BackgroundInflammation is hypothesized to be a key event in the growth of sporadic vestibular schwannoma (VS). In this study we sought to investigate the relationship between inflammation and tumor growth in vivo using the PET tracer 11C-(R)-PK11195 and dynamic contrast enhanced (DCE) MRI derived vascular biomarkers.MethodsNineteen patients with sporadic VS (8 static, 7 growing, and 4 shrinking tumors) underwent prospective imaging with dynamic 11C-(R)-PK11195 PET and a comprehensive MR protocol, including high temporal resolution DCE-MRI in 15 patients. An intertumor comparison of 11C-(R)-PK11195 binding potential (BPND) and DCE-MRI derived vascular biomarkers (Ktrans, vp, ve) across the 3 different tumor growth cohorts was undertaken. Tissue of 8 tumors was examined with immunohistochemistry markers for inflammation (Iba1), neoplastic cells (S-100 protein), vessels (CD31), the PK11195 target translocator protein (TSPO), fibrinogen for vascular permeability, and proliferation (Ki-67). Results were correlated with PET and DCE-MRI data.ResultsCompared with static tumors, growing VS displayed significantly higher mean 11C-(R)-PK11195 BPND (−0.07 vs 0.47, P = 0.020), and higher mean tumor Ktrans (0.06 vs 0.14, P = 0.004). Immunohistochemistry confirmed the imaging findings and demonstrated that TSPO is predominantly expressed in macrophages. Within growing VS, macrophages rather than tumor cells accounted for the majority of proliferating cells.ConclusionWe present the first in vivo imaging evidence of increased inflammation within growing sporadic VS. Our results demonstrate that 11C-(R)-PK11195 specific binding and DCE-MRI derived parameters can be used as imaging biomarkers of inflammation and vascular permeability in this tumor group.

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OBJECTIVEInflammation and angiogenesis may play a role in the growth of sporadic and neurofibromatosis type 2 (NF2)–related vestibular schwannoma (VS). The similarities in microvascular and inflammatory microenvironment have not been investigated. The authors sought to compare the tumor microenvironment (TME) in sporadic and NF2-related VSs using a combined imaging and tissue analysis approach.METHODSDiffusion MRI and high-temporal-resolution dynamic contrast-enhanced (DCE) MRI data sets were prospectively acquired in 20 NF2-related and 24 size-matched sporadic VSs. Diffusion metrics (mean diffusivity, fractional anisotropy) and DCE-MRI–derived microvascular biomarkers (transfer constant [Ktrans], fractional plasma volume, tissue extravascular-extracellular space [ve], longitudinal relaxation rate, tumoral blood flow) were compared across both VS groups, and regression analysis was used to evaluate the effect of tumor size, pretreatment tumor growth rate, and tumor NF2 status (sporadic vs NF2-related) on each imaging parameter. Tissues from 17 imaged sporadic VSs and a separate cohort of 12 NF2-related VSs were examined with immunohistochemistry markers for vessels (CD31), vessel permeability (fibrinogen), and macrophage density (Iba1). The expression of vascular endothelial growth factor (VEGF) and VEGF receptor 1 was evaluated using immunohistochemistry, Western blotting, and double immunofluorescence.RESULTSImaging data demonstrated that DCE-MRI–derived microvascular characteristics were similar in sporadic and NF2-related VSs. Ktrans (p < 0.001), ve (p ≤ 0.004), and tumoral free water content (p ≤ 0.003) increased with increasing tumor size and pretreatment tumor growth rate. Regression analysis demonstrated that with the exception of mean diffusivity (p < 0.001), NF2 status had no statistically significant effect on any of the imaging parameters or the observed relationship between the imaging parameters and tumor size (p > 0.05). Tissue analysis confirmed the imaging metrics among resected sporadic VSs and demonstrated that across all VSs studied, there was a close association between vascularity and Iba1+ macrophage density (r = 0.55, p = 0.002). VEGF was expressed by Iba1+ macrophages.CONCLUSIONSThe authors present the first in vivo comparative study of microvascular and inflammatory characteristics in sporadic and NF2-related VSs. The imaging and tissue analysis results indicate that inflammation is a key contributor to TME and should be viewed as a therapeutic target in both VS groups.

We have evaluated deficiencies in existing diagnostic criteria for neurofibromatosis 2 (NF2). Methods: Two large databases of individuals fulfilling NF2 criteria (n=1361) and those tested for NF2 variants with criteria short of diagnosis (n=1416) were interrogated. We assessed the proportions meeting each diagnostic criterion with constitutional or mosaic NF2 variants and the specificity with regard to refuted diagnosis. Results: There was no evidence for usefulness of old criteria 'glioma' or 'neurofibroma'. 'Ependymoma' had 100% specificity and high levels of confirmed NF2 diagnosis (67.7%). Those with bilateral vestibular schwannoma (VS) alone aged ≥60 years had the lowest confirmation rate (6.6%) and reduced specificity (80%). Siblings as a firstdegree-relative, without an affected parent, had 0% specificity. All three individuals with a unilateral VS and an affected sibling were proven not to have NF2. The biggest overlap was with LZTR1-associated schwannomatosis. In this category, seven individuals with a unilateral VS plus ≥2 non-dermal schwannomas reduced specificity to 67%. Conclusion: The present study has confirmed important deficiencies in NF2 diagnostic criteria. The term 'glioma' should be dropped and replaced by 'ependymoma'. Similarly 'neurofibroma' should be removed. Dropping 'sibling' from first-degreerelatives should be considered and testing of LZTR1 should be recommended for unilateral VS.

Background Limited data exists on the disease course of Neurofibromatosis Type 2 (NF2) to guide clinical trial design. Methods A prospective database of patients meeting NF2 diagnostic criteria, reviewed between 1990–2020, was evaluated. Follow-up to first vestibular schwannoma (VS) intervention and death was assessed by univariate analysis and stratified by age at onset, era referred and inheritance type. Interventions for NF2-related tumours were assessed. Cox regression was performed to determine the relationship between individual factors from time of diagnosis to NF2-related death. Results Three-hundred-and-fifty-three patients were evaluated. During 4643.1 follow-up years from diagnosis to censoring 60 patients (17.0%) died. The annual mean number of patients undergoing VS surgery or radiotherapy declined, from 4.66 and 1.65 respectively per 100 NF2 patients in 1990-1999 to 2.11 and 1.01 in 2010-2020, as the number receiving bevacizumab increased (2.51 per 100 NF2 patients in 2010-2020). Five patients stopped bevacizumab to remove growing meningioma or spinal schwannoma. 153/353 (43.3%) had at least one neurosurgical intervention/radiation treatment within 5 years of diagnosis. Patients asymptomatic at diagnosis had longer time to intervention and better survival compared to those presenting with symptoms. Those symptomatically presenting &lt;16 and &gt;40 years had poorer overall survival than those presenting at 26-39 years (P=0.03 and P=0.02 respectively) but those presenting between 16-39 had shorter time to VS intervention. Individuals with de novo constitutional variants had worse survival than those with de novo mosaic or inherited disease (P=0.004). Conclusion Understanding disease course improves prognostication, allowing for better informed decisions about care.

Questionnaires and invasive diagnostic tests are established for diagnosing gastro-esophageal reflux disease (GERD) but shown not to be sensitive or specific for diagnosing laryngopharyngeal reflux (LPR) where vast majority of reflux events are weakly acidic or non-acidic. The research question addressed in the current multicentre study was to determine if the measurement of salivary pepsin is a sensitive, specific and reliable diagnostic test for LPR. Five UK voice clinics recruited a total of 1011 patients presenting with symptoms of LPR and a small group of subjects (n = 22) recruited as asymptomatic control group. Twenty-six patients failed to provide demographic information; the total patient group was 985 providing 2927 salivary pepsin samples for analysis. Study participants provided 3 saliva samples, the first on rising with two samples provided post-prandial (60 min) or post-symptom (15 min). The control group provided one sample on rising and two post-prandial providing a total of 66 samples. Pepsin analysis was carried out using Peptest as previously described. High prevalence of pepsin in patient groups (75%) represents a mean pepsin concentration of 131 ng/ml. The greatest prevalence for pepsin was in the post-prandial sample (155 ng/ml) and the lowest in the morning sample (103 ng/ml). The mean pepsin concentration in the control group was 0 ng/ml. Patients across all 5 clinics showed high prevalence of salivary pepsin (ranging from 69 to 86%), and the overall sensitivity was 76.4% and specificity 100%. Pepsin was shown to be an ideal biomarker for detecting airway reflux and LPR.

Objective Necrotising otitis externa is an invasive, infective condition, with minimal evidence underpinning its diagnosis and management. This work aimed to analyse literature from the past decade, to identify emerging themes and important topics for future research. Methods A robust literature search and review were conducted by two researchers. Sixty studies were filtered into the final review. A grounded theory approach was used to identify core themes. Data within these themes formed the basis of the review. Results There is no consensus regarding a clinical definition or outcome measures of necrotising otitis externa, and there exists no level 1, 2 or 3 evidence to diagnose, investigate, monitor or treat necrotising otitis externa. Emerging themes in the literature direct researchers to important topics for future clinical trials, including risk factors, microbiological culture, management strategies and radiology. Conclusion In order to optimise understanding and management of necrotising otitis externa, future research requires robust clinical trials and consistently reported outcome measures.

Objective Evidence for the management of acute otitis externa (AOE) is limited, with unclear diagnostic criteria and variably reported outcome measures that may not reflect key stakeholder priorities. We aimed to develop 1) a definition, 2) diagnostic criteria and 3) a core outcome set (COS) for AOE. Study design COS development according to Core Outcome Measures in Effectiveness Trials (COMET) methodology and parallel consensus selection of diagnostic criteria/definition. Setting Stakeholders from the United Kingdom. Subjects and methods Comprehensive literature review identified candidate items for the COS, definition and diagnostic criteria. Nine individuals with past AOE generated further patient-centred candidate items. Candidate items were rated for importance by patient and professional (ENT doctors, general practitioners, microbiologists, nurses, audiologists) stakeholders in a three-round online Delphi exercise. Consensus items were grouped to form the COS, diagnostic criteria, and definition. Results Candidate COS items from patients (n = 28) and literature (n = 25) were deduplicated and amalgamated to a final candidate list (n = 46). Patients emphasised quality-of-life and the impact on daily activities/work. Via the Delphi process, stakeholders agreed on 31 candidate items. The final COS covered six outcomes: pain; disease severity; impact on quality-of-life and daily activities; patient satisfaction; treatment-related outcome; and microbiology. 14 candidate diagnostic criteria were identified, 8 reaching inclusion consensus. The final definition for AOE was ‘diffuse inflammation of the ear canal skin of less than 6 weeks duration’. Conclusion The development and adoption of a consensus definition, diagnostic criteria and a COS will help to standardise future research in AOE, facilitating meta-analysis. Consulting former patients throughout development highlighted deficiencies in the outcomes adopted previously, in particular concerning the impact of AOE on daily life.