Is FLAIRectomy Directly Correlated with Prolonged Survival in Glioblastoma? A Prospective National Multicenter Study on Correlation Between Extent of Tumor Resection and Clinical Outcome.

Abstract

Several articles have demonstrated a positive correlation between glioblastoma supramarginal resection, based on MRI fluid-attenuated inversion-recovery (FLAIR) sequences (ie, FLAIRectomy), and prolonged survival. This study analyses the efficacy, safety, and reliability of FLAIRectomy in a multicentric cohort of patients, correlating the extent of FLAIR resection (EOFR) with clinical outcome and survival. One hundred fifty glioblastoma or grade IV astrocytoma patients (82 men), with a mean age of 58.2 years (range 36-82 years), from 3 neurosurgical centers were included. In all cases, supramarginal resection was deemed feasible preoperatively; multicentric neoplasms or tumors with enhancing nodule involving eloquent areas were excluded. Analysis of EOFR was based on comparison between preoperative and postoperative 3-dimensional FLAIR images. EOFR was compared with extent of tumor resection (EOTR) based on gadolinium-enhanced T1 sequences; theses data were also statistically correlated with survival parameters as well as with clinical and biomolecular data. EOFR rate was 78.8% in the entire cohort, whereas EOTR based on T1 sequences was 98.3%. Mean progression free survival (PFS) and overall survival (OS) were 16.33 and 28.4 months, respectively. Adjusted Cox-regression models showed that a higher EOTR based on T1 sequences and EOFR were both associated with improved OS in individuals with either isocytrate dehydrogenase-1 wild-type or isocytrate dehydrogenase-1 mutated tumors. After adjustment, only the EOFR retained a statistically significant association with OS. Specifically, the risk of mortality decreased by 6.8% and 12.1% with each one-unit increase in EOFR, respectively. Further analysis based on artificial intelligence demonstrated that the cluster of patients with higher values of PFS and OS received greater rate of FLAIRectomy. This multicenter study demonstrates that EOFR is a more reliable predictor of PFS and OS than extent of resection based on gadolinium-enhanced T1 sequences, if supramarginal resection is performed according to specific preoperative planning. 3-dimensional FLAIR navigation-guided resection may represent the optimal strategy to achieve a real FLAIRectomy.