Vestibularschwannoma(VS)isaslow-growingbenignneoplasm.TherehasbeenanevolutioninthemanagementofVSfromactivetreatments(microsurgeryandstereotacticradiotherapy)toconservativemanagement(waitandscan).RegularMRIscanningisnecessarytomonitortumorprogression.Conservativemanagementcausessignificantlylesscomplicationsandoffersahigherqualityoflifecomparedwithactivetreatments.ThemeangrowthrateofVSvariesfrom0.4to2.9mm/year,andspontaneousshrinkageisobservedin3.8percentoftumorsduringobservation.Ifsignificantgrowthoccurs,activetreatmentisconsidered.Significantgrowthisdefinedasanincreaseofatleast3mminthelargestextrameataldiameterinanyplanebetweenthefirstandlastavailablescans.Thevestibulocochlearnerveissurroundedbycerebrospinalfluid,whichprovidesnaturalcontrastforMRI;thus,gadoliniummaynotbeneededtodetectVS.Specificsequenceshavehighsensitivity,specificity,andaccuracyfordetectionofprogression.HypointensesignalintheipsilateralinnerearfluidmightbeausefulsigntodistinguishVSfrommeningioma.Inthispaper,wesummarizethecurrentstatusofresearchonconservativemanagementandnon-contrastMRIforthedetectionofVS.
