Does where you live influence how your vestibular schwannoma is managed? Examining geographical differences in vestibular schwannoma treatment across the United States

Health-Related Quality of Life in Patients With a Stable or Growing Vestibular Schwannoma Managed by Wait and Scan or Stereotactic Radiosurgery

OBJECTIVE

To assess the effect of wait and scan (W&S) and stereotactic radiosurgery (SRS) on health-related quality of life (HRQoL) over time in patients with a stable vestibular schwannoma (VS) and growing VS.

STUDY DESIGN

Longitudinal, multicenter, observational study.

SETTING

Tertiary expert center for VS (Radboudumc Nijmegen) and Gamma-Knife center ETZ Hospital Tilburg.

METHODS

Changes in HRQoL, measured with the Penn Acoustic Neuroma Quality-of-Life (PANQOL), and the physical and mental component summary scores (PCS and MCS, respectively) derived from the 36-Item Short Form Health Survey (SF-36), were compared among patients managed by W&S and SRS between 2017 and 2022. Second, HRQoL over time in patients with a growing VS was compared between W&S and SRS.

RESULTS

Differences in PANQOL total and subdomain scores, PCS and MCS scores over time in the W&S (n = 73) and SRS (n = 170) groups were nonsignificant and on average did not exceed the minimal clinically important differences (mean difference of -2.56 [PANQOL total], 1.22 [PCS], and -1.76 [MCS]; all P > .05). In growing VS, comparison of W&S (n = 29) and SRS (n = 154) also revealed no significant difference (mean difference of 1.19 (PANQOL total), 1.83 (PCS) and -0.12 (MCS); all P > .05).

CONCLUSION

Differences in HRQoL in patients with VS are minor and not significantly different or clinically relevant between patients managed with W&S or SRS. Similarly, patients with a growing VS managed with W&S or SRS exhibit no significant or clinical relevant difference in HRQoL during follow-up. This can aid clinicians in the counseling of patients regarding HRQoL when deciding on a management strategy after diagnosis or documented growth.

Spontaneous Regression of a Large Vestibular Schwannoma: Is Nonoperative Management Reasonable?

Vestibular schwannomas (VSs) are the most common cerebellopontine tumors. The natural history of smaller-sized VSs (<30 mm) has been well-studied, leading to the recommendation of a "watch and wait" approach. However, large VSs (>30 mm) have not been extensively studied, mainly because of their rarity. As such, most patients are conventionally offered surgery which carries a significant risk of neurological morbidity. Here, we report a case of a giant VS (>40 mm) in a 30-year-old man who regressed spontaneously. He was lost to follow-up for 18 years and, upon re-presentation, the symptomatology drastically improved and repeat imaging demonstrated a marked reduction in tumor size. Referring to similar cases in other studies, we postulate that most large and giant VSs undergo a phase of growth and stasis, followed by regression due to shifts in the balance between tumorigenic and regressive factors. Taken together with emerging molecular data, further studies are required to better understand the history of large and giant VSs to shape more personalized treatment options. This potentially includes non-operative management as a tenable option.

Management of sporadic intracanalicular vestibular schwannomas: A critical review and International Stereotactic Radiosurgery Society (ISRS) practice guidelines

BACKGROUND

The choice of an appropriate strategy for intracanalicular vestibular schwannoma (ICVS) is still debated. We conducted a systematic review and meta-analysis with the aim to compare treatment outcomes amongst management strategies (conservative surveillance (CS), microsurgical resection (MR), or stereotactic radiosurgery (SRS)) aiming to inform guideline recommendations on behalf of the International Stereotactic Radiosurgery Society (ISRS).

METHODS

Using PRISMA guidelines, we reviewed manuscripts published between January 1990 and October 2021 referenced in PubMed or Embase. Inclusion criteria were peer-reviewed clinical studies or case series reporting a cohort of ICVS managed with CS, MR, or SRS. Primary outcome measures included tumor control, the need for additional treatment, hearing outcomes, and posttreatment neurological deficits. These were pooled using meta-analytical techniques and compared using meta-regression with random effect.

RESULTS

Forty studies were included (2371 patients). The weighted pooled estimates for tumor control were 96% and 65% in SRS and CS series, respectively (P < .001). Need for further treatment was reported in 1%, 2%, and 25% for SRS, MR, and CS, respectively (P = .001). Hearing preservation was reported in 67%, 68%, and 55% for SRS, MR, and CS, respectively (P = .21). Persistent facial nerve deficit was reported in 0.1% and 10% for SRS and MR series, respectively (P = .01).

CONCLUSIONS

SRS is a noninvasive treatment with at least equivalent rates of tumor control and hearing preservation as compared to MR, with the caveat of better facial nerve preservation. As compared to CS, upfront SRS is an effective treatment in achieving tumor control with similar rates of hearing preservation.

Upfront Radiosurgery vs a Wait-and-Scan Approach for Small- or Medium-Sized Vestibular Schwannoma: The V-REX Randomized Clinical Trial

Importance

Current guidelines for treating small- to medium-sized vestibular schwannoma recommend either upfront radiosurgery or waiting to treat until tumor growth has been detected radiographically.

Objective

To determine whether upfront radiosurgery provides superior tumor volume reduction to a wait-and-scan approach for small- to medium-sized vestibular schwannoma.

Design, Setting, and Participants

Randomized clinical trial of 100 patients with a newly diagnosed (<6 months) unilateral vestibular schwannoma and a maximal tumor diameter of less than 2 cm in the cerebellopontine angle as measured on magnetic resonance imaging. Participants were enrolled at the Norwegian National Unit for Vestibular Schwannoma from October 28, 2014, through October 3, 2017; 4-year follow-up ended on October 20, 2021.

Interventions

Participants were randomized to receive either upfront radiosurgery (n = 50) or to undergo a wait-and-scan protocol, for which treatment was given only upon radiographically documented tumor growth (n = 50). Participants underwent 5 annual study visits consisting of clinical assessment, radiological examination, audiovestibular tests, and questionnaires.

Main Outcomes and Measures

The primary outcome was the ratio between tumor volume at the trial end at 4 years and baseline (V4:V0). There were 26 prespecified secondary outcomes, including patient-reported symptoms, clinical examinations, audiovestibular tests, and quality-of-life outcomes. Safety outcomes were the risk of salvage microsurgery and radiation-associated complications.

Results

Of the 100 randomized patients, 98 completed the trial and were included in the primary analysis (mean age, 54 years; 42% female). In the upfront radiosurgery group, 1 participant (2%) received repeated radiosurgery upon tumor growth, 2 (4%) needed salvage microsurgery, and 45 (94%) had no additional treatment. In the wait-and-scan group, 21 patients (42%) received radiosurgery upon tumor growth, 1 (2%) underwent salvage microsurgery, and 28 (56%) remained untreated. For the primary outcome of the ratio of tumor volume at the trial end to baseline, the geometric mean V4:V0 was 0.87 (95% CI, 0.66-1.15) in the upfront radiosurgery group and 1.51 (95% CI, 1.23-1.84) in the wait-and-scan group, showing a significantly greater tumor volume reduction in patients treated with upfront radiosurgery (wait-and-scan to upfront radiosurgery ratio, 1.73; 95% CI, 1.23-2.44; P = .002). Of 26 secondary outcomes, 25 showed no significant difference. No radiation-associated complications were observed.

Conclusion and relevance

Among patients with newly diagnosed small- and medium-sized vestibular schwannoma, upfront radiosurgery demonstrated a significantly greater tumor volume reduction at 4 years than a wait-and-scan approach with treatment upon tumor growth. These findings may help inform treatment decisions for patients with vestibular schwannoma, and further investigation of long-term clinical outcomes is needed.

Trial Registration

ClinicalTrials.gov Identifier: NCT02249572.

Neurotology Workforce in the United States: Gender Diversity and Geographic Distribution

OBJECTIVE

The workforce of neurotology has changed with increasing numbers of accredited programs and diverse representation among trainees over the past several decades. This study aims to describe the characteristics, density, and geographic variation of the current neurotology workforce in the United States.

STUDY DESIGN

Cross-sectional study.

SETTING

American Board of Otolaryngology-Head and Neck Surgery portal and online search.

METHODS

The study cohort included physicians certified in Neurotology by the American Board of Otolaryngology as of 2021 (n = 372). Physician characteristics including years of practice, gender, practice setting, and location were collected. Geographic variation analysis was performed by the state, county, and hospital referral region. Associations between the number of neurotologists per population and socioeconomic characteristics were assessed using multivariable regression analysis.

RESULTS

Among 372 neurotologists, 65% practiced in academic settings and 13% were female. The percentage of female neurotologists increased from 0% among neurotologists with ≥30 years of practice to 23% among <10 years of practice. There were no differences in a practice setting by gender. The geographical analysis demonstrated that the average number of neurotologists was 1.1 per 1 million Americans. In a multivariable model, the density of neurotologists was significantly higher within counties with the highest quartiles of college education (β = .6 [95% confidence interval, CI: 0.3-0.8]) and income (β = .3 [95% CI: 0.1-0.6]).

CONCLUSION

The number of board-certified neurotologists has gradually increased and there have been trends toward greater gender diversity. The geographical distribution of neurotology practice was concentrated in counties with higher socioeconomic status as expected given the referral-based nature of the subspecialty. There should be efforts to reach out to low socioeconomic communities to ensure equivalent access to neurotological care.

Comparing Patient Satisfaction After Upfront Treatment Versus Wait-and-Scan for Small Sporadic Vestibular Schwannoma

OBJECTIVE

Management of small vestibular schwannoma (VS) remains controversial, as patients are typically candidates for all three management options including microsurgery, stereotactic radiosurgery, or wait-and-scan. This study compares patient satisfaction across treatment modalities in patients with small VS.

STUDY DESIGN

Cross-sectional study.

SETTING

Survey distributed to members of the Acoustic Neuroma Association and Mayo Clinic patients.

METHODS

Patients with small (<1 cm in any location) sporadic VS who completed at least one survey regarding treatment history and patient satisfaction were included.

RESULTS

Among 346 patients with small VS, 106 (31%) underwent microsurgery, 78 (23%) radiosurgery, 152 (44%) wait-and-scan, and 10 (3%) multimodal treatment. Collectively, 307 (89%) patients indicated "Yes, I am happy with my treatment type and in hindsight I would not change anything," and 39 (11%) indicated "No, in hindsight I would have chosen a different treatment type." Satisfaction differed significantly by treatment group with 85, 86, 96, and 40% of patients in the microsurgery, radiosurgery, wait-and-scan, and multimodal groups reporting that they were satisfied with treatment, respectively ( p < 0.001). Satisfaction also differed significantly among those undergoing upfront treatment with microsurgery or radiosurgery (81%), initial wait-and-scan followed by treatment (88%), and wait-and-scan only groups (96%; p = 0.001). Specifically, the wait-and-scan only group demonstrated greater satisfaction compared with the other two treatment strategies ( p < 0.05 for both).

CONCLUSIONS

Patient satisfaction with the management of small VS is generally high. Management with wait-and-scan, even if treatment is eventually pursued, may offer higher patient satisfaction compared with upfront treatment.

Impact of Demographics and Clinical Features on Initial Treatment Pathway for Vestibular Schwannoma

OBJECTIVE

To identify demographic and clinical features impacting initial treatment pathway for vestibular schwannoma.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care academic medical center.

PATIENTS

Patients diagnosed with vestibular schwannoma between 2009 and 2019.

INTERVENTIONS

Observation, stereotactic radiosurgery, or microsurgical resection.

MAIN OUTCOME MEASURES

χ 2 Test, one-way analysis of variance, and multivariate logistic regression were used to correlate demographic and clinical factors with initial treatment pathway for 197 newly diagnosed vestibular schwannoma patients.

RESULTS

Among 197 patients, 93 (47%) were initially treated with observation, 60 (30%) with stereotactic radiation (Gamma Knife) and 44 (22%) with surgical resection. Age univariately had no statistically significant impact on initial pathway, but those undergoing surgery trended toward a younger demographic (49.1 yr [surgery] versus 57.2 yr [observation] versus 59.0 yr [Gamma Knife]). Men were more likely to be initially observed than women ( p = 0.04). Patients initially observed were more likely to have a lower Koos classification ( p < 0.001) and have better tumor-ear hearing ( p = 0.03). Only 34.4% of patients living outside the local geographic region were initially observed compared with 53.0% living locally ( p = 0.055). Surgeon correlated with initial treatment ( p = 0.04) but did not maintain significance when adjusting for hearing level or tumor size. A multiple linear regression model found age, maximum tumor diameter, and Koos class to correlate with initial treatment pathway ( p < 0.0001, r2 = 0.42).

CONCLUSION

Initial treatment pathway for newly diagnosed vestibular schwannoma is impacted by demographic factors such as age, sex, and geographic proximity to the medical center. Clinical features including hearing level and tumor size also correlated with initial treatment modality.

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.

Hearing Preservation in Observed Sporadic Vestibular Schwannoma: A Systematic Review

OBJECTIVE

To characterize the natural history of hearing loss for patients presenting with serviceable hearing (SH) who undergo a wait-and-scan approach for sporadic vestibular schwannoma (VS) using aggregate time-to-event survival analysis.

STUDY DESIGN

Systematic review.

SETTING

Published international English literature, January 1, 2000 to May 31, 2020.

PATIENTS

Patients with sporadic VS entering a wait-and-scan approach with SH at diagnosis.

INTERVENTIONS

Observation with serial MRI and audiometry.

RESULTS

In total, 3,652 patients from 26 studies were included for analysis. Mean age at diagnosis was 58.8 years (SD, 4.1). Mean follow-up was 49.2 months (SD, 26.5). In total, 755 patients (21%) failed conservative treatment and underwent radiosurgery or microsurgery at the time of last follow-up. The average loss to follow-up was 6.9% (SD, 11.1). A total of 1,674 patients had SH at the time of diagnosis. Survival rates for maintaining SH were 96% at 1 year, 77% at 3 years, 62% at 5 years, and 42% at 10 years following diagnosis.

CONCLUSION

In this systematic review, aggregate data from 3,652 patients across 26 studies show consistent patterns in progression of hearing loss during observation for patients with sporadic VS as a function of time. As an easy-toremember conservative benchmark for those presenting with SH at diagnosis: approximately 75% retain SH at 3 years, 60% at 5 years, and 40% at 10 years.

Progression of Hearing Loss in Observed Non-Growing Vestibular Schwannoma

OBJECTIVE

To assess hearing outcomes in observed vestibular schwannoma (VS) with focus on non-growing tumors.

STUDY DESIGN

Retrospective review.

SETTING

Two tertiary neurotology centers.

PATIENTS AND INTERVENTIONS

Patients with sporadic VS undergoing at least 3 years' observation.

MAIN OUTCOME MEASURES

Changes in pure tone averages (PTA) and word recognition scores (WRS) normalized to the contralateral ear.

RESULTS

During the study period, 39 of 105 included patients (37.1%) had tumor growth. Patients with tumor growth had a mean normalized increase in PTA of 8.0 dB HL (p = 0.008) corresponding to a normalized average worsening of their PTA of 1.8 dB per year. Patients with non-growing tumors less than 5 mm in maximal dimension did not have significant ongoing normalized hearing loss (p > 0.05). Patients with non-growing tumors more than or equal to 5 mm had a mean normalized increase in PTA of 7.4 dB HL (p = 0.001) corresponding to an average of 2.0 dB HL per year, which was similar to the loss observed in growing tumors regardless of size (p > 0.05). Normalized decline in PTA of at least 5 dB HL was seen in 72% of patients with growing tumors, 53% of patients with nongrowing tumors more than or equal to 5 mm, and 38% of patients with non-growing tumors less than 5 mm.

CONCLUSIONS

A long-term analysis of hearing outcomes in observed vestibular schwannoma is presented. With observation, VS more than or equal to 5 mm is associated with continued hearing loss even without tumor growth, while non-growing tumors less than 5 mm are not associated with continuing hearing loss. These data inform expectations for observed VS for providers and patients.

Predicting surgical decision-making in vestibular schwannoma using tree-based machine learning

OBJECTIVE

Vestibular schwannomas (VSs) are the most common neoplasm of the cerebellopontine angle in adults. Though these lesions are generally slow growing, their growth patterns and associated symptoms can be unpredictable, which may complicate the decision to pursue conservative management versus active intervention. Additionally, surgical decision-making can be controversial because of limited high-quality evidence and multiple quality-of-life considerations. Machine learning (ML) is a powerful tool that utilizes data sets to essentialize multidimensional clinical processes. In this study, the authors trained multiple tree-based ML algorithms to predict the decision for active treatment versus MRI surveillance of VS in a single institutional cohort. In doing so, they sought to assess which preoperative variables carried the most weight in driving the decision for intervention and could be used to guide future surgical decision-making through an evidence-based approach.

METHODS

The authors reviewed the records of patients who had undergone evaluation by neurosurgery and otolaryngology with subsequent active treatment (resection or radiation) for unilateral VS in the period from 2009 to 2021, as well as those of patients who had been evaluated for VS and were managed conservatively throughout 2021. Clinical presentation, radiographic data, and management plans were abstracted from each patient record from the time of first evaluation until the last follow-up or surgery. Each encounter with the patient was treated as an instance involving a management decision that depended on demographics, symptoms, and tumor profile. Decision tree and random forest classifiers were trained and tested to predict the decision for treatment versus imaging surveillance on the basis of unseen data using an 80/20 pseudorandom split. Predictor variables were tuned to maximize performance based on lowest Gini impurity indices. Model performance was optimized using fivefold cross-validation.

RESULTS

One hundred twenty-four patients with 198 rendered decisions concerning management were included in the study. In the decision tree analysis, only a maximum tumor dimension threshold of 1.6 cm and progressive symptoms were required to predict the decision for treatment with 85% accuracy. Optimizing maximum dimension thresholds and including age at presentation boosted accuracy to 88%. Random forest analysis (n = 500 trees) predicted the decision for treatment with 80% accuracy. Factors with the highest variable importance based on multiple measures of importance, including mean minimal conditional depth and largest Gini impurity reduction, were maximum tumor dimension, age at presentation, Koos grade, and progressive symptoms at presentation.

CONCLUSIONS

Tree-based ML was used to predict which factors drive the decision for active treatment of VS with 80%–88% accuracy. The most important factors were maximum tumor dimension, age at presentation, Koos grade, and progressive symptoms. These results can assist in surgical decision-making and patient counseling. They also demonstrate the power of ML algorithms in extracting useful insights from limited data sets.

Neuro-Ophthalmic Complications of Vestibular Schwannoma Resection: Current Perspectives

Vestibular schwannomas (VSs), also called acoustic neuromas, are benign intracranial neoplasms of the vestibulocochlear (VIII) cranial nerve. Management options include “wait-and-scan,” stereotactic radiosurgery and surgical resection. Due to the proximity of the VIII nerve to the facial (VII) nerve in the cerebello-pontine angle, the VII nerve is particularly vulnerable to the effects of surgical resection. This can result in poor eye closure, lagophthalmos and resultant corneal exposure post VS resection. Additionally, compression from the tumor or resection can cause trigeminal (V) nerve damage and a desensate cornea. The combination of an exposed and desensate cornea puts the eye at risk of serious ocular complications including persistent epithelial defects, corneal ulceration, corneal vascularization, corneal melting and potential perforation. The abducens (VI) nerve can be affected by a large intracranial VS causing raised intracranial pressure (a false localizing sign) or as a result of damage to the VI nerve at the time of resection. Other types of neurogenic strabismus are rare and typically transient. Contralaterally beating nystagmus as a consequence of vestibular dysfunction is common post-operatively. This generally settles to pre-operative levels as central compensation occurs. Ipsilaterally beating nystagmus post-operatively should prompt investigation for post-operative cerebrovascular complications. Papilledema (and subsequent optic atrophy) can occur as a result of a large VS causing raised intracranial pressure. Where papilledema follows surgical resection of a VS, it can indicate that cerebral venous sinus thrombosis has occurred. Poor visual function following VS resection can result as a combination of all these potential complications and is more likely with larger tumors.

Lifetime Cost and Quality-Adjusted Life-Years Across Management Options for Small- and Medium-Sized Sporadic Vestibular Schwannoma

OBJECTIVE

Despite the growing emphasis on healthcare costs, limited data address this aspect of care within the vestibular schwannoma (VS) literature. We sought to determine which strategy confers the lowest lifetime cost and greatest quality-adjusted life-years (QALYs) for patients with small- to medium-sized sporadic VS tumors.

STUDY DESIGN

A Markov model was created to determine the most cost-effective management algorithm. Tumor characteristics, magnetic resonance imaging surveillance schedule, treatment outcomes, and health-related quality of life values were derived from previously published data. Cost estimates were based on CMS Fee Schedule reimbursement rates.

SETTING

Economic Evaluation Service within the Kern Center for the Science of Healthcare Delivery.

PATIENTS

Patients diagnosed with small- to medium-sized sporadic VS.

INTERVENTIONS

Upfront microsurgery following diagnosis, upfront radiosurgery following diagnosis, observation with microsurgery reserved for observed tumor growth, and observation with radiosurgery reserved for observed tumor growth.

RESULTS

Across patient ages at time of diagnosis ranging from 18 to 70 years, observation with subsequent radiosurgery used for tumor growth was the most cost-effective management algorithm while upfront microsurgery was the least. When presented with a hypothetical 50-year-old patient, the strategy with the lowest lifetime cost and highest QALYs was observation with subsequent radiosurgery reserved for tumor growth ($32,161, 14.11 QALY), followed by observation with microsurgery reserved for tumor growth ($34,503, 13.94 QALY), upfront radiosurgery ($43,456, 14.02 QALY), and lastly, upfront microsurgery ($47,252, 13.60 QALY). Sensitivity analyses varying mortality rates, estimated costs, health-related quality of life, and progression to nonserviceable hearing demonstrated consistent ranking among treatments.

CONCLUSIONS

When considering initial management of small- and medium-sized sporadic VSs, neither lifetime cost nor QALYs support upfront microsurgery or radiosurgery, even for younger patients. Initial observation with serial imaging, reserving radiosurgery or microsurgery for patients exhibiting tumor growth, confers the greatest potential for optimized lifetime healthcare cost and QALY outcomes.

The natural history of vestibular schwannoma growth-prospective 40-year data from an unselected national cohort

BACKGROUND

Optimal management of vestibular schwannoma (VS) is still debated and thus international consensus has not been achieved. Treatment options are observation, radiotherapy, and surgery. Knowledge on the natural history of tumor growth is essential for choice of treatment modality. The aim is to present intra-/extrameatal tumor growth and management data from a prospective, unselected national cohort of patients diagnosed with VS during the period 1976-2015.

METHODS

Since 1976, all data from patients diagnosed with sporadic VS in Denmark have been referred to our national treatment center, where they have been entered prospectively into the national database. Data on tumor localization, growth, and treatment were retrieved. Growth definition: >2 mm by linear measurement, in accordance with the Tokyo 2001 consensus-meeting recommendations.

RESULTS

3637 cases of VS were diagnosed, in which 1304 patients had surgery and 21 received radiotherapy post diagnosis. 2312 patients were observed with mean follow-up of 7.33 years. Of these, 434(19%; 102 intra-and 332 extrameatal tumors) changed to active treatment during the observation period due to tumor growth. 5 years after diagnosis, 21% of the intrameatal tumors exhibited growth during observation, whereas 37% of extrameatal tumors had grown, increasing to 25% intrameatal and 42% extrameatal after 10 years. Following growth, the intrameatal tumors were mostly observed further and the extrameatal mostly underwent surgery. Tumor growth occurred mainly within the first 5 years post diagnosis.

CONCLUSION

This natural history study documents the growth occurrence of both intra-and extrameatal VS during the first 12 years after diagnosis and should be used in patient counseling, management, and treatment decision making.

Working Toward Consensus on Sporadic Vestibular Schwannoma Care: A Modified Delphi Study

OBJECTIVE

To address variance in clinical care surrounding sporadic vestibular schwannoma, a modified Delphi study was performed to establish a general framework to approach vestibular schwannoma care. A multidisciplinary panel of experts was established with deliberate representation from key stakeholder societies. External validity of the final statements was assessed through an online survey of registered attendees of the 8th Quadrennial International Conference on Vestibular Schwannoma.

STUDY DESIGN

Modified Delphi method.

METHODS

The panel consisted of 16 vestibular schwannoma experts (8 neurotology and 8 neurosurgery) and included delegates representing the AAOHNSF, AANS/CNS tumor section, ISRS, and NASBS. The modified Delphi method encompassed a four-step process, comprised of one prevoting round to establish a list of focus areas and three subsequent voting rounds to successively refine individual statements and establish levels of consensus. Thresholds for achieving moderate consensus, at ≥67% agreement, and strong consensus, at ≥80% agreement, were determined a priori. All voting was performed anonymously via the Qualtrics online survey tool and full participation from all panel members was required before procession to the next voting round.

RESULTS

Through the Delphi process, 103 items were developed encompassing hearing preservation (N = 49), tumor control and imaging surveillance (N = 20), preferred treatment (N = 24), operative considerations (N = 4), and complications (N = 6). As a result of item refinement, moderate (4%) or strong (96%) consensus was achieved in all 103 final statements. Seventy-nine conference registrants participated in the online survey to assess external validity. Among these survey respondents, moderate (N = 21, 20%) or strong (N = 73, 71%) consensus was achieved in 94 of 103 (91%) statements, and no consensus was reached in 9 (9%). Of the four items with moderate consensus by the expert panel, one had moderate consensus by the conference participants and three had no consensus.

CONCLUSION

This modified Delphi study on sporadic vestibular schwannoma codifies 100% consensus within a multidisciplinary expert panel and is further supported by 91% consensus among an external group of clinicians who regularly provide care for patients with vestibular schwannoma. These final 103 statements address clinically pragmatic items that have direct application to everyday patient care. This document is not intended to define standard of care or drive insurance reimbursement, but rather to provide a general framework to approach vestibular schwannoma care for providers and patients.

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.

Quality of Life in Vestibular Schwannoma Patients: A Longitudinal Study

OBJECTIVE

To examine differences in quality of life in patients with vestibular schwannoma following a single treatment modality: observation, stereotactic radiosurgery (SRS), or microsurgery.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary academic medical center.

PATIENTS

Patients diagnosed with sporadic vestibular schwannoma who had completed at least 2 Penn Acoustic Neuroma Quality of Life (PANQOL) surveys.

INTERVENTIONS

Treatment via SRS, microsurgery, or observation.

MAIN OUTCOME MEASURES

PANQOL total survey and subdomain scores.

RESULTS

One hundred and thirty-four patients (94 observations, 24 SRS, 16 microsurgeries) were included. The mean number of PANQOL surveys completed was 2.8 (range 2-5). The total PANQOL scores were significantly lower in the SRS group, but not the microsurgery group, compared with observation at the time of diagnosis (observation 550.4 ± 58.4; SRS 471.4 ± 37.4; microsurgery 492.6 ± 40.7; p = 0.03). Over time, there were no significant differences in the change of PANQOL scores across the 3 groups (SRS PANQOL score worsened 6.8/year compared with observation, p = 0.3; microsurgery PANQOL score worsened 7.8/year compared with observation, p = 0.5). Anxiety was the only subdomain that significantly worsened over time in the microsurgery group (microsurgery PANQOL score worsened 3.8/year compared with observation; p = 0.009).

CONCLUSION

Despite differences in PANQOL scores at baseline, changes in total PANQOL score over time were not found to be statistically significant, regardless of the treatment group chosen. Overall, these results hold implications for patient counseling when considering treatment choice and quality of life predictions.

Impact of Treatment on Vestibular Schwannoma-Associated Symptoms: A Prospective Study Comparing Treatment Modalities

OBJECTIVE

The degree to which various treatment modalities modify vestibular schwannoma (VS)-associated symptoms has received limited attention. The purpose of this study was to determine how different treatment modalities affect subjective symptoms in those presenting with VS.

STUDY DESIGN

Prospective survey.

SETTING

Tertiary neurotology referral center.

METHODS

Patients with sporadic VS who received treatment at our institution were prospectively surveyed with a VS symptom questionnaire. Those who completed a baseline survey prior to treatment and at least 1 posttreatment survey were included. The prospective survey evaluated the severity of self-reported symptoms (Likert scale, 1-10), including tinnitus, dizziness or imbalance, headaches, and hearing loss.

RESULTS

A total of 244 patients were included (mean age, 57 years). The mean duration of follow-up was 2.1 years, and the median number of surveys completed was 2 (interquartile range, 1-3). Seventy-eight (32%) cases were managed with observation, 118 (48%) with microsurgery, and 48 (20%) with radiosurgery. Multivariable analyses revealed no statistically significant difference in the change in tinnitus (P = .15), dizziness or imbalance (P = 0.66), or headaches (P = .24) among treatment groups. Evaluation of clinically important differences demonstrated that microsurgery leads to significant bidirectional changes in headaches.

CONCLUSIONS

Limited prospective data exist regarding the progression or resolution of subjective symptoms in those presenting with VS. This study suggests that tinnitus, dizziness or imbalance, and headaches are unlikely to be significantly modified by treatment modality and generally should not be used to direct treatment choice.

Regional variation in vestibular schwannoma management and patient support group participation across the United States

PURPOSE

The Acoustic Neuroma Association (ANA) represents the largest existing patient support organization for those diagnosed with vestibular schwannoma (VS) in the United States. Yet, the degree to which the ANA is actually utilized across the country is unknown. Moreover, evidence suggests that there may exist significant regional variation in management practices of VS across the United States.

MATERIALS AND METHODS

Patient participation in the ANA by state and geographical region, as well as their management approach, was reviewed through a cross-sectional survey performed from February 2017 through January 2019, patients diagnosed with sporadic VS.

RESULTS

Among 878 patients studied, the District of Columbia had the largest proportion of ANA patients relative to state population (0.85 per 100,000 persons), followed by New Hampshire (0.74), Maine (0.60), and New Jersey (0.42). Comparatively, Mississippi (0.03), Hawaii (0.07), and Rhode Island (0.09) harbored significantly lower participation rates (p = 0.001). Significant treatment variations were observed across the United States: in Maine, Iowa, Missouri, Kansas, and New Hampshire, an average of 73% (range, 70-75) of patients underwent microsurgery, whereas only 24% (range, 0-35) of patients in Colorado, New York, Massachusetts, Connecticut, and West Virginia underwent microsurgery (p < 0.001). After controlling for patient age and tumor size, patients were significantly more likely to undergo a retrosigmoid approach than the translabyrinthine approach for medium- to large-sized tumors in the Northeast (OR = 4.18; p = 0.001) and Western United States (OR = 2.94; p = 0.009).

CONCLUSIONS

Large regional variation exists surrounding patient participation in the ANA as well as management practices across the United States.

Middle Cranial Fossa Approach to Vestibular Schwannoma Resection in the Older Patient Population

OBJECTIVE

Compare outcomes of middle cranial fossa approach (MCF) to vestibular schwannoma (VS) resection in patients 60 years of age and older to patients under 60.

STUDY DESIGN

Retrospective case series.

SETTING

Tertiary referral center.

PATIENTS

Charts of 216 consecutive VS patients over 18 years of age were reviewed to identify 67 patients who underwent MCF approach to VS resection between 2006 and 2017.

INTERVENTION(S)

Age at time of surgery.

MAIN OUTCOME MEASURE(S)

Measured outcomes included postoperative hearing results, facial nerve function, length of hospital stay, wound complications, cerebrospinal fluid leak, myocardial infarction, cerebrovascular accident, seizure, deep vein thrombosis, 30-day readmission, and return to operating room.

RESULTS

Sixty-seven patients underwent VS resection via MCF approach including 16 patients > = 60 years (mean 64.4 SD 3.3) and 51 patients < 60 years (mean 45.7 SD 10.2). Between these two groups, there were no differences in sex, tumor laterality, tumor size (10.4 mm versus 9.8 mm, p = 0.6), or other demographic characteristics. Postoperatively, there were no differences between groups in complication rates. Rates of HB 1 or 2 facial nerve function were similar (93.8% versus 88.2%, p = 0.7) as were rates of maintenance of class A or B hearing (58.3% versus 44.4%, p = 0.7).

CONCLUSIONS

Patients over 60 undergoing MCF for VS resection experienced similar rates of postoperative complications, facial nerve outcomes, and hearing preservation compared with younger patients. MCF for VS may be considered in the older population. Further research is warranted to evaluate appropriate limitations for this approach based on age.

Hearing and Quality of Life Over Time in Vestibular Schwannoma Patients: Observation Compared to Stereotactic Radiosurgery

OBJECTIVE

To examine quality of life changes for patients with vestibular schwannoma (VS) undergoing observation or stereotactic radiosurgery (SRS).

STUDY DESIGN

Retrospective review.

SETTING

Academic medical center.

PATIENTS

Patients with VS who underwent observation or SRS and had at least two audiograms and Penn Acoustic Neuroma Quality of Life (PANQOL) surveys, a quality of life survey for patients with VS.

INTERVENTIONS

SRS or observation.

MAIN OUTCOME MEASURES

Pure-tone average (PTA), speech discrimination score (SDS), PANQOL score; controlling for tumor size, baseline hearing, and other factors.

RESULTS

One hundred twenty-three patients met inclusion criteria: 89 underwent observation and 34 SRS. There was no significant difference in the rate of decline measured by PTA (PTA worsened at a rate of 0.25 dB/yr more in the observation group compared with the SRS group, p = 0.77) and SDS (SDS worsened at a rate of 2.1%/yr more in the SRS group compared with the observation group, p = 0.82). Kaplan-Meier analysis demonstrated the SRS group had a higher probability to progress to class D hearing over observation (hazard ratio 7.1, p = 0.005). The rate of change of the SRS PANQOL scores was significantly improved in the total (p = 0.005) and hearing (p = 0.04) domain score compared with observation. However, both groups regress to a similar PANQOL total and hearing domain score over time.

CONCLUSION

PANQOL scores were higher at baseline in the observation group than in the SRS group. However, over time, PANQOL scores in the observation group decreased while PANQOL scores in the SRS group increased, resulting in PANQOL scores that were equivalent by the end of follow-up.

The Patient-Centered Approach: A Review of the Literature and Its Application for Acoustic Neuromas

Patient-centered care is defined as "care that is consistent with and respects the values, needs, and wishes of patients" and is best achieved when clinicians involve patients and their support system in health care discussions and decisions. While this approach has been well established and supported in more general medical specialties, such as primary care, that may encompass a more holistic approach, it has rarely been described in surgical disciplines. Acoustic neuromas (ANs) can be unique among other skull base and intracranial pathologies, in that the management of these tumors can vary from patient to patient depending on various factors. Moreover, typical options, including observation, radiation, and surgery, may often have equipoise for some patients and their tumors. Therefore, a patient-centered approach, strongly guided by the expertise of experienced skull base surgeons, may likely be the most appropriate type of care for patients with ANs. Herein, we review the documented use of patient-centered care in other aspects of medicine, propose the benefits of this approach for patients with ANs, and provide ways this can be better implemented in practice.

Repeat Stereotactic Radiosurgery for Progressive or Recurrent Vestibular Schwannomas

BACKGROUND

Stereotactic radiosurgery (SRS) is a highly effective management approach for patients with vestibular schwannomas (VS), with 10-yr control rates up 98%. When it fails, however, few data are available to guide management.

OBJECTIVE

To perform a retrospective analysis of patients who underwent 2 SRS procedures on the same VS to assess the safety and efficacy of this practice.

METHODS

This study was opened to centers of the International Gamma Knife Research Foundation (IGKRF). Data collected included patient characteristics, clinical symptoms at the time of SRS, radiosurgery dosimetric data, imaging response, clinical evolution, and survival. Actuarial analyses of tumor responses were performed.

RESULTS

Seventy-six patients from 8 IGKRF centers were identified. Median follow-up from the second SRS was 51.7 mo. Progression after the first SRS occurred at a median of 43 mo. Repeat SRS was performed using a median dose of 12 Gy. Actuarial tumor control rates at 2, 5, and 10 yr following the second SRS were 98.6%, 92.2%, and 92.2%, respectively. Useful hearing was present in 30%, 8%, and 5% of patients at first SRS, second SRS, and last follow-up, respectively. Seventy-five percent of patients reported stable or improved symptoms following the second SRS. Worsening of facial nerve function attributable to SRS occurred in 7% of cases. There were no reports of radionecrosis, radiation-associated edema requiring corticosteroids, radiation-related neoplasia, or death attributable to the repeat SRS procedure.

CONCLUSION

Patients with progressing VS after radiosurgery can be safely and effectively managed using a second SRS procedure.

Patient Demographics Influencing Vestibular Schwannoma Size and Initial Management Plans

OBJECTIVE

To explore patient demographics as to predicting vestibular schwannoma (VS) size and treatment plan within a single institution.

METHODS

Using a large tertiary referral skull base center database, all patients with sporadic VS who presented to the center between 2009 and 2018 were reviewed.

RESULTS

A total of 816 patients with VS over 18 years of age were included. The median age was 56.8 years (range: 18.6-90.9 years). The median tumor diameter at diagnosis was 11.9 mm (range: 0.6-51.1 mm). With multivariate analysis, older age was associated with decreased tumor size (0.23 mm, 95% confidence interval [CI]: 0.17-0.29), whereas married patients had larger tumors (2.5 mm, 95% CI: 0.92-4.09). When comparing observation, radiation, or surgery, older patients are more likely to pursue observation as compared with surgery and radiation (odds ratio [OR]: 1.08, 95% CI: 1.06-1.10 and OR: 1.20, 95% CI: 1.08-1.33), respectively. Married patients were less likely to pursue observation as compared with surgery (OR: 0.49, 95% CI: 0.29-0.82). Each additional mile a patient lives farther from the center increases his or her odds of pursuing treatment (OR: 1.002, 95% CI: 1.001-1.003).

CONCLUSIONS

Older age is associated with smaller tumors, whereas married patients have larger tumors at diagnosis as compared with nonmarried patients. Furthermore, married patients are more likely to pursue treatment, specifically surgery, as compared with nonmarried patients, whereas patients who live farther from the center are more likely to pursue treatment.

Geographical Differences in Intracranial Meningioma Management: Examining 65,973 Patients across the United States

Background  Age, tumor size and location, overall health, and patient preference are primary considerations driving treatment decision-making for intracranial meningiomas. However, even for the same individual patient, treatment recommendations may vary between centers and providers. Objective  To study associations between geography, disease presentation, and management of intracranial meningioma in the United States. Methods  The population-based Surveillance, Epidemiology, and End Results(SEER) data were queried between 2004 and 2014 for cases of intracranial meningioma. Results  A total of 65,808 patients with intracranial meningioma were identified. Univariate analyses demonstrated strong associations between geographic location, age, and size of tumor at presentation. The mean age for all registries was 64.2 years, with a range from 62.0 (Utah registry) to 66.6 (Detroit registry). The greatest proportion of small tumors (<1 cm) were identified in the Utah registry (13.9% of tumors), while the greatest proportion of large tumors (> 4cm) were noted in the Hawaii registry (30.7% of tumors). Multivariable analysis demonstrated that the impact of geography on treatment selection was just as important as other established variables. For example, the distribution in tumor size between New Mexico and Greater California registries is nearly identical; however, the odds ratio for surgery was 1.5 times greater for the New Mexico population. Conclusion  These data suggest that disease presentation and treatment are significantly influenced by regional referral patterns, provider or institutional treatment preferences, and regional availability of subspecialty expertise. Understanding such biases is important for patients, referring physicians, and treatment providers in an effort to provide balanced counseling and treatment.

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.

Recent Trends in Vestibular Schwannoma Management: An 11-Year Analysis of the National Cancer Database

Objective

A better understanding of the natural history of vestibular schwannoma (VS) has resulted in a change in treatment paradigms. It has also been proposed that increased use of high-resolution magnetic resonance imaging has allowed for an increased identification of small tumors. The aim of this study was to evaluate recent trends in the presentation and primary management of VS in the United States.

Study Design

Retrospective analysis of the National Cancer Database (NCDB).

Setting

NCDB database.

Subjects and Methods

All patients with a diagnosis of VS between 2004 and 2014 were included. Data were analyzed with univariable and multivariable logistic regression.

Results

In total, 28,190 patients (mean age 55 years, 52.9% female) with VS were analyzed. Linear regression showed a small decrease in average tumor size over time (–0.06 mm/year, P = .03). Overall, 11,121 patients (40%) received surgery, 8512 (30%) radiation, and 7686 (27%) observation. Controlling for patient, tumor, and treatment center factors, the odds ratio (OR) for receiving surgery in 2014 was 0.60 (confidence interval [CI], 0.50-0.71) while the OR for receiving radiation was 0.75 (CI, 0.64-0.87) as compared to those diagnosed in 2004. The largest increases in observation rates occurred among tumors ≤2 cm ( P < .001).

Conclusion

There was not a clinically significant change in the average tumor size at diagnosis. Although surgery remained the most common treatment modality in the United States, there was a strong shift in the management of VS away from primary surgery and radiation and toward a “wait-and-scan” approach.

An international comparison of diagnostic and management strategies for vestibular schwannoma

Objective

To compare international diagnostic and management strategies for vestibular schwannoma (VS).

Methods

A web-based questionnaire was sent to 130 otolaryngologists, mainly identified through the European Skull Base Society. It contained questions on general information including guideline usage as well as questions on diagnosis (focussing on selection of patients for MRI) and management of VS, including case scenarios. Descriptive statistics were reported.

Results

Thirty-six otolaryngologists working in 11 different countries completed the questionnaire (response rate: 28%). Guidelines for diagnosis and management of VS are used by 44% and 42% of respondents, respectively. In the diagnostic strategy for VS, different types and combinations of audiovestibular function tests are used when deciding whether a patient should undergo an MRI. Respondents apply 18 different definitions of asymmetrical hearing loss. Variation was also apparent from reported considerations on management of VS. Most respondents (84%) prefer a wait-and-scan strategy in case of a small intrameatal VS (Koos 1). Variety in management strategies increases for patients with a medium to large sized VS (Koos 2, 3 and 4). The details of each management strategy (wait-and-scan, microsurgery, stereotactic radiosurgery and fractionated radiotherapy) also differ among respondents.

Conclusions

A large variation in diagnostic and management strategies for VS was identified between respondents. More evidence and/or consensus seem warranted to reduce uncertainties for patients, and differences in outcome and costs that might result from the variety of strategies currently being applied.

Electronic supplementary material

The online version of this article (10.1007/s00405-018-5199-6) contains supplementary material, which is available to authorized users.

A Cross-Sectional Survey of the North American Skull Base Society Part 3: The State of Lateral Skull Base Surgery Training in North America

Introduction  Optimal management of vestibular schwannoma (VS) demands involvement of an experienced multidisciplinary team. As the number of training programs in neurotology and skull base neurosurgery continues to rise, ensuring that trainees are capable of evidence-based decision-making and treatment, whether microsurgical or radiosurgical, is of paramount importance. The purpose of this study is to characterize the landscape of neurotologic and neurosurgical fellowship training programs in North America, with special reference to VS management. Methods  A 64-item web-based survey assessing VS practice trends was devised by members of the North American Skull Base Society (NASBS) Research Task Force and distributed electronically to NASBS membership via SurveyMonkey as a cross-sectional study. Participation was entirely voluntary and there was no remuneration for survey completion. The survey link was active from November 29 to December 14, 2016. Results  Of 719 members of the NASBS who were emailed a survey link, a total of 57 were returned (8%) completed surveys. Of all respondents, 51 (89%) claimed to have formal training in skull base neurosurgery or neurotology. Thirty-three respondents (65%) were skull base neurosurgeons while the remainder were neurotologists ( n  = 18; 35%). Institutions with fellowship programs tended to have a higher surgical, radiosurgical, and overall case volume than those with a residency program alone. However, 20% of respondents at institutions with fellowship programs reported evaluating less than 50 new diagnoses of VS per year and 12% reported a surgical case volume of less than 10 cases per year. Conclusion  As the number of skull base training programs expands, it is our duty to ensure that trainees gain sufficient experience to enter independent practice with the ability to exercise informed decision-making and safely perform VS surgery and radiosurgery. In the current training climate, implementing multidisciplinary care models, formalized training requirements, and emerging surgical simulators will support the development of minimum proficiencies in VS care.

Knowledge silos: assessing knowledge sharing between specialties through the vestibular schwannoma literature

OBJECTIVEIt is common for a medical disorder to be managed or researched by individuals who work within different specialties. It is known that both neurosurgeons and neurotologists manage vestibular schwannoma (VS) patients. While overlap in specialty focus has the potential to stimulate multidisciplinary collaboration and innovative thinking, there is a risk of specialties forming closed-communication loops, called knowledge silos, which may inhibit knowledge diffusion. This study quantitatively assessed knowledge sharing between neurosurgery and otolaryngology on the subject of VS.METHODSA broad Web of Science search was used to download details for 4439 articles related to VS through 2016. The publishing journal's specialty and the authors' specialties (based on author department) were determined for available articles. All 114,647 of the article references were categorized by journal specialty. The prevalence of several VS topics was assessed using keyword searches of titles.RESULTSFor articles written by neurosurgeons, 44.0% of citations were from neurosurgery journal articles and 23.4% were from otolaryngology journals. The citations of otolaryngology authors included 11.6% neurosurgery journals and 56.5% otolaryngology journals. Both author specialty and journal specialty led to more citations of the same specialty, though author specialty had the largest effect. Comparing the specialties' literature, several VS topics had significantly different levels of coverage, including radiosurgery and hearing topics. Despite the availability of the Internet, there has been no change in the proportions of references for either specialty since 1997 (the year PubMed became publicly available).CONCLUSIONSPartial knowledge silos are observed between neurosurgery and otolaryngology on the topic of VS, based on the peer-reviewed literature. The increase in access provided by the Internet and searchable online databases has not decreased specialty reference bias. These findings offer lessons to improve cross-specialty collaboration, physician learning, and consensus building.

Priorities in the Neurotology Fellowship Match: A Survey Study of Program Directors and Fellows

OBJECTIVES

To ascertain motivations and priorities for neurotology fellowship applicants and program directors during the match process.

METHODS

Anonymous online survey distributed to 20 fellowship program directors and 40 current and incoming neurotology fellows. A 5-point Likert scale was used to assess the priorities of fellowship applicants and program directors in the match process.

RESULTS

Twenty-four of 40 (60%) current or incoming fellows and 14 of 20 (65%) program directors responded to the survey. Fellows rated surgical exposure and volume as their highest priorities. In addition to neurotology case load, fellows highly valued exposure to otologic surgery. Salary, call, and work/life balance were among the lowest rated factors among fellows. Program directors attached the highest priority to the applicant interview performance, followed by strength of letters of recommendation and quality of prior research. Ethnicity, sex, and likelihood of an applicant ranking a program highly were the lowest rated factors among program directors.

CONCLUSION

Among neurotology fellows, operative case load and breadth of surgical exposure are highly valued components of accredited fellowship training. Among neurotology fellowship program directors, candidates' performance during the fellowship interview appears to be highly valued, more so than the strength of applicants' letters of recommendation or prior research credentials.

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 Cross-sectional Survey of the North American Skull Base Society on Vestibular Schwannoma, Part 2: Perioperative Practice Patterns of Vestibular Schwannoma in North America

Introduction  Perioperative care of vestibular schwannoma (VS) patients is extremely variable across surgeons and institutions making practice patterns difficult to standardize. No data currently exist detailing this practice variability. Methods  The North American Skull Base Society membership was electronically surveyed regarding perioperative care of surgically operated VS patients. Results  There were 87 respondents to the survey. Surgical positioning, surgical approach utilized, and perioperative medical adjuncts are quite variable. However, of those performing retrosigmoid approaches, 49% perform this in the supine position, while 33% use a park-bench position with only 2% using the sitting position. In those performing translabyrinthine approaches, 86% perform this in supine position. Although the use of neuromonitoring appears to be standard of care (98%), other than the seventh nerve, there is substantial variability between respondents regarding monitoring of additional cranial nerves. Postoperative antibiotics are used by 65%, postoperative steroids 81%, and postoperative chemical deep vein thrombosis prophylaxis in 68% of survey respondents. Conclusion  Although the perioperative adjuncts to VS surgery are variable, there does appear to be a trend in common practice. Therefore, making surgeons aware of these trends may lead to standardized practice or alternatively trials of these variances to instruct which truly improve patient outcomes.

Geographic distribution of vestibular schwannomas in West Scotland between 2000-2015

Background

Although the natural history of vestibular schwannomas (VS) has been previously studied, few studies have investigated associated epidemiological factors, primarily because of the lack of large available cohorts.

Objective

The objective of this study was to perform a multi-scale geographical analysis of the period prevalence of VS in West Scotland from 2000 to 2015.

Methods

Adults diagnosed with sporadic VS were identified through the National Health Services of West Scotland database and geocoded to the unit postcode. To assess whether the cohort of VS cases could be pooled into a period prevalence measure, the locations of VS cases were analyzed by sex using Cross-L and Difference-K functions. VS period prevalence was examined at two aggregate spatial scales: the postcode district and a coarser scale of NHS Health Boards. The spatial structure of period prevalence within each level of spatial aggregation was measured using univariate global and local Moran’s I. Bivariate local Moran’s I was used to examine the between-scale variability in period prevalence from the postcode district level to the NHS Health Boards levels. Prior to spatial autocorrelation analyses, the period prevalence at the postcode district was tested for stratified spatial heterogeneity within the NHS Health Boards using Wang’s q-Statistic.

Results

A total of 512 sporadic VS were identified in a population of over 3.1 million. Between 2000 and 2015, VS period prevalence was highest within the NHS Health Boards of Greater Glasgow and Clyde, Ayrshire and Arran and the Western Isles. However, at the NHS scale, period prevalence exhibited no spatial autocorrelation globally or locally. At the district scale, Highland exhibited the most unusual local spatial autocorrelation. Bivariate local Moran’s I results indicated general stability of period prevalence across the postcode district to Health Boards scales. However, locally, some postcode districts in Greater Glasgow and Clyde, Ayrshire and Arran exhibited unusually low district to zone spatial autocorrelation in period prevalence, as did the southern parts of the Western Isles. Some unusually high period prevalence values between the postcode district to Health Board scale were found in Tayside, Forth Valley and Dumfries and Galloway.

Conclusion

Geographic variability in VS in West Scotland was identified in this patient population, showing that there are areas, even remote, with unusually high or low period prevalence. This can be partially attributed to links between primary and tertiary care. Potential genetic or environmental risk factors that may contribute to geographic variation in this disease within Scotland are also a possibility but require further investigation.

The Impact of Radiation Oncologists on the Early Adoption of Hypofractionated Radiation Therapy for Early-Stage Breast Cancer

PURPOSE

Despite multiple randomized trials showing the efficacy of hypofractionated radiation therapy in early-stage breast cancer, the United States has been slow to adopt this treatment. The goal of this study was to evaluate the impact of individual radiation oncologists on the early adoption of hypofractionated radiation therapy for early-stage breast cancer.

METHODS

We identified 22,233 Medicare beneficiaries with localized breast cancer that was diagnosed from 2004 to 2011 who underwent breast-conserving surgery with adjuvant radiation. Multilevel, multivariable logistic models clustered by radiation oncologist and geographic practice area were used to determine the impact of the provider and geographic region on the likelihood of receiving hypofractionated compared with standard fractionated radiation therapy while controlling for a patient's clinical and demographic covariates. Odds ratios (OR) describe the impact of demographic or clinical covariates, and the median OR (MOR) describes the relative impact of the individual radiation oncologist and geographic region on the likelihood of undergoing hypofractionated radiation therapy.

RESULTS

Among the entire cohort, 2333 women (10.4%) were treated with hypofractionated radiation therapy, with unadjusted rates ranging from 0.0% in the bottom quintile of radiation oncologists to 30.4% in the top quintile. Multivariable analysis found that the individual radiation oncologist (MOR 3.08) had a greater impact on the use of hypofractionation than did geographic region (MOR 2.10) or clinical and demographic variables. The impact of the provider increased from the year 2004 to 2005 (MOR 2.82) to the year 2010 to 2011 (MOR 3.16) despite the publication of long-term randomized trial results in early 2010. Male physician and radiation oncologists treating the highest volume of breast cancer patients were less likely to perform hypofractionation (P<.05).

CONCLUSIONS

The individual radiation oncologist strongly influenced the likelihood of a patient's receiving hypofractionated radiation therapy, and this trend increased despite the publication of long-term data showing equivalence to standard fractionation. Future research should focus on physician-related factors that influence this decision.