Gamma knife-based stereotactic radiosurgery boost after whole-brain radiotherapy in patients with up to three brain metastases: Effects on survival, functional independence, and neurocognitive function

Abstract

Background: Brain metastases are a major cause of mortality and morbidity in cancer patients and are seen as a terminal event in the natural course of disease. Whole-brain radiotherapy (WBRT) has remained the most commonly used treatment for multiple metastases. Although it provides symptomatic relief, the effects have low durability and local failure is common. Stereotactic radiosurgery (SRS) techniques such as Gamma Knife have been shown to be as effective as surgery in control of limited (1–3) metastases. Aim: The aim of this is to study the role of SRS boost after WBRT in patients of 1–3 brain metastases. Objective: (1) To compare the survival of patients with 1–3 brain metastases treated with WBRT with versus without SRS boost. (2) To compare the duration of functional independence (FI) and normal neurocognitive function (NNF) posttreatment in the patients belonging to the two groups. Materials and Methods: Twenty-six patients with 1–3 brain metastases received WBRT to a dose of 30 Gy in 10 fractions. Half the patients (13) were also given an SRS boost of 16–20 Gy by the Gamma Knife technique. All patients were followed up at twelve weekly intervals for a period of 9 months and assessed for survival, FI (Karnofsky Performance Status Score (KPS) >60%) and NNF (Hindi Mental Status Examination Score >24). Results: At 9 months, the median survival in the SRS boost group was 27 weeks compared to 22 weeks in the no boost group. The mean duration of FI and NNF was 24 and 12 weeks in the boost and nonboost groups, respectively. The differences between two groups were not statistically significant. Conclusions: Although results are not significant, a definite trend toward improvement in median survival, FI, and neurocognitive function in patients who received an SRS boost after WBRT is seen.