Identifying Factors Associated with the Growth of Vestibular Schwannomas: a Systematic Review.

Abstract

BACKGROUND\nSurveillance imaging is a valid management option for selected vestibular schwannomas (VS). An ideal protocol for radiological 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 optimise outcomes.\n\n\nMETHODS\nThe review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic review of five 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 published between January 2015 and January 2020. We conducted an individual patient data meta-analysis (IPD-MA) using a one-stage multivariate mixed effect logistic regression model.\n\n\nRESULTS\nA 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 tumour size. Our review showed that size at diagnosis (OR = 1.15, 95% CI [1.11-1.18], p < 0.0001) and intracanalicular localization (OR = 0.49, 95% CI [0.26-0.90], p=0.023) were associated with VS growth.\n\n\nCONCLUSIONS\nThe factors most frequently reported as being associated with growth within the literature were size of VS at diagnosis and localisation of an intracanalicular component. Greater attention should be placed on these criteria within the surveillance imaging algorithm for VS.