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Objective To investigate the strategy of endoscopy-assisted microsurgery for treating vestibular schwannomas and evaluate its feasibility and significance in the surgical management. Methods The clinical data of 85 cases of surgically treated vestibular schwannoma admitted to Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School from January 2018 to June 2023 were analyzed retrospectively. Preoperative enhanced magnetic resonance imaging (MRI) scanning was performed, followed by tumor resection using a posterior keyhole approach via the suboccipital sigmoid sinus. According to the different surgical methods, 45 cases were divided into the group of internal auditory canal removal and resection of internal auditory canal tumors with the assistance of neuroendoscopy, and 40 cases in the group of simple microscopic resection. Tumor resection rate, facial nerve retention rate, facial paralysis, and complications were observed. Results There were no significant differences in baseline data between the two groups (P>0.05) except for age and tumor size (both P<0.01). The total resection rate of tumors in the internal auditory canal in the observation group (91.1%) was higher than that in the control group (60.0%) (P<0.05). The postoperative follow-up showed that the recurrence rate of tumor residual in the observation group (4.44%) was lower than that in the control group (15.0%) (P<0.05). There was no significant difference in facial nerve function and facial nerve preservation rate between the two groups (P>0.05). There was no significant difference in postoperative complications such as cerebrospinal fluid leakage and cerebellar contusion between the two groups. There was no death or disability in this group. Conclusions Neuroendoscopic assisted microsurgery for the treatment of acoustic neuroma has a definite therapeutic effect, high. safety, and is beneficial for the assessment and preservation of the facial nerve, especially in terms of the total resection rate of tumors in the internal auditory canal, when compared to full process microscopic resection. [ABSTRACT FROM AUTHOR]

Objective: To examine patient characteristics that impact serial observation adherence among vestibular schwannoma (VS) patients. Study Design: Retrospective chart review. Setting: Single tertiary care center. Methods: We selected for VS patients from 201 to 2020 who elected for serial observation as initial management. Patients under 18, with previous management, bilateral or intralabyrinthine VS, and neurofibromatosis type 2 were excluded. Demographics, tumor characteristics, and follow‐up status were extracted. Single and multiple logistic regression was used to identify patient characteristics impacting follow‐up. Results: We identified 507 VS patients who chose serial observation as initial management. Most were female (56.0%), white (73.0%), and married (72.8%). The mean age was 59.3 and most had private insurance (56.4%). Median Charlson Comorbidity Index was 2.00. Mean pure tone audiometry (PTA) average was 41.7 Hz. Average tumor size was 9.04 mm. Of 507 patients, 358 (70.6%) returned for at least one follow‐up. On multiple logistic regression analysis, patients with private insurance (odds ratio [OR]: 0.39, confidence interval [CI]: 0.22‐0.68; P =.001), racial minority background (OR: 0.54, CI: 0.35‐0.83; P =.005), worse PTA averages (OR: 0.99, CI: 0.98‐1.00; P =.044), and older age at diagnosis (OR: 0.97, CI: 0.95‐1.00; P =.038) were less likely to follow‐up. Conclusion: Private health insurance, racial minority background, worse PTA average, and older age were associated with decreased follow‐up among adult VS patients electing serial observation. Patients with these characteristics may require additional support to ensure serial observation adherence. [ABSTRACT FROM AUTHOR]

The objective of this study is to preliminarily investigate the surgical safety, efficacy, techniques, and clinical value of fully neuroendoscopic surgery for the resection of cerebellopontine angle (CPA) tumors via a retrosigmoid approach. The clinical data of 47 cerebellopontine angle area (CPA) tumors that were treated by full neuroendoscopic surgery from June 2014 to June 2023 were retrospectively analyzed. The efficacy and advantages of the surgical techniques were evaluated based on indicators such as duration of the surgery, neuroendoscopic techniques, intraoperative integrity of nerves and blood vessels, extent of tumor resection, outcomes or postoperative symptoms, and incidence of complications. The 47 cases of cerebellopontine angle tumors include 34 cases of epidermoid cysts, 7 cases of vestibular schwannomas, and 6 cases of meningiomas. All patients underwent fully neuroendoscopic surgery. Twenty tumors were removed using the one-surgeon two-hands technique, and 27 tumors were removed using the two-surgeons four-hands technique. The anatomical integrity of the affected cranial nerves was preserved in all 47 cases. None of the patients suffered a postoperative hemorrhage, cerebrospinal fluid leak, and aseptic or septic meningitis, or died. The rate of total tumor resection was 72.3% (34/47), and the symptom improvement rate was 89.4% (42/47). All patients were followed up for 2 to 12 months, and none died nor showed any signs of tumor recurrence. By analyzing 47 fully neuroendoscopic resections of CPA tumors using the posterior sigmoid sinus approach in our center, we believe that such method allows complete, safe, and effective resection of CPA tumors and is thereby worthy of clinical promotion. [ABSTRACT FROM AUTHOR]

Vestibular schwannoma is the most common benign neoplasm of the cerebellopontine angle. Its first symptoms include hearing loss, tinnitus, and vestibular symptoms, followed by cerebellar and brainstem symptoms, along with palsy of the adjacent cranial nerves. However, the clinical picture has unpredictable dynamics and currently, there are no reliable predictors of tumor behavior. Hence, it is desirable to have a fast routine method for analysis of vestibular schwannoma tissues at the molecular level. The major objective of this study was to verify whether a technique using in‐sample specific protein digestion with trypsin would have the potential to provide a proteomic characterization of these pathological tissues. The achieved results showed that the use of this approach with subsequent liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) analysis of released peptides allowed a fast identification of a considerable number of proteins in two differential parts of vestibular schwannoma tissue as well as in tissues of control healthy samples. Furthermore, mathematical analysis of MS data was able to discriminate between pathological vestibular schwannoma tissues and healthy tissues. Thus, in‐sample protein digestion combined with LC‐MS/MS separation and identification of released specific peptides followed by mathematical analysis appears to have the potential for routine characterization of vestibular schwannomas at the molecular level. Data are available via ProteomeXchange with identifier PXD045261. [ABSTRACT FROM AUTHOR]

Abstract Background Long-term follow-up using volumetric measurement could significantly assist in the management of vestibular schwannomas (VS). Manual segmentation of VS from MRI for treatment planning and follow-up assessment is labor-intensive and time-consuming. This study aims to develop a deep learning technique to fully automatically segment VS from MRI. Methods This study retrospectively analyzed MRI data of 737 patients who received gamma knife radiosurgery for VS. Treatment planning T1-weighted isotropic MR and manually contoured gross tumor volumes (GTV) were used for model development. A 3D convolutional neural network (CNN) was built on ResNet blocks. Spatial attenuation and deep supervision modules were integrated in each decoder level to enhance the training for the small tumor volume on brain MRI. The model was trained and tested on 587 and 150 patient data, respectively, from this institution (n = 495) and a publicly available dataset (n = 242). The model performance were assessed by the Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), average symmetric surface (ASSD) and relative absolute volume difference (RAVD) of the model segmentation results against the GTVs. Results Measured on combined testing data from two institutions, the proposed method achieved mean DSC of 0.91 ± 0.08, ASSD of 0.3 ± 0.4 mm, HD95 of 1.3 ± 1.6 mm, and RAVD of 0.09 ± 0.15. The DSCs were 0.91 ± 0.09 and 0.92 ± 0.06 on 100 testing patients of this institution and 50 of the public data, respectively. Conclusions A CNN model was developed for fully automated segmentation of VS on T1-Weighted isotropic MRI. The model achieved good performance compared with physician clinical delineations on a sizeable dataset from two institutions. The proposed method potentially facilitates clinical workflow of radiosurgery for VS patient management.

Background: Long-term follow-up using volumetric measurement could significantly assist in the management of vestibular schwannomas (VS). Manual segmentation of VS from MRI for treatment planning and follow-up assessment is labor-intensive and time-consuming. This study aims to develop a deep learning technique to fully automatically segment VS from MRI. Methods: This study retrospectively analyzed MRI data of 737 patients who received gamma knife radiosurgery for VS. Treatment planning T1-weighted isotropic MR and manually contoured gross tumor volumes (GTV) were used for model development. A 3D convolutional neural network (CNN) was built on ResNet blocks. Spatial attenuation and deep supervision modules were integrated in each decoder level to enhance the training for the small tumor volume on brain MRI. The model was trained and tested on 587 and 150 patient data, respectively, from this institution (n = 495) and a publicly available dataset (n = 242). The model performance were assessed by the Dice similarity coefficient (DSC), 95% Hausdorff distance (HD95), average symmetric surface (ASSD) and relative absolute volume difference (RAVD) of the model segmentation results against the GTVs. Results: Measured on combined testing data from two institutions, the proposed method achieved mean DSC of 0.91 ± 0.08, ASSD of 0.3 ± 0.4 mm, HD95 of 1.3 ± 1.6 mm, and RAVD of 0.09 ± 0.15. The DSCs were 0.91 ± 0.09 and 0.92 ± 0.06 on 100 testing patients of this institution and 50 of the public data, respectively. Conclusions: A CNN model was developed for fully automated segmentation of VS on T1-Weighted isotropic MRI. The model achieved good performance compared with physician clinical delineations on a sizeable dataset from two institutions. The proposed method potentially facilitates clinical workflow of radiosurgery for VS patient management. [ABSTRACT FROM AUTHOR]

Introduction: Intralabyrinthine schwannomas, including the intracochlear variety, are rare benign tumors. They can cause a number of symptoms and have the potential to grow to involve other critical structures of the inner ear and skull base. While surgical resection is feasible, there is typically permanent hearing dysfunction as a result of resection and subsequent fibrosis. Here, we present 2 cases of intracochlear schwannomas (ICS) that were successfully resected with simultaneous cochlear implant placement. Methods: Patient 1 presented with an intravestibulocochlear schwannoma. This patient underwent a translabyrinthine approach. Endoscopic assistance was used to dissect the tumor from the vestibule and basal turn of the cochlea, through an enlarged round window approach. A cochlear implant was placed via a round window cochleostomy. Patient 2 presented with an intracochlear schwannoma involving the basal and middle turns of the cochlea. The patient underwent a trans-otic approach for resection. A large portion of the cochlear promontory required unroofing for complete exposure of the tumor. A cochlear implant was then placed via a round window cochleostomy. Results: Upon cochlear implant activation, Patient 1's sound field thresholds using the implant were near the normal range of hearing, ranging from 25 to 50 dB HL from 250 to 6000 Hz. Patient 2's 6-month post-operative cochlear implant sound field testing ranged from 20 to 30 dB HL from 250 to 6000 Hz and speech recognition testing revealed 59% on AZ Bio sentences compared to 0% pre-operatively. Conclusion: Simultaneous cochlear implantation after resection of intracochlear schwannomas is safe and successful in restoring hearing. Attention to adequate exposure and endoscopic assistance, when required, allow for gross total resection while minimizing trauma to cochlear structures. In such cases, immediate cochlear implantation allows for hearing rehabilitation before likely cochlear fibrosis can occur. [ABSTRACT FROM AUTHOR]

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Background: Vestibular schwannomas (VSs) exhibit a range of tumor behaviors, such as growth patterns and auditory dysfunction. Recent research has offered insights into the inflammatory microenvironment in modulating tumor dynamics. This study investigates the role of inflammatory genes and immune infiltration in VS pathogenesis., Methods: We retrieved mRNA microarray data of VSs and normal nerves from the GEO database (GSE141801, GSE108524, and GSE56597), focusing on bioinformatic analysis of inflammatory response genes. Based on the evidence provided by bioinformatics analysis, we assessed the expression levels of Iba-1, IL-10, IL-10RA, and IL-18 in 31 VS patients via immunohistochemistry and delved into their association with tumor size and auditory dysfunction., Results: We identified 1117 differentially expressed genes (DEGs) in VSs compared to normal nerves, showing an upregulation in inflammatory pathways. Intersection with inflammatory response genes (IRG) yielded 41 significant IRG-DEGs. Network analysis identified a core module of 10 IRG-DEGs and 11 hub genes, most of which were inflammatory cytokines. Immune infiltration analysis showed macrophage activation and M2 polarization. These findings were validated in an independent dataset (GSE39645). To further explore the association between inflammation and tumor behaviors, immunohistochemistry analysis was conducted on VS samples and the results exhibited notable associations between the macrophage marker (Iba1) and inflammatory cytokines (IL-10, IL-10RA, and IL-18) with both tumor size and auditory dysfunction. In particular, the multiple regression analysis of inflammatory cytokines demonstrated that IL-10 and IL-10RA were statistically significant predictors of tumor size, while IL-18 was associated with hearing loss., Conclusion: Our study underscores the role of inflammation in VS pathogenesis, showing that macrophage activation with M2 polarization and the expression of inflammatory cytokines, especially IL-10/IL-10RA and IL-18, are linked to tumor size and auditory function. This study highlights the inflammatory landscape's impact on VS behaviors, providing a basis for targeted therapeutic strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Gan et al.)

The auditory brainstem response (ABR) and middle latency response (MLR) are two sets of evoked potentials that have made major contributions to the field of diagnostic audiology. Many of these contributions were guided by clinical research audiologists. Though many of these auditory evoked potentials (AEPs) are still being used diagnostically by audiologists, there has been a steep decline in their popularity both clinically and in the research laboratory. This is indeed most unfortunate because these AEPs could and should be advancing our field and benefitting many patients. In this article, some critical research is overviewed that addresses some of the reasons why these AEPs (ABR and MLR) are not being utilized as frequently as they should be for neuroauditory assessments. Reflecting on our past when ABR and MLR were more commonly used can serve as a model for our future. Multiple applications and the diagnostic value of these AEPs are presented in an effort to convince audiologists that these electrophysiologic procedures should be revisited and reapplied in the clinic and research settings. It is argued that the dwindling use of ABR and MLR (and AEPs in general) in the field of audiology is not only remarkably premature but also lacks good scientific grounding. While on the other hand, if applied clinically, the value of these AEPs is both substantial and promising. [ABSTRACT FROM AUTHOR]

Purpose: Stereotactic radiosurgery (SRS) is a standard treatment modality for vestibular schwannomas (VSs). However, there is a paucity of data on tumor control and neurological preservation for larger VSs. We aimed to investigate the long-term effectiveness of SRS for Koos grade IV compared with I-III VSs. Methods: We included 452 patients with VSs (50 Koos grade IV and 402 Koos grade I‒III) who were treated with SRS at our institution from 1990 to 2021. Tumor control and functional preservation were calculated using the Kaplan–Meier method and compared between groups with the log-rank test. Results: The median post-SRS follow-up period was 68 months. Progression-free survival rates were 91% at 5 and 10 years for Koos grade IV VSs, and 95% and 92%, respectively, for Koos grade I‒III VSs (p = 0.278). In Koos grade IV VSs, functional preservation rates of the facial and trigeminal nerves were both 96% at 5 years (both 98% for Koos grade I‒III VSs; facial, p = 0.410; trigeminal, p = 0.107). Hearing preservation rates were 61% at 5 years for Koos grade IV VSs and 78% for Koos grade I–III VSs (p = 0.645). Symptomatic transient tumor expansion was more common with Koos grade IV VSs (8.0% vs. 2.5%, p = 0.034), although all related symptoms diminished in accordance with tumor shrinkage. Conclusion: SRS may contribute to long-term tumor control and adequate neurological preservation in the treatment of Koos grade IV VSs, comparable to those in the treatment of Koos grade I‒III VSs. [ABSTRACT FROM AUTHOR]

Surgical anatomy training in a dedicated research laboratory and attendance to focused “hands-on” dissection courses are of high educational importance in order to acquire and maintain surgical expertise in skull base surgery, both for young and more experienced surgeons. Nevertheless, transitioning surgical skills and anatomic knowledge from the laboratory to the operative room it is not free of challenges, especially during skull base approaches where the three-dimensional surgical orientation can be quite complex. We present a “step-by-step” and “side-by-side” surgical anatomy report on a translabyrinthine approach that was practiced in the laboratory then performed in the operative room by the surgical team, and we compare surgical anatomy exposures while discussing intraoperative techniques, nuances and challenges, both in the laboratory and the operative room.

Objective: We aimed to explore the application and prospects of the subperineural resection technique for tumor separation and removal under the perineurium during surgery for vestibular schwannomas (VSs). Methods: This study retrospectively analyzed 124 patients with VSs who underwent surgery via a retrosigmoid approach from July 2015 to October 2020 in the Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University. The data will be discussed with regard to the following aspects: clinical features, surgical strategies, tumor resection extent, facial–acoustic function preservation, and postoperative complications. Results: Gross total resection (GTR) of the tumor was achieved in 104 patients, with a GTR rate of 83.9%, and subtotal resection (STR) of the tumor was achieved in 20 patients. There was no significant difference in facial and acoustic nerve functional preservation between GTR and STR, as well as in tumor resection between solid and cystic tumors. The retention rate reached 97.6% in terms of complete anatomical facial nerve preservation. Facial nerve function was assessed using the House–Brackmann (HB) grading score. Consequently, HB grades of I–II, III–IV, and V–VI were determined for 96 (77.4%), 25 (20.2%), and 3 (2.4%) cases, respectively, 1 week postoperatively and accounted for 110 cases (88.7%), 13 cases (10.5%), and 1 case (0.8%), respectively, at 6 months. Fifteen of 35 (42.9%) patients with serviceable hearing before the operation still had serviceable hearing at 6 months postoperatively. There were 5 cases of cerebellar or brainstem bleeding after the operation, and one patient died. Multivariate logistic regression analysis showed that older age (≥60 years, p = 0.011), large tumor (>3 cm, p = 0.004), and cystic tumor (p = 0.046) were independent risk factors associated with the extent of adhesion between the tumor and the brainstem and facial–acoustic nerve. Conclusion: We successfully applied the subperineural resection technique to a large series of patients with VSs and achieved satisfactory results. Accurate identification of the perineurium and subperineural resection of the tumor can effectively reduce the disturbance of the facial–acoustic nerve during the operation and provide an intuitive basis for judging the tumor boundary. The subperineural resection technique may be conducive to improving the rate of total tumor resection and facial–acoustic nerve functional preservation in the surgical treatment of VSs. [ABSTRACT FROM AUTHOR]

Simple Summary: The standard of care for radiotherapy of symptomatic or progressive vestibular schwannomas (VS) is photon beam single-dose radiosurgery (applying 1 × 12 Gy) or (hypo)fractionated radiotherapy (applying 3 × 6 Gy up to 32 × 1.8 Gy). Only few centers also enable irradiation with protons. Proton therapy offers unique physical properties whereby healthy tissue around the tumor can be protected although a very high dose is applied to the target lesion. In patients with benign brain tumors such as vestibular schwannomas reduction of treatment-related side effects is very important. Few data comparing photon vs. proton beam radiotherapy for patients with VS are available. Thus, a detailed evaluation of differences in tumor control, symptoms and quality of life in patients with VS after photon beam vs. proton beam radiotherapy is needed. Background: To evaluate differences in local tumor control (LC), symptoms and quality of life (QOL) of 261 patients with VS after stereotactic radiosurgery/hypofractionated stereotactic radiotherapy (SRS/HFSRT) vs. fractionated radiotherapy (FRT) vs. fractionated proton therapy (FPT) were studied. Methods: For SRS/HFSRT (n = 149), the median fraction dose applied was 12 Gy. For FRT (n = 87) and FPT (n = 25), the median cumulative doses applied were 57.6 Gy and 54 Gy (RBE), respectively. FRT and FPT used single median doses of 1.8 Gy/Gy (RBE). Median follow-up was 38 months. We investigated dosimetry for organs at risk and analyzed toxicity and QOL by sending out a questionnaire. Results: LC was 99.5% at 12 months after RT with no statistical difference between treatment groups (p = 0.19). LC was significantly lower in NF2 patients (p = 0.004) and in patients with higher tumor extension grade (p = 0.039). The hearing preservation rate was 97% at 12 months after RT with no statistical difference between treatment groups (p = 0.31). Facial and trigeminal nerve affection after RT occurred as mild symptoms with highest toxicity rate in FPT patients. Conclusion: SRS/HFSRT, FRT and FPT for VS show similar overall clinical and functional outcomes. Cranial nerve impairment rates vary, potentially due to selection bias with larger VS in the FRT and FPT group. [ABSTRACT FROM AUTHOR]

Jianfei Long,1,* Yu Zhang,1,* Xiang Huang,2 Junwei Ren,2 Ping Zhong,2 Bin Wang1 1Department of Pharmacy, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China; 2Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ping ZhongDepartment of Neurosurgery, Huashan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai 200040, People’s Republic of ChinaEmail zhp228899@163.comBin WangDepartment of Pharmacy, Huashan Hospital, Fudan University, No. 12 Middle Wu Lu Mu Qi Road, Shanghai 200040, People’s Republic of ChinaTel +86 13916606721Email wangbin@huashan.org.cnAbstract: Vestibular schwannomas (VSs, also known as acoustic neuromas) are benign intracranial tumors commonly managed with observation, surgery, and radiotherapy. There is currently no approved pharmacotherapy for VS patients, which is why we conducted a detailed search of relevant literature from PubMed and Web of Science to explore recent advances and experiences in drug therapy. VSs feature a long course of disease that requires treatment to have minimal long-term side effects. Conventional chemotherapeutic agents are characterized by neurotoxicity or ototoxicity, poor effect on slow-growing tumors, and may induce new mutations in patients who have lost tumor suppressor function, and therefore are unsuitable for treating VSs. Along with the well-investigated molecular pathophysiology of VS and the increasingly accessible technology such as drug repositioning platform, many molecular targeted inhibitors have been identified and shown certain therapeutic effects in preclinical experiments or clinical trials.Keywords: vestibular schwannomas, drug therapy, therapeutic targets, VEGFR inhibitor

ObjectiveWe aimed to explore the application and prospects of the subperineural resection technique for tumor separation and removal under the perineurium during surgery for vestibular schwannomas (VSs).MethodsThis study retrospectively analyzed 124 patients with VSs who underwent surgery via a retrosigmoid approach from July 2015 to October 2020 in the Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University. The data will be discussed with regard to the following aspects: clinical features, surgical strategies, tumor resection extent, facial–acoustic function preservation, and postoperative complications.ResultsGross total resection (GTR) of the tumor was achieved in 104 patients, with a GTR rate of 83.9%, and subtotal resection (STR) of the tumor was achieved in 20 patients. There was no significant difference in facial and acoustic nerve functional preservation between GTR and STR, as well as in tumor resection between solid and cystic tumors. The retention rate reached 97.6% in terms of complete anatomical facial nerve preservation. Facial nerve function was assessed using the House–Brackmann (HB) grading score. Consequently, HB grades of I–II, III–IV, and V–VI were determined for 96 (77.4%), 25 (20.2%), and 3 (2.4%) cases, respectively, 1 week postoperatively and accounted for 110 cases (88.7%), 13 cases (10.5%), and 1 case (0.8%), respectively, at 6 months. Fifteen of 35 (42.9%) patients with serviceable hearing before the operation still had serviceable hearing at 6 months postoperatively. There were 5 cases of cerebellar or brainstem bleeding after the operation, and one patient died. Multivariate logistic regression analysis showed that older age (≥60 years, p = 0.011), large tumor (>3 cm, p = 0.004), and cystic tumor (p = 0.046) were independent risk factors associated with the extent of adhesion between the tumor and the brainstem and facial–acoustic nerve.ConclusionWe successfully applied the subperineural resection technique to a large series of patients with VSs and achieved satisfactory results. Accurate identification of the perineurium and subperineural resection of the tumor can effectively reduce the disturbance of the facial–acoustic nerve during the operation and provide an intuitive basis for judging the tumor boundary. The subperineural resection technique may be conducive to improving the rate of total tumor resection and facial–acoustic nerve functional preservation in the surgical treatment of VSs.

We present the updated recommendations of the French Society for Radiation Oncology on benign intracranial tumours. Most of them are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumours. Some grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumours are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumour, or a local relapse. Indications have to be discussed at a multidisciplinary panel, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumours, are commonly realized, to avoid as much a possible the occurrence of late side effects. [ABSTRACT FROM AUTHOR]

Objective: To explore the role of neuroendoscope assistance during surgical resection of the intracanalicular portion of vestibular schwannomas via the retrosigmoid approach and the subsequent early facial nerve outcomes. Methods: Patients of vestibular schwannoma with intracanalicular extensions undergoing retrosigmoid dissection at a single institution were retrospectively analyzed in this study. Several surgical techniques were applied to ensure maximal and safe removal of tumors. Tumors extending less than 10 mm into the internal acoustic canal (IAC) were classified as Grade A, while those extending over 10 mm into IAC were taken as Grade B. Neuroendoscope was applied at the end of microscopic phase to search for potential remnants for Grade B tumors. Absolute tumor extension was defined and measured. House and Brackmann (HB) scale was used to evaluate immediate CN VII outcomes. Results: Of the 61 patients, there were 38 females and 23 males. A total of 18 (29.51%) cases were Koos Grade II, 12 (19.67%) cases Koos Grade III, and 31 (50.82%) cases Koos Grade IV. There were 38 cases (62.30%) of Grade A and 23 cases (37.70%) of Grade B. Gross total resection was achieved in 60 cases (98.36%). Four cases of intracanalicular remnants were detected and completely removed under endoscopic visualizations. There was a significantly higher proportion (17%, p = 0.02) of intracanalicular remnants in Grade B than Grade A. CN VII and VIII were anatomically preserved in all cases. A total of 55 cases (90.16%) retained good (HB Grades 1 and 2) facial nerve outcomes. Conclusions: In Grade B vestibular schwannomas, after maximal microsurgical removal, endoscopic evaluation of the intracanalicular portion revealed residual tumors in 17% of the patients. Hence endoscopic evaluation of the potential intracanalicular remnants for tumor extending over 10 mm within IAC (Grade B) is recommended. [ABSTRACT FROM AUTHOR]

Vestibular schwannoma is the third most common benign intracranial tumor that can occur sporadically or be associated with neurofibromatosis type 2 (neurofibromatosis type 2 vestibular schwannoma [NF2-VS]). The aim of this study is to provide a comprehensive bioinformatic analysis of methylated-differentially expressed genes (MDEGs) in NF2-VS. Transcriptional sequencing datasets (GSE141801 and GSE108524) and gene methylation microarrays (GSE56598) from the Gene Expression Omnibus database were used to identify and analyze MDEGs in NF2-VS. A protein–protein interaction (PPI) network was built, and the hub genes and modules were identified. Finally, potential pharmacotherapy targeting MDEGs were extracted for NF2-VS. A total of 57 hypermethylation–low expression genes and 88 hypomethylation–high expression genes were identified. Pathways associated with aberrantly MDEGs included P13K-AKT, MAPK, and Ras, which were also involved in NF2-VS. Six hub genes (EGFR, CCND1 , CD53, CSF1R, PLAU , and FGFR1) were identified from the PPI network. Modification of the aforementioned genes altered cell-to-cell communication, response to stimulus, cellular regulation, and membrane and protein bindings. Thirty drugs targeting these pathways were selected based on the hub genes. Analysis of MDEGs may enrich the understanding of the molecular mechanisms of NF2-VS pathogenesis and lay the groundwork for potential biomarkers and therapeutic targets for NF2-VS. [ABSTRACT FROM AUTHOR]

ObjectiveTo explore the role of neuroendoscope assistance during surgical resection of the intracanalicular portion of vestibular schwannomas via the retrosigmoid approach and the subsequent early facial nerve outcomes.MethodsPatients of vestibular schwannoma with intracanalicular extensions undergoing retrosigmoid dissection at a single institution were retrospectively analyzed in this study. Several surgical techniques were applied to ensure maximal and safe removal of tumors. Tumors extending less than 10 mm into the internal acoustic canal (IAC) were classified as Grade A, while those extending over 10 mm into IAC were taken as Grade B. Neuroendoscope was applied at the end of microscopic phase to search for potential remnants for Grade B tumors. Absolute tumor extension was defined and measured. House and Brackmann (HB) scale was used to evaluate immediate CN VII outcomes.ResultsOf the 61 patients, there were 38 females and 23 males. A total of 18 (29.51%) cases were Koos Grade II, 12 (19.67%) cases Koos Grade III, and 31 (50.82%) cases Koos Grade IV. There were 38 cases (62.30%) of Grade A and 23 cases (37.70%) of Grade B. Gross total resection was achieved in 60 cases (98.36%). Four cases of intracanalicular remnants were detected and completely removed under endoscopic visualizations. There was a significantly higher proportion (17%, p = 0.02) of intracanalicular remnants in Grade B than Grade A. CN VII and VIII were anatomically preserved in all cases. A total of 55 cases (90.16%) retained good (HB Grades 1 and 2) facial nerve outcomes.ConclusionsIn Grade B vestibular schwannomas, after maximal microsurgical removal, endoscopic evaluation of the intracanalicular portion revealed residual tumors in 17% of the patients. Hence endoscopic evaluation of the potential intracanalicular remnants for tumor extending over 10 mm within IAC (Grade B) is recommended.

Background: The medical community has shown a growing interest in developing methods for measuring and comparing objective patient outcomes coupled with subjective patient assessments. Questionnaires enable healthcare professionals to obtain the patient's perspective about their experienced vestibular schwannomas (VS) symptoms quickly. To date, in Poland, a cross-cultural adapted version of a disease-specific questionnaire for the measurement of quality of life (QoL) in patients with VS has not been produced., Objectives: This study aimed to adapt the questionnaire evaluating disease-specific QoL in patients with VS (Penn Acoustic Neuroma Quality-of-Life Scale; PANQOL) to Polish and evaluate its psychometric properties., Material and Methods: One-hundred twenty-four patients aged between 24 and 85 years (mean (M) = 60.17 ±standard deviation (SD) = 13.27) diagnosed with VS and treated with Gamma Knife were included in the study. We used a questionnaire translated from English into Polish by a bilingual professional, verified through a back-translation. The final version consisted of 26 items. The internal consistency of the Polish version of the PANQOL scale domains was measured using the Cronbach's alpha (α). To verify the validity of PANQOL subscales, a correlation analysis was conducted between the domains of PANQOL and other questionnaires, including the Assessment of Quality of Life (AQoL-8D), the Glasgow Benefit Inventory (GBI), the 5 Well-Being Index (WHO-5), the Skarzynski Tinnitus Scale (STS) for the presence of dizziness, and the Gardner-Robertson classes., Results: The majority of PANQOL domains showed excellent or good internal consistency (for a PANQOL total of 0.934; for subscales in the range of 0.916-0.424). Our analysis showed strong correlations between the total PANQOL score and AQoL-8D utility score, as well as between the subscales. We observed weak to moderately significant relationships between GBI and PANQOL domains (r = 0.18-0.43), the WHO-5 (r = 0.18-0.56) and the STS scale (r = -0.40- -0.19)., Conclusions: The results demonstrated that the POL-PANQOL is a reliable and valid questionnaire for measuring QoL.

Purpose: The aim of this study was to investigate an imaging biomarker based on contrast enhanced T1-weighted and T2-weighted magnetic resonance imaging (MRI) to determine the hearing loss related to acoustic neuromas (AN). Methods: In this retrospective study, 441 acoustic neuromas treated with microsurgery were included. The diagnostic and follow-up MRI and audiometry of these patients were compared. Results: We discovered a new MRI grading biomarker based on the percentage of tumor filling the inner auditory canal (TFIAC classification). The area under the receiver operating characteristics (AUROC) curve was highest for TFIAC (0.675), followed by period of observation (0.615) and tumor size (0.6) (P < 0.001). The percentage of patients in TFIAC grade III (90.1%) experiencing hypoacusis prior to microsurgery was significantly higher than that in TFIAC grade I (72.7%, P = 0.037) and TFIAC grade IV patients had a higher rate of non-serviceable hearing compared to TFIAC grade III patients (P < 0.001). During the follow-up, TFIAC grade IV patients experienced a significantly higher rate of non-serviceable hearing than TFIAC grade III patients in all ANs (P < 0.001) and in serviceable hearing acoustic neuroma cases prior to surgery (TFIAC grade IV 55.4%, TFIAC grade III 69.0%, P = 0.045). The TFIAC grade IV patients experienced a significantly higher rate of facial nerve dysfunction than TFIAC grade III patients after surgery (grade IV 48.0%, grade III 26.1%, P < 0.001). Conclusion: The TFIAC classification serves as a potential imaging biomarker for preoperative and postoperative hearing prediction in ANs, which may aid neurosurgeons in predicting hearing loss and selecting optimal surgical strategies. [ABSTRACT FROM AUTHOR]

ObjectiveHearing loss is the most common initial symptom in patients with sporadic vestibular schwannomas (SVS). Hearing preservation is an important goal of both conservative and surgical therapy. However, the mechanism of SVS-associated hearing loss remains unclear. Thus, we performed this systematic review to summarize the current understanding of hearing loss in the SVS and distill a testable hypothesis to further illuminate its underlying mechanism.MethodsA systematic review querying four databases (PubMed, Medline, Embase, and Web of Science) was performed to identify studies evaluating hearing loss in patients with SVS and exploring the potential mechanisms of hearing impairment.ResultsA total of 50 articles were eligible and included in this review. After analysis, the retrieved studies could be categorized into four types: (1) 29 studies explore the relationship between hearing loss and the growth pattern of the tumor (e.g., tumor size/volume, growth rate, tumor location, etc.); (2) ten studies investigate the potential role of cochlear dysfunction in hearing deterioration, including structural abnormality, protein elevation in perilymph, and cochlear malfunctioning; (3) two studies looked into SVS-induced impairment of auditory pathway and cortex; (4) in the rest nine studies, researchers explored the molecular mechanism underlying hearing loss in SVS, which involves molecular and genetic alterations, inflammatory response, growth factors, and other tumor-associated secretions.ConclusionsMultiple factors may contribute to the hearing impairment in SVS, including the growth pattern of tumor, cochlear dysfunction, impairment of auditory pathway and cortex, genetic and molecular changes. However, our current understanding is still limited, and future studies are needed to explore this multifactorial hypothesis and dig deeper into its underlying mechanism.

Objective: Hearing loss is the most common initial symptom in patients with sporadic vestibular schwannomas (SVS). Hearing preservation is an important goal of both conservative and surgical therapy. However, the mechanism of SVS-associated hearing loss remains unclear. Thus, we performed this systematic review to summarize the current understanding of hearing loss in the SVS and distill a testable hypothesis to further illuminate its underlying mechanism. Methods: A systematic review querying four databases (PubMed, Medline, Embase, and Web of Science) was performed to identify studies evaluating hearing loss in patients with SVS and exploring the potential mechanisms of hearing impairment. Results: A total of 50 articles were eligible and included in this review. After analysis, the retrieved studies could be categorized into four types: (1) 29 studies explore the relationship between hearing loss and the growth pattern of the tumor (e.g., tumor size/volume, growth rate, tumor location, etc.); (2) ten studies investigate the potential role of cochlear dysfunction in hearing deterioration, including structural abnormality, protein elevation in perilymph, and cochlear malfunctioning; (3) two studies looked into SVS-induced impairment of auditory pathway and cortex; (4) in the rest nine studies, researchers explored the molecular mechanism underlying hearing loss in SVS, which involves molecular and genetic alterations, inflammatory response, growth factors, and other tumor-associated secretions. Conclusions: Multiple factors may contribute to the hearing impairment in SVS, including the growth pattern of tumor, cochlear dysfunction, impairment of auditory pathway and cortex, genetic and molecular changes. However, our current understanding is still limited, and future studies are needed to explore this multifactorial hypothesis and dig deeper into its underlying mechanism. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective The objective of this study was to determine the performance of the standard alarm criterion of motor evoked potentials (MEPs) of the facial nerve in surgeries performed for resections of vestibular schwannomas or of other lesions of the cerebellopontine angle. Methods This retrospective study included 33 patients (16 with vestibular schwannomas and 17 with other lesions) who underwent the resection surgery with transcranial MEPs of the facial nerve. A reproducible 50% decrease in MEP amplitude, resistant to a 10% increase in stimulation intensity, was applied as the alarm criterion during surgery. Facial muscular function was clinically evaluated with the House–Brackmann score (HBS), pre- and postsurgery at 3 months. Results In the patient group with vestibular schwannoma, postoperatively, the highest sensitivity and negative predictive values were found for a 30% decrease in MEP amplitude, that is, a criterion stricter than the 50% decrease in MEP amplitude criterion, prone to trigger more warnings, used intraoperatively. With this new criterion, the sensitivity would be 88.9% and the negative predictive value would be 85.7%. In the patient group with other lesions of the cerebellopontine angle, the highest sensitivity and negative predictive values were found equally for 50, 60, or 70% decrease in MEP amplitude. With these criteria, the sensitivities and the negative predictive values would be 100.0%. Conclusion Different alarm criteria were found for surgeries for vestibular schwannomas and for other lesions of the cerebellopontine angle. The study consolidates the stricter alarm criterion, that is, a criterion prone to trigger early warnings, as found previously by others for vestibular schwannoma surgeries (30% decrease in MEP amplitude). [ABSTRACT FROM AUTHOR]

INTRODUCTION: Vestibular Schwannomas cause significant morbidity and quality of life can be affected in major way if not promptly managed. There are various therapeutic options available to cure the disease but cyber knife stereotactic radiosurgery is one of leading therapeutic option to manage vestibular schwannomas with minimal to or no complications. OBJECTIVE: To evaluate radiological tumor control, hearing preservation status and complication rates by use of fractionated stereotactic radiosurgery I radiotherapy, specifically cyber knife device in patients with vestibular schwannomas. METHODS: It is a retrospective review of patients treated at Jinnah Postgraduate Medical Centre treated between December 2018 to April 2021, and patient's charts and radiological images were reviewed from medical record and symptom control and complication rate was assessed from clinical follow up notes after giving a certain dose of SRT for vestibular schwannomas. RESULTS: 130 (56.52%) were women and 100 (43.47%) were men, among 230 cases. After stereotactic radiosurgery/ radiotherapy the median follow-up duration was 24 months (interquartile range: 10-42 months). With the median follow-up the radiographic control evaluation ratio was 95.7% (IQR: 18.5 months). Among 230 patients, results of 129 (56%) patients showed stable response, 98 (42%) showed improving response and three (1.3%) showed worsening response. However there were no statistically significant changes between pre and post treatment symptoms (p>0.05). New onset facial paresis was noted in two (1 %) patients. CONCLUSION: The outcome of treatment of vestibular schwannomas by using stereotactic radiosurgery resulted in good ratio of tumor control. Ratios of toxicity and hearing preservation status were approximate to the published literature. [ABSTRACT FROM AUTHOR]

Our goal was to develop a 3D tumor slice model, replicating the individual tumor microenvironment and for individual pharmaceutical testing in vestibular schwannomas with and without relation to NF2. Tissue samples from 16 VS patients (14 sporadic, 2 NF2-related) were prospectively analyzed. Slices of 350 µm thickness were cultured in vitro , and the 3D tumor slice model underwent thorough evaluation for culturing time, microenvironment characteristics, morphology, apoptosis, and proliferation rates. Common drugs - Lapatinib (10 µM), Nilotinib (20 µM), and Bevacizumab (10 µg/ml) - known for their responses in VS were used for treatment. Treatment responses were assessed using CC3 as an apoptosis marker and Ki67 as a proliferation marker. Standard 2D cell culture models of the same tumors served as controls. The 3D tumor slice model accurately mimicked VS ex vivo , maintaining stability for three months. Cell count within the model was approximately tenfold higher than in standard cell culture, and the tumor microenvironment remained stable for 46 days. Pharmacological testing was feasible for up to three weeks, revealing interindividual differences in treatment response to Lapatinib and intraindividual variability in response to Lapatinib and Nilotinib. The observed effects were less pronounced in tumor slices than in standard cell culture, indicating the model's proximity to in vivo tumor biology and enhanced realism. Bevacizumab had limited impact in both models. This study introduces a 3D tumor slice model for sporadic and NF2-related VS, demonstrating stability for up to 3 months, replication of the schwannoma microenvironment, and utility for individualized pharmacological testing. • 3D slice cultures can be generated from vestibular schwannoma. • 3D slice cultures replicate the microenvironment of vestibular schwannoma. • The apoptosis and proliferation rates of tumors remain stable. • 3D slice cultures provide insights into variations in treatment responses. • 3D slice cultures have the potential as an in vitro screening model. [ABSTRACT FROM AUTHOR]

Cystic vestibular schwannomas (VS) form a rare subgroup that differs from the solid variant clinically and radiologically. Certain unique features reported in cystic VS are larger size, presentation with atypical initial symptoms such as dysgeusia, vertigo, facial pain and gait unsteadiness, short duration of symptoms, rapid progression of symptoms or sudden deterioration and frequent involvement of facial nerve. Gamma Knife radiosurgery (GKRS) is a safe and effective treatment for VS, achieving tumor control and resulting in a very low morbidity rate. Here, we described two cases of cystic vestibular schwannomas prior to GKRS and their radiological appearances post-GKRS.

Surveillance imaging is a valid management option for selected vestibular schwannomas (VS). An ideal protocol for radiologic monitoring would highlight growth-related risk factors and tailor management accordingly. This study aims to identify variables associated with the growth of sporadic VS to enhance surveillance imaging, enable early intervention, and optimize outcomes. The review was conducted according to the PRISMA guidelines. A systematic review of 5 databases (PubMed, Ovid, Cochrane Library, Web of Science, and Google Scholar) was performed to identify negative and positive growth predictors of sporadic vestibular schwannomas. The search was limited to studies reported between January 2015 and January 2020. We conducted an individual patient data meta-analysis using a 1-stage multivariate mixed-effect logistic regression model. A total of 437 studies were identified, of which 25 met our criteria for full-text analysis. Articles that measured VS with comparable methods were determined eligible for meta-analysis inclusion. The selected articles were highly heterogeneous in their use of grading scales and assessment of tumor size. Our review showed that size at diagnosis (odds ratio, 1.15; 95% confidence interval, 1.11–1.18; P < 0.0001) and intracanalicular localization (odds ratio, 0.49; 95% confidence interval, 0.26–0.90; P = 0.023) were associated with VS growth. The factors most frequently reported as being associated with growth within the literature were size of VS at diagnosis and localization of an intracanalicular component. Greater attention should be placed on these criteria within the surveillance imaging algorithm for VS. [ABSTRACT FROM AUTHOR]

Vestibular schwannoma surgery is a challenging operative procedure. Intricate anatomy of vital neurovascular structures demands a meticulous planning and execution. The cerebellopontine angle is an unforgiving area of skull bases surgery which can have grave implications on patient outcome even after a successful tumor removal. As more and more tumors are being detected at early stage, functional preservation of seventh and eighth nerve complex is increasingly being demanded. The key to any minimally invasive approach is to minimize the collateral damage while ensuring complete tumor removal. Binocular microscopy is the workhorse for illumination and dissection via retrosigmoid approach. However, as instrumentation has improved, endoscopic dissections are increasingly being performed. The following video presents the step-by-step nuances for an endoscope-assisted microsurgery for small vestibular schwannomas with stress on endoscopic drilling of the meatal wall to deliver out intracanacular tumor while preserving the labrynthine structures. [ABSTRACT FROM AUTHOR]

Purpose of Review: "Brain tumor is a bump in the road." Sheryl Crow a famous singer was quoted talking about her meningioma, a benign brain tumor that caused her to forget her lyrics. In this review, we focus on low-grade gliomas in adults and benign brain tumors, such as meningiomas, vestibular schwannomas, and pituitary tumors, since these individuals survive a long time and morbidity is a major issue. Recent Findings: As per the NCI dictionary definition, cancer survivorship focuses on the health and well-being of a person with cancer from the time of diagnosis until the end of life. This includes the physical, mental, emotional, social, and financial effects of cancer that begin at diagnosis and continue through treatment and beyond. Summary: The survivorship experience also includes issues related to follow-up care (including regular health and wellness checkups), late effects of treatment, cancer recurrence, second cancers, and quality of life. Family members, friends, and caregivers are also considered part of the survivorship experience (NCI Dictionary: https://www.cancer.gov/publications/dictionaries/cancer-terms). [ABSTRACT FROM AUTHOR]

Introduction: Evidence-based, clinical practice guidelines in the management of central nervous system tumors (CNS) continue to be developed and updated through the work of the Joint Section on Tumors of the Congress of Neurological Surgeons (CNS) and the American Association of Neurological Surgeons (AANS). Methods: The guidelines are created using the most current and clinically relevant evidence using systematic methodologies, which classify available data and provide recommendations for clinical practice. Conclusion: This update summarizes the Tumor Section Guidelines developed over the last five years for non-functioning pituitary adenomas, low grade gliomas, vestibular schwannomas, and metastatic brain tumors. [ABSTRACT FROM AUTHOR]

Abstract Background Gamma Knife radiosurgery is the principal alternative to microsurgical resection for acoustic neuromas (vestibular schwannomas). However; its increasing use worldwide and evolution of Gamma Knife device precision and safety had led to its acceptance as primary management for small- and medium-sized vestibular schwannomas. We tried to evaluate the tumor volume changes that occur with these tumors following Gamma Knife radiosurgery. Methods Eighteen patients with stereotactic radiosurgery with Gamma Knife through the year 2016 completed 1-year MRI follow-up at the 3rd, 6th, and 12th month after the Gamma Knife treatment. All the patients had unilateral vestibular schwannomas; the mean dose of radiation to the tumors was 12 Gy (range 10–14 Gy). Post treatment imaging was done with a high-resolution 3 T MRI scanner. Tumor sizes are calculated by using Onis software. Results Four patterns of volumetric changes were noticed. Most of the tumors increased in size on the third month follow-up MRI (89%); 15 (83%) tumors on the sixth month returned to their initial pre-Gamma Knife radiosurgery (PGKR) sizes. On the last (12th month) follow-up MRI with tumor sizes compared to initial PGKR sizes, 8 (44%) tumors showed no change, 6 (33%) tumors became smaller, and 4 (22%) tumors increase in size. Tumor control rate was 78% for the first year after Gamma Knife radiosurgery. Conclusions The third month follow-up MR images are practically not informative and might lead to unnecessary intervention; sixth month follow-up MR images are a crucial point and they may predict tumor behavior. Age, gender, and Koos stage whether stage II or III are not affecting tumor control. Gamma Knife radiosurgery is an effective intervention for Koos II and Koos III vestibular schwannomas.

The cerebellopontine angle (CPA) is a cerebrospinal fluid-filled space, found at the junction between the cerebellum and pons. Vestibular schwannoma (VS) is the most common CPA tumor. Typical initial symptoms are unilateral or asymmetrical hearing impairment, tinnitus in the affected ear, or imbalance or vertigo. We report an unusual case of the patient who presented with right sensorineural hearing loss but was found to have left VS in the normal hearing ear. [ABSTRACT FROM AUTHOR]

Purpose: Vestibular schwannomas (VSs) are uncommon benign brain tumors, generally treated using Gamma Knife radiosurgery (GKRS). However, due to the possible adverse effect of transient tumor enlargement (TTE), large VS tumors are often surgically removed instead of treated radiosurgically. Since microsurgery is highly invasive and results in a significant increased risk of complications, GKRS is generally preferred. Therefore, prediction of TTE for large VS tumors can improve overall VS treatment and enable physicians to select the most optimal treatment strategy on an individual basis. Currently, there are no clinical factors known to be predictive for TTE. In this research, we aim at predicting TTE following GKRS using texture features extracted from MRI scans. Methods: We analyzed clinical data of patients with VSs treated at our Gamma Knife center. The data was collected prospectively and included patient‐ and treatment‐related characteristics and MRI scans obtained at day of treatment and at follow‐up visits, 6, 12, 24 and 36 months after treatment. The correlations of the patient‐ and treatment‐related characteristics to TTE were investigated using statistical tests. From the treatment scans, we extracted the following MRI image features: first‐order statistics, Minkowski functionals (MFs), and three‐dimensional gray‐level co‐occurrence matrices (GLCMs). These features were applied in a machine learning environment for classification of TTE, using support vector machines. Results: In a clinical data set, containing 61 patients presenting obvious non‐TTE and 38 patients presenting obvious TTE, we determined that patient‐ and treatment‐related characteristics do not show any correlation to TTE. Furthermore, first‐order statistical MRI features and MFs did not significantly show prognostic values using support vector machine classification. However, utilizing a set of 4 GLCM features, we achieved a sensitivity of 0.82 and a specificity of 0.69, showing their prognostic value of TTE. Moreover, these results increased for larger tumor volumes obtaining a sensitivity of 0.77 and a specificity of 0.89 for tumors larger than 6 cm3. Conclusions: The results found in this research clearly show that MRI tumor texture provides information that can be employed for predicting TTE. This can form a basis for individual VS treatment selection, further improving overall treatment results. Particularly in patients with large VSs, where the phenomenon of TTE is most relevant and our predictive model performs best, these findings can be implemented in a clinical workflow such that for each patient, the most optimal treatment strategy can be determined. [ABSTRACT FROM AUTHOR]

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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.