OTOTOXICITY AFTER INTENSITY-MODULATED RADIATION THERAPY AND CISPLATIN-BASED CHEMOTHERAPY IN CHILDREN WITH MEDULLOBLASTOMA

Purpose To report the incidence of Pediatric Oncology Group (POG) Grade 3 or 4 ototoxicity in a cohort of patients treated with craniospinal irradiation (CSI) followed by posterior fossa (PF) and/or tumor bed (TB) boost using intensity-modulated radiation therapy (IMRT) Methods and Materials From 1998 to 2006,44 patients with medulloblastoma were treated with CSI followed by IMRT to the PF and/or TB and cisplatin-based chemotherapy Patients with standard risk disease were treated with 18 to 23 4 Gy CSI followed by either a (1) PF boost to 36 Gy and TB boost to 54 to 55 8 Gy or (2) TB boost to 55 8 Gy Patients with high-risk disease received 36 to 39 6 Gy CSI followed by a (1) PF boost to 54 to 55 8 Gy, (2) PF boost to 45 Gy and TB boost to 55 8 Gy, or (3) TB boost to 55 8 Gy Median audiogram follow up was 41 months (range, 11-92 4 months) Results POG Grade Ototoxicity 0, 1, 2, 3 and 4 was found in 29, 32, 11, 13 and 3 ears respectively, with POG Grade 3 or 4 accounting for 18 2% of cases There was a statistically significant difference in mean radiation dose (D(mean)) cochlea according to degree of ototoxicity, with D(mean) cochlea increasing with severity of hearing loss (p = 0 027) Conclusions Severe ototoxicity was seen in 18 2% of ears in children treated with IMRT boost and cisplatin-based chemotherapy Increasing dose to the cochlea was associated with increasing severity of hearing loss (C) 2010 Elsevier Inc