In a German trial reported in the Journal of Clinical Oncology, Roder et al found that intraoperative magnetic resonance imaging (MRI)-guided surgery did not improve the rate of complete resection vs fluorescence-guided surgery with aminolevulinic acid (5-ALA) in newly diagnosed patients with glioblastoma.
Study Details
In the investigator-initiated multicenter trial, patients were assigned by center to receive intraoperative MRI–guided (n = 150) or 5-ALA–guided (n = 127) surgery between July 2015 and June 2020. The primary endpoint was complete resection of contrast enhancement on early postoperative MRI. Resectability and extent of resection were evaluated by independent blinded centralized review of preoperative and postoperative MRI with 1-mm slices. Complete resection was defined as residual tumor measuring ≤ 0.175 cm³.
Key Findings
Complete resection was achieved in 115 patients (81%) in the intraoperative MRI group vs 90 patients (78%) in the 5-ALA group (odds ratio = 1.09, 95% confidence interval [CI] = 0.57–2.08, P = .79). In an analysis defining complete resection as residual tumor = 0 cm³, complete resection was achieved in 65% of patients in the intraoperative MRI group vs 72% of those in the 5-ALA group (P = .16).
Among intraoperative factors, mean incision-suture time was longer in the intraoperative MRI group (316 vs 215 minutes, P < .001). Intraoperative neuromonitoring and neuronavigation were used to similar degrees in the two groups, but ultrasound was used more frequently in the 5-ALA group (54% vs 34%, P = .001).
Similar median progression-free survival (hazard ratio [HR] = 0.908, P = .50) and median overall survival (HR = 0.997, P = .99) were observed for the 5-ALA group vs the intraoperative MRI group. Among all patients, residual tumor = 0 cm³ vs > 0 cm3 was associated with significantly better progression-free survival (HR = 1.77, P < .001) and overall survival (HR = 1.59, P = .048). The overall survival benefit was marked among patients with MGMT unmethylated tumors (HR = 2.35, P = .006).
The investigators concluded, “We could not confirm superiority of [intraoperative MRI] over 5-ALA for achieving complete resections. Neurosurgical interventions in newly diagnosed glioblastoma shall aim for safe complete resections with 0 cm³ contrast-enhancing residual disease, as any other residual tumor volume is a negative predictor for progression-free and overall survival.”
Constantin Roder, MD, of Eberhard Karls University Tübingen, Center for Neuro-Oncology, Comprehensive Cancer Center Tübingen-Stuttgart, Tübingen, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.
