The role of Gliadel wafers in the treatment of newly diagnosed GBM: a meta-analysis

Standard treatment for high-grade glioma (HGG) includes surgery followed by radiotherapy and/or chemotherapy. Insertion of carmustine wafers into the resection cavity as a treatment for malignant glioma is currently a controversial topic among neurosurgeons. Our meta-analysis focused on whether carmustine wafer treatment could significantly benefit the survival of patients with newly diagnosed glioblastoma multiforme (GBM). We searched the PubMed and Web of Science databases without any restrictions on language using the keywords "Gliadel wafers", "carmustine wafers", "BCNU wafers", or "interstitial chemotherapy" in newly diagnosed GBM for the period from January 1990 to March 2015. Randomized controlled trials (RCTs) and cohort studies/clinical trials that compared treatments designed with and without carmustine wafers and which reported overall survival or hazard ratio (HR) or survival curves were included in this study. Moreover, the statistical analysis was conducted by the STATA 12.0 software. Six studies including two RCTs and four cohort studies, enrolling a total of 513 patients (223 with and 290 without carmustine wafers), matched the selection criteria. Carmustine wafers showed a strong advantage when pooling all the included studies (HR = 0.63, 95% confidence interval (CI) = 0.49-0.81; P = 0.019). However, the two RCTs did not show a statistical increase in survival in the group with carmustine wafer compared to the group without it (HR = 0.51, 95% CI = 0.18-1.41; P = 0.426), while the cohort studies demonstrated a significant survival increase (HR = 0.59, 95% CI = 0.44-0.79; P < 0.0001). Carmustine-impregnated wafers play a significant role in improving survival when used for patients with newly diagnosed GBM. More studies should be designed for newly diagnosed GBM in the future.