Research in context
Evidence before this study
To our knowledge, there have been no completed randomised, controlled trials to assess the efficacy of stereotactic radiosurgery (SRS) to improve local control after surgical resection of brain metastases. Whole brain radiotherapy (WBRT) after surgical resection has been the standard of care but it is associated with cognitive deficits. Many clinicians have advocated the use of SRS after surgical resection to improve local control and avoid the cognitive side-effects of WBRT. We searched PubMed for articles published in English between Jan 1, 1980, and Dec 31, 2016, which reported the use of radiation to improve local tumour control after surgical resection of brain metastases. Search terms included “brain”, “local control”, “metastasis”, “neoplasm”, “radiation”, “surgery”, and “survival”. Numerous retrospective studies have been reported, but these are subject to various limitations. We filtered for randomised, controlled trials and identified 49 articles. We then limited the search results to studies that specifically addressed the use of radiation to increase local tumour control after surgical resection of brain metastases, which yielded three studies. All three studies evaluated the utility of WBRT in the context of surgical resection of brain metastases. No study evaluated the use of SRS after surgical resection. Therefore, level 1 evidence supporting the use of SRS to improve local control after surgical resection of brain metastases is absent. Moreover, the most recent study evaluating the use of radiation after surgical resection (using WBRT) was in 1998. Since that time, surgical techniques have evolved substantially and no recent studies have evaluated local control after surgical resection alone.
Added value of this study
The results of this trial add to the existing evidence for the management of brain metastases by showing a significant improvement in local control when SRS is used after resection of one to three brain metastases compared with that for resection alone. The results also reinforce that surgical resection alone is insufficient to provide durable local control.
Implications of all the available evidence
Our results suggest that SRS might be an alternative to WBRT for patients after surgical resection of one to three brain metastases. Future trials should explore increased radiation doses to improve local control and report outcomes with respect to quality of life.