Feasibility of Electrode-Location Estimates Based on Preoperative CT-Imaging for Anatomy-Based Fitting in Cochlear Implant Recipients

Objectives: To investigate whether there is a difference between electrode frequencies estimated in OTOPLAN according to anatomy using a preoperative CT scan and electrode frequencies based on postoperative cone beam computer tomography (CBCT). Study design: Monocentric retrospective registry study. Setting: Tertiary academic medical center. Patients: Twenty-three CI recipients between 2004 and 2025. Interventions: CI. Main outcome measures: Comparison between frequency maps and angular insertion depth predicted from preoperative measurements and estimated from postoperative DVT imaging data. In addition, the frequency map should be compared with that provided by the standard setting of the CI fitting software. Results: When comparing preoperative CT and postoperative CBCT, there were no significant differences for electrode contacts 1 and 2. Estimated preoperative frequency values are closer to the postoperative measured values than to the standard settings. Conclusions: The use of preoperative scans to predict the frequency map for anatomy-based fitting cannot be recommended; however, when applied with caution, such simulations may serve as a useful starting point for fitting in special cases.