The use of cochlear-enhancement imaging to predict hearing preservation following vestibular schwannoma removal.

Background: Hearing preservation is challenging for patients after the removal of large vestibular schwannomas (VSs). Here, using preoperative magnetic resonance (MR) imaging, we investigated the significance of cochlear enhancement (CE) for predicting postoperative hearing preservation.

Methods: Between January 2014 and December 2019, 34 VS-patients with serviceable hearing underwent tumor-removal surgery using a retrosigmoid approach. The presence or absence of CE using both T2-weighted and gadolinium-enhanced T1-weighted MR images was assessed in VS patients using the pixel-analysis method. Segmented volumetric analyses were also performed using GrowCut 3D slicer software.

Results: There were 17 patients (50%) without CE and 17 (50%) with CE. Ten of the 17 non-CE patients (58.8%) had postoperative hearing preservation. In contrast, only 3 of the 17 patients with CE (17.6%) had postoperative hearing preservation. There were no significant tumor-characteristic differences between the two groups. The presence of CE on both the T2-weighted and the gadolinium-enhanced T1-weighted MR images correlated significantly with postoperative hearing outcomes (P=0.032). Only pure-tone averages were significantly different between the two groups (P=0.049).

Conclusions: Preoperative serviceable hearing is likely to be preserved after surgery in non-CE VS patients. Preoperative CE assessment using MR imaging may be a useful predictor for postoperative hearing outcomes in VS patients.