A Systematic Review and Meta-Analysis of Supramarginal Resection versus Gross Total Resection in Glioblastoma: Can We Enhance Progression-Free Survival Time and Preserve Postoperative Safety?

SIMPLE SUMMARY: Glioblastoma tumor cells are frequently found in areas distant from conventional imaging abnormalities. These cells are thought to play a role in tumor progression after surgery of the initially defined tumor region on MRI. Supramarginal resection (SMR) is an emerging technique in neuro-oncological surgery that may improve tumor control. However, the impact of SMR on PFS and postoperative complications has not been investigated so far. This study performed the first systematic review and meta-analysis of the literature on SMR and further investigated the impact of SMR on PFS and postoperative complications. The results of this study suggest that while the current evidence is of low quality, SMR may improve PFS without affecting postoperative surgical complications. However, prospective research with larger patient cohorts and clearly defined SMR techniques is needed to confirm these findings. ABSTRACT: To date, gross total resection (GTR) of the contrast-enhancing area of glioblastoma (GB) is the benchmark treatment regarding surgical therapy. However, GB infiltrates beyond those margins, and most tumors recur in close proximity to the initial resection margin. It is unclear whether a supramarginal resection (SMR) enhances progression-free survival (PFS) time without increasing the incidence of postoperative surgical complications. The aim of the present meta-analysis was to investigate SMR with regard to PFS and postoperative surgical complications. We searched for eligible studies comparing SMR techniques with conventional GTR in PubMed, Cochrane Library, Web of Science, and Medline databases. From 3158 initially identified records, 11 articles met the criteria and were included in our meta-analysis. Our results illustrate significantly prolonged PFS time in SMR compared with GTR (HR: 11.16; 95% CI: 3.07–40.52, p = 0.0002). The median PFS of the SMR arm was 8.44 months (95% CI: 5.18–11.70, p < 0.00001) longer than the GTR arm. The rate of postoperative surgical complications (meningitis, intracranial hemorrhage, and CSF leaks) did not differ between the SMR group and the GTR group. SMR resulted in longer median progression-free survival without a negative postoperative surgical risk profile. Multicentric prospective randomized trials with a standardized definition of SMR and analysis of neurologic functioning and health-related quality of life are justified and needed to improve the level of evidence.