The Long-Term Outcomes of Wait-and-Scan and the Role of Radiotherapy in the Management of Vestibular Schwannomas

Scoring System Assessing Risks of Growth in Sporadic Vestibular Schwannoma

BACKGROUND AND OBJECTIVES

Surveillance studies offer sparse knowledge of predictors of future growth in sporadic vestibular schwannomas (VS).Our aim was identification of these risk factors. We propose a scoring system to estimate the risk of growth in sporadic vestibular schwannoma.

METHODS

This retrospective study is based on the demographic and radiological data of 615 adult patients under the surveillance for single VS in our center. Univariate analysis, multivariate regression, and Kaplan-Meier analysis were used when appropriate. The regression coefficient-based "VS score" was calculated based on Cox proportional-hazards regression.

RESULTS

During surveillance, 285 tumors (46%) remained stable, 314 tumors (51%) grew, and 16 tumors (3%) shrank. The significant risks factors for future growth identified both in univariate and multivariate analyses were younger age at onset, cystic morphology, larger tumor volume, and cisternal location (as per Hannover grade). The proportion of growing tumors was 40%, 75%, and 96% among the homogeneous VS, primary cystic, and VS transformed to cystic, respectively. Moreover, tumor growth during the 1st year was significant predictor of continuous growth. Our "VS score" includes variables such as age, sex, morphology, and Hannover grade. The score extends between -3 and 6 points. Kaplan-Meier, confusion matrix, and receiver operating characteristic analysis proved high accuracy of our scoring model.

CONCLUSION

Our retrospective study revealed that younger age, cystic morphology, cisternal extent, larger volume, and growth during 1st year were strong predictors of future growth. Moreover, we propose a scoring system that accurately estimates the risks of future tumor growth.

Steroid Efficacy on Audiologic Recovery in Patients With Sudden Sensorineural Hearing Loss and Vestibular Schwannoma: A Retrospective Review

OBJECTIVES

The objectives of this study are to (i) estimate the incidence of vestibular schwannoma (VS) among patients in an integrated healthcare system who present for evaluation of sudden sensorineural hearing loss (SSNHL) and (ii) evaluate the efficacy of empiric steroid therapy on audiologic recovery among SSNHL patients ultimately diagnosed with VS.

METHODS

A retrospective chart review was performed on patients presenting with SSNHL in 2021 at a multicenter integrated healthcare system serving over 4 million members. Patient demographics, audiometric data, VS diagnosis, therapeutic steroid intervention, and data regarding treatment response were recorded. A clinically significant audiometric improvement was defined as (i) an increase of 15% in word recognition score, (ii) a decrease of 15 dB in four-frequency pure-tone average (PTA) using frequencies of 500, 1000, 2000, and 4000 Hz, or (iii) a PTA of <20 dB on follow-up audiogram.

RESULTS

Six hundred fifty-eight patients were reviewed, of which 309 (56.0% male; mean, 57.5 years) met the inclusion criteria with audiometric data and magnetic resonance imaging data. Ten patients (70.0% male; mean, 51.3 years) were found to have VS. Of these, five patients received oral steroid therapy alone, and five had combination therapy (oral + intratympanic steroid injections). No patients received intratympanic steroid therapy alone. Median PTA improvement with steroid therapy was 3.1-dB hearing loss, and median word recognition score improvement was 16.5%. Six of 10 patients demonstrated clinically significant audiometric improvement with steroid therapy.

CONCLUSION

This study represents the largest US-based study showcasing the prevalence of VS in patients originally presenting with SSNHL. It also reinforces previous findings that VS does not preclude trials of steroid therapy.

Spontaneous shrinkage of vestibular schwannoma with the recovery of impaired hearing: A case report and literature review

Background

Sporadically occurring vestibular schwannomas (VSs) are the most frequent tumors in the cerebellopontine cistern and internal meatus and are commonly associated with hearing loss. These tumors have demonstrated spontaneous shrinkage rates of 0-22%; however, the relationship between tumor shrinkage and changes in hearing remains unclear.

Case Description

We report a case of a 51-year-old woman with a diagnosis of a left-sided VS and accompanying moderate hearing loss. The patient was treated with a conservative approach for 3 years, and the tumor showed a regression along with an improvement in her hearing ability during the yearly follow-ups.

Conclusion

The spontaneous shrinkage of a VS along with an associated improvement in hearing is a rare phenomenon. Our case study may support that the "wait and scan" approach is an alternative option for patients with VS and moderate hearing loss. Further investigations are needed to understand spontaneous VS regression and hearing changes.

Vestibular Impairment in Patients with Vestibular Schwannoma: A Journey through the Pitfalls of Current Literature

Vestibular Schwannoma is the most common tumour of Ponto Cerebellar Angle and is capable of strongly impacting the patient's quality of life. In recent decades, the proposals for the management of the disease have multiplied, just as the diagnostic capacity has improved. While in the past, the primary objective was the preservation of the facial function, and subsequently also of the auditory function, the attention to the vestibular symptomatology, which appears to be one of the main indicators of deterioration of quality of life, is still unsatisfactory. Many authors have tried to provide guidance on the best possible management strategy, but a universally recognized guideline is still lacking. This article offers an overview of the disease and the proposals which have advanced in the last twenty years, evaluating their qualities and defects in a critical reading.

Management of Vestibular Schwannoma with Normal Hearing

INTRODUCTION

This work aimed to study the management of vestibular schwannoma (VS) patients with normal hearing (NH).

METHODS

A retrospective study was undertaken in a Quaternary referral center for skull base pathologies. Among 4,000 VS patients 162 met our strict audiological criteria for NH. These patients were divided into 2 management groups, wait and scan (W&S) (45/162, 25%) and operated patients (123/162, 75%), and 6 patients were included in both groups.

RESULTS

Our management strategy achieved the goals for treatment of VS. First goal, all tumors were completely removed except for 2 intentional residuals. Second goal, facial nerve (FN) function preservation (House Brackmann I, II, and III) was 95.9%. Third goal, possible hearing preservation (HP) attempts occurred in (50/122) (40.9%) with an HP rate in 44% of the patients. Additionally, there were only 2 cases of postoperative complications with no CSF leakage. The prospect of HP in NH patients did not differ with respect to tumor size. However, patients with normal preoperative ABR seemed to have better chances of HP and good FN function and vice versa. HP rate was superior for the MCFA as opposed to the RS + RLA. W&S group demonstrated hearing stability in 88.9% of the patients and FN function stability of HB I in 100% of the patients.

CONCLUSIONS

Surgical resection is a reasonable and definitive management option for VS with NH. Nevertheless, choosing to manage cases with observation remains an appropriate management option for NH patients. ABR might be considered as an adjuvant tool indicating better prognosis for HP.

Spontaneous Volumetric Tumor Regression During Wait-and-Scan Management of 952 Sporadic Vestibular Schwannomas

OBJECTIVE

Spontaneous tumor shrinkage during wait-and-scan management of sporadic vestibular schwannoma is generally considered an uncommon phenomenon. However, most data informing this understanding stem from single-slice linear tumor measurements taken in the axial imaging plane. The objective of the current work was to characterize the regression capacity of sporadic vestibular schwannomas using volumetric tumor measurements.

STUDY DESIGN

Retrospective cohort study using slice-by-slice, three-dimensional volumetric tumor measurements.

SETTING

Three tertiary referral centers.

PATIENTS

Patients with sporadic vestibular schwannoma.

INTERVENTIONS

Wait-and-scan.

MAIN OUTCOME MEASURES

Regression-free survival rates with regression defined as a decrease of at least 20% of the tumor volume.

RESULTS

Among 952 patients undergoing a total of 3,505 magnetic resonance imaging studies during observation, 123 experienced volumetric tumor regression after diagnosis at a median of 1.2 years (interquartile range, 0.6-2.9 yr). Volumetric regression-free survival rates (95% confidence interval; number still at risk) at 1, 3, and 5 years after diagnosis were 94% (92-95%; 662), 86% (83-89%; 275), and 78% (73-82%; 132), respectively. Among 405 patients who demonstrated an initial period of tumor growth but continued wait-and-scan management, 48 experienced volumetric regression at a median of 1.2 years (interquartile range, 0.8-2.6 yr) after initial growth. Volumetric regression-free survival rates at 1, 3, and 5 years after initial growth were 94% (92-97%; 260), 84% (79-89%; 99), and 75% (67-83%; 43), respectively. Ultimately, only 82 of the 952 patients studied showed exclusively volumetric tumor regression (i.e., without any periods of tumor growth) by the time of last follow-up.

CONCLUSION

Spontaneous volumetric tumor shrinkage during wait-and-scan management occurs more frequently than suggested by previous studies using linear tumor measurements and can even occur after previous episodes of documented tumor growth. These data further highlight the dynamic nature of vestibular schwannoma growth. To this end, the application of natural history data to patient management requires a nuanced approach that parallels the complex tumor behavior of vestibular schwannoma.

Whole Tumor Radiomics Analysis for Risk Factors Associated With Rapid Growth of Vestibular Schwannoma in Contrast-Enhanced T1-Weighted Images

OBJECTIVE

To investigate the features associated with rapid growth of vestibular schwannoma using radiomics analysis on magnetic resonance imaging (MRI) together with clinical factors.

METHODS

From August 2005 to February 2019, 67 patients with vestibular schwannoma underwent contrast-enhanced T1-weighted MRI at least twice as part of their diagnosis. After excluding 3 cases with an extremely short follow-up period of 15 days or less, 64 patients were finally enrolled in this study. Ninety-three texture features were extracted from the tumor image data using 3D Slicer software (http://www.slicer.org/). We determined the texture features that significantly affected maximal tumor diameter growth of more than 2 mm/year using Random Forest and Bounty. We also analyzed age and tumor size as clinical factors. We calculated the areas under the curve (AUCs) using receiver operating characteristic analysis for prediction models using texture, clinical, and mixed factors by Random Forest and 5-fold cross-validation.

RESULTS

Two texture features, low minimum signal and high inverse difference moment normalized (Idmn), were significantly associated with rapid growth of vestibular schwannoma. The mixed model of texture features and clinical factors offered the highest AUC (0.69), followed by the pure texture (0.67), and pure clinical (0.63) models. The minimum signal was the most important variable followed by tumor size, Idmn, and age.

CONCLUSIONS

Our radiomics analysis found that texture features were significantly associated with the rapid growth of vestibular schwannoma in contrast-enhanced T1-weighted images. The mixed model offered a higher diagnostic performance than the pure texture or clinical models.

Wait and Scan Management of Intra-canalicular Vestibular Schwannomas: Analysis of Growth and Hearing Outcome

OBJECTIVE

To report on the results of intracanalicular vestibular schwannomas (ICVS) that were managed by wait and scan and to analyze the possible predictors of tumor growth and hearing deterioration throughout the observation period.

STUDY DESIGN

A retrospective case series.

SETTING

Quaternary referral center for skull base pathologies.

PATIENTS

Patients with sporadic ICVS managed by wait and scan.

INTERVENTION

Serial resonance imaging (MRI) with size measurement and serial audiological evaluation.

MAIN OUTCOME MEASURE

Tumor growth defined as 2 mm increase of maximal tumor diameter, further treatment, and hearing preservation either maintain initial modified Sanna hearing class, or maintain initial serviceable hearing (class A/B).

RESULTS

339 patients were enrolled. The mean follow-up was 36.5±31.7 months with a median of 24 months. Tumor growth occurred in 141 patients (40.6%) either as slow growth (SG) in 26.3% of cases or fast growth (FG) in 15.3% of cases. Intervention was performed in only 64 cases (18.8%). Out of 271 patients who underwent hearing analysis, 86 patients (33.5%) showed hearing deterioration to a lower hearing class of the modified Sanna classification. Tumor growth and older age were predictors of hearing deterioration. Of the 125 cases with initial serviceable hearing (Class A/B), 91 cases (72.8%) maintained serviceable hearing at last follow-up. Tumor growth and a worse initial pure tone average (PTA) were predictors of hearing deterioration.

CONCLUSIONS

Wait and scan management of ICVS is a viable option and only 18.8% of patients needed further treatment. Hearing tends to deteriorate over time.

Gamma Knife Radiosurgery for Large Vestibular Schwannoma More Than 10 cm3: A Single-Center Indian Study

Introduction Gamma Knife radiosurgery (GKRS) is an effective treatment for benign vestibular schwannomas (VSs). The established cutoffs have recently been challenged, as recent literature expanded the horizon of GKRS to larger tumors. Even though microsurgery remains the primary option for large VS, GKRS can provide reasonable tumor control and is more likely to avoid cranial neuropathies associated with open surgery.

Methods We analyzed patients with VS with volume exceeding 10 cm3 who underwent GKRS at our center from January 2006 to December 2016. Clinicoradiological and radiosurgical data were collected from medical records for statistical analysis. Follow-up was performed every 6 months with a clinical assessment along with magnetic resonance imaging (MRI) of the brain and audiometric evaluation in patients with serviceable hearing.

Results The study included 34 patients (18 males and 16 females) with an average age of 45.5 years. The mean tumor volume was 10.9 cm3 (standard deviation [SD], ± 0.83), with a median tumor dose of 12 Gy (interquartile range, 11.5–12) and a mean follow-up of 34.7 months (SD, ± 23.8). Tumor response was graded as regression in 50%, stable in 44.1%, and increase or GKRS failure in 2 cases (5.8%). Treatment failure was noted in five cases (14.7%), requiring microsurgical excision and a ventriculoperitoneal shunt post-GKRS. The tumor control rate for the cohort is 85.3%, with a facial preservation rate of 96% (24/25) and hearing loss in all (5/5), while three patients developed new-onset hypoesthesia. We noted that gait ataxia and involvement of cranial nerve V or VII at initial presentation were associated with GKRS failure in univariate analysis.

Conclusion Microsurgery should remain the first-choice treatment option for large VSs. GKRS is a viable alternative with good tumor control and improved or stabilized cranial neuropathies with a low complication rate.

Diagnostic Validity of Auditory Brainstem Response for the Initial Screening of Vestibular Schwannoma

BACKGROUND AND OBJECTIVES

To investigate the diagnostic validity of auditory brainstem response (ABR) in the screening of vestibular schwannoma (VS).

SUBJECTS AND METHODS

Forty patients diagnosed with VS using magnetic resonance imaging who had undergone ABR before treatment between 2005 and 2015 were included. ABR results were considered positive when findings met at least one of the following criteria: 1) absent evoked response, 2) desynchronization of waves other than wave I, 3) interpeak latency (IPL) between waves I and III >2.5 ms, 4) IPL between waves I and V >4.4 ms, 5) wave V interaural latency difference >0.2 ms, and 6) interaural difference in IPL between waves I and V >0.2 ms.

RESULTS

The overall sensitivity of ABR was 85.0%. For tumors measuring <10 mm, the sensitivity of ABR was 66.7%, whereas it increased to 90.3% for tumors measuring >10 mm. The sensitivity of tumors confined to the internal acoustic canal was 73.3% compared with 100.0% for tumors confined to the cerebellopontine angle. In patients with serviceable hearing, the mean tumor size was 7.8±2.9 mm in patients with a normal ABR and 15.1±9.4 mm in patients with an abnormal ABR, indicating a significant difference (p<0.05).

CONCLUSIONS

ABR alone is insufficient for the screening of VS, bearing the risk of false-negative outcomes when examining small, intracanalicular tumors. However, ABR can be inexpensively applied for the screening of VS measuring >10 mm in patients with serviceable hearing, supporting the need for further active diagnostic and treatment modalities in clinical practice.

Long-term natural history and patterns of sporadic vestibular schwannoma growth: A multi-institutional volumetric analysis of 952 patients

BACKGROUND

The current study aims to characterize the natural history of sporadic vestibular schwannoma volumetric tumor growth, including long-term growth patterns following initial detection of growth.

METHODS

Volumetric tumor measurements from 3505 serial MRI studies were analyzed from unselected consecutive patients undergoing wait-and-scan management at three tertiary referral centers between 1998 and 2018. Volumetric tumor growth was defined as a change in volume ≥20%.

RESULTS

Among 952 patients undergoing observation, 622 experienced tumor growth with initial growth-free survival rates (95% CI) at 1, 3, and 5 years following diagnosis of 66% (63-69), 30% (27-34), and 20% (17-24). Among 405 patients who continued to be observed despite demonstrating initial growth, 210 experienced subsequent tumor growth with subsequent growth-free survival rates at 1, 3, and 5 years following initial growth of 77% (72-81), 37% (31-43), and 24% (18-31). Larger tumor volume at initial growth (HR 1.13, P = .02) and increasing tumor growth rate (HR 1.31; P < .001) were significantly associated with an increased likelihood of subsequent growth, whereas a longer duration of time between diagnosis and detection of initial growth was protective (HR 0.69; P < .001).

CONCLUSIONS

While most vestibular schwannomas exhibit an overall propensity for volumetric growth following diagnosis, prior tumor growth does not perfectly predict future growth. Tumors can subsequently grow faster, slower, or demonstrate quiescence and stability. Larger tumor size and increasing tumor growth rate portend a higher likelihood of continued growth. These findings can inform timing of intervention: whether upfront at initial diagnosis, after detection of initial growth, or only after continued growth is observed.

Adherence to Long-Term Follow-up in Patients With Sporadic Vestibular Schwannomas Managed With Serial Observation

Objectives

To examine the long-term adherence to serial imaging of patients with sporadic vestibular schwannoma and analyze factors associated with being lost to follow-up.

Study Design

Retrospective chart review with telephone interview.

Setting

Single tertiary care center.

Methods

Patients with a sporadic vestibular schwannoma and started on observational surveillance management between January 2005 and December 2010 were included. Demographic data, tumor size, hearing and vestibular changes, and follow-up length were recorded. Patient factors were analyzed for association with being lost to follow-up.

Results

In total, 122 patients were included with a median length of follow-up of 5 months (range, 0-146). After initial surveillance, 22.1% (n = 27) of patients had a change in management to either microsurgery or radiosurgery. Of the remaining 77.9% (n = 95), nearly half (44.2%, n = 42) never returned for a second visit, and all but 3 were eventually lost to follow-up. There was no association between sex, race, age at diagnosis, initial tumor size, insurance status, household income, or driving distance to hospital and being lost to follow-up. Of 26 interviewed patients initially lost to follow-up, 11 (42.3%) sought care at another institution, 5 (19.2%) chose to no longer receive care, 1 (3.8%) had transportation difficulties, and 9 (36.4%) had poor understanding of their diagnosis or instructions.

Conclusions

The length of follow-up for patients undergoing surveillance of sporadic vestibular schwannoma varies widely, and patients are commonly lost to follow-up. Further efforts should be made to identify at-risk patients and provide adequate education to improve long-term surveillance.

Determinants of Vestibular Schwannoma Growth

OBJECTIVE

Management of vestibular schwannomas (VS) involves surgery, radiotherapy, or surveillance, based on patient and tumor factors. We recently described conditional probability as a more accurate method for stratifying VS growth risk. Building on this, we now describe determinants of VS growth, allowing clinicians to move toward a more personalized approach to growth-risk profiling.

METHODS

Retrospective analysis of a prospectively collected database in a tertiary referral skull base unit between 2005 and 2014. Inclusion of patients with unilateral VS managed on surveillance protocol for a minimum of 5 years. Analysis of patient age, sex, tumor location, tumor size, and symptomology using conditional probability.

RESULTS

A total of 340 patients met inclusion criteria. The conditional probability of growth of extracanalicular VS was significantly higher versus intracanalicular (IC) VS (30% versus 13%, p < 0.001) as was small-sized VS versus IC VS (28 versus 13%, p = 0.002), but only in the first year after diagnosis. Sex, age, and presenting symptoms did not significantly affect VS growth.

CONCLUSION

In our series, extracanalicular VS were more likely to grow than IC VS and small-sized VS more likely to grow than IC VS, but only in the first year after diagnosis. Conversely, sex, age, and presenting symptoms did not affect the conditional probability of VS growth.

Cochleo-facial corridor to the vestibule and fundus of the internal auditory canal through oval window: a minimal invasive and cochlea sparing approach

PURPOSE

This cadaveric work aimed to test the effectiveness of a modified surgical corridor (ExpTSA: expanded transcanal supracochlear approach) developed for anatomic cochlear preservation in selected vestibular schwannoma patients necessitating to perform cochlear implantation for appropriate cases to achieve the best outcome.

METHODS

The ears of 10 cadavers (at mean age 75.70 ± 13.75 years, range 45-92 years) were dissected from the external auditory canal (EAC) to the internal auditory canal by ExpTSA under the guidance of a microscope and endoscope. All stages of the surgical process were recorded step by step and evaluated morphometrically.

RESULTS

The vestibular base was successfully reached in all ears without damaging the cochlear morphology and facial nerve. The vestibular base was 23.33 ± 2.02 mm away from the entrance (external orifice) and 10.26 ± 1.33 mm from the exit (internal orifice) of EAC. The oval window and vestibular base were measured to be 2.94 ± 1.05 mm and 5.87 ± 1.24 mm deep from the facial nerve, respectively. The normal areas of the oval window, the exit and entrance of EAC were found as 2.90 ± 0.81 mm², 42.52 ± 13.66 mm², and 110.73 ± 25.32 mm², respectively. After ExpTSA procedure, the areas of the oval window (11.04 ± 2.83 mm²), the exit (122.45 ± 20.41 mm²) and entrance (167.49 ± 30.94 mm²) of EAC were expanded approximately 280%, 188%, and 50%, respectively.

CONCLUSION

The ExpTSA may be performed for accessing to the vestibule and fundus of IAC for tumor removal of intravestibular schwannoma patients (with or without fundus involvement) with unserviceable hearing, preserving the cochlear morphology.

Efficacy and comorbidities of hypofractionated and single-dose radiosurgery for vestibular schwannomas: a systematic review and meta-analysis

Background

Vestibular schwannomas (VS) are tumors of the cerebellopontine angle with significant morbidity, causing hearing loss, tinnitus, and trigeminal and facial nerve compromise. An effective alternative to microsurgical resection is stereotactic radiosurgery (SRS), which can be delivered in either single-fraction (SRS) or hypofractionated stereotactic radiotherapy (hSRT) (3-5 treatments) regimens. It remains unclear which fractionation regimen provides superior outcomes.

Methods

Ovid MEDLINE, EMBASE, CINAHL, and Cochrane Reviews were searched for studies either comparing hSRT with SRS or focusing on hSRT alone in treating VS. Primary endpoints included tumor control, serviceable hearing, tinnitus, and cranial nerve V and VII symptoms. A random-effects analysis was employed to compare pre- and post-treatment effects (hSRT alone) or SRS and hSRT outcomes (two-arm studies).

Results

This analysis included 21 studies focusing on hSRT alone and 13 studies comparing SRS and hSRT. Significant heterogeneity was observed. Overall, when hSRT was analyzed alone, crude tumor control was achieved in 94% (95% CI: 88%, 99%) of 1571 patients. There was no difference between pre- and post-treatment odds ratios (OR) of tinnitus, facial, or trigeminal impairment. Serviceable hearing was diminished following hSRT (OR = 0.60, 95% CI: 0.44, 0.83). Comparison with SRS showed no difference with respect to tumor control, serviceable hearing, trigeminal or facial nerve impairment.

Conclusions

hSRT achieved excellent tumor control and, with the exception of serviceable hearing, did not result in worse post-treatment cranial nerve symptomatology. Analysis of comparative studies between hSRT and SRS did not reveal any significant difference in either tumor control or treatment morbidities.

MRI monitoring of small and medium-sized vestibular schwannomas: predictors of growth

Background: Vestibular schwannomas are among the most common intracranial tumours. Their growth is difficult to predict.Objectives: To study the evolution of small and medium-sized vestibular schwannomas (VSs) and identify factors predictive of growth.Material and methods: This was a retrospective longitudinal study at a tertiary referral centre from January 2011 to January 2018. The inclusion criteria were radiological diagnosis of sporadic unilateral VS of stage I or II. Radiological and clinical data were analysed descriptively and by multivariate logistic regression to identify factors predictive of growth.Results: A total of 1105 cases were discussed in multidisciplinary meetings and 336 patients were included with a mean age of 57.8 years and a mean follow-up time of 24 months. Around two thirds of these patients (62.8%) had non-progressive tumours. Factors identified as predictive of VS growth were the size at diagnosis (OR = 2.622, 95% CI, 1.50-4.66; p = .001) and internal auditory canal filling (OR = 7.672; 95% CI, 4.52-13.43; p < .001).Conclusions and significance: Monitoring is the primary treatment modality for small or medium-sized VSs. As reported here for the first time, internal auditory canal filling is significantly associated with VS growth.

Clinical Practice Guideline: Sudden Hearing Loss (Update)

OBJECTIVE

Sudden hearing loss is a frightening symptom that often prompts an urgent or emergent visit to a health care provider. It is frequently but not universally accompanied by tinnitus and/or vertigo. Sudden sensorineural hearing loss affects 5 to 27 per 100,000 people annually, with about 66,000 new cases per year in the United States. This guideline update provides evidence-based recommendations for the diagnosis, management, and follow-up of patients who present with sudden hearing loss. It focuses on sudden sensorineural hearing loss in adult patients aged ≥18 years and primarily on those with idiopathic sudden sensorineural hearing loss. Prompt recognition and management of sudden sensorineural hearing loss may improve hearing recovery and patient quality of life. The guideline update is intended for all clinicians who diagnose or manage adult patients who present with sudden hearing loss.

PURPOSE

The purpose of this guideline update is to provide clinicians with evidence-based recommendations in evaluating patients with sudden hearing loss and sudden sensorineural hearing loss, with particular emphasis on managing idiopathic sudden sensorineural hearing loss. The guideline update group recognized that patients enter the health care system with sudden hearing loss as a nonspecific primary complaint. Therefore, the initial recommendations of this guideline update address distinguishing sensorineural hearing loss from conductive hearing loss at the time of presentation with hearing loss. They also clarify the need to identify rare, nonidiopathic sudden sensorineural hearing loss to help separate those patients from those with idiopathic sudden sensorineural hearing loss, who are the target population for the therapeutic interventions that make up the bulk of the guideline update. By focusing on opportunities for quality improvement, this guideline should improve diagnostic accuracy, facilitate prompt intervention, decrease variations in management, reduce unnecessary tests and imaging procedures, and improve hearing and rehabilitative outcomes for affected patients.

METHODS

Consistent with the American Academy of Otolaryngology-Head and Neck Surgery Foundation's "Clinical Practice Guideline Development Manual, Third Edition" (Rosenfeld et al. Otolaryngol Head Neck Surg. 2013;148[1]:S1-S55), the guideline update group was convened with representation from the disciplines of otolaryngology-head and neck surgery, otology, neurotology, family medicine, audiology, emergency medicine, neurology, radiology, advanced practice nursing, and consumer advocacy. A systematic review of the literature was performed, and the prior clinical practice guideline on sudden hearing loss was reviewed in detail. Key Action Statements (KASs) were updated with new literature, and evidence profiles were brought up to the current standard. Research needs identified in the original clinical practice guideline and data addressing them were reviewed. Current research needs were identified and delineated.

RESULTS

The guideline update group made strong recommendations for the following: (KAS 1) Clinicians should distinguish sensorineural hearing loss from conductive hearing loss when a patient first presents with sudden hearing loss. (KAS 7) Clinicians should educate patients with sudden sensorineural hearing loss about the natural history of the condition, the benefits and risks of medical interventions, and the limitations of existing evidence regarding efficacy. (KAS 13) Clinicians should counsel patients with sudden sensorineural hearing loss who have residual hearing loss and/or tinnitus about the possible benefits of audiologic rehabilitation and other supportive measures. These strong recommendations were modified from the initial clinical practice guideline for clarity and timing of intervention. The guideline update group made strong recommendations against the following: (KAS 3) Clinicians should not order routine computed tomography of the head in the initial evaluation of a patient with presumptive sudden sensorineural hearing loss. (KAS 5) Clinicians should not obtain routine laboratory tests in patients with sudden sensorineural hearing loss. (KAS 11) Clinicians should not routinely prescribe antivirals, thrombolytics, vasodilators, or vasoactive substances to patients with sudden sensorineural hearing loss. The guideline update group made recommendations for the following: (KAS 2) Clinicians should assess patients with presumptive sudden sensorineural hearing loss through history and physical examination for bilateral sudden hearing loss, recurrent episodes of sudden hearing loss, and/or focal neurologic findings. (KAS 4) In patients with sudden hearing loss, clinicians should obtain, or refer to a clinician who can obtain, audiometry as soon as possible (within 14 days of symptom onset) to confirm the diagnosis of sudden sensorineural hearing loss. (KAS 6) Clinicians should evaluate patients with sudden sensorineural hearing loss for retrocochlear pathology by obtaining magnetic resonance imaging or auditory brainstem response. (KAS 10) Clinicians should offer, or refer to a clinician who can offer, intratympanic steroid therapy when patients have incomplete recovery from sudden sensorineural hearing loss 2 to 6 weeks after onset of symptoms. (KAS 12) Clinicians should obtain follow-up audiometric evaluation for patients with sudden sensorineural hearing loss at the conclusion of treatment and within 6 months of completion of treatment. These recommendations were clarified in terms of timing of intervention and audiometry and method of retrocochlear workup. The guideline update group offered the following KASs as options: (KAS 8) Clinicians may offer corticosteroids as initial therapy to patients with sudden sensorineural hearing loss within 2 weeks of symptom onset. (KAS 9a) Clinicians may offer, or refer to a clinician who can offer, hyperbaric oxygen therapy combined with steroid therapy within 2 weeks of onset of sudden sensorineural hearing loss. (KAS 9b) Clinicians may offer, or refer to a clinician who can offer, hyperbaric oxygen therapy combined with steroid therapy as salvage therapy within 1 month of onset of sudden sensorineural hearing loss.

DIFFERENCES FROM PRIOR GUIDELINE

Incorporation of new evidence profiles to include quality improvement opportunities, confidence in the evidence, and differences of opinion Included 10 clinical practice guidelines, 29 new systematic reviews, and 36 new randomized controlled trials Highlights the urgency of evaluation and initiation of treatment, if treatment is offered, by emphasizing the time from symptom occurrence Clarification of terminology by changing potentially unclear statements; use of the term sudden sensorineural hearing loss to mean idiopathic sudden sensorineural hearing loss to emphasize that >90% of sudden sensorineural hearing loss is idiopathic sudden sensorineural hearing loss and to avoid confusion in nomenclature for the reader Changes to the KASs from the original guideline: KAS 1-When a patient first presents with sudden hearing loss, conductive hearing loss should be distinguished from sensorineural. KAS 2-The utility of history and physical examination when assessing for modifying factors is emphasized. KAS 3-The word "routine" is added to clarify that this statement addresses nontargeted head computerized tomography scan that is often ordered in the emergency room setting for patients presenting with sudden hearing loss. It does not refer to targeted scans, such as temporal bone computerized tomography scan, to assess for temporal bone pathology. KAS 4-The importance of audiometric confirmation of hearing status as soon as possible and within 14 days of symptom onset is emphasized. KAS 5-New studies were added to confirm the lack of benefit of nontargeted laboratory testing in sudden sensorineural hearing loss. KAS 6-Audiometric follow-up is excluded as a reasonable workup for retrocochlear pathology. Magnetic resonance imaging, computerized tomography scan if magnetic resonance imaging cannot be done, and, secondarily, auditory brainstem response evaluation are the modalities recommended. A time frame for such testing is not specified, nor is it specified which clinician should be ordering this workup; however, it is implied that it would be the general or subspecialty otolaryngologist. KAS 7-The importance of shared decision making is highlighted, and salient points are emphasized. KAS 8-The option for corticosteroid intervention within 2 weeks of symptom onset is emphasized. KAS 9-Changed to KAS 9A and 9B. Hyperbaric oxygen therapy remains an option but only when combined with steroid therapy for either initial treatment (9A) or salvage therapy (9B). The timing of initial therapy is within 2 weeks of onset, and that of salvage therapy is within 1 month of onset of sudden sensorineural hearing loss. KAS 10-Intratympanic steroid therapy for salvage is recommended within 2 to 6 weeks following onset of sudden sensorineural hearing loss. The time to treatment is defined and emphasized. KAS 11-Antioxidants were removed from the list of interventions that the clinical practice guideline recommends against using. KAS 12-Follow-up audiometry at conclusion of treatment and also within 6 months posttreatment is added. KAS 13-This statement on audiologic rehabilitation includes patients who have residual hearing loss and/or tinnitus who may benefit from treatment. Addition of an algorithm outlining KASs Enhanced emphasis on patient education and shared decision making with tools provided to assist in same.

Long term results of primary radiosurgery for vestibular schwannomas

BACKGROUND

Stereotactic radiosurgery (SRS) has become a primary option for management for both newly diagnosed vestibular schwannomas (VS), as well as VS that enlarge after initial observation.

METHODS

A retrospective review of our prospectively maintained data base found 871 patients who underwent Gamma knife® SRS as their initial (primary) management between 1987 and 2008. Follow-up ranged from 1-25 years (median = 5.2 years) Median tumor volume was 0.9 cc (0.02-36) and median margin dose was 13 Gy (12-25).

RESULTS

Progression free survival (PFS) after SRS was 97% at 3 years, 95% at 5 years, and 94% at 10 years. Freedom from delayed surgical resection was found in 98.7% of patients. Smaller tumor volume was significantly associated with improved PFS. There were 326 patients with serviceable hearing (Gardner-Robertson 1 or 2) at the time of SRS with audiological follow-up of ≥ 1 year. Serviceable hearing preservation rates after SRS were 89.8% at 1 year, 76.9% at 3 years, 68.4% at 5 years, 62.5% at 7 years, and 51.4% at 10 years. Factors associated with improved serviceable hearing preservation included younger age, Gardner-Robertson grade 1 at SRS, and absence of subjective complaints of dysequilibrium or vertigo (vestibulopathy). Fifty-one patients (5.8%) developed trigeminal neuropathy. Fourteen (1.6%) developed a transient House-Brackmann grade 2 or 3 facial neuropathy.

CONCLUSIONS

In this report with extended follow-up, primary SRS achieved tumor growth control in 94% of patients. Optimization of long- term cranial nerve outcomes remains an important achievement of this management strategy for VS.

Decision Making in the Wait-and-Scan Approach for Vestibular Schwannomas: Is There a Price to Pay in Terms of Hearing, Facial Nerve, and Overall Outcomes?

BACKGROUND

The wait-and-scan modality has emerged as an important strategy in the management of vestibular schwannoma (VS) as it has been demonstrated that many tumors grow slowly or do not show any growth over long periods.

OBJECTIVE

To analyze long-term outcomes of wait-and-scan in the treatment of patients with VS, discuss the factors contributing to the decision making, determine the inherent risks of the policy, and compare our results with literature.

METHODS

In total, 576 patients with sporadic unilateral VS who were managed with wait-and-scan were reviewed retrospectively. Of these, a subset of 154 patients with 5-yr follow-up was separately analyzed. The tumor characteristics including patterns of growth, rate of growth, hearing outcomes, and likely factors affecting the above parameters were analyzed.

RESULTS

The mean period of follow-up was 36.9 ± 30.2 mo. The mean age was 59.2 ± 11.6 yr. Thirteen different patterns of tumor growth were observed. Eighty-four (54.5%) of 154 tumors with 5-yr follow-up showed no growth throughout 5 yr. Fifty-six (36.4%) tumors showed mixed growth rates. Only 57 (37%) patients had serviceable hearing at the start of follow-up, but 32 (56.1%) maintained it at the end of follow-up. One hundred fifty (26%) of the 576 patients who failed wait-and-scan had to be taken up for surgery.

CONCLUSION

While there may be no price to pay in wait-and-scan as far as hearing is concerned, this may not be the case for facial nerve outcomes, wherein the results may be better if the patients are taken earlier for surgery.

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.

Effect of Gamma Knife Radiosurgery on Vestibular Schwannoma with Serviceable Hearing: A Single-Center Indian Study

OBJECTIVE

Gamma Knife radiosurgery (GKRS) is an established treatment modality for vestibular schwannomas (VSs). The tumor control and hearing preservation rates suggest that GKRS is a good alternative treatment for small- and medium-size VS. Data are lacking from India regarding GKRS for VSs. Our aim was to find the hearing preservation and tumor control rates and the factors contributing to these.

METHODS

In a retrospective 9-year study period, 87 patients had undergone GKRS for unilateral VS with Gardner-Robertson (GR) class I or II serviceable hearing. All 87 had been evaluated with magnetic resonance imaging and audiometry before GKRS and during follow-up to assess for the factors influencing tumor control and hearing preservation.

RESULTS

Of the 87 patients, 77 with a minimum follow-up of 2 years and magnetic resonance imaging and audiometry evaluations available were included in the present study. The median follow-up period was 30 months. The tumor control rate and hearing preservation rate was 96.1% and 79.2%, respectively. Hearing preservation was not affected by the tumor volume. However, age >40 years, pre-GKRS pure tone average <30 decibels, speech discrimination score >85%, pre-GKRS Gardner-Robertson grade I hearing, mean cochlear dose <4 Gy, and pre-GKRS Ohata class of laterality C, D, E were significant on univariate analysis. The multivariate analysis revealed that age >40 years (P = 0.017), pre-GKRS pure tone average <30 decibels (P = 0.002), and Gardner-Robertson class I (P = 0.001) were significant factors. No patient developed cranial nerve dysfunction, hydrocephalus, or malignant degeneration.

CONCLUSION

For most patients with small VSs, GKRS will be an effective alternative treatment to microsurgery with retained serviceable hearing and good tumor control.

When Should We Stop Scanning Older Patients with Vestibular Schwannomas?

Objective  Observation is a well-accepted management for small- to medium-sized vestibular schwannomas (VSs). Although there are good data on the natural history of this disease within adults, no studies have looked specifically at those aged over 70 years. Thus, there is a need for a surveillance protocol to determine if and when we can stop imaging safely patients aged 70 years and over with a new diagnosis of VSs when managed with observation. Design  Over a 13-year period, we retrospectively analyzed all skull base unit patients with a sporadic unilateral VSs managed with an imaging surveillance protocol. All data were collected prospectively with a minimum follow-up of 5 years. Setting  Tertiary referral skull base unit Participants  Patients aged 70 years and over with sporadic VSs at diagnosis Main Outcome Measures  Main outcome measures Results  A total of 112 patients met inclusion criteria. The median age at diagnosis was 74 years (range: 70-87 years). The mean follow-up was 82 months (range: 60-144). The size of the VSs at diagnosis was intracanalicular (IC) in 46%, small in 41%, medium in 12%, and large in 2%. Growth was more likely where tumors were extracanalicular (EC) rather than IC at presentation ( p  = 0.036) and within the first 18 months after diagnosis ( p  < 0.001). Twenty-nine percent of VSs displayed growth (6% continued surveillance, 23% received active treatment). Good hearing at diagnosis did not predict tumor stability for IC or EC tumors ( p  = 0.162 and p  = 0.536). Conclusions  Since no VSs grew after 42 months from diagnosis, our data support an initial magnetic resonance imaging (MRI) at 6 months after diagnosis followed by an annual MRI for 3 years. At this point, consideration could be given to discussing discontinuation or further imaging with patients.

Middle Fossa Approach for Resection of Vestibular Schwannomas: A Decade of Experience

BACKGROUND

The middle cranial fossa (MCF) approach is a challenging surgical technique for the resection of small and intermediate sized, primarily intracanalicular, vestibular schwannomas (VS), with the goal of hearing preservation (HP).

OBJECTIVE

To describe a decade-long, single institutional experience with the MCF approach for resection of VS.

METHODS

This is a retrospective cohort study of 63 patients who underwent the MCF approach for resection of VS from 2006 to 2016. Audiometric data included pure-tone average (PTA), low-tone pure-tone average (LtPTA), word recognition score, and American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification at presentation and follow-up. Patients with postoperative serviceable (AAO-HNS class A-B) and/or useful (AAO-HNS class A-C) hearing were compared to those without HP. Facial nerve function was assessed using the House–Brackmann scale.

RESULTS

The mean age and duration of follow-up were 50 ± 13 yr and 21 ± 21 mo, respectively. The mean tumor size was 10 ± 4 mm. The serviceable and usable HP rates were 54% and 50%, respectively. Some residual hearing was preserved in 71% of patients. Large tumor size (P = .05), volume (P = .03), and extrameatal tumor extension (P = .03) were associated with poor audiometric outcomes. The presence of a fundal fluid cap (P = .01) was a favorable finding. At definitive testing, LtPTA was significantly better preserved than traditional PTA (P = .01). Facial nerve outcomes, tumor control rates, and durability of audiometric outcomes were excellent. 47% of patients pursued aural rehabilitation.

CONCLUSION

In our series, the MCF approach for VS provided excellent rates of tumor and facial nerve function, with durable serviceable HP.

Expanded transcanal transpromontorial approach to the internal auditory canal and cerebellopontine angle: a cadaveric study

The aim of this paper is to describe and evaluate the feasibility of an expanded endoscopic transcanal transpromotorial approach (ExpTTA) to the internal auditory canal and the cerebellopontine angle. To this end, we performed a cadaveric dissection study in September 2015. In total, 2 heads (4 sides) were dissected focusing on anatomical landmarks and surgical feasibility. Data from dissections were reviewed and analysed for further consideration. In all 4 sides of the cadavers the procedure was feasible. In all cadavers, it was necessary to extensively drill the temporo-mandibular joint and to calibrate the external ear canal to allow adequate room to manoeuver the instruments and optics and to comfortably access the cerebellopontine angle. In addition, thorough skeletonisation of the carotid artery and the jugular bulb were necessary for the same purpose. In conclusion, ExpTTA appeared to be successful to access the internal auditory canal and cerebellopontine angle region. Potential extensive and routine application of this type of approach in lateral skull base surgery will depend on the development of technology and surgical refinements and on the diffusion of skull base endoscopic skills among otolaryngologists and neurosurgical community.

"Wait and scan" management of patients with vestibular schwannoma and the relevance of non-contrast MRI in the follow-up

Vestibular schwannoma (VS) is a slow-growing benign neoplasm. There has been an evolution in the management of VS from active treatments (microsurgery and stereotactic radiotherapy) to conservative management (wait and scan). Regular MRI scanning is necessary to monitor tumor progression. Conservative management causes significantly less complications and offers a higher quality of life compared with active treatments. The mean growth rate of VS varies from 0.4 to 2.9 mm/year, and spontaneous shrinkage is observed in 3.8 percent of tumors during observation. If significant growth occurs, active treatment is considered. Significant growth is defined as an increase of at least 3 mm in the largest extrameatal diameter in any plane between the first and last available scans. The vestibulocochlear nerve is surrounded by cerebrospinal fluid, which provides natural contrast for MRI; thus, gadolinium may not be needed to detect VS. Specific sequences have high sensitivity, specificity, and accuracy for detection of progression. Hypointense signal in the ipsilateral inner ear fluid might be a useful sign to distinguish VS from meningioma. In this paper, we summarize the current status of research on conservative management and non-contrast MRI for the detection of VS.

Developing an algorithm for cost-effective, clinically judicious management of peripheral nerve tumors

Peripheral nerve tumors such as neurofibromas and schwannomas have become increasingly identified secondary to improved imaging modalities including magnetic resonance neurogram and ultrasound. Given that a majority of these peripheral nerve tumors are benign lesions, it becomes important to determine appropriate management of such asymptomatic masses. We propose a normal cost-effective management paradigm for asymptomatic peripheral nerve neurofibromas and schwannomas that has been paired with economic analyses. Specifically, our management paradigm identifies patients who would benefit from surgery for asymptomatic peripheral nerve tumors, while providing cost-effective recommendations regarding clinical exams and serial imaging for such patients.

Growth rate of vestibular schwannoma

Vestibular schwannoma (VS) is the most common tumor in the extra-axial posterior fossa compartment in adults. Growth rate is paramount to decision making regarding treatment and follow up of these tumors. We conducted a comprehensive review of the literature to answer four questions: What percentage of newly diagnosed VS will grow on follow-up? What factors correlate to tumor growth? What is the "normal" growth rate for sporadic VS? What factors characterize VS with rapid growth? Thirty-seven reports, with more than 4000 patients, fit our review criteria. One third of newly diagnosed VS will grow on follow-up of 1-3years. However, after 5years, up to one half will grow. Patient age and sex do not influence growth of VS. Hearing loss and vertigo at presentation do not predict tumor growth. It is unclear whether balance disturbance or tinnitus predict tumor growth. Tumor size and location do not predict tumor growth. Growth in the first year of observation is a strong predictor of tumor growth. The average growth rate of a VS is 0.99-1.11mm/year. However, the expected growth rate for VS that have been shown to grow at first follow-up is 3mm/year. Factors that may predict tumor growth of above 4mm/year are cystic and hemorrhagic features in the tumor, and hormonal treatment. VS grow at an average 1mm/year. VS that have been shown to grow at first follow-up should be considered for treatment, unless contraindicated. Long term follow-up is recommended for VS.