Purpose: To analyze the efficacy and safety of surgery compared to radiosurgery (RS), combined or not with whole brain radiotherapy (WBRT), for localized metastatic brain disease. Methods: A systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The inclusion criteria were limited to randomized controlled trials (RCTs) that compared surgery and RS for patients with up to 3 metastases (median diameter ≤ 4 cm). The primary outcomes were represented by overall survival (OS) and local brain progression-free survival (PFS), with the rate of complications as a secondary outcome. The pooled estimates were calculated using random forest models. The risk of bias was evaluated using the RoB2 revised tool and the certainty of the evidence was assessed according to the GRADE guidelines. Results: In total, 11,256 records were identified through database and register searches. After study selection, 3 RCTs and 353 patients were included in the quantitative synthesis. Surgery and RS represented the main intervention arms in all the included RCTs. Conclusions: A low level of evidence suggests that RS alone and surgery followed by WBRT provide an equal rate of local brain PFS in patients with localized metastatic brain disease. There is a very low level of evidence that surgery and RS as main interventions offer equivalent OS in the population investigated. A reliable assessment of the complication rates among surgery and RS was not achievable. The lack of high-certainty evidence either for superiority or equivalence of these treatments emphasizes the need for further, more accurate, RCTs comparing surgery and RS as local treatment in patients with oligometastatic brain disease.
Keywords: brain metastasis; oligometastasis; progression-free survival; radiosurgery; radiotherapy; solitary brain metastasis; surgery; surgical resection; survival; whole brain radiotherapy.