Whole brain radiotherapy for the treatment of multiple brain metastases

Whole brain radiotherapy for the treatment of newly diagnosed multiple brain metastases

BACKGROUND

This is an update to the review published in the Cochrane Library (2012, Issue 4).It is estimated that 20% to 40% of people with cancer will develop brain metastases during the course of their illness. The burden of brain metastases impacts quality and length of survival.

OBJECTIVES

To assess the effectiveness and adverse effects of whole brain radiotherapy (WBRT) given alone or in combination with other therapies to adults with newly diagnosed multiple brain metastases.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase to May 2017 and the National Cancer Institute Physicians Data Query for ongoing trials.

SELECTION CRITERIA

We included phase III randomised controlled trials (RCTs) comparing WBRT versus other treatments for adults with newly diagnosed multiple brain metastases.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and abstracted information in accordance with Cochrane methods.

MAIN RESULTS

We added 10 RCTs to this updated review. The review now includes 54 published trials (45 fully published reports, four abstracts, and five subsets of data from previously published RCTs) involving 11,898 participants.Lower biological WBRT doses versus controlThe hazard ratio (HR) for overall survival (OS) with lower biological WBRT doses as compared with control (3000 cGy in 10 daily fractions) was 1.21 (95% confidence interval (CI) 1.04 to 1.40; P = 0.01; moderate-certainty evidence) in favour of control. The HR for neurological function improvement (NFI) was 1.74 (95% CI 1.06 to 2.84; P = 0.03; moderate-certainty evidence) in favour of control fractionation.Higher biological WBRT doses versus controlThe HR for OS with higher biological WBRT doses as compared with control (3000 cGy in 10 daily fractions) was 0.97 (95% CI 0.83 to 1.12; P = 0.65; moderate-certainty evidence). The HR for NFI was 1.14 (95% CI 0.92 to 1.42; P = 0.23; moderate-certainty evidence).WBRT and radiosensitisersThe addition of radiosensitisers to WBRT did not confer additional benefit for OS (HR 1.05, 95% CI 0.99 to 1.12; P = 0.12; moderate-certainty evidence) or for brain tumour response rates (odds ratio (OR) 0.84, 95% CI 0.63 to 1.11; P = 0.22; high-certainty evidence).Radiosurgery and WBRT versus WBRT aloneThe HR for OS with use of WBRT and radiosurgery boost as compared with WBRT alone for selected participants was 0.61 (95% CI 0.27 to 1.39; P = 0.24; moderate-certainty evidence). For overall brain control at one year, the HR was 0.39 (95% CI 0.25 to 0.60; P < 0.0001; high-certainty evidence) favouring the WBRT and radiosurgery boost group.Radiosurgery alone versus radiosurgery and WBRTThe HR for local brain control was 2.73 (95% CI 1.87 to 3.99; P < 0.00001; high-certainty evidence)favouring the addition of WBRT to radiosurgery. The HR for distant brain control was 2.34 (95% CI 1.73 to 3.18; P < 0.00001; high-certainty evidence) favouring WBRT and radiosurgery. The HR for OS was 1.00 (95% CI 0.80 to 1.25; P = 0.99; moderate-certainty evidence). Two trials reported worse neurocognitive outcomes and one trial reported worse quality of life outcomes when WBRT was added to radiosurgery.We could not pool data from trials related to chemotherapy, optimal supportive care (OSC), molecular targeted agents, neurocognitive protective agents, and hippocampal sparing WBRT. However, one trial reported no differences in quality-adjusted life-years for selected participants with brain metastases from non-small-cell lung cancer randomised to OSC and WBRT versus OSC alone.

AUTHORS' CONCLUSIONS

None of the trials with altered higher biological WBRT dose-fractionation schemes reported benefit for OS, NFI, or symptom control compared with standard care. However, OS and NFI were worse for lower biological WBRT dose-fractionation schemes than for standard dose schedules.The addition of WBRT to radiosurgery improved local and distant brain control in selected people with brain metastases, but data show worse neurocognitive outcomes and no differences in OS.Selected people with multiple brain metastases from non-small-cell lung cancer may show no difference in OS when OSC is given and WBRT is omitted.Use of radiosensitisers, chemotherapy, or molecular targeted agents in conjunction with WBRT remains experimental.Further trials are needed to evaluate the use of neurocognitive protective agents and hippocampal sparing with WBRT. As well, future trials should examine homogeneous participants with brain metastases with focus on prognostic features and molecular markers.

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

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.