Cognitive functioning and health-related quality of life of long-term survivors with brain metastases up to
21 months after gamma knife radiosurgery.

Neurosurg. 2021;88(5):E396–405. DOI: 10.1093/neuros/nyaa586.
Verhaak E, Schimmel WCM, Gehring K, Hanssens PEJ, Sitskoorn MM.

Background
Survival rates have improved in the past years for patients with brain metastases (BMs).

Objective
To evaluate cognitive functioning and health-related quality of life (HRQoL) after Gamma Knife radiosurgery (GKRS) in a relatively large sample of long-term survivors.

Methods
Data from 38 long-term survivors (assessments available ≥ 12 mo post-GKRS) with, at time of enrollment, 1 to 10 newly diagnosed BMs, expected survival > 3 mo, and Karnofsky Performance Status ≥ 70 were analyzed. Cognitive functioning and HRQoL were assessed pre-GKRS (n = 38) and at 3 (n = 38), 6 (n = 37), 9 (n = 37), 12 (n = 34), 15 (n = 28), and 21 (n = 21) mo post-GKRS. The course of cognitive test performance and of HRQoL over time was analyzed using linear mixed models. Individual changes in cognitive performance and HRQoL from pre-GKRS to 21 mo were determined using reliable change indexes (RCIs) and clinical meaningful cutoffs, respectively.

Results
Cognitive performances and HRQoL of long-term survivors remained stable or improved up to 21 mo after GKRS. Improvements were found for immediate and delayed verbal memory, working memory, information processing speed, and emotional well-being. On the individual level, most patients had stable or improved test performances or HRQoL. For physical well-being only, most patients (47.6%) showed a decline (vs 28.6% improvement or 23.8% no change) from pre-GKRS until 21 mo post-GKRS.

Conclusion
Up to 21 mo after GKRS, cognitive functioning and overall HRQoL improved or remained stable in long-term survivors. In long-term survivors with 1 to 10 BMs, GKRS did not cause (additional) cognitive deteriorations or declines in HRQoL at longer-term follow-up.