RADI-10. Is there any benefit for post-operative radiation in brain metastases? A systematic review and meta-analysis of Randomized controlled trials

PURPOSE: The benefits of adding upfront post-operative radiation (either whole-brain or cavity radiation) have been debated, particularly due to the possible detriment in cognition post-radiation. We sought to compare the efficacy and safety between the surgical resection of brain metastases (BM) plus radiotherapy versus surgical resection alone. MATERIALS AND METHODS: We searched various biomedical databases from 1983 to 2019, for eligible randomized controlled trials (RCT). Outcomes studied were local recurrence (LR), overall survival (OS), and serious (Grade 3 +) adverse events (AE). We used the random-effects model to pool outcomes. The methodological quality of each study was assessed using the Cochrane Risk of Bias tool. RESULTS: We included 5 RCTs comprising of 673 patients. The odds ratio (OR) for LR ranged from 0.06–0.34 with a pooled odds ratio of 0.26 (95% confidence interval (CI) 0.19–0.37, P< 0.001), strongly favoring the patients who received postoperative radiation. The overall survival (OS) was only reported in 3 studies and did not show any significant difference. The hazard ratio (HR) ranged from 1.01–1.29 with a pooled HR of 1.1 (95% CI 0.90–1.34, P=0.37). The treatment-related toxicities were inconsistently reported to draw any meaningful conclusions. The risk of bias was predominantly due to the lack of blinding and was deemed to be high, affecting all outcomes. CONCLUSION: Our analysis confirms that postoperative radiation should be recommended after surgical resection of BM, for it significantly reduces the risk of local recurrence. However, we did not find any improvement in OS, suggesting that improvements in local control at the tumor bed alone may not impact survival. Balancing local control, and possible neuro-cognitive effects of whole-brain radiation, post-operative cavity radiation seems to be an attractive option.