COX inhibitor use during definitive radiotherapy is associated with worse hearing preservation in patients with vestibular schwannoma

Purpose Patients with vestibular schwannoma undergoing definitive radiotherapy commonly experience hearing loss due to tumor and treatment effects; however, there is limited data evaluating concurrent medication use and other clinicopathologic factors associated with hearing preservation during and after radiotherapy. We performed a retrospective cohort study reviewing consecutive patients from 2004 to 2019 treated with radiotherapy for vestibular schwannoma at our institution. Methods Ninety four patients with concurrent medications, baseline audiograms, and post-radiotherapy audiograms available were evaluable. We performed chi-squared analyses of the frequency of various clinicopathologic factors and t-tests evaluating the degree of hearing loss based on audiograms. Results At a median follow-up of 35.7 months (mean: 46.5 months), the baseline pure-tone average (PTA) of the ipsilateral ear worsened from 38.4 to 59.5 dB following completion of radiotherapy (difference: 21.1, 95% CI 17.8–24.4 dB, p < 0.001). 36 patients (38.3%) reported regular use of cyclooxygenase (COX) inhibitors (including acetaminophen and NSAIDs) during radiotherapy. The mean increase in PTA was significantly higher for patients taking COX inhibitors (25.8 dB vs 18.1 dB, p = 0.024) in the ipsilateral ear but not for the contralateral side. COX inhibitor use remained independently associated with worse PTA in the multivariate analysis. Conclusion COX inhibitor use during definitive radiotherapy is associated with worse hearing loss in the affected ear but not for the contralateral side. This suggests the ototoxic effects of COX inhibitors may influence the effects of radiotherapy. These results could have clinical implications and warrant further investigation.