Current imaging tools for vestibular schwannoma

Hearing preservation surgery for vestibular schwannoma: a systematic review and meta-analysis

The aim of this systematic review is to analyse the role of hearing preservation surgery for vestibular schwannoma. The complications and hearing outcomes of the single surgical techniques were investigated and compared with those of less invasive strategies, such as stereotactic radiotherapy and wait and scan policy. This systematic review and meta-analysis was performed according to the PRISMA guidelines. All included studies were published in English between 2000 and 2022. Literature data show that hearing preservation is achieved in less than 25% of patients after surgery and in approximately half of cases after stereotactic radiotherapy, even if data on long-term preservation are currently not available.

Temporal lobe injury with middle fossa approach to intracanalicular vestibular schwannomas: a systematic review

There are several surgical approaches for vestibular schwannoma (VS) resection. However, management has gradually shifted from microsurgical resection, toward surveillance and radiosurgery. One of the arguments against microsurgery via the middle fossa approach (MFA) is the risk of temporal lobe retraction injury or sequelae. Here, we sought to evaluate the incidence of temporal lobe retraction injury or sequela from a MFA via a systematic review of the existing literature. This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Relevant studies reporting temporal lobe injury or sequela during MFA for VS were identified. Data was aggregated and subsequently analyzed to evaluate the incidence of temporal lobe injury. 22 studies were included for statistical analysis, encompassing 1522 patients that underwent VS resection via MFA. The overall rate of temporal lobe sequelae from this approach was 0.7%. The rate of CSF leak was 5.9%. The rate of wound infection was 0.6%. Meningitis occurred in 1.6% of patients. With the MFA, 92% of patients had good facial outcomes, and 54.9% had hearing preservation. Our series and literature review support that temporal lobe retraction injury or sequelae is an infrequent complication from an MFA for intracanalicular VS resection.

Case Report: Use of novel AR registration system for presurgical planning during vestibular schwannoma resection surgery

Background and importance

Vestibular schwannomas are benign tumors and are the most common tumor found in the cerebellopontine angle. Surgical management of these lesions involves consideration of various operative approaches, which can have profound effects on procedural course and patient outcomes. Therefore, a comprehensive understanding of the location of the tumor and surrounding anatomical structures is vital for a positive outcome. We present a case of a 47-year-old female patient with vestibular schwannoma. A novel mixed reality (MR) system was used to register patient-specific 3D models onto the patient's head for operative planning and anatomical visualization.

Case description

A 47-year-old female presented with a history of left-sided hearing loss, tinnitus, and episodic left facial tingling. Magnetic Resonance Imaging (MRI) demonstrated a 3.3 cm enhancing lesion in the left cerebellopontine angle at the with mass effect on the brachium pontis and medulla. Surgical resection was performed via retrosigmoid craniotomy.

Conclusions

In this study, we report the use of Augmented Reality (AR) visualization for planning of vestibular schwannoma resection. This technology allows for efficient and accurate registration of a patient's 3D anatomical model onto their head while positioned in the operating room. This system is a powerful tool for operative planning as it allows the surgeon to visualize critical anatomical structures where they lie on the patient's head. The present case demonstrates the value and use of AR for operative planning of complex cranial lesions.

Cost considerations for vestibular schwannoma screening and imaging: a systematic review

Vestibular schwannomas (VS) account for approximately 8% of all intracranial neoplasms. Importantly, the cost of the diagnostic workup for VS, including the screening modalities most commonly used, has not been thoroughly investigated. Our aim is to conduct a systematic review of the published literature on costs associated with VS screening. A systematic review of the literature for cost of VS treatment was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The terms "vestibular schwannoma," "acoustic neuroma," and "cost" were queried using the PubMed and Embase databases. Studies from all countries were considered. Cost was then corrected for inflation using the US Bureau of Labor Statistics Inflation Calculator, correcting to April 2022. The search resulted in an initial review of 483 articles, of which 12 articles were included in the final analysis. Screening criteria were used for non-neurofibromatosis type I and II patients who complained of asymmetric hearing loss, tinnitus, or vertigo. Patients included in the studies ranged from 72 to 1249. The currency and inflation-adjusted mean cost was $418.40 (range, $21.81 to $487.03, n = 5) for auditory brainstem reflex and $1433.87 (range, $511.64 to $1762.15, n = 3) for non-contrasted computed tomography. A contrasted magnetic resonance imaging (MRI) scan was found to have a median cost of $913.27 (range, $172.25-$2733.99; n = 8) whereas a non-contrasted MRI was found to have a median cost of $478.62 (range, $116.61-$3256.38, n = 4). In terms of cost reporting, of the 12 articles, 1 (8.3%) of them separated out the cost elements, and 10 (83%) of them used local prices, which include institutional costs and/or average costs of multiple institutions. Our findings describe the limited data on published costs for screening and imaging of VS. The paucity of data and significant variability of costs between studies indicates that this endpoint is relatively unexplored, and the cost of screening is poorly understood.

Brazilian Society of Otology task force - Vestibular Schwannoma ‒ evaluation and treatment

OBJECTIVE

To review the literature on the diagnosis and treatment of vestibular schwannoma.

METHODS

Task force members were educated on knowledge synthesis methods, including electronic database search, review and selection of relevant citations, and critical appraisal of selected studies. Articles written in English or Portuguese on vestibular schwannoma were eligible for inclusion. The American College of Physicians' guideline grading system and the American Thyroid Association's guideline criteria were used for critical appraisal of evidence and recommendations for therapeutic interventions.

RESULTS

The topics were divided into 2 parts: (1) Diagnosis - audiologic, electrophysiologic tests, and imaging; (2) Treatment - wait and scan protocols, surgery, radiosurgery/radiotherapy, and systemic therapy.

CONCLUSIONS

Decision making in VS treatment has become more challenging. MRI can diagnose increasingly smaller tumors, which has disastrous consequences for the patients and their families. It is important to develop an individualized approach for each case, which highly depends on the experience of each surgical team.

MRI Screening in Vestibular Schwannoma: A Deep Learning-based Analysis of Clinical and Audiometric Data

Objective

To find a more objective method of assessing which patients should be screened for a vestibular schwannoma (VS) with magnetic resonance imaging (MRI) using a deep-learning algorithm to assess clinical and audiometric data.

Materials and Methods

Clinical and audiometric data were collected for 592 patients who received an audiogram between January 2015 and 2020 at Duke University Health Center with and without VS confirmed by MRI. These data were analyzed using a deep learning-based analysis to determine if the need for MRI screening could be assessed more objectively with adequate sensitivity and specificity.

Results

Patients with VS showed slightly elevated, but not statistically significant, mean thresholds compared to those without. Tinnitus, gradual hearing loss, and aural fullness were more common in patients with VS. Of these, only the presence of tinnitus was statistically significant. Several machine learning algorithms were used to incorporate and model the collected clinical and audiometric data, but none were able to distinguish ears with and without confirmed VS. When tumor size was taken into account the analysis was still unable to distinguish a difference.

Conclusions

Using audiometric and clinical data, deep learning-based analyses failed to produce an adequately sensitive and specific model for the detection of patients with VS. This suggests that a specific pattern of audiometric asymmetry and clinical symptoms may not necessarily be predictive of the presence/absence of VS to a level that clinicians would be comfortable forgoing an MRI.

Evaluation and Management of Tinnitus: Are There Opportunities for Improvement?

OBJECTIVE

To review current information about diagnosis and management of tinnitus aiming to identify opportunities for achieving a cost-effective, efficient, evidence-based approach that meets the needs of tinnitus sufferers.

DATA SOURCES

PubMed/MEDLINE.

REVIEW METHODS

In total, 249 relevant published reports were reviewed. Pertinent keywords and MeSH terms identified reports via PubMed and EMBASE. Acknowledged experts were consulted on ways to improve tinnitus management.

CONCLUSIONS

There may be opportunities to improve evaluation and management of patients with tinnitus using modern modes of communication and a multidisciplinary therapeutic approach.

IMPLICATIONS FOR PRACTICE

Tinnitus can adversely affect quality of life while being time-consuming and costly to evaluate and manage. Based on both personal experience and the reports of others, patients with tinnitus who choose to see a physician primarily want to know two things: (1) that the tinnitus that is so distressing will not remain at the same level of severity forever and (2) that something can be done to help cope with the tinnitus that is so annoying. Recent advancements in internet communications, social media, information technology, artificial intelligence, machine learning, holistic medical care, mind-body integrative health care, and multidisciplinary approaches in medical therapeutics may be possibly making new ways of meeting the needs of patients with tinnitus.

High-Resolution T2-Weighted Imaging for Surveillance in Postoperative Vestibular Schwannoma: Equivalence with Contrast-Enhanced T1WI for Measurement and Surveillance of Residual Tumor

BACKGROUND AND PURPOSE

Patients with surgically resected vestibular schwannoma will undergo multiple postoperative surveillance examinations, typically including postcontrast sequences. The purpose of this study was to compare high-resolution T2WI with gadolinium T1WI in the postoperative assessment of vestibular schwannoma.

MATERIALS AND METHODS

This was a retrospective study of patients with a history of resected vestibular schwannoma at a single institution. High-resolution T2WI and gadolinium T1WI were independently evaluated for residual disease. In addition, 3D and 2D measurements were performed in the group of patients with residual tumor. Statistical analysis was performed to evaluate the agreement between sequences on the binary assessment (presence/absence of tumor on initial postoperative examination) and to evaluate the equivalence of measurements for the 2 sequences on 3D and 2D quantitative assessment in individuals with residual disease.

RESULTS

One hundred forty-eight patients with retrosigmoid-approach resection of vestibular schwannomas were included in the final analysis. There was moderate-to-substantial agreement between the 2 sequences for the evaluation of the presence versus absence of tumor (Cohen κ coefficient = 0.78; 95% CI, 0.68-0.88). The 2 sequences were significantly equivalent for 2D and 3D quantitative assessments (short-axis P value = .021; long-axis P value = .015; 3D P value = .039).

CONCLUSIONS

In this retrospective study, we demonstrate moderate-to-substantial agreement in the categoric assessment for the presence versus absence of tumor and equivalence between the 2 sequences for both 2D and volumetric tumor measurements as performed in the subset of patients with measurable residual. On the basis of these results, high-resolution T2WI alone may be sufficient for early postoperative imaging surveillance in this patient population.

Factors Influencing Personalized Management of Vestibular Schwannoma: A Systematic Review

Management of vestibular schwannoma (VS) is a complex process aimed at identifying a clinical indication for fractionated stereotactic radiotherapy (sRT) or microsurgical resection or wait and scan (WS). The aim of the review was to clarify which patient and tumor parameters may lead to different therapeutic choices, with a view to a personalized VS approach. A systematic review according to Preferred Reporting Items for Systematic Review and Meta-Analysis criteria was conducted between February and March 2022. The authors defined six parameters that seemed to influence decision-making in VS management: 1-incidental VS; 2-tumor size; 3-tumor regrowth after sRT; 4-subtotal resection; 5-patients' age; 6-symptoms. The initial search yielded 3532 articles, and finally, 812 articles were included. Through a qualitative synthesis of the included studies, management strategies were evaluated and discussed. An individualized proposal of procedures is preferable as compared to a single gold-standard approach in VS decision-making. The most significant factors that need to be considered when dealing with a VS diagnosis are age, tumor size and hearing preservation issues.

Preoperative vestibular evoked myogenic potentials (VEMPs), caloric test, and pure tone audiometry to identify the vestibular nerve branch of schwannoma origin: preliminary results in a series of 26 cases

Vestibular schwannoma (VS) is a benign tumor which develops in the internal auditory canal and the cerebellopontine angle, potentially diminishing hearing or balance. Most VS tumors arise from one of two vestibular branches: the superior or inferior vestibular nerve. Determining the specific nerve of origin could improve patient management in terms of preoperative counseling, treatment selection, and surgical decision-making and planning. The aim of this study was to introduce a preoperative testing protocol with high accuracy to determine the nerve branch of origin. The nerve of origin was predicted on the basis of preoperative vestibular evoked myogenic potentials (VEMPs), caloric stimulation test, and pure tone audiometry on 26 recipients. The acquired data were entered into a statistic scoring system developed to allocate the tumor origin. Finally, the nerve of origin was definitively determined intraoperatively. Receiver operating characteristic (ROC) curves analysis of preoperative testing data showed the possibility of predicting the branch of origin. In particular, ROC curve of combined VEMPs absence, nystagmus detectable at caloric stimulation, and PTA < 75 dB HL allowed to obtain high accuracy for inferior vestibular nerve implant of the tumor (area under the curve-AUC = 0.8788, p = 0.012). In 24 of 26 cases, the preoperatively predicted tumor origin was the same as the origin determined during surgery. Preoperative audiological and vestibular evaluation can predict the vestibular tumor branch of origin with high accuracy. Despite the necessity of larger prospective cohort studies, these findings may change preoperative approach, possible functional aspects, and counseling with the patients.

Pediatric tinnitus: The role of neuroimaging

Tinnitus is defined as the perception of sound without an external source and can be categorized as either pulsatile or nonpulsatile (ie, continuous). A variety of etiologies have been reported to cause pediatric tinnitus, many with long-lasting implications due to hearing and concentration impairments. Therefore, imaging can be an essential part of the accurate and timely diagnosis of treatable etiologies. We describe neuroimaging findings in different etiologies of pediatric tinnitus. Etiologies of pulsatile tinnitus are frequently vascular in nature and include vascular loops, congenital vascular anomalies or variants, high riding jugular bulbs with or without a jugular bulb diverticulum, idiopathic intracranial hypertension, aneurysms, internal auditory canal hemangiomas, and petrous apex cephaloceles. Etiologies of continuous tinnitus frequently affect the middle/inner ear structures and include vestibular schwannomas, cholesteatomas, trauma, Chiari malformations, and labyrinthitis ossificans. CT and MR are often complementary modalities: CT is better suited to evaluate the integrity of the temporal osseous structures and MR is better suited to evaluate the vestibulocochlear nerve and to assess for the presence of any masses or malformations. Prompt diagnosis of the etiology of tinnitus in pediatric patients is important to avoid any potential long-term developmental impairments. In the approach to pediatric tinnitus, categorizing the symptoms as either pulsatile versus nonpulsatile and then being aware of the possible causes and imaging findings of either can assist both the clinician and the radiologist in making an expeditious diagnosis.

MRI and MR angiography evaluation of pulsatile tinnitus: A focused, physiology-based protocol

BACKGROUND AND PURPOSE

Pulsatile tinnitus (PT) is the subjective sensation of a pulse-synchronous sound, most often due to a cerebrovascular etiology. PT can severely impact quality of life and may indicate a life-threatening process, yet a timely and accurate diagnosis can often lead to effective treatment. Clinical assessment with a history and physical examination can often suggest a diagnosis for PT, but is rarely definitive. Therefore, PT should be evaluated with a comprehensive and targeted radiographic imaging protocol. MR imaging provides a safe and effective means to evaluate PT. Specific MR sequences may be used to highlight different elements of cerebrovascular anatomy and physiology. However, routine MR evaluation of PT must comply with economic and practical constraints, while effectively capturing both common and rarer, life-threatening etiologies of PT.

METHODS

In this state-of-the-art review, we describe our institutional MR protocol for evaluating PT.

RESULTS

This protocol includes the following dedicated sequences: time-of-flight magnetic resonance angiography; arterial spin labeling; spoiled gradient recalled acquisition in the steady state; time-resolved imaging of contrast kinetics; diffusion weighted imaging, and 3-dimensional fluid-attenuated inversion recovery.

CONCLUSIONS

We describe the physiologic and clinical rationale for including each MR sequence in a comprehensive PT imaging protocol, and detail the role of MR within the broader evaluation of PT, from clinical presentation to treatment.

Clinical usefulness of labyrinthine three-dimensional fluid-attenuated inversion recovery magnetic resonance images in idiopathic sudden sensorineural hearing loss

PURPOSE OF REVIEW

Literature on the use of current magnetic resonance imaging (MRI) for patients with idiopathic sudden sensorineural hearing loss (ISSNHL) is reviewed, emphasizing the role of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) MRI. The discussion focuses on the diagnostic role of temporal bone MRI using 3D-FLAIR and the relationship between MRI findings, clinical symptoms, and hearing outcome.

RECENT FINDINGS

The currently suggested MRI protocol for SSNHL includes a 3D T2-weighted steady-state free procession sequence or its equivalent, pre and postcontrast T1-weighted, and pre and postcontrast 3D-FLAIR sequences. The 3D-FLAIR image identifies an underlying labyrinthine condition in 24-57% of patients with ISSNHL, contributing to understanding the pathophysiologic mechanisms (e.g., labyrinthitis or labyrinthine hemorrhage). Recent studies demonstrated consistent results that initial hearing loss could be related to the signal change on the 3D-FLAIR image. Various results on 3D-FLAIR image value prediction for the final hearing outcome were shown.

SUMMARY

3D-FLAIR MRI application identifies an underlying labyrinthine condition. Abnormal MRI findings correlate with initial hearing loss and accompanying symptoms and hearing outcome. Performing temporal bone MRI with 3D-FLAIR sequence may clarify probable ISSNHL pathophysiology, improve diagnostic accuracy, provide prognostic information to physicians, and possibly guide toward a more specific treatment.