LAUSR

confirm these findings, other multi-centre studies would be valuable. Also, in the current study, the dose of radiotherapy var-ied between patients and was determined as per standard of care. How-ever, defining the optimal dose of radiotherapy and the context of previous irradiation may be critical in determining the immune response. 8 There is a clear need for improved predictors of response to immunotherapy. It may be hypothesised that response to radiotherapy and immunotherapy combination may be associated with expression of the Programmed Death-1 Receptor Ligand (PD-L1). However, the patients that we report were treated with nivolumab. In contrast to pembrolizumab treatment, where the PD-L1 combined positive score (CPS) is routinely performed for all patients, as the drug is not licensed in the setting of CPS negative patients, this is not the case for nivolumab treatment where the licensing indication is in the platinum-resistant setting irrespective of the PD-L1 score. As such, PD-L1 expression was not available for analysis in this study.