BackgroundRecently, it has been shown that at group level, patients with limited brain metastases treated with stereotactic radiotherapy (SRT) maintain their pre-treatment levels of neurocognitive functioning (NCF) and health-related quality of life (HRQoL). The aim of this study was to evaluate NCF and HRQoL changes over time at the individual patient level.MethodsNCF (seven domains assessed with a standardized test battery) and HRQoL (eight predetermined scales assessed with the EORTC QLQ-C30 and BN20 questionnaires) were measured prior to SRT and at 3 and/or 6 months follow-up. Changes in NCF and HRQoL were evaluated at (1) a domain/scale level and (2) patient level.ResultsA total of 55 patients were examined, of which the majority showed stable NCF 3 months after SRT, on both the domain level (78–100% of patients) and patient level (67% of patients). This was different for HRQoL, where deterioration in the different scales was observed in 12–61% of patients, stable scores in 20–71%, and improvement in 16–40%, 3 months after SRT. At patient level, most patients (64%) showed both improvement and deterioration in different HRQoL scales. Results were similar between 3 and 6 months after SRT.ConclusionIn line with results at group level, most brain oligometastases patients with ≥ 6 months follow-up and treated with SRT maintained their pre-treatment level of NCF during this period. By contrast, changes in HRQoL scores differed considerably at domain and patient level, despite stable HRQoL scores at group level.