Since the study was a one-arm study without a control, the reported hippocampal failure rate of 4.5% remains controversially discussed. Multiple studies described the hippocampus and limbic circuit to be a generally rare site of brain metastases in many cancers. NSCLC shows a specifically low rate of hippocampal brain metastasis (2.8% of all brain metastases) and risk modelling revealed a only slightly increased absolute risk (+0.2%) after HS-WBRT. Thus, since in the treatment of NSCLC, the efficient prevention of BM and potential CNS micrometastases is currently outweighed by the associated neurotoxicity and a lack of survival benefit, HS-WBRT may provide a possibility to tip the scale toward prophylactic WBRT, at least for a specific subgroup at high risk.