Intraoperative MRI for newly diagnosed supratentorial glioblastoma: a multicenter-registry comparative study to conventional surgery

Abstract

OBJECTIVEIntraoperative MRI (iMRI) is used in the surgical treatment of glioblastoma, with uncertain effects on outcomes. The authors evaluated the impact of iMRI on extent of resection (EOR) and overall survival (OS) while controlling for other known and suspected predictors.METHODSA multicenter retrospective cohort of 640 adult patients with newly diagnosed supratentorial glioblastoma who underwent resection was evaluated. iMRI was performed in 332/640 cases (51.9%). Reviews of MRI features and tumor volumetric analysis were performed on a subsample of cases (n = 286; 110 non-iMRI, 176 iMRI) from a single institution.RESULTSThe median age was 60.0 years (mean 58.5 years, range 20.5–86.3 years). The median OS was 17.0 months (95% CI 15.6–18.4 months). Gross-total resection (GTR) was achieved in 403/640 cases (63.0%). Kaplan-Meier analysis of 286 cases with volumetric analysis for EOR (grouped into 100%, 95%–99%, 80%–94%, and 50%–79%) showed longer OS for 100% EOR compared to all other groups (p < 0.01). Additional resection after iMRI was performed in 104/122 cases (85.2%) with initial subtotal resection (STR), leading to a 6.3% mean increase in EOR and a 2.2-cm3 mean decrease in tumor volume. For iMRI cases with volumetric analysis, the GTR rate increased from 54/176 (30.7%) on iMRI to 126/176 (71.5%) postoperatively. The EOR was significantly higher in the iMRI group for intended GTR and STR groups (p = 0.02 and p < 0.01, respectively). Predictors of GTR on multivariate logistic regression included iMRI use and intended GTR. Predictors of shorter OS on multivariate Cox regression included older age, STR, isocitrate dehydrogenase 1 (IDH1) wild type, no O6-methylguanine DNA methyltransferase (MGMT) methylation, and no Stupp therapy. iMRI was a significant predictor of OS on univariate (HR 0.82, 95% CI 0.69–0.98; p = 0.03) but not multivariate analyses. Use of iMRI was not associated with an increased rate of new permanent neurological deficits.CONCLUSIONSGTR increased OS for patients with newly diagnosed glioblastoma after adjusting for other prognostic factors. iMRI increased EOR and GTR rate and was a significant predictor of GTR on multivariate analysis; however, iMRI was not an independent predictor of OS. Additional supporting evidence is needed to determine the clinical benefit of iMRI in the management of glioblastoma.

The Neurosurgeon’s Armamentarium for Gliomas: An Update on Intraoperative Technologies to Improve Extent of Resection

“…The use of a robotic-assisted exoscope in combination with neuronavigation that incorporated diffusion tensor tractography (DTI) for eloquent pathway visualization, permitted for large EOR (over 78%) of contrast-enhancing tumor tissue and six-month PFS in 86% of patients [90]. These findings are comparable to recent studies on GBM surgery using other adjuncts [69,71,83]. Combined use of the exoscope and fluorescence-guided surgery is currently under active investigation.…”

“…iMRI was a significant predictor of GTR on multivariate analysis. However, iMRI was not an independent predictor of overall survival [83].…”

Intraoperative MR Imaging during Glioma Resection

“…45 Shah et al reported in a retrospective multicenter registry comparative study of patients with newly diagnosed glioblastoma that ioMR imaging increased the gross total resection, which in turn was associated with improved overall survival after adjustment for other prognostic factors. 228 However, ioMR imaging was not an independent predictor of overall survival in multivariate analysis. 228 Another significant aspect of the ioMR imaging procedure concerns a possible increase in surgical site infection because craniotomy patients need to be moved into unsterilized diagnostic MR scanner.…”

“…228 However, ioMR imaging was not an independent predictor of overall survival in multivariate analysis. 228 Another significant aspect of the ioMR imaging procedure concerns a possible increase in surgical site infection because craniotomy patients need to be moved into unsterilized diagnostic MR scanner. We were able to identify only two reports dealing with this issue, where it was noted that the rate of surgical site infection and the frequency of new neurologic deficits after ioMR image-guided surgery were within the normal range of pediatric neuro-oncologic surgery, 229 as well as wide age ranged (1-84 years old) at the multi-theater type system.…”

“…45 Shah et al reported in a retrospective multicenter registry comparative study of patients with newly diagnosed glioblastoma that ioMR imaging increased the gross total resection, which in turn was associated with improved overall survival after adjustment for other prognostic factors. 228 However, ioMR imaging was not an independent predictor of overall survival in multivariate analysis. 228 …”