ANovel Imaging Grading Biomarker for Predicting Hearing Loss in Acoustic Neuromas.

Abstract

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). 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. We discovered anew 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 gradeIII (90.1%) experiencing hypoacusis prior to microsurgery was significantly higher than that in TFIAC gradeI (72.7%, P = 0.037) and TFIAC gradeIV patients had ahigher rate of non-serviceable hearing compared to TFIAC gradeIII patients (P < 0.001). During the follow-up, TFIAC gradeIV patients experienced asignificantly higher rate of non-serviceable hearing than TFIAC gradeIII patients in all ANs (P < 0.001) and in serviceable hearing acoustic neuroma cases prior to surgery (TFIAC gradeIV 55.4%, TFIAC gradeIII 69.0%, P = 0.045). The TFIAC gradeIV patients experienced asignificantly higher rate of facial nerve dysfunction than TFIAC gradeIII patients after surgery (gradeIV 48.0%, gradeIII 26.1%, P < 0.001). The TFIAC classification serves as apotential imaging biomarker for preoperative and postoperative hearing prediction in ANs, which may aid neurosurgeons in predicting hearing loss and selecting optimal surgical strategies.