Vestibular Schwannoma Patients Research Articles

509 Modern Hearing Preservation Outcomes After Vestibular Schwannoma Stereotactic Radiosurgery

INTRODUCTION: For patients with vestibular schwannoma (VS), stereotactic radiosurgery (SRS) has proven effective in controlling tumor growth, while hearing preservation remains a key goal. METHODS: During the years 2013-2018, 353 patients underwent Gamma-knife surgery for VS at our institution. We followed 175 patients with pre-SRS serviceable hearing (Gardner-Robertson Score, GR 1 and 2). Volumetric and dosimetry data were collected, including Biological Effective Dose (BED), integral doses (ID) of total and intra-canalicular (IC) tumor components and hearing outcomes. RESULTS: Mean age was 56 years, 74 (42%) had baseline GR of 2, and mean cochlear dose was 3.5 Gy. Time to serviceable hearing loss (GR 3-4) was 38 months (95% CI, 26-46), with 77% and 62% hearing preservation in the 1st and 2nd years. Patients optimal for best hearing outcomes were younger than 58 with baseline GR of 1, free canal space 0.041cc (diameter of 4.5 mm) and mean cochlear dose <3.1 Gy. For such patients, hearing preservation rates were 92% by 12 months and 81% by 2 years, staying stable for >5 years post-SRS, significantly higher than the rest of the population. CONCLUSIONS: Hearing preservation after SRS for VS patients with serviceable hearing is correlated to the specific baseline GR score (1 or 2), age, cochlear dose and BED. Increased tumor-free canal space correlates with better outcomes. The most durable hearing preservation correlates with factors commonly associated with smaller tumors away from the cochlea.

Proton Radiotherapy for Vestibular Schwannomas in Patients with NF2-Related Schwannomatosis: A Case Series.

(1) Background: This study aimed to evaluate the efficacy and treatment-related toxicity of proton radiotherapy (PRT) for vestibular schwannoma (VS) in patients with neurofibromatosis type 2-related schwannomatosis (NF2). (2) Methods: Consecutive NF2 patients treated with PRT for VS between 2004 and 2016 were retrospectively evaluated, focusing on tumor volume, facial and trigeminal nerve function, hearing, tinnitus, vestibular symptoms, and the need for salvage therapy after PRT. (3) Results: Eight patients were included (median age 36 years, 50% female). Median follow-up was 71 months. Five (63%) patients received fractionated PRT and three (38%) received PRT radiosurgery for VS. Six patients (75%) received prior VS surgery; three also received bevacizumab. Six patients (75%) did not require salvage therapy after PRT. Two patients (25%) with residual hearing lost it after PRT, and six had already lost ipsilateral hearing prior to PRT. Tumor and treatment-related morbidity could be evaluated in six patients. Following PRT, conditions that occurred or worsened were: facial paresis in five (83%), trigeminal hypoesthesia in two (33%), tinnitus in two (33%), and vestibular symptoms in four patients (67%). (4) Conclusion: After PRT for VS, the majority of the NF2 patients in the cohort did not require additional therapy. Tumor and/or treatment-related cranial nerve deficits were common. This is at least partly explained by the use of PRT as a salvage treatment after surgery or bevacizumab, in the majority of cases. There remains the further opportunity to elucidate the efficacy and toxicity of proton radiotherapy as a primary treatment.

The characteristics of brain structural remodeling in patients with unilateral vestibular schwannoma.

Brain structural remodeling alters related brain function. However, few studies have assessed morphological alterations of unilateral vestibular schwannoma (VS) patients. Therefore, this study examined the characteristics of brain structural remodeling in unilateral VS patients. We recruited 39 patients with unilateral VS (19 left, 20 right) and 24 matched normal controls (NCs). We obtained brain structural imaging data using 3T T1-weighted anatomical and diffusion tensor imaging scans. Then, we evaluated both gray and white matter (WM) changes using FreeSurfer software and tract-based spatial statistics, respectively. Furthermore, we constructed a structural covariance network to assess brain structural network properties and the connectivity strength between brain regions. Compared with NCs, VS patients showed cortical thickening in non-auditory areas (e.g., the left precuneus), especially left VS patients, along with reduced cortical thickness in the right superior temporal gyrus (auditory areas). VS patients also showed increased fractional anisotropy in extensive non-auditory-related WM (e.g., the superior longitudinal fasciculus), especially right VS patients. Both left and right VS patients showed increased small-worldness (more efficient information transfer). Left VS patients had a single reduced-connectivity subnetwork in contralateral temporal regions (right-side auditory areas), but increased connectivity between some non-auditory regions (e.g., left precuneus and left temporal pole). VS patients exhibited greater morphological alterations in non-auditory than auditory areas, with structural reductions seen in related auditory areas and a compensatory increase in non-auditory areas. Left and right VS patients show differential patterns of brain structural remodeling. These findings provide a new perspective on the treatment and postoperative rehabilitation of VS.

The Effect of Metformin on Vestibular Schwannoma Growth: A Systematic Review and Meta-analysis.

To systematically review and evaluate metformin's potential impact on vestibular schwannoma (VS) growth. PubMed, Cochrane Library, and Embase. A retrospective cohort study was performed on sporadic VS patients undergoing initial observation who had at least two magnetic resonance imaging studies. Patients were stratified by metformin use during the observation period. Primary endpoint was VS growth, defined as at least a 2 mm increase in diameter. Survival free of tumor growth was evaluated between groups. Systematic review and meta-analysis were performed to produce a pooled odds ratio [OR]. Study heterogeneity was assessed and post-hoc power analysis was performed. A total of 123 patients were included, of which 17% were taking metformin. Median patient age was 56.6 years (range, 25.1-84.5). There were no statistically significant differences between the groups. Survival analysis did not demonstrate a statistically significant difference in time to VS growth between groups (hazard ratio=0.61, 95% confidence interval [CI]=0.29-1.29). Furthermore, logistic regression analysis did not demonstrate a statistically significant difference between groups in the odds of VS growth (OR=0.46, 95% CI=0.17-1.27). Systematic review identified 3 studies. Meta-analysis suggested that metformin reduces the odds of developing VS growth (pooled OR=0.45, 95% CI=0.29-0.71). Studies demonstrated low between-study heterogeneity. Power analysis demonstrated a sample size of 220 patients with equal randomization would be required to prospectively identify a true difference with 80% power. Metformin use may reduce the odds of VS growth. A randomized trial would be ideal to identify an unbiased estimate of metformin's effect on VS growth. Laryngoscope, 133:2066-2072, 2023.

Intratumoral hemorrhage in vestibular schwannomas after stereotactic radiosurgery.

Vestibular schwannomas (VSs) are benign tumors of the cerebellopontine angle that are typically managed with stereotactic radiosurgery (SRS). Intratumoral hemorrhage (ITH) of VSs is a rare occurrence that results in worsening vestibular and new cranial nerve deficits. Few reports have described the management and outcomes of this entity after SRS. To further delineate the incidence and impact of this event, the authors performed a retrospective review of their VS SRS patients at a single center. Between 1987 and 2022, 2058 patients with VSs underwent Gamma Knife radiosurgery (GKRS) at the University of Pittsburgh Medical Center. The authors performed a review of the prospectively maintained VS database at their center to identify patients with ITH. The presentation, management, and clinical and imaging outcomes of the patients are reported. A total of 1902 VS patients had sufficient clinical and imaging follow-up data. Five Koos grade III (n = 1) and IV (n = 4) VS patients developed ITH after GKRS, resulting in a cumulative incidence rate of 0.26%. The age at presentation ranged from 62 to 79 years, and 3 patients were male. The time from VS diagnosis to GKRS ranged from 1 to 13 months, and the time from GKRS to ITH ranged from 2 to 130 months. Three patients had bleeding risk factors. One patient required urgent surgical intervention due to the ITH volume, while the other 4 patients were initially observed. Three patients remained stable and required no delayed intervention; 1 patient required delayed resection because of symptom progression and hemorrhagic expansion. Histopathological analysis revealed multiple fragments of S-100-positive cells, hemorrhage, and hemosiderin-laden macrophages. At last follow-up, 4 patients had clinically improved and 1 patient remained stable. ITH after VS radiosurgery is a rare phenomenon with a cumulative incidence rate of 0.26% in this series. Patient-tailored management in the form of observation or resection is based on patient presentation, acuity, and ITH size.

How to position the patient? A meta-analysis of positioning in vestibular schwannoma surgery via the retrosigmoid approach.

Patient positioning is a matter of ongoing debate in the surgical treatment of vestibular schwannoma (VS). Main endpoints of this discussion are preservation of facial nerve functioning, extent of resection, and complications. In this meta-analysis, we aim to investigate the impact of patient positioning on VS surgery via the retrosigmoid approach. We searched for eligible comparative trials on PubMed, Cochrane library, and Web of Science. Positioning groups were compared regarding facial nerve outcome, extent of resection, postoperative hydrocephalus, postoperative CSF leaks, perioperative venous air embolism, and perioperative mortality. Two groups of positions were defined, and the following positions were allocated to those groups: (1) Semi-sitting and Sitting-position; (2) Lateral position, supine position with extensive head rotation, lateral oblique (=Fukushima/Three-quarter prone), and park-bench position. From 374 full-text screenings, 7 studies met the criteria and were included in our meta-analysis comprising 1640 patients. Our results demonstrate a significantly better long-term (≥6 months) outcome of the facial nerve after VS surgery in the semi-sitting positioning (OR: 1.49, 95%CI: 1.03-2.15, p = 0.03). Positioning did not influence the extent of resection, rate of postoperative CSF leaks, and the presence of a postoperative hydrocephalus. Overall incidence of venous air embolisms was significantly associated with VS surgery in sitting positioning (OR: 6.77, 95% CI: 3.66-12.54, p < 0.00001). Perioperative mortality was equal among both positioning groups. Semi-sitting positioning seems to be associated with an improved facial nerve outcome after VS surgery via the retrosigmoid approach. Venous air embolisms are significantly more often observed among VS patients who underwent surgery in the sitting position, but the perioperative mortality is equal in both positioning groups. Both positioning groups are a safe procedure. Multicentric prospective randomized trials are needed to evaluate the risk-benefit ratio of each positioning in VS surgery via the retrosigmoid approach.

Salvage radiosurgery following subtotal resection of vestibular schwannomas: does timing influence tumor control?

The goal of microsurgical resection of vestibular schwannoma (VS) is gross-total resection (GTR) to provide oncological cure. However, a popular strategy is to halt the resection if the surgical team feels the risk of cranial nerve injury is imminent, achieving a maximally safe subtotal resection (STR) instead. The tumor remnant can then be treated with stereotactic radiosurgery (SRS) once the patient has recovered from the immediate postoperative period, or it can be followed with serial imaging and treated with SRS in a delayed fashion if residual tumor growth is seen. In this study, the authors evaluated the efficacy of this multimodality approach, particularly the influence of timing and dose of SRS on radiological tumor control, need for salvage treatment, and cranial nerve function. VS patients treated with initial microsurgery and subsequent radiosurgery were retrospectively included from two tertiary treatment centers and dichotomized depending on whether SRS was given upfront (defined as before 12 months) or later. Radiological tumor control was defined as less than 20% tumor volume expansion and oncological tumor control as an absence of salvage treatment. Facial and cochlear nerve functions were assessed after surgery, at the time of SRS, and at last follow-up. Finally, a systematic literature review was conducted according to PRISMA guidelines. A total of 110 VS patients underwent SRS following microsurgical resection, with a mean preradiosurgical tumor volume of 2.2 cm3 (SD 2.5 cm3) and mean post-SRS follow-up time of 5.8 years (SD 4.1 years). The overall radiological tumor control and oncological tumor control were 77.3% and 90.9%, respectively. Thirty-five patients (31.8%) received upfront SRS, while 75 patients (68.2%) were observed for a minimum of 12 months prior to SRS. The timing of SRS did not influence the radiological tumor control (p = 0.869), the oncological tumor control (p = 0.560), or facial nerve (p = 0.413) or cochlear nerve (p = 0.954) function. An escalated marginal dose (> 12 Gy) was associated with greater tumor shrinkage (p = 0.020) and superior radiological tumor control (p = 0.020), but it did not influence the risk of salvage treatment (p = 0.904) or facial (p = 0.351) or cochlear (p = 0.601) nerve deterioration. Delayed SRS after close observation of residuals following STR is a safe alternative to upfront SRS regarding tumor control and cranial nerve preservation in selected patients.

Twelve-Month Outcomes of Simultaneous Translabyrinthine Resection and Cochlear Implantation.

Audiometric outcomes at 12 months following simultaneous translabyrinthine (TL) resection of vestibular schwannoma (VS) and cochlear implantation (CI). Prospective cohort study. Tertiary referral center. Adult patients undergoing TL resection of sporadic, unilateral VS ≤ 2 cm were prospectively enrolled. Preoperative testing included binaural AZBio in noise and quiet and unilateral Consonant-Nucleus-Consonant (CNC). Tinnitus Handicap Index (THI) and Speech, Spatial, and Qualities of Hearing (SSQ) questionnaires were also completed. Patients underwent TL resection with simultaneous CI. The preoperative test battery was repeated at 1, 3, 6, and 12 months after activation. Statistical analysis was performed to characterize short-term outcomes (preoperative to 3 months), longer-term outcomes (3-12 months), and overall changes during the preoperative to 12-month period. AZBio, CNC, and THI improved at 3 months with no significant changes thereafter and showed durable improvement at 12 months compared to preoperative testing. While SSQ did not improve at 12 months, a subset of patients showed either recovery or improvement of SSQ-spatial subscores. Patients with cerebellopontine angle tumors had poorer performance, although the impact of tumor size and location could not be deduced based on the small sample size. Patients undergoing simultaneous CI and TL resection of VS had durable improvements in speech perception and tinnitus severity 12 months following surgery. Subjective improvements in localization were not observed. Additional studies are needed to determine which VS patients are optimal candidates for CI.

The Relevance of Biologically Effective Dose for Hearing Preservation After Stereotactic Radiosurgery for Vestibular Schwannomas: A Retrospective Longitudinal Study.

Stereotactic radiosurgery has become a common treatment approach for small-to-medium size vestibular schwannomas. To evaluate relationship between time (beam-on and treatment) and risk of hearing decline after stereotactic radiosurgery for vestibular schwannomas in patients with Gardner-Robertson (GR) baseline classes I and II. This retrospective longitudinal single-center study included 213 patients with GR I and II treated between June 2010 and December 2019. Risk of passing from GR classes I and II (coded 0) to other classes III, IV, and V (coded 1) and the increase in pure tone average (continuous outcome) were evaluated using a mixed-effect regression model. Biologically effective dose (BED) was further assessed for an alpha/beta ratio of 2.47 (Gy 2.47 ). Binary outcome analysis revealed sex, dose rate, integral dose, time [beam-on time odds ratio 1.03, P = .03, 95% CI 1.00-1.06; treatment time ( P = .02) and BED ( P = .001) as relevant. Fitted multivariable model included the sex, dose rate, and BED. Pure tone average analysis revealed age, integral dose received by tumor, isocenter number, time (beam-on time odds ratio 0.20, P = .001, 95% CI 0.083-0.33) and BED ( P = .005) as relevant. Our analysis showed that risk of hearing decline was associated with male sex, higher radiation dose rate (cutoff 2.5 Gy/minute), higher integral dose received by the tumor, higher beam-on time ≥20 minutes, and lower BED. A BED between 55 and 61 was considered as optimal for hearing preservation.

Immunological Analysis of Vestibular Schwannoma Patients.

Vestibular schwannoma is a benign intracranial tumor of the vestibulocochlear nerve. Although it is a well-known pathology, growth factors and cytokine changes in vestibular schwannoma patients have not been totally elucidated. The objective of our study was to evaluate the concentration changes of transforming growth factor beta1, vascular endothelial growth factor, immunoglobulins A, M, and carcinoembryonic antigen in vestibular schwannoma patients. In our study, we performed an immunological analysis of 35 patients with vestibular schwannoma of different stages. According to the evolution of vestibular schwannoma, 20 patients did not show tumor growth, but 15 patients had a growing tumor. The level of vascular endothelial growth factor in the blood serum of study groups exceeded the control values by 8 times and transforming growth factor beta1 by 1.65. Increased values of immunoglobulin A and immunoglobulin M were observed in patients with intracanal, second, and third stages of tumor, compared with the control group. Carcinoembryonic antigen was found to be of increased values in patients with intracanal and third-stage vestibular schwannoma, in comparison to the control group. Growth factors such as vascular endothelial growth factor and transforming growth factor beta1 can play a significant role in the genesis of vestibular schwannoma. In vestibular schwannoma patients, their investigation is appropriate both in the process of monitoring and in the assessment of treatment effectiveness. Immunoglobulins M and A can be used as additional markers of vestibular schwannoma, especially in tumor growth. Carcinogenic embryonic antigen has high values only in the late stages of vestibular schwannoma development.

A systematic review of targeted therapy for vestibular schwannoma in patients with NF2-related schwannomatosis.

One of the hallmarks of NF2-related Schwannomatosis (NF2-related SWN) is bilateral vestibular schwannomas (VS) that can cause progressive hearing impairment in patients. This systematic review was performed to investigate the efficacy and toxicity of tested targeted agents. The systematic search was conducted on PubMed and EMBASE Ovid databases from inception to October 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The incidence of outcomes in studies involving bevacizumab and other targeted therapies was extracted. The bevacizumab results were pooled, and 95% confidence intervals (95% CI) were calculated. Sixteen studies (8 prospective and 8 retrospective) testing 6 drugs were selected out of 721 search results. There were 10 studies concerning bevacizumab, with a total of 200 patients. The pooled radiographic response rate (RR) was 38% (95% CI: 31 - 45%) and the pooled hearing response rate (HR) was 45% (95% CI: 36 - 54%). The most frequent bevacizumab-related toxicities were hypertension and menorrhagia. Of other targeted therapies showing activity, lapatinib had a RR of 6% and a HR of 31%. A VEGFR vaccine showed RR in 29% and HR in 40% of patients. Both agents had a manageable safety profile. Bevacizumab, in comparison to other targeted agents, showed the highest efficacy. Lower dosage of bevacizumab shows comparable efficacy and may reduce toxicity. Other targeted agents, administered alone or as combination therapy, have the potential to improve outcomes for VS in patients with NF2-related SWN, but future clinical studies are needed.

Age, MIB1 expression and widening of the internal acoustic meatus are associated with poor preoperative hearing in vestibular schwannoma patients.

Age, MIB1 expression and widening of the internal acoustic meatus are associated with poor preoperative hearing in vestibular schwannoma patients.

Long-Term Outcomes of Hearing Preservation After Retrosigmoid Removal of Large Vestibular Schwannoma.

Hearing preservation after large vestibular schwannoma (VS) removal is challenging and the long-term outcomes of postoperatively preserved hearing have not been elucidated. We aimed to clarify long-term outcomes of hearing preservation after the retrosigmoid large VS removal and to recommend a strategy for treating large VS. Hearing preservation with total/nearly total (T/NT) tumor removal was accomplished in six of 129 patients who underwent retrosigmoid large VS (≥3 cm) removal. We evaluated the long-term outcomes of these six patients. Preoperative hearing of these six patients was 15-68 dB by pure tone audiometry (PTA) (Class I: 2, II: 3, and III: 1 by the Gardner-Robertson (GR) classification). Postoperatively, magnetic resonance imaging (MRI) with gadolinium administration confirmed T/NT removal, the preserved hearing was 36-88 dB (Class II: 4 and III: 2), and no facial palsy occurred. After long-term follow-up (8-16 [median: 11.5] years), five patients maintained hearing of 46-75 dB (Class II: 1 and III: 4) while one lost hearing. Three patients showed small tumor recurrence on MRI; two recurrences were controlled by gamma knife (GK) and one showed minimal change only by observation. Hearing preserved after T/NT removal of large VS is maintained for a long time (>10 years), though tumor recurrence on MRI is somewhat common. Detecting small recurrence early, and regular MRI follow-up contributes to the long-term maintenance of hearing. Hearing preservation with tumor removal is a challenging yet worthwhile strategy in large VS patients with preoperative hearing.

Labyrinthine Fluid Signal Intensity on T2-Weighted MR Imaging in Patients With Vestibular Schwannomas Undergoing Proton Radiotherapy: A Longitudinal Assessment.

In vestibular schwannoma patients, a loss of signal intensity (SI) on T2-weighted magnetic resonance imaging (MRI) has been reported within the ipsilateral labyrinth. The purpose of this study was to quantitatively evaluate the occurrence and course of this intensity loss in relation to proton radiotherapy and its possible association with hearing loss. Retrospective chart review. Tertiary referral center. Patients who received proton therapy for a vestibular schwannoma and underwent at least two high-resolution T2-weighted cisternographic sequence (constructive interference in steady state/fast imaging employing steady-state acquisition/DRIVE) MRIs and audiometry assessments. Relative T2 SIs from the vestibules and basal/apical cochlear turns of the labyrinth, bilaterally. Ninety-five MRI scans from 34 patients were included. The apical turn of the ipsilateral cochlea showed a lower mean cochlear SI than on the contralateral side (±3.5 versus 5.0). The mean relative cochlear SI did not significantly change after proton radiotherapy. The ipsilateral vestibule showed a higher SI than the cochlea. The relative mean cochlear SI was not directly correlated to (the degree of) hearing loss before or after proton radiotherapy, nor did it predict future hearing loss. The relative mean cochlear SI on cisternographic T2-MRI in vestibular schwannoma patients is diminished on the treated side, when compared with the ipsilateral vestibule and the contralateral cochlea/vestibule. The SI of the ipsilateral cochlea does not further decrease after proton radiotherapy and seems to be related to the tumor rather than the therapy. The diminished cochlear SI does not correlate with subsequent loss of hearing.

Joint Vestibular Schwannoma Enlargement Prediction and Segmentation Using a Deep Multi-task Model.

To develop a deep-learning-based multi-task (DMT) model for joint tumor enlargement prediction (TEP) and automatic tumor segmentation (TS) for vestibular schwannoma (VS) patients using their initial diagnostic contrast-enhanced T1-weighted (ceT1) magnetic resonance images (MRIs). Initial ceT1 MRIs for VS patients meeting the inclusion/exclusion criteria of this study were retrospectively collected. VSs on the initial MRIs and their first follow-up scans were manually contoured. Tumor volume and enlargement ratio were measured based on expert contours. A DMT model was constructed for jointly TS and TEP. The manually segmented VS volume on the initial scan and the tumor enlargement label (≥20% volumetric growth) were used as the ground truth for training and evaluating the TS and TEP modules, respectively. We performed 5-fold cross-validation with the eligible patients (n=103). Median segmentation dice coefficient, prediction sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) were measured and achieved the following values: 84.20%, 0.68, 0.78, 0.72, and 0.77, respectively. The segmentation result is significantly better than the separate TS network (dice coefficient of 83.13%, p=0.03) and marginally lower than the state-of-the-art segmentation model nnU-Net (dice coefficient of 86.45%, p=0.16). The TEP performance is significantly better than the single-task prediction model (AUC=0.60, p=0.01) and marginally better than a radiomics-based prediction model (AUC=0.70, p=0.17). The proposed DMT model is of higher learning efficiency and achieves promising performance on TEP and TS. The proposed technology has the potential to improve VS patient management. NA Laryngoscope, 133:2754-2760, 2023.

Decision Making for Active Surveillance in Vestibular Schwannoma.

To describe the experiences of patients who elected for the active surveillance treatment option for their vestibular schwannoma (VS). Twenty-two patients participated in semistructured patient interviews. Interviews were conducted between March and April 2021 via telephone with audio recordings and notes taken during each interview. Adults diagnosed with a VS and at any point after their diagnosis underwent a period of active surveillance were recruited based on the diagnosis made by MRI. Patients were excluded if they chose to undergo treatment immediately, had a diagnosis of neurofibromatosis type 2, or if they had a confirmed alternative diagnosis. This intervention was a qualitative interview to assess patient experiences with their VS treatment decision. Identifying abstract categories that represent many of the stories told by the participants that produces a theory grounded in the data with explanatory power. Factors that influenced patients' treatment decisions were perceived physician bias, selfeducation, and personal accounts of VS patients through support groups, and side effects/complications of the various treatment options. Patients who opted for active surveillance as a treatment option reported high satisfaction with their decision and greater confidence in future treatments that would be necessary based on tumor growth. Future work should be done to increase shared decision making between the physician and patient to arrive at a treatment plan that aligns with their goals of care as well as potentially reducing overtreatment of VS.

Vestibular Complaints Impact on the Long-Term Quality of Life of Vestibular Schwannoma Patients.

To analyze the effect of dizziness-related symptoms on the long-term quality of life (QoL) of patients with unilateral vestibular schwannoma. In this cross-sectional study, patients with a unilateral vestibular schwannoma diagnosed between 2004 and 2013 completed a disease-specific QoL questionnaire (Penn Acoustic Neuroma Quality of Life [PANQOL]) and the Dizziness Handicap Inventory (DHI) in 2020. Linear regression was performed to assess the correlation between QoL and the DHI total score, and the scores of the DHI functional, emotional, and physical subdomains. Potential confounders such as age, sex, tumor size at baseline, and treatment modality (active surveillance, surgery, or radiotherapy) were included in the model. In total, 287 of 479 patients (59%) experienced dizziness with a median follow-up of 10 years. The DHI total score was significantly associated with the PANQOL total score. On average, we found a reduction of 0.7 points on the PANQOL for each additional point on the DHI. The DHI emotional subdomain was the most prominent determinant of poorer QoL. Each point on the DHI emotional subscale was associated with a reduction of 1.3 on the PANQOL score. Treatment modality did not have a clinically relevant effect on dizziness-related QoL. Even mild dizziness can have a significant and clinically relevant effect on the QoL of patients with unilateral vestibular schwannoma in the long term. This holds true for all treatment modalities. Addressing the vestibular problems may improve QoL in vestibular schwannoma patients, and DHI subscale analysis may help tailor the optimal vestibular intervention.

RADT-33. INTRATUMORAL HEMORRHAGE IN VESTIBULAR SCHWANNOMAS FOLLOWING GAMMA KNIFE STEREOTACTIC RADIOSURGERY

Abstract INTRODUCTION Intratumoral hemorrhage (ITH) is a rare occurrence in vestibular schwannomas (VS) resulting in worsening vestibular and cranial nerve deficits. Scarce data described the occurrence, management, and outcomes of ITH after stereotactic radiosurgery (SRS). OBJECTIVE The aim of this study is to delineate the incidence, presentation, management, and outcomes of ITH in VS patients following SRS. METHODS A total of 2058 patients with VS underwent Gamma Knife radiosurgery (GKRS) at the University of Pittsburgh Medical Center between 1987 and 2022. The authors identified patients with ITH. Their presentation, management, clinical, and imaging outcomes are reported and analyzed. RESULTS A total of 1902 VS patients had sufficient clinical and imaging follow-up data. Five Koos III (n = 1) and IV (n = 4) VS patients developed ITH after GKRS, resulting in a cumulative incidence rate of 0.26%. The age at presentation ranged from 62 to 79 years, and 3 of the patients were males. The time from VS diagnosis to GKRS ranged from 1-13 months, and the time from GKRS to ITH ranged from 2-130 months. Three patients had bleeding risk factors. One patient required urgent surgical intervention due to the ITH volume, while the other four patients initially were observed. Three remained stable and required no delayed intervention. Histopathological analysis revealed multiple fragments of S-100–positive cells, hemorrhage, and hemosiderin-laden macrophages. At last follow-up, 4 patients had clinically improved, and one remained stable.ConclusionVS ITH following SRS is a rare complication with a cumulative incidence rate of 0.26%. Patient-tailored management is vital based on patient presentation, acuity, and ITH size and characteristics.

The Diagnostic Accuracy of Pure-Tone Audiometry Screening Protocols for Vestibular Schwannoma in Patients with Asymmetrical Hearing Loss-A Systematic Review and Meta-Analysis.

(1) Background: Magnetic resonance imaging (MRI) is the gold standard investigation for all patients who present with asymmetrical hearing loss (AHL) and a high index of suspicion for vestibular schwannoma (VS). However, pure-tone audiometry (PTA) is an investigation that can be used for the screening of these patients in order to reduce the costs. The aim of this systematic review and meta-analysis was to evaluate the diagnostic accuracy of different PTA protocols for VS in patients with ASHL, when compared with MRI; (2) Methods: Medline, Embase, and Cochrane databases were used to find relevant studies. All prospective and retrospective observational studies that evaluated the accuracy of PTA protocols for the screening of VS were assessed, according to the international guidelines; (3) Results: We analyzed seven studies (4369 patients) of poor-to-moderate quality. Their pooled sensitivity was good (0.73-0.93), but their specificity was low (0.31-0.60). All protocols were located in the right lower quadrant on the likelihood scattergram, and the post-test probabilities for positive and negative diagnosis of these protocols were extremely low; (4) Conclusions: PTA protocols cannot be used for a proper screening or diagnosis of vestibular schwannoma despite their good sensibility, and MRI remains the gold standard for this purpose.

INNV-04. PRIMARY TREATMENT OF SMALL-TO-MEDIUM(&amp;lt; 3CM) SPORADIC VESTIBULAR SCHWANNOMAS: SYSTEMATIC REVIEW &amp; META-ANALYSIS (2010 TO 2020)

Abstract INTRODUCTION Over the past two decades, the treatment of small-to-medium (&amp;lt; 3cm) sporadic vestibular schwannomas (VS) has experienced a definite shift to stereotactic radiosurgery vis-a-vis microsurgery. We performed a systematic review and meta-analysis of VS patients primarily treated with stereotactic radiosurgery (SRS) or microsurgery (MS), with particular attention to hearing preservation outcomes (HPO), tumor control (TC), and facial nerve dysfunction (FND). Materials and METHODS A systematic review was conducted (Medline database) for the period, 2010 to 2020. Studies with mean/median follow-up of &amp;gt;/= 3 years were included. Studies had to report an acceptable standardized hearing metric. HPO, TC, and treatment complications (with special attention to FND) were compared between the MS and SRS groups. RESULTS Thirty-two studies met our inclusion criteria: 10 for microsurgery and 23 for radiosurgery (one comparative study included in both arms). HPO were comparable between MS group and SRS group (56% and 59%, p=0.1527). TC was significantly better in MS group (98%) versus SRS group (92%) [p &amp;lt; 0.0001]. FND was significantly higher in MS group (11%) versus SRS group (2%) [p &amp;lt; 0.0001]. CONCLUSION The ability to diagnose small sporadic VS earlier, allows patients time to consider all possible treatment options which include observation, radiosurgery, or microsurgery. The data presented in this study will assist physicians in their ability to appropriately counsel patients on the benefits and risks of both treatment modalities with the most recent evidence on the factors that contribute greatly to patients’ quality of life: HPO, TC and FND.