XRT-01. LONG-TERM HEARING LOSS IN CHILDREN WITH MEDULLOBLASTOMA AFTER PROTON IRRADIATION AND CHEMOTHERAPY

Abstract PURPOSE To evaluate the incidence and risk factors for hearing loss (HL) among children with medulloblastoma treated proton irradiation cisplatin. METHODS We identified ≥3 years of age at Texas Children’s Hospital between 2007-2022. Audiograms were graded using International Society Pediatric Oncology-Boston scale (SIOP-Boston). Time to grade HL was evaluated Kaplan-Meier multivariable Cox models estimate hazard ratios (HR) 95% confidence intervals (CI). RESULTS Seventy-eight patients (65.4% male) craniospinal (CSI) a median 7.6 (range: 3-21). The mean cochlear dose 31.5±9 Gy, cumulative cisplatin 295±50 mg/m2. Fifty-six (72%) received amifostine. Patients completed 9 audiograms 4-22) audiogram follow-up 49 months 3-177). Grade documented in 25 (32%). In adjusted models, (HR=1.12, CI: 1.06-1.18) CSI (HR=0.81, 0.68-0.98) associated HL. Among who after or 7 age, estimated probability three post-CSI 12.6% (95% 4.1-34.6) exposed <36 Gy 35.6% 17.4-63.6) >36 irradiation. before 16.5% 5.6-43) radiation 66.7% 35.4-93.7) CONCLUSION Long-term shows that ≥36 are higher HL, regardless amifostine dose.