Whole brain radiation therapy (WBRT) alone versus WBRT and radiosurgery for the treatment of brain metastases

Abstract

Background: Historically, whole brain radiation therapy (WBRT) has been the main treatment for brain metastases. Stereotactic radiosurgery (SRS) delivers high dose focused radiation and is being increasingly utilized to treat brain metastases. The benefit of adding radiosurgery to WBRT is unclear.

Objectives: To assess the efficacy of WBRT plus radiosurgery versus WBRT alone in the treatment of of brain metastases.

Search strategy: We searched the following electronic databases: Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2009), MEDLINE (1966 to 2009), EMBASE (1980 to 2009) and CancerLit (1975 to 2009) in order to identify trials for inclusion in this review.

Selection criteria: The review was restricted to randomised controlled trials (RCTs) that compared use of radiosurgery and WBRT versus WBRT alone for upfront treatment of adult patients with newly diagnosed metastases (single or multiple) in the brain resulting from any primary, extracranial cancer

Data collection and analysis: The Generic Inverse Variance method, random effects model in RevMan 5 was used for the meta-analysis.

Main results: A meta-analysis of two trials with a total of 358 participants, found no statistically significant difference in overall survival (OS) between WBRT plus radiosurgery and WBRT alone groups (HR = 0.82, 95% CI 0.65 to 1.02). For patients with one brain metastasis median survival was significantly longer in WBRT plus SRS group (6.5 months) versus WBRT group (4.9 months, P = 0.04). Patients in the WBRT plus radiosurgery group had decreased local failure compared to patients who received WBRT alone (HR = 0.27, 95% CI 0.14 to 0.52). Furthermore, a statistically significant improvement in performance status scores and decrease in steroid use was seen in the WBRT plus SRS group. Unchanged or improved KPS at 6 months was seen in 43% of patients in the combined therapy group versus only 28% in WBRT group (P = 0.03). Overall, risk of bias in the included studies was unclear.

Authors' conclusions: Given the unclear risk of bias in the included studies, the results of this analysis have to be interpreted with caution. Analysis of all included patients, SRS plus WBRT, did not show a survival benefit over WBRT alone. However, performance status and local control were significantly better in the SRS plus WBRT group. Furthermore, significantly longer OS was reported in the combined treatment group for RPA Class I patients as well as patients with single metastasis.