Medulloblastoma is one of the most common forms of childhood brain cancer. Radiotherapy is frequently used to treat medulloblastoma, however, many tumours exhibit radioresistance. Despite being used for more than a century, the exact mechanisms of acquired radioresistance remain poorly understood. Importantly, the epigenetic fingerprint from radiotherapy has not been extensively characterised. Epigenetic mechanisms are of particular interest in medulloblastoma due to its low mutational load. It was hypothesised that medulloblastoma cells undergo epigenetic reprogramming during radiotherapy and that these changes drive resistance. Here, a radiotherapy naïve cell line (ONS-76), derived from a primary tumour, was used to model radioresponse. Firstly, the impact of a single 2 gray dose of radiotherapy on the transcriptional and proteomic profile of cells was assessed using RNA-seq and mass spectrometry respectively. Epigenetic changes were then measured following single and repeated exposure to radiotherapy. Global levels of DNA methylation were determined using an ELISA, while Micro-C was used to assess the impact on 3D chromatin structure. In summary, RNA-seq revealed 601 significantly upregulated genes and 372 down regulated genes (n=3). Mass spectrometry identified 361 proteins with significantly increased abundance and 217 with decreased abundance (n=4). DNA methylation analysis revealed a slight increase in methylation following a single dose of irradiation and a decrease in methylation following repeated doses. The difference in methylation between single and repeated doses was statistically significant (P=0.012). Analysis of Micro-C data is currently underway and will reveal the epigenetic landscape underpinning changes in gene expression. This study will be the first to evaluate chromatin conformation post radiotherapy in brain cancer cells. It has the potential to uncover the mechanisms of radioresistance and identify candidates as targets for radiosensitisation. This may ultimately enable lower doses of radiotherapy to be delivered, therefore, reducing toxicity to the developing brain.