.5%) patients, and there was a distinct cluster of 9 patients (6.6%) regaining serviceable hearing after GKS, whereas in 36 patients (26.5%) was stable. Four patients developed facial nerve dysfunction, including 3 periodic hemifacial spasm and 1 partial paresis, which resolved spontaneously within 12 months of GKS. None of the operated patients showed new, debilitating neurological deficits, including trigeminal sensory disturbances or hydrocephalus.

CONCLUSIONS

GKS is a highly effective treatment for IVS, associated with low morbidity and good tumor growth control.

Therapy of Sporadic and NF2-Related Vestibular Schwannoma

Vestibular schwannoma (VS) is a benign primary brain tumor that occurs sporadic or as part of a genetic syndrome. The most common cause is the mutation of the NF2 tumor suppressor gene that is involved in the production of the protein merlin. Merlin plays a role in cell growth and cell adhesion. In patients with NF2, the VSs arise bilaterally and coincide with other brain tumors. In sporadic VS, the tumor is typically unilateral and does not coincide in combination with other tumors. MRI is the standard imaging technique and can be used to assess the size and aspect of the tumor as well as the progression of disease. The preferred management of large VS in both VS types is surgery with or without adjuvant radiation. The management for the medium- or small-sized VS includes wait and scan, radiotherapy and/or surgery. This choice depends on the preference of the patient and institutional protocols. The outcomes of surgical and radiotherapy treatments are improving due to progress in surgical equipment/approaches, advances in radiation delivery techniques and dose optimizations protocols. The main purpose of the management of VS is preserving function as long as possible in combination with tumor control.

Stereotactic radiosurgery for management of vestibular schwannoma: a short review

Management options for newly diagnosed vestibular schwannoma (VS) include observation, surgery, or radiation. There are no randomized trials to guide management of patients with VS. This article is a short review of the role of stereotactic radiosurgery in management of newly diagnosed VS.

Incidental Effect of Long-Term Tacrolimus Treatment on Sporadic Vestibular Schwannoma Volume Shrinkage and Clinical Improvement

OBJECTIVE

We describe the effect of long-term tacrolimus delivery on sporadic vestibular schwannoma (VS).

PATIENT

A 48-year-old woman who was diagnosed a right VS.

INTERVENTION

Long-term tacrolimus delivery following liver transplant.

MAIN OUTCOME MEASURES

Clinical examination, audiometric test, and gadolinium-contrasted magnetic resonance imaging.

RESULTS

During the reported follow-up period, the patient felt hearing improvement especially in noisy environment. This was consistent with a clear audiometric improvement. Over a 26 months follow-up period, we noticed a 50% volume regression and a 40% decrease in the intensity of enhancement of the tumor after gadolinium injection.

CONCLUSION

Tacrolimus, an immunosuppressant used to prevent rejection in organ transplant, could lead to VS volume shrinkage and hearing improvement. Tacrolimus could be an interesting new therapeutic weapon, especially for VS in Neurofibromatosis type 2.

Quality of Life Within the First 6 Months of Vestibular Schwannoma Diagnosis With Implications for Patient Counseling

OBJECTIVE

To evaluate quality-of-life (QOL) in patients with sporadic vestibular schwannoma (VS) with particular focus on those recently diagnosed.

STUDY DESIGN

Cross-sectional survey, Penn Acoustic Neuroma Quality of Life (PANQOL) instrument.

SETTING

Acoustic Neuroma Association and a single tertiary referral center.

PATIENTS

Patients with sporadic VS.

MAIN OUTCOME MEASURES

Domain-specific and total PANQOL scores comparing treatment modalities after adjusting for baseline covariates of interest.

RESULTS

Among all 1,288 respondents there were 229 (18%) who were recently diagnosed and had not yet selected a treatment modality, 303 (24%) who were observed, 185 (14%) who underwent radiosurgery alone, 507 (39%) who underwent microsurgery alone, and 64 (5%) who underwent radiosurgery and microsurgery. After adjusting for covariates of interest, total PANQOL scores were highest for the observation cohort (65; 95% CI 62-68), lowest for patients treated with multimodality therapy (56; 51-61) and those recently diagnosed (58; 55-62), and intermediate for those who received microsurgery alone (60; 58-62) and radiosurgery alone (61; 57-64) (global comparison, p = 0.001). When comparing groups that received single-modality therapy, there were no statistically significant differences in total PANQOL scores at short (0-5 yr), intermediate (6-10 yr), or long-term (≥11 yr) follow-up after adjusting for baseline covariates (all, p > 0.05).

CONCLUSION

A new diagnosis of VS frequently imparts significant anxiety on the patient and leads to a temporary reduction in QOL. Notably, anxiety domain QOL scores among patients with newly diagnosed VS are poorer than patients who have observed their tumor for 6 months or longer. When feasible, an initial period of observation may afford patients valuable time to reconcile with the new diagnosis, to learn more about treatment options, and to discover whether there is tumor growth. In turn, this valuable information can be used to inform sound decision-making regarding tumor management.

Can an Imaging Marker of Consistency Predict Intraoperative Experience and Clinical Outcomes for Vestibular Schwannomas? A Retrospective Review

Objective  The main purpose of this article is to determine if vestibular schwannoma consistency as determined by tissue intensity on T2-weighted magnetic resonance imagings (MRIs) is predictive of intraoperative experience and postoperative clinical outcomes. Study Design  Retrospective chart review. Setting  Tertiary referral center. Patients  Seventy-seven patients diagnosed with vestibular schwannomas who were treated with microsurgical resection. Intervention  Diagnostic. Main Outcome Measures  Intraoperative measures include totality of resection, surgical time and cranial nerve VII stimulation and postoperative measures include House-Brackmann grade and perioperative complications. Results  Tumor consistency determined via tissue intensity on MRI was only found to correlate with surgical time, with a softer tumor being associated with a longer surgical time ( p  < 0.0001). However, this was primarily driven by tumor volume with larger tumors being associated with longer surgical time based on multivariate analysis. None of the other intraoperative or postoperative measures considered were found to correlate with tumor consistency. Conclusions  Tumor consistency determined by MRI is not predictive of intraoperative experience or postoperative outcomes in vestibular schwannomas. Tumor volume is the strongest driver of these outcome measures as opposed to tumor consistency.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Hearing Preservation Outcomes in Patients With Sporadic Vestibular Schwannomas

Question 1

What is the overall probability of maintaining serviceable hearing following stereotactic radiosurgery utilizing modern dose planning, at 2, 5, and 10 yr following treatment?

Recommendation

Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled that there is moderately high probability (>50%-75%) of hearing preservation at 2 yr, moderately high probability (>50%-75%) of hearing preservation at 5 yr, and moderately low probability (>25%-50%) of hearing preservation at 10 yr.

Question 2

Among patients with AAO-HNS (American Academy of Otolaryngology-Head and Neck Surgery hearing classification) class A or GR (Gardner-Robertson hearing classification) grade I hearing at baseline, what is the overall probability of maintaining serviceable hearing following stereotactic radiosurgery, utilizing modern dose planning, at 2, 5, and 10 yr following treatment?

Recommendation

Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled that there is a high probability (>75%-100%) of hearing preservation at 2 yr, moderately high probability (>50%-75%) of hearing preservation at 5 yr, and moderately low probability (>25%-50%) of hearing preservation at 10 yr.

Question 3

What patient- and tumor-related factors influence progression to nonserviceable hearing following stereotactic radiosurgery using ≤13 Gy to the tumor margin?

Recommendation

Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled regarding the probability of successful hearing preservation based on the following prognostic data: the most consistent prognostic features associated with maintenance of serviceable hearing are good preoperative word recognition and/or pure tone thresholds with variable cut-points reported, smaller tumor size, marginal tumor dose ≤12 Gy, and cochlear dose ≤4 Gy. Age and sex are not strong predictors of hearing preservation outcome.

Question 4

What is the overall probability of maintaining serviceable hearing following microsurgical resection of small to medium-sized sporadic vestibular schwannomas early after surgery, at 2, 5, and 10 yr following treatment?

Recommendation

Level 3: Individuals who meet these criteria and are considering microsurgical resection should be counseled that there is a moderately low probability (>25%-50%) of hearing preservation immediately following surgery, moderately low probability (>25%-50%) of hearing preservation at 2 yr, moderately low probability (>25%-50%) of hearing preservation at 5 yr, and moderately low probability (>25%-50%) of hearing preservation at 10 yr.

Question 5

Among patients with AAO-HNS class A or GR grade I hearing at baseline, what is the overall probability of maintaining serviceable hearing following microsurgical resection of small to medium-sized sporadic vestibular schwannomas early after surgery, at 2, 5, and 10 yr following treatment?

Recommendation

Level 3: Individuals who meet these criteria and are considering microsurgical resection should be counseled that there is a moderately high probability (>50%-75%) of hearing preservation immediately following surgery, moderately high probability (>50%-75%) of hearing preservation at 2 yr, moderately high probability (>50%-75%) of hearing preservation at 5 yr, and moderately low probability (>25%-50%) of hearing preservation at 10 yr.

Question 6

What patient- and tumor-related factors influence progression to nonserviceable hearing following microsurgical resection of small to medium-sized sporadic vestibular schwannomas?

Recommendation

Level 3: Individuals who meet these criteria and are considering microsurgical resection should be counseled regarding the probability of successful hearing preservation based on the following prognostic data: the most consistent prognostic features associated with maintenance of serviceable hearing are good preoperative word recognition and/or pure tone thresholds with variable cut-points reported, smaller tumor size commonly less than 1 cm, and presence of a distal internal auditory canal cerebrospinal fluid fundal cap. Age and sex are not strong predictors of hearing preservation outcome.

Question 7

What is the overall probability of maintaining serviceable hearing with conservative observation of vestibular schwannomas at 2, 5, and 10 yr following diagnosis?

Recommendation

Level 3: Individuals who meet these criteria and are considering observation should be counseled that there is a high probability (>75%-100%) of hearing preservation at 2 yr, moderately high probability (>50%-75%) of hearing preservation at 5 yr, and moderately low probability (>25%-50%) of hearing preservation at 10 yr.

Question 8

Among patients with AAO-HNS class A or GR grade I hearing at baseline, what is the overall probability of maintaining serviceable hearing with conservative observation at 2 and 5 yr following diagnosis?

Recommendation

Level 3: Individuals who meet these criteria and are considering stereotactic radiosurgery should be counseled that there is a high probability (>75%-100%) of hearing preservation at 2 yr, and moderately high probability (>50%-75%) of hearing preservation at 5 yr. Insufficient data were available to determine the probability of hearing preservation at 10 yr for this population subset.

Question 9

What patient and tumor-related factors influence progression to nonserviceable hearing during conservative observation?

Recommendation

Level 3: Individuals who meet these criteria and are considering observation should be counseled regarding probability of successful hearing preservation based on the following prognostic data: the most consistent prognostic features associated with maintenance of serviceable hearing are good preoperative word recognition and/or pure tone thresholds with variable cut-points reported, as well as nongrowth of the tumor. Tumor size at the time of diagnosis, age, and sex do not predict future development of nonserviceable hearing during observation.  The full guideline can be found at: https://www.cns.org/guidelines/guidelines-manage-ment-patients-vestibular-schwannoma/chapter_3.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Multi-option therapy vs observation for small acoustic neuroma: hearing-focused management

The current treatment options for acoustic neuromas (AN) – observation, microsurgery and radiotherapy – should assure no additional morbidity on cranial nerves VII and VIII. Outcomes in terms of disease control and facial function are similar, while the main difference lies in hearing. From 2012 to 2016, 91 of 169 patients (54%) met inclusion criteria for the present study, being diagnosed with unilateral, sporadic, intrameatal or extrameatal AN up to 1 cm in the cerebello-pontine angle; the remaining 78 patients (46%) had larger AN and were all addressed to surgery. The treatment protocol for small AN included observation, translabyrinthine surgery, hearing preservation surgery (HPS) and radiotherapy. Hearing function was assessed according to the Tokyo classification and the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) classification. Sixty-one patients (71%) underwent observation, 19 (22%) HPS and 6 (7%) translabyrinthine surgery; 5 patients were lost to follow-up. Median follow-up was 25 months. In the observation group, 24.6% of patients abandoned the wait-and-see policy for an active treatment; the risk of switching from observation to active treatment was significant for tumour growth (p = 0.0035) at multivariate analysis. Hearing deteriorated in 28% of cases without correlation with tumour growth; the rate of hearing preservation for classes C-D was higher than for classes A-B (p = 0.032). Patients submitted to HPS maintained an overall preoperative hearing class of Tokyo and AAO-HNS in 63% and 68% of cases, respectively. Hearing preservation rate was significantly higher for patients presenting with preoperative favourable conditions (in-protocol) (p = 0.046). A multi-option management for small AN appeared to be an effective strategy in terms of hearing outcomes.

Severity of Tinnitus Distress Negatively Impacts Quality of Life in Patients With Vestibular Schwannoma and Mimics Primary Tinnitus

Objective: Quality of life (QoL) and subjective symptoms are predominantly used to evaluate treatment outcome of patients with vestibular schwannoma (VS). However, for patients undergoing conservative treatment-the most frequently used intervention-the association between QoL and subjective symptoms is unclear. Moreover, it is unknown whether VS-related tinnitus could be associated with the audiological and psychological status of the patient. Our overall aim is to provide objective evidence of this association to better guide treatment of VS. Methods: In a prospective study, we analyzed factors that influence VS-related tinnitus and QoL in 72 patients receiving conservative management of unilateral sporadic VS. This was done through questionnaires that assessed QoL, anxiety, depression, and audiological examinations. We used the SF-36 Short Form to assess QoL; the Tinnitus Handicap Inventory, Dizziness Handicap Inventory, Facial Clinimetric Evaluation Scale, Visual Analog Scale for hearing impairment to assess symptoms subjectively; and pure tone audiometry, the speech discrimination for hearing measurements. For psychological status, we used the Hospital Anxiety and Depression Scale. For analyses, we used Pearson correlation analysis and multiple regression between variables and QoL. Results: Correlation and regression analyses revealed that the severity of tinnitus distress had the largest negative impact on QoL in all domains of SF-36. The severity of tinnitus was significantly associated with subjective hearing impairment and the degree of depression and anxiety. Hearing thresholds had no statistical association with severity of tinnitus. Conclusions: To our knowledge, this is the first study to investigate VS-related tinnitus with respect to both patients' hearing status and psychological condition. Our results suggest that tinnitus distress strongly affects VS patients' QoL and that its characteristics are similar to primary tinnitus. An intervention for VS-related tinnitus, therefore, should assess to what extent tinnitus bothers patients, and it should reduce any unpleasant emotions that may exacerbate symptoms. This approach should improve their QoL.

In search of the most cost-effective monitoring strategy for vestibular schwannoma: A decision analytical modelling study

Objectives

To assess the cost‐effectiveness of frequently used monitoring strategies for vestibular schwannoma (VS).

Design

A state transition model was developed to compare six monitoring strategies for patients with VS: lifelong annual monitoring; annual monitoring for the first 10 years after diagnosis; scanning at 1‐5, 7, 9, 12, 15 years after diagnosis and subsequently every 5 years; a personalised monitoring strategy for small and large tumours; scanning at 1, 2 and 5 years after diagnosis and no monitoring. Input data were derived from literature and expert opinion. Quality‐adjusted life years (QALYs) and healthcare costs of each strategy were modelled over lifetime. Net monetary benefits (NMBs) were calculated to determine which strategy provided most value for money. Sensitivity analyses were performed to address uncertainty.

Results

Omitting monitoring is least effective with 18.23 (95% CI 16.84‐19.37) QALYs per patient, and lifelong annual monitoring is most effective with 18.66 (95% CI 17.42‐19.65) QALYs. Corresponding costs were €6526 (95% CI 5923‐7058) and €9429 (95% CI 9197‐9643) per patient, respectively. Lifelong annual monitoring provided the best value with a NMB of €363 765 (339 040‐383 697), but the overall probability of being most cost‐effective compared to the other strategies was still only 23%. Sensitivity analysis shows that there is large uncertainty in the effectiveness of all strategies, with largely overlapping 95% confidence intervals for all strategies.

Conclusions

Due to the largely overlapping 95% confidence intervals of all monitoring strategies for VS, it is unclear which monitoring strategy provides most value for money at this moment.

Long-term outcome after Gamma Knife radiosurgery for acoustic neuroma of all Koos grades: a single-center study

OBJECTIVE

The authors present long-term follow-up data on patients treated with Gamma Knife radiosurgery (GKRS) for acoustic neuroma.

METHODS

Six hundred eighteen patients were radiosurgically treated for acoustic neuroma between 1992 and 2016 at the Department of Neurosurgery, Medical University Vienna. Patients with neurofibromatosis and patients treated too recently to attain 1 year of follow-up were excluded from this retrospective study. Thus, data on 557 patients with spontaneous acoustic neuroma of any Koos grade are presented, as are long-term follow-up data on 426 patients with a minimum follow-up of 2 years. Patients were assessed according to the Gardner-Robertson (GR) hearing scale and the House-Brackmann facial nerve function scale, both prior to GKRS and at the times of follow-up.

RESULTS

Four hundred fifty-two patients (81%) were treated with radiosurgery alone and 105 patients (19%) with combined microsurgery-radiosurgery. While the combined treatment was especially favored before 2002, the percentage of cases treated with radiosurgery alone has significantly increased since then. The overall complication rate after GKRS was low and has declined significantly in the last decade. The risk of developing hydrocephalus after GKRS increased with tumor size. One case (0.2%) of malignant transformation after GKRS was diagnosed. Radiological tumor control rates of 92%, 91%, and 91% at 5, 10, and 15 years after GKRS, regardless of the Koos grade or pretreatment, were observed. The overall tumor control rate without the need for additional treatment was even higher at 98%. At the last follow-up, functional hearing was preserved in 55% of patients who had been classified with GR hearing class I or II prior to GKRS. Hearing preservation rates of 53%, 34%, and 34% at 5, 10, and 15 years after GKRS were observed. The multivariate regression model revealed that the GR hearing class prior to GKRS and the median dose to the cochlea were independent predictors of the GR class at follow-up.

CONCLUSIONS

In small to medium-sized spontaneous acoustic neuromas, radiosurgery should be recognized as the primary treatment at an early stage. Although minimizing the cochlear dose seems beneficial for hearing preservation, the authors, like others before, do not recommend undertreating intracanalicular tumors in favor of low cochlear doses. For larger acoustic neuromas, radiosurgery remains a reliable management option with tumor control rates similar to those for smaller acoustic neuromas; however, careful patient selection and counseling are recommended given the higher risk of side effects. Microsurgery must be considered in acoustic neuromas with significant brainstem compression or hydrocephalus.

Cochlear Implantation in Sporadic Vestibular Schwannoma: A Systematic Literature Review

Objective  This study was aimed to perform a systematic literature review by examining outcomes in patients with sporadic vestibular schwannoma (VS) undergoing ipsilateral cochlear implant (CI). Data Sources  PubMed-NCBI (National Center for Biotechnology Information) and Scopus databases were searched through October 2017. Study Selection  Studies reporting auditory outcomes for each patient when a CI was placed with an ipsilateral sporadic VS were included. Main Outcome Measures  Demographic variables, VS characteristics, preoperative hearing metrics, duration of deafness, CI type, approach to tumor resection, postoperative auditory outcomes, and postoperative tinnitus outcomes were reported for each eligible patient within studies. Each study was evaluated for quality and bias. Results  Fifteen studies and 45 patients met inclusion criteria. Mean speech discrimination score (SDS) improved from 30.0 to 56.4% after CI placement. The majority when reported had an improvement in tinnitus. Preoperative ipsilateral SDS was a negative predictor of postoperative SDS, while neither tumor resection status, tumor location, duration of deafness, ipsilateral pure tone average, nor timing of CI placement had a significant effect on patient outcome. Conclusions  Notwithstanding the challenges inherent with surveillance magnetic resonance imaging (MRI) in the setting of a cochlear implant magnet, select sporadic vestibular schwannoma patients can be considered for cochlear implantation.

Hearing preservation in small acoustic neuroma: observation or active therapy? Literature review and institutional experience

BACKGROUND

Current imaging modalities enable early diagnosis of a large number of small acoustic neuromas in patients with well-preserved hearing, whose best management is still a debatable matter.

METHODS

Comparing the hearing outcome of the various therapeutical approaches, including observation, radiosurgery, or resective surgery, is not easy because of the numerous classifications measuring hearing in different ways. In this review, a literature review was performed and papers selected dealing with small tumors, short- and long-term hearing, tumor control or radical resection, and effect of pre-treatment hearing and size on outcome. Two different surgical institutional series of sporadic vestibular schwannomas provided us comparative data on the outcome of observation alone.

RESULTS AND CONCLUSIONS

Our experience suggests that active treatment with hearing preservation surgery, unlike observation alone, offers a better chance of hearing preservation, also enabling a more effective treatment of the tumor and an appropriate rehabilitation with hearing aids or cochlear implants.

Natural History of Sporadic Vestibular Schwannoma: A Volumetric Study of Tumor Growth

Objective

(1) Assess 3-dimensional volumetric growth of untreated sporadic vestibular schwannomas (VSs) in a large cohort of patients treated with conservative observation. (2) Compare volumetric and conventional linear diameter measurements for detecting tumor growth.

Study Design

Case series with chart review.

Setting

Tertiary skull base referral center.

Subjects and Methods

Patients with sporadic VS who elected initial conservative treatment with at least 2 serial magnetic resonance imaging (MRI) scans were included. Tumor volume was determined with 3-dimensional segmentation of MRI sequences. The volumetric threshold for tumor growth was an increase ≥20% from baseline tumor volume. Tumor size based on linear diameter was assessed with the 1995 American Academy of Otolaryngology—Head and Neck Surgery Foundation guidelines for VS outcome reporting, with growth defined as an increase ≥2 mm.

Results

A total of 361 patients were included with a median radiologic follow-up of 4.1 years (interquartile range [IQR], 2.5-6.8). At diagnosis, 232 VSs (64%) were purely intracanalicular, and 129 (36%) extended into the cerebellopontine angle. The median baseline tumor volume was 0.161 cm3 (IQR, 0.054-0.418). Overall, 69% of tumors demonstrated volumetric growth at a median of 1.1 years (IQR, 0.6-2.1) after initial MRI. In contrast, based on linear measurement assessment, 48% of tumors demonstrated growth at a median of 1.8 years (IQR, 0.8-3.1) from first MRI scan. Disequilibrium, facial hypoesthesia, aural fullness, initial tumor size, and nonincidental diagnosis were associated with tumor growth.

Conclusion

Three-dimensional volumetric assessment of VS provides a more sensitive measure of tumor growth when compared with linear diameter assessment. Through volumetric analysis, the current study revealed that a significant proportion of VSs demonstrate growth during observation.

Patient Motivation and Long-Term Satisfaction with Treatment Choice in Vestibular Schwannoma

OBJECTIVES

To ascertain primary motivation and long-term satisfaction with treatment selection in patients with vestibular schwannoma.

METHODS

A multicenter, cross-sectional survey was performed. Patients with small- to medium-sized sporadic vestibular schwannoma who underwent stereotactic radiosurgery (SRS; n = 247), microsurgery (n = 144), or observation (n = 148) between 1998 and 2008 were surveyed regarding their motivation behind treatment selection and hindsight satisfaction with their choice of management.

RESULTS

"Physician recommendation" was the most commonly stated reason for modality selection in all 3 groups. The second and third most common reasons for selecting SRS included "less invasive option than surgery" in 80 patients (32%) and "less recovery time than surgery" in 16 patients (6%). The second and third most common reasons for selecting observation included "to avoid side-effects of treatment" in 25 patients (17%) and "symptoms not severe enough to warrant intervention" in 22 patients (15%). The second and third most common reasons for selecting microsurgery included "do not want tumor in head" in 35 patients (24%) and "most definitive treatment" in 15 patients (10%). Overall, 232 patients (96%) treated with SRS, 141 observed patients (97%), and 121 patients (85%) who underwent microsurgical treatment were satisfied with their original decision (P < 0.001).

CONCLUSIONS

Motivation behind treatment selection varies between individuals. Those who select observation and SRS commonly reference less invasiveness and lower risk, whereas those who select microsurgery are commonly motivated by having their tumor physically removed and the more definitive nature of treatment. Posttreatment satisfaction is highest in patients who undergo SRS and observation, although all 3 groups report high levels of satisfaction.

A Cross-sectional Survey of the North American Skull Base Society: Current Practice Patterns of Vestibular Schwannoma Evaluation and Management in North America

Background  Very few studies have examined vestibular schwannoma (VS) management trends across centers and between providers. The objective of this study is to examine current practice trends, variance in treatment philosophies, and nuanced or controversial aspects of VS care across North America. Methods  This is a cross-sectional survey of North American Skull Base Society (NASBS) members who report regular involvement in VS care. Results  A total of 57 completed surveys were returned. Most respondents claimed to have over 20 years of experience and the majority reported working in an academic practice with an affiliated otolaryngology and/or neurosurgery residency program. Sixty-three percent of respondents claimed to evaluate VS patients in clinic with both an otolaryngologist and neurosurgeon involved. Eighty-six percent of respondents claimed to operate on VS with both an otolaryngologist and neurosurgeon involved, while only 18% of neurosurgeons and 9% of otolaryngologists performed surgery alone. There was a wide range in the number of cases evaluated at each center annually. Similarly, there was wide variation in the number of patients treated with microsurgery and radiation at each center. Additional details regarding management preferences for microsurgery, stereotactic radiosurgery, stereotactic radiotherapy, and conservative observation are presented. Conclusion  VS management practices vary between providers and centers. Overall, most centers employ a multidisciplinary approach to management with collaboration between otolaryngology and neurosurgery. Overall, survey responses concur with previous studies suggesting a shift toward conservatism in management.

A Unified Methodological Framework for Vestibular Schwannoma Research

Vestibular schwannomas are the most common neoplasms of the cerebellopontine angle, making up 6-8% percent of all intracranial growths. Though these tumors cause sensorineural hearing loss in up to 95% of affected individuals, the molecular mechanisms underlying this hearing loss remain elusive. This article outlines the steps established in our laboratory to facilitate the collection and processing of various primary human tissue samples for downstream research applications integral to the study of vestibular schwannomas. Specifically, this work describes a unified methodological framework for the collection, processing, and culture of Schwann and schwannoma cells from surgical samples. This is integrated with parallel processing steps now considered essential for current research: the collection of tumor and nerve secretions, the preservation of RNA and the extraction of protein from collected tissues, the fixation of tissue for the preparation of sections, and the exposure of primary human cells to adeno-associated viruses for application to gene therapy. Additionally, this work highlights the translabyrinthine surgical approach to collect this tumor as a unique opportunity to obtain human sensory epithelium from the inner ear and perilymph. Tips to improve experimental quality are provided and common pitfalls highlighted.