Usefulness and Impact of Intraoperative Imaging for Glioma Resection on Patient Outcome and Extent of Resection: A Systematic Review and Meta-Analysis.

BACKGROUND: Diffusion tensor imaging (DTI), functional magnetic resonance imaging (fMRI), and intraoperative magnetic resonance imaging (iMRI) permit greater visualization and more accurate presurgical planning. Meta-analysis of these techniques for maximizing resection, postoperative functionality, and survival may further validate purported strengths of these techniques compared with standard neuronavigation. METHODS: A systematic search of the PubMed database was conducted in line with the PRISMA guidelines for meta-analysis with the following keywords: "Diffusion tensor imaging" OR "intraoperative MRI" OR "functional MRI" AND "glioma surgery resection outcome." Articles found to meet inclusion criteria were segregated and analyzed and resulting data were compared with standard neuronavigation (control cohort). RESULTS: A total of 435 articles were identified, with 29 distinct studies meeting inclusion criteria, including DTI (n = 3), fMRI (n = 5), and iMRI (n = 21). Nine studies directly compared results with standard navigation. Mean gross total resection (GTR) rates were not different among cases using DTI, fMRI, iMRI, or traditional neuronavigation (P = 0.136). On controlling for covariates, more patients received GTR in the advanced imaging cohort, although statistically insignificant (46.5% [95% confidence interval, 38.0%-55.0%] vs. 30.4% [95% confidence interval, 11.6%-49.1%]; P = 0.127; partial η2 = 0.217). Patients undergoing advanced imaging showed attenuated incidence of postsurgical permanent neurologic deficits, although also statistically insignificant (11.3% vs. 13.8%; P = 0.838). CONCLUSIONS: Current data are overall insufficient to support the notion that advanced imaging techniques are superior, either as a combined cohort or individually, in achieving GTR, improved symptom resolution, or survival compared with traditional neuronavigation.