Surgical resection of symptomatic brain metastasis (BM) with mass effect is a mainstay treatment for affected patients.1, 2, 3 Without adjuvant radiation, nearly one-half of the resected BM recurs locally adjacent to the resection cavity.4,5 In the landmark randomized controlled trial (RCT) by Patchell et al., postresection whole brain radiation therapy reduced the likelihood of local recurrence (LR) from 46% to 10%6 BM 1 year after treatment. With increasing recognition of neurotoxicity associated with whole brain radiation,7,8 a preference for postresection cavity radiosurgery (post-SRS) has emerged over whole brain radiation therapy. As demonstrated in a recent RCT, post-SRS reduced BM LR from 57% to 28% 1 year after surgical resection, constituting class I data in support of this treatment paradigm.4

More recent, radiosurgery studies have focused on minimizing the spread of BM to the leptomeninges, also known as leptomeningeal disease (LMD). The development of LMD in BM patients represents a serious setback as it is often associated with neurologic deterioration. Moreover, limited therapeutic options are available.9,10 A prevailing hypothesis is that manipulation during surgical resection may facilitate tumor seeding, increasing the LMD risk.11,12 In this context, preoperative SRS (pre-SRS) followed by surgical resection of the radiated BM has been proposed, with the theoretical concept that pre-SRS might sterilize the tumor before resection and minimize the risk of seeding. Pre-SRS is also proposed to enhance oxygen-based free radical damage to the tumor and enhance local control.13 A limited number of case series have provided support for pre-SRS.14, 15, 16

Here, we performed a comprehensive literature review collating available studies on the clinical outcomes of pre-SRS and post-SRS. Using meta-analysis methods, we generated pooled estimates of LR, LMD, radiation necrosis (RN), as well as overall survival (OS).