Carboplatin-Induced Ototoxicity in Children Treated for Retinoblastoma

The chemotherapy regimen comprising carboplatin, vincristine, and etoposide (JOE) is commonly used to treat retinoblastoma. Carboplatin-induced ototoxicity is infrequently reported. Extended high-frequency hearing loss may impair cochlear function and speech-in-noise recognition and elevate hearing thresholds. The aim was to assess hearing loss in retinoblastoma survivors treated with carboplatin-containing chemotherapy.

This cross-sectional study was conducted at a single-center Pediatric Hematology-Oncology unit between 2021 and 2022. Survivors treated for retinoblastoma from 2011 to 2019 were enrolled. Hearing was evaluated using otoacoustic emissions, conventional pure-tone audiometry (500-8000 Hz), and extended high-frequency audiometry (9000-20,000 Hz).

Forty-two survivors (53 eyes; 76% intraocular, 24% extraocular) were evaluated. Median number of cycles of JOE received: 6 (IQR: 6, 9); cumulative carboplatin dose: 3152 mg/m² (IQR: 2214, 4564); median age at diagnosis: 33 months (IQR: 19, 44); median age at hearing assessment: 89 months (IQR: 19, 44); and median duration from diagnosis to hearing assessment: 51 months (IQR: 30, 79). Extended high-frequency hearing loss was observed in 17 (41%) survivors, predominantly in bilateral ears (65%). Two (5%) among the 17 also had hearing loss (40 dB) at 8000 Hz. No participant had clinically perceptible hearing loss or required hearing aids. There was a lack of association of hearing loss with age, duration from diagnosis to audiometry, weight-for-age, socioeconomic status, or cumulative carboplatin dose (p > 0.05).

Extended high-frequency sensorineural hearing loss was observed in 41% of survivors of retinoblastoma, though it was not clinically evident. Periodic hearing assessment is recommended to monitor the progression of hearing loss.