BACKGROUNDCisplatin is often the cytotoxic drug of choice for chemoradiation therapy (CRT) for head and neck squamous cell carcinoma (HNSCC), but it can lead to irreversible hearing loss. There may be similar oncologic outcomes but different toxicity profiles depending on whether cisplatin is given at 75-100 mg/m2 every 3 weeks or 30-40 mg/mg2 weekly. This study compares cisplatin-induced hearing loss in patients with HNSCC receiving similar cumulative doses of cisplatin administered either on higher-dose or lower-dose treatment schedules.METHODSUsing the Enhancing Cancer Hearing Outcomes (ECHO) dataset from 5 academic centers, we conducted a multicenter retrospective cohort study of adults (≥18 years) with HNSCC receiving cisplatin-based CRT. Participants were grouped by cisplatin dose schedule: every 3 weeks (≥75 mg/m²) or weekly (<75 mg/m²). Hearing loss was assessed using American Speech-Language-Hearing Association (ASHA) and Common Terminology Criteria for Adverse Events (CTCAE) v5.0 threshold shift criteria based on audiograms obtained ≤120 days before and after treatment. Risk differences and predictors of hearing loss were evaluated using χ2 analyses and multivariate regression. Kaplan-Meier curves assessed overall and disease-free survival.RESULTSAmong 564 participants (1,127 ears), lower-dose weekly cisplatin was associated with significantly lower incidence of hearing loss (ASHA criteria: 57% vs. 82%; CTCAE criteria: 39% vs. 69%). CTCAE grade ≥2 hearing loss occurred in 18% of the weekly group versus 50% of the 3-week group. Multivariate analysis confirmed treatment schedule as an independent predictor of ototoxicity. Two-year survival outcomes did not differ between groups.CONCLUSIONSWeekly low-dose cisplatin significantly reduced the incidence and severity of hearing loss without compromising survival, supporting its broader use in CRT for HNSCC.