1.5-T Field Intraoperative Magnetic Resonance Imaging Improves Extent of Resection and Survival in Glioblastoma Removal

OBJECTIVE: Gross total resection (GTR) of glioblastoma may be achieved with the aid of intraoperative magnetic resonance imaging (Io-MRI), which detects residual tumor during surgery, with the aim of maximizing resection, therefore reducing the risk of recurrence. Moreover, intraoperative fiber tracking and neuronavigated electrophysiologic cortical and subcortical mapping may help prevent postoperative deficits. METHODS: There were 114 patients who underwent surgical removal of newly diagnosed supratentorial glioblastoma between January 2009 and January 2013: 78 (group A) were operated on with the aid of Io-MRI, and 36 were operated on without Io-MRI (group B). The protocol included preoperative magnetic resonance imaging and Io-MRI with diffusion tensor imaging in all the cases that presented eloquent areas of involvement. The extent of resection (EOR) was compared in the 2 groups 24-72 hours after surgery. RESULTS: The first Io-MRI detected a GTR in 31 patients (39.7%) and a residual tumor in 47 patients (60.3%) in group A. Twenty-one patients had residual tumor within eloquent areas: Io-MRI with fiber tracking permitted further resection, achieving GTR in 12 patients. GTR was radiologically detected in the remaining 26 patients (33.3% of group A) who had residual tumor in noneloquent areas after 1 or 2 further resection extensions. Io-MRI enhanced both EOR and 6-month progression-free survival (6-PFS): the overall GTR for group A amounted to 88.5% (n = 69), whereas for group B it was 44% (n = 16). 6-PFS accounted for 73% (n = 57) for group A and 38.9% (n = 14) for group B. CONCLUSIONS: Our experience suggests that Io-MRI may lead to EOR optimization and associated 6-PFS improvement.