P08.07.A Long-term multidimensional assessment of fatigue and fatigue as predictor of survival in patients with brain metastases after Gamma Knife radiosurgery

Abstract

Abstract Background The aim of this study was to assess long-term multidimensional fatigue and (change in) fatigue as predictor for survival in patients with brain metastases (BM) up to 21 months after Gamma Knife radiosurgery (GKRS). Material and Methods Patients with 1 to 10 BM, expected survival >3 months, and Karnofsky Performance Status ≥70 were included. Fatigue was measured with the Multidimensional Fatigue Inventory (MFI). Linear mixed models were used to evaluate fatigue up to 21 months after GKRS. Fatigue before GKRS and changes in fatigue in the first three months after GKRS were evaluated as predictors for survival duration. Results Patients with BM experienced significantly higher levels of fatigue on all subscales prior to GKRS (n=92) compared to Dutch controls (n=104), all p’s≤.001. Over 21 months, levels of physical fatigue increased significantly (p=.001), and levels of mental fatigue decreased significantly (p=.004). Between pre-GKRS and 3 months, there was a significant increase in levels of general (p<.001) and physical fatigue (p<.001), followed by stable fatigue scores between 3 (n=67) and 6 (n=53) months, 6 and 12 (n=34) months and 12 and 21 (n=21) months. Minimal clinically important (MCI) increases in general (p=.023, time ratio=0.61) and in physical fatigue (p=.008, time ratio=0.56) from pre-GKRS to 3 months thereafter were independent negative predictors of survival time (i.e., an MCI increase in these domains predicted a reduction of 39% and 44% respectively in survival time compared to stable or decreased fatigue). Conclusion Results indicate that up to 21 months after GKRS fatigue is a persistent problem in patients with BM. Except for an increase in general and physical fatigue up to 3 months after treatment, fatigue remained stable up to 21 months after GKRS. In addition, an MCI increase in general or physical fatigue within three months after GKRS may be related to worse survival outcome.