INITIAL FINDINGS FROM A RETROSPECTIVE STUDY OF AUDIOLOGICAL THRESHOLDS IN CHILDREN WITH CRANIAL RADIOTHERAPY IN COMBINATION WITH PLATIN-BASED CHEMOTHERAPY.

Cranial Radiotherapy (CRT) is a common aspect of treatment for brain tumours in childhood. Larger cochlear dose of radiation correlates with greater hearing loss (eg. Hua et al, 2008), especially in combination with Cisplatin chemotherapy (eg. Paulinho et al, 2010). Animal studies and clinical studies in adults suggest asymmetrical hearing loss (Miller et al, 2007; Van der Putten, 2006). We initiated a retrospective study in a pediatric population with brain tumours to investigate the effects of CRT on audiological thresholds, as part of our involvement in PANCare-Life. Initial results include a comparison of post-chemotherapy thresholds of 186 patients (57 who had CRT, 129 who did not) to investigate progressive audiological changes after cessation of platin treatment. Thresholds were categorized according to the Münster system, focusing on minimal high-frequency changes (Schmidt et al, 2007). No significant difference was found in the number or degree of bilateral threshold changes between CRT and non-CRT groups. A robust tendency (p = 0.05, Fisher's exact) towards asymmetrical deterioration was found in the CRT group, alongside decreased likelihood of threshold improvement. These initial results support the suggestion that CRT can lead to asymmetrical post-treatment deterioration in hearing thresholds in children and underline the necessity of audiological follow up after cessation of platin therapy, especially in children with combined cranial irradiation. The 57 CRT patients were treated using various radiotherapeutic methods. We identified 31 children treated in the last 5 years with a single radiotherapeutic approach as the basis for a further study to substantiate our observations. [ABSTRACT FROM AUTHOR]