Hearing loss in children with brain tumors treated with cisplatin and carboplatin-based high-dose chemotherapy with autologous bone marrow rescue

Carboplatin is less ototoxic than cisplatin, but ototoxicity may occur with carboplatin at higher doses. We evaluated hearing in children with brain tumors treated with conventional dose cisplatin followed by high-dose carboplatin. Children under 6 years of age, newly diagnosed with brain tumors, were treated after surgery with cisplatin, Etoposide, cyclophosphamide, and vincristine, followed by consolidation with carboplatin, ThioTEPA, Etoposide, and autologous bone marrow rescue. Hearing was assessed before and after consolidation, utilizing standard audiometric techniques. Seven of the 11 evaluable patients developed high-frequency sensorineural hearing loss after induction therapy. Hearing deteriorated after consolidation in five patients, with pure tone threshold shifts of up to 65 dB between 2,000 and 8,000 Hz. Of these five patients, audiological abnormalities were documented in four prior to consolidation, one received cranial irradiation after consolidation, and all five received aminoglycoside antibiotics for at least 2 weeks, with toxic drug levels in four. Three patients have subsequently required hearing aids. Significant ototoxicity is common in these patients. Ototoxicity related to consolidation therapy is likely due to the high dose of carboplatin used, prior cisplatin therapy, aminoglycosides, and, in one patient, cranial irradiation. Audiological assessment is essential in children treated with dose-intensive chemotherapy regimens containing cisplatin and carboplatin for identification and rehabilitation of ototoxicity.