A systematic review and meta-analysis of supratotal versus gross total resection for glioblastoma

Purpose: Due to the infiltrative nature of glioblastoma (GBM) outside of the contrast-enhancing region on MRI, there is interest in exploring supratotal resections (SpTR) that extend beyond the contrast-enhancing portion of the tumor. However, there is currently no consensus on the potential survival benefit of SpTR in GBM compared to gross total resection (GTR). In this study, we compare the impact of SpTR versus GTR on overall survival (OS) of GBM patients. Methods: We performed a systematic review and meta-analysis of literature published on PubMed, Embase, The Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov, from inception to August 16, 2018, to identify articles comparing OS after SpTR versus GTR. Results: We identified 8902 unique citations, of which 11 articles met study inclusion criteria. 810 patients underwent SpTR out of a total of 2056 patients. 9 of 11 studies demonstrated improved outcomes with SpTR compared to GTR (median improvement in OS of 10.5 months), with no significant difference in postoperative complication rate. Overall study quality was variable, with ten studies presenting level IV evidence and one study presenting level IIIb evidence. Subgroup meta-analysis based on SpTR definition demonstrated a statistically significant 35% lower risk of mortality in patients who underwent anatomical SpTR compared to patients who underwent GTR (Hazard ratio = 0.65, 95% CI 0.47- 0.91, p = 0.003). Conclusion: Our systematic review indicates SpTR may be associated with improved OS compared to GTR for GBM, especially with anatomical SpTR. However, this is limited by variable study design and significant clinical and methodological heterogeneity among studies. There is need for prospective clinical data to further guide parameters regarding the use of SpTR in GBM.