Research in context
Evidence before this study
Whole brain radiotherapy (WBRT) is the standard of care to improve intracranial control after resection of brain metastasis. However, stereotactic radiosurgery (SRS) to the surgical cavity is widely used in an attempt to reduce cognitive toxicity, despite the lack of high-level comparative data substantiating efficacy in the postoperative setting. We searched PubMed and the abstracts of major conferences (such as the American Society of Clinical Oncology and American Society for Radiation Oncology) using the terms “brain metastases”, “irradiation (or radiotherapy)”, “radiosurgery”, and “surgery (or resection)”, with no language restrictions, and with no constraints imposed on the timeframe for the search, for randomised evidence to support this practice. We found only one relevant randomised clinical trial. The trial was underpowered and did not demonstrate non-inferiority of SRS compared with WBRT for neurological or cognitive failure in the postoperative setting.
Added value of this study
To our knowledge, this study is the only adequately powered randomised clinical trial directly comparing SRS with WBRT, the standard of care in the postoperative setting. Additionally, this trial assesses both quality of life and cognitive function, which are especially important endpoints in this patient population given the absence of a substantiated given the absence of a substantiated survival advantage with adjuvant radiotherapy.
Implications of all the available evidence
The combined evidence suggests that SRS to the surgical cavity results in no significant difference in survival and improved preservation of quality of life and cognitive outcomes compared with WBRT. Taken in context with other phase 3 trials assessing SRS to the surgical bed, the implication for clinical care is that SRS in the postoperative setting is a viable treatment option to improve surgical bed control and should be considered a standard of care and a less toxic alternative than WBRT. The implication for future research is that continued refinement of the SRS technique, such as fractionated or preoperative radiosurgery, is needed to further improve outcomes such as surgical bed control.